RX8 Project – Part 19, Canbus #4, The Comeback!

Lets be clear before we start – This will not allow you to start a car with a factory ECU with the wrong key or by bypassing the immobiliser. This is to do with making things like engine swaps work fully in the car without the factory ECU connected.

I’m going to apologise right now, there’s quite a lot of background about how I investigated the process of the ECU talking to the immobiliser in this one, if you don’t care and just want the CAN info scroll down a bit. I’ll write a complete update of all the codes when this phase of work is all done.

As some of you are probably aware my RX8 engine swap has been going on some time for a variety of reasons but specifically due to not having cover and so not easily being able to hook the car CANbus up to my computer to do live diagnostics I had hit something of a problem. I couldn’t generate data fast enough to fake all the devices on the bus reliably to test things on my desk away from the car but had no-where undercover to work with it connected to a PC so largely I’d planned to concentrate on organising a garage – something that should have happened more than a year ago now but due to the pandemic and related 2020 problems that not gone as well as hoped!

Anyway a few months ago on trying to find a CAN diagram for the car to aid answering a comment someone posted on here (yes I do try to answer them but I know sometimes it takes a while – I’m hoping to keep a better eye on it this year!) I came across a video from a guy called Dave Blackhurst (this one) which was rather interesting as he apparently had my two main issues from my previous code sorted, specifically the immobiliser system (the thing I want to look at here) and the power steering.

So to see how he was doing it I went to the linked Github and downloaded his Arduino code and on opening it I was largely very familiar code, specifically a whole set of variable declarations for the various dash instruments and a large section of code related to using a boolean variable to set the correct bit in the corresponding CAN packet so individual warning lights can be turned on or off and the speed/RPM etc to all be set easily on the cluster. So this was basically a development of my previous work

Now just to be clear this isn’t a complaint. This is just the first time I’d see my work go full circle and someone else actually develop it further which was quite exciting. If I hadn’t wanted it used and developed I wouldn’t have posted it online! Even better was it gave me a kick to have another go at it and at the very least try this new and improved code which said it fixed all the issues because if true Dave might have just solved my remaining problems!

So back to the immobiliser. I’d never managed to get the immobiliser light to go out despite trying all sorts of combinations of data from the logs I had but after seeing what Dave had done I realised I’d been missing a critical bit of information. The CAN logs I’d previously worked from were predominantly provided but someone else who contacted me via the blog and so were from two other cars and not my own. Additionally you can see in the early blog posts I actually built my own CANbus board several years ago which worked but had some speed issues with all the work it was doing. This was because when I started this project several years ago there was little else available for sensible money so it was the only real option. Long story short the immobiliser relies on a very short data exchange which occurs when the ignition key is first turned on and is never repeated and basically it had just been missed by the loggers that I had data from previously so I may never have figured it out!

Excited at the prospect of this just being a load the code and go I wondered if in the intervening years better hardware was available for this job than my old Arduino Nano based DIY job and there are now various Arduino expansion shields for CAN but to me these were all rather clunky solutions so I started looking at the “Feather” range which has a couple options but again these were a board and a piggback interface which isn’t what I wanted and there’s a new one which is the Adafruid Feather M4 CAN which looked pretty good but doesn’t seem to have ever actually been in stock anywhere so moving on.

Adafruit Feather M4 CAN

Following this I had a realisation – if if was going on the car it really didn’t need an integrated battery. Previously I’d started using Leonardo based modules for projects and these proved very quick for most tasks and have integrated USB meaning data throughput can be faster so I tried to find a Leonardo based CAN module. Eventually I found a company who I’ve used before for various neat modules do basically exactly what I was after for a reasonable price, enter Hobbytronics and their L-CANBUS board.

Leonardo CAN BUS board
Hobbytronics Leonardo Canbus

Looks just the job and even comes with the headers and 9 way connector unsoldered. and the board itself has pads for screw terminals to be soldered in place of the 9 way connector for bare wire connections. This time round I decided I wasn’t going to mess about with screw terminals while testing so I splashed out and bought a £10 OBD2 – 9 Way D-Sub CAN cable off eBay to go with it (unfortunately Hobbytronics were out of stock of the cable). This also had the advantage of including 12V and ground connections which are routed to the board regulator so the module is powered directly off the OBD2 port on the car making testing really easy.

I also decided being powered off the car that rather than risk shorting the module/car it needed a case and since I recently was given what I believe is still the cheapest 3d printer on eBay by a friend who got so annoyed with it he bought one that was actually good, so I designed a 3d printable one :

It’s pretty basic, the holes should be undersize for an M2.5 laptop screw so they basically thread cut it when you first put them in. Not ideal but it’s what I had. M2.5 sized plastic screws with a coarser thread would be better but either way it held fine. This case also leaves the USB accessible.

Anyway, back to the point we now have some nice neat hardware so I tweaked the code to run on this module (different CAN pins to the normal Adafruit CAN shields) and flashed it. After plugging it into the car…nothing happened. Once I’d reflashed the Leonardo with CLK_OUT enabled as per the instructions following a conversation with Hobbytronics who were very helpful (in their defence it says to do it right on the product page but I’d not read that bit!) I loaded it again and when hooked up to the car what I got was the basic warning lights went off, but the immobiliser and power steering that I’d hoped to resolve were still there. Time to delve a bit deeper!

So looking at Dave’s code here’s the bit to resolve the immobiliser:

 if(CAN_MSGAVAIL == CAN0.checkReceive()) { 
  // Check to see whether data is read
 }
    CAN0.readMsgBufID(&ID, &len, buf);    // Read data

        
    //Keyless Control Module and Immobiliser want to have a chat with the PCM, this deals with the conversation
    
    if(ID == 0x47) { //71 Dec is 47 Hex - Keyless Chat
      
      //***** Fixed Coding for Dave Blackhurst's Car *******
      if(buf[1] == 127 && buf[2] == 2) {      
        // Look for 0x 06 7F 02 00 00 00 00 00
      }
        CAN0.sendMsgBuf(0x041, 0, 8, send41a);// 0x041 = 65
        // send41a = 0x 07 0C 30 F2 17 00 00 00
      }
      if(buf[1] == 92 && buf[2] == 244) {     
        // Look for 0x 08 5C F4 65 22 01 00 00
      }
        CAN0.sendMsgBuf(0x041, 0, 8, send41b);
        // send41b = 0x 81 7F 00 00 00 00 00 00
      }

I’ve added in the codes being looked for or sent in each case which Dave identified from scanning the bus on his RX8 just to make it easier to see what’s going on. Breaking this down ID 0x47 is the immobiliser module sending data out which generally seems to just keep repeating 0x06 01 FF 00 00 00 00 00 when in normal use with the car running as factory I have that from my previous logs. So this first code starting 0x 06 7F 02 is something from the immobiliser which triggers the exchange. The code basically just reads any incoming data then checks the ID is 0x47 (i.e. it’s coming from the immobiliser) and that two bytes match the what he knows the CAN data should be (simpler than checking the whole code) , specifically byte 1 being 127 (7F) and byte 2 being 2. He then sends the recorded response to this (send41a – 0x 07 0C 30…) back to the immobiliser which would normally be done by the PCM (ECU) in the car when present. Then we look for the response from the immobiliser matches what we expect (0x 08 5C F4….) and sends a second reply to the immobiliser (send41b – 0x 81 7F 00….). I started thinking the module wasn’t talking to the CANbus right but after some fault finding and adding a diagnostic LED blink at critical points I found it was on the bus but just wasn’t seeing the right data coming from the immobiliser to respond to. Now I knew this exchange worked on Dave’s car but not on mine so clearly the codes we have aren’t universal in some way but I needed to work out what was going on but at least I knew what to look for.

Back when I was trying to find the code to disable the power steering light from Labview I bought a device called the USBtin which is a neat little PCB which is basically just a USB to CAN adapter but it has a built in protocol to control it so you can read the data via software like Putty or relative easily develop custom applications to connect to it. Now facing this problem I decided to give it a go and see if it was actually fast enough to catch this exchange in the first few fractions of a second of the ignition being on. I blew the dust of the original ECU for the car and hooked it back up to the bus (there’s no engine but I hoped that wouldn’t matter for this bit) loaded the basic USBtinViewer onto a tabled and hooked it up.

Ok it’s a photo of a tablet screen but anyway, the point is the USBtin is clearly fast enough to catch all the data because the monitor mode shows it’s caught the exchange because it’s logged packets to ID 0x41 and 0x47 and the last message to 0x41 matches the last one from Dave’s car (send41b – 0x 81 7F…). So it’s got the data, unfortunately to see what was sent both ways I had to trawl through the trace mode which just lists every CAN packet on the bus but after a bit of searching I found this:

So going through it first and ignoring all the extra data (there will be more to follow on this) there’s the default message from the immobiliser sending 06 01 FF… highlighted in yellow, then shortly afterward we see what looks very similar to Dave’s first message of the exchange but where his was 0x 06 7F 02, mine critically is 0x 06 7F 01. Looking back to Dave’s code for this we find that he was specifically looking for byte 2 = 2 and mine is 1, which is probably why it never triggered on my car. Now because that first packet we need to match starts 0x 06 7F … on both cars I can just change the check to look for that combination instead but at this point I also realised the outgoing data from the ECU (0x 07…) and return from the immobiliser (0x 08…) are totally different for my car so rather than mess about I just swapped out both to match what I’d logged for my car (assuming the codes may be car specific to stop PCM’s (ECU’s) being swapped between vehicles they’re not coded to or something) and tried it again, but this time…

Yes this time it cleared the security light! Definitely progress!

But for me making it work isn’t really enough and I like to understand why something works and hopefully make it better!

First off I tried again but this time with the matching done using the updated positions for the consistent bits of the code common to both cars. Specifically getting rid of the check for the byte 2 being any value because this appeared to change from car to car. What we can reasonably assume is fixed from this data is byte 0 because they always seem to indicate the step in the exchange with the exception of the initialisation state and first request state which both start “06” however byte 1 gives us if the immobiliser is still starting (0x 06 01…) and making a request to the PCM (0x 06 7F) and these match on both cars. We then send back one of the first response packets (0x 07….) and wait for the next request which byte comparing the data both cars start with byte 0 = 08 and based on the rest it’s reasonable to assume again this is the sequence step and so universal. Then Dave looks for a value of byte 2 which differs between our cars, however I have noticed that byte 5 for both cars is always 01 so this would work for both. So we end up with this :

      
      byte send41a[8] = {7,120,192,226,94,0,0,0};                      
      // Reply to 47 first  : 0x 07 78 C0 E2 5E 00 00 00 
      // Bytes 0 is the same, bytes 3 & 4 dont seem to matter, 
      // 5,6,7 are zero
      
      byte send41b[8] = {129,127,0,0,0,0,0,0};                         
      // Reply to 47 second : 0x 81 7F
      
      //***** Fixed Coding for Jon's Car *******
      // Some experimentation showed that on the initial request
      // for my car byte 2 was a 01 not a 02
      // however all codes so far begin 06 7F 
      // for either car so this was used.
      // Similarly in the second message from the 
      // immobiliser bytes 1-4 change but byte 5 
      // is always 01 on either vehicle

      if(buf[0] == 0x6 && buf[1] == 0x7F ) {                      
        // 0x 06 7F 01 00 00 00 00 32
        
        // printhex(buf,8);                                        
        // Transmit out received request on debug serial port 
        // - breaks timings on vehicle.
        
        CAN0.sendMsgBuf(0x041, 0, 8, send41a);                    
        // 0x 07 78 C0 E2 5E 00 00 00 
      }
      if(buf[0] == 0x8 && buf[5] == 0x1 ) {                        
        // 0x 08 94 29 BC 91 01 00 32
        
        CAN0.sendMsgBuf(0x041, 0, 8, send41b);                     
        // 0x 81 7F 00 00 00 00 00 00  
      }

I’ve included the notes I made at the time – the printhex is a function I wrote to dump these arrays out to the serial port easily as two digit hex pairs for monitoring what’s going on at different times. As noted here it breaks the timings of the exchange between the ECU and immobiliser but if we want to check something we just add it in and at least we can see what the data was. I’ll do a separate post for that as it might be useful to others. Not unexpectedly matching in this way worked fine but more interestingly I tried my car with Dave’s codes matching in this new way and interestingly it actually worked with no security light…

Well that raises even more questions because in theory I’d just swapped my ECU for his (in terms of the code exchange at least) and it authenticated!

So I went back to my car, reconnected the original ECU, powered it up with the USB logger again and noticed that each time I turned my ignition on the code exchange was different so clearly the idea of the code being fixed for a pair of ECU and immobiliser was wrong. After a number of goes and recording all the results a few things started to become apparent.

Firstly the initial request from the immobiliser had some variations on bytes 7 and 8 which always matched the byte 7 and 8 in the second request but the bytes we look for (byte 0 and 1 shown in green) are always 06 7F in every try.

Second, the first response given by the ECU indeed always starts 07 (light blue), but the next 4 bytes change each time the ignition is turned on (bright blue).

Third, bytes 0 and 5 in the second request are always 08 and 01 respectively (orange) however the 4 bytes between change each time the ignition is turned on (yellow).

Fourth, the second response is always the same (pink).

So what I think is going on here is actually something slightly different. If we assume for a moment the ECU knows the code or processing going on in the immobiliser we get a proper challenge/response interaction. I think the first message sent by the immobiliser is basically a “ready” message telling the ECU to send a block of data. The ECU then responds with a 4 byte block of data which is randomised each start. The immobiliser then performs some function we don’t know and sends the result back to the ECU where it checks the result against what it should be and gives a pass or fail back to the immobiliser so it updates the dash light. The last packet is always the same because we’re using everything from one car so its a pass so we don’t know what a mismatch fail looks like yet but I’m going to look into this at some point.

Now the interesting result of this outcome is with our Arduino we’re not checking if the code response actually matches and if my theory is right the outbound 4 bytes can be absolutely anything as it’s basically just a seed value, then the immobiliser will will reply with a coded version which we just ignore and so long as we reply with a pass message at that point (0x 81 7F 00 00 00 00 00 00)the immobiliser turns the dash light off.

To prove this out I set up the Arduino to send different random numbers in each of bytes 1-4 to the immobiliser in the initial response and indeed while the response from the immobiliser bytes 1-4 change as in response the immobiliser light went out on the dash every time.

My final theory is that the immobiliser module is reading the data from the chip in the key, and using that to transform the initial data from the ECU to create the response and since the ECU knows the key code and whatever this transformation is it knows if it’s the right key or not.

Now hopefully that problems solved for all RX8’s, I’m aware I haven’t posted a full, complete code like I have done previously but that’s because it has all sorts of other features going in this currently and I’ve not finished and tidied the rest of it yet. I’ve also considered the situation where there might be an RX8 out there that doesn’t match the code pattern found in my current sample of two vehicles so I’ve actually added a feature where if you jumper a wire onto a digital input and connect the Arduino to a car with the original ECU in place it will read out the entire code exchange and store all the codes for that car in EEPROM on the Arduino. If you then take the jumper off and pull out the ECU, when you turn the ignition on again the Arduino will use the codes it just stored instead of the defaults. Again I’ll write this up properly when it’s all finished.

Finally thanks to Dave Blackhurst for your work on this. While your solution didn’t work for my immobiliser it gave me the drive to have another go and enough information to go in the right direction and hopefully we’re a step closer to a universal engine/motor swap solution for everyone.

More to follow!

Living with a Scirocco 1.4 TSI 160 (118kW) – Part 3, Supercharger Bypass Valve (P10A4 Fault)

Sometime last year I was having problems finding a spot in a carpark so ended up sat in the car with it idling for several minutes and when I went to pull away the engine warning light flashed on almost immediately – not something anyone wants to see!

For the rest of the drive the car would mostly work ok at low engine RPM but the engine all but refused to go above approximately 3000rpm which is around the RPM the turbo takes over from the supercharger on this engine and the supercharger is disengaged by its electronic clutch. The curious bit was that at hitting the cut off there was a sudden loss of power at that RPM rather than it staying consistent and just holding an RPM limit suggesting it wasn’t a limp mode as such. My initial suspicion was that the turbo wasn’t spooling up so whether the wastegate was stuck open or something I didn’t know.

Luckily I bought VCDS which is an excellent tool for diagnosing and performing adjustments and if you do a lot of work on VW’s well worth the investment so I hooked that up to see what fault the check engine light was actually reporting and saw the following :

A quick Google of the code P10A4 identifies specific air regulating flap in question but this could also be found by a brief search of the engine bay – there aren’t many flaps in the intake! VW refers to this part as J808.

Image of the TSI160 engine with intake flap highlighted

What this flap actually does is when the supercharger disengages the flap opens providing an unrestricted flow to the intake of the turbo. Obviously if this doesn’t open when the supercharger disengages suddenly the air supply to the engine is closed and you get a massive power loss. You can see what’s going on in the image below which is taken from VW’s manual for this engine – SSP-359. This isn’t a workshop manual but does explain the design and behaviour of this engine in a good level of detail.

There are quite a few guides on how to replace this part such as using the one at workshop-manuals.com . This is an excellent resource but I do recommend using an ad blocker before going there as there are so many ads it’s very annoying otherwise!

My approach to get at the flap was to start at the airbox end and disconnect all the lines going into the intake tract (there are many in all directions so carefully work along it). Eventually once everything is detached you can undo the three long screws which hold the intake pipes on either side tight against the flap and so hold it in place. In my case I ended up detaching the section of pipe after the flap as well so I could lift the whole intake pipe up to get access to the bottom screw nearest the engine as its very awkward to get at otherwise.

Anyway as usual I didn’t want to replace the part if I could avoid it and luckily I found some comments somewhere saying the problem was caused by oil weeping from the intake into the flap unit clogging up the motor so I wondered if it could be cleaned because fundamentally there’s very little that can go wrong inside as they are basically just a motor. Luckily at this point knowing this was likely the problem I figured I couldn’t make it any worse than dead so started trying to work out what was going on.

So looking at the casing of the valve I came to the conclusion there was a simple gearing mechanism inside but based on the space between the clear position of the motor under the curved housing the likelihood was that the gear on the motor itself was small and so I could not explain why there was a significant large area in the housing below it which would likely be a handy cavity with no obvious purpose. The problem being caused by oil makes sense – the motor sits in the bottom of the housing which is underneath the intake pipework so any oil leaking into the housing would pool around the motor. I think the leak is through the spindle bearing for the flap.

So I came up with a plan which may be apparent already because I neglected to take any “before” pictures. I didn’t want to cut the unit open because even though the two halves appeared to be screwed together it looked like the seam had been sealed in some way (presumably part of why oil gets trapped inside) and while nothing appeared to be spring return I really didn’t want to risk it. So I decided to drill a small hole into the extra casing I identified earlier by using the casing as a guide as to where the gear and so end of the motor was. I then carefully drilled a small hole approximate 4mm in the casing and indeed there’s clear space behind this area.

My plan was basically to just flush the inside out with brake cleaner to remove all the oil residue so the hole was just a little large than the straw on the spray can. Sure enough on blasting some into it immediately the predictable brown runoff started pouring out. Another interesting thing happened as well – some residue started to run out of the seam inside the intake passage suggesting this isn’t sealed from the internal workings and in fact the seal on the unit is only on the very outer edge if the housing which may well explain the leaking issue! anyway several passes with brake clean and sloshing it about inside to rinse out as much as possible (I recommend just keep replacing the brake clean until it runs out clear) and it should be ok again hopefully. At this stage you might want to spray a small amount of lithium grease through the hole onto the gears for longevity but if you do just keep it small so you don’t just end up fouling everything with that instead!

Next, make sure the thing is totally clear of brake clean! I held mine under a hot air hand drier for about 10 minute to make it hot enough to drive off all the vapour then left it out in the sun for about half and hour. The last thing you want is a it catching fire!

The final thing I wanted to do is cover up the hole, particularly now knowing the intake wasn’t sealed from the innards. To solve this I tapped the new hole out to M5 and carefully checking the clearance I had behind the cover I put a short button head in place that wouldn’t foul the motor drive gear. Hopefully this also means If I ever have this problem again cleaning it should be easier. You can see the new M5 button head below.

After putting it back into the car I used VCDS to clear the fault code and so reset the engine warning light and took it on a test drive to confirm everything was fine. I think in total this took me about three hours but I was figuring it out as I went so you could probably do it in less.

While this was done during 2020 and so I have been using the car less due to travel limitations and working from home I can confirm that now five months later the car still works well and I have had no further issues following this repair.

Living with a Scirocco 1.4 TSI 160 (118kW) – Part 2, Turbo Replacement

It’s been a little over a year since I posted the introduction blog article on this car and more specifically on the unusual twin charged engine it has. Unsurprisingly over the last year or so I’ve found a few things that need a little work but generally the car has been excellent, needing minimal thought but certainly has some aspects to be aware of for prospective owners to keep the the engine working correctly.

When I bought the car it was a bit lacking power compared to what I was expecting and when accelerated hard in one gear (which due to a seemingly large gap between the supercharger and turbo rev ranges required revving it high) and changed up it would randomly have no power at all. I managed to trace this to a couple problems both related to the turbo wastegate. Firstly the requirement to rev it high was caused by serious wear on the wastegate pivot meaning the wastegate didn’t fully close so the turbo wouldn’t spin up properly. A temporary bodge to get round this is to tighten up the actuator rod to take up the slack but while this sort of helps it actually wears the housing even faster but it can get you by while you wait for a replacement. The second problem of lacking power after a high RPM change was that the wastegate actuator rod was actually bent and touching the turbo housing so it was actually getting temporarily stuck when fully extended so going into the next gear the turbo was basically just dumping the exhaust out the wastegate rather than doing anything useful. So this definitely needed looking at!

First off let me just say I initially looked at the position of the turbo nicely sat at the top front of the engine and thought a couple hours and it’d be done. I was wrong, very wrong! It looks lovely and easily accessible but it just isn’t as easy as it looks for many reasons mostly relating to it not being a turbo mounted to a manifold. the entire exhaust side manifold and turbo are a single unit so you need sufficient clearance to pull the whole unit out.

There it is under the heat shield – looks simple right?

I used various guides to do this swap and generally was in a rush (that didn’t work out so well) so I have very few photos of this but the information is fairly widely available anyway (try searching for guides to the mk6 Golf with the same engine) this is to highlight a few points people may find useful. I suggest referring to workshop manuals for a handy guide with diagrams of each section you need but strongly recommend an ad blocker before you do.

  1. The hard plastic boost pipe which runs from the supercharger to the turbo inlet is retained at the turbo end by a single M6 torx bolt with the threads tapped into the aluminium casting. On the rebuilt unit I bought this thread turned out to be ruined to the point it was impossible to tighten. I suspect this is because undoing the captive fastener during disassembly tries to push a metal sleeve out of the plastic. This is fine in itself but I think it wears the aluminium, similarly tightening it back in will also be hard on it. The reality is the pipe should be pulled back a little at a time as the screw is undone to prevent the load on the threads but this is a bit awkward to achieve as the pipe has very little ‘give’ in it. I strongly recommend checking this before you start – I had to call in a favour because having spent a lot of time swapping the turbo it was rapidly approaching closing time for all the shops to get anything to repair this and without it the car shouldn’t be run. If you’re in any doubt just buy an M6 helicoil kit and put a shiny new insert in place in the aluminium casting because there is only the one screw and if it fails your car will not be happy! Helicoils in softer materials are actually stronger than directly tapping the material the right size because the insert is a stronger material than what it’s going into and because they’re fitted by screwing into a larger thread in the parent material than the desired final thread they have a larger contact surface area in that material.

2. To fully undo all the bolts of the manifold flange you have to undo the alternator mounting bolts and twist it out the way. To do this you have to take off the alternator belt by releasing the tensioner then remove the top mounting bolt for the alternator entirely and slacken the other. This requires removing the engine bay undertrays as well but if you’re doing this job save some time and just pull them all off now. The alternator can then be rotated down and away from the block to get at the bolt. Someone out there might have some creative way of getting at that bolt but I had nothing that would get at it from any angle and couldn’t see any other way if could be done because it’s in a recess with manifold one side, oil filter casting the other and alternator in front of it.

3. Remove the radiator fans. In the picture above you can see how tight this is relative to the turbo and so you need to do this to have enough clearance both to get tools in to undo the manifold nuts and also to remove the the turbo itself from the exhaust studs. Removing these is done from the underside and also involves removal of the pipe between the turbo outlet and intercooler to give sufficient space. You need this removed to change the turbo anyway so it’s no inconvenience.

You’re looking to remove pipe sections 15, 16 and 17 for clearance. Item 11 are two bolts holding the charge pipe to the engine. The radiator sits between the charge cooler and this charge pipe.

The fan module can be removed as a single unit downwards with both fans in place by simply removing the four bolts holding it to the radiator and unplugging it at its electrical connector (item 13 on the bottom edge in the image above).

4. Buy a fitting kit off eBay or somewhere – there are load available but this is the simplest way of making sure you have all the replacement seals and gaskets you might need. Get the most comprehensive one you can find if you can’t easily go to get more parts once this car is apart!

5. The oil drain hose from the turbo is an absolute pig to get at.

The part I’m referring to here is number 12 above and consists of a section of solid pipe at the turbo end with a very short section of hose crimped on. I used a socket on a series of extension bars to get the bolt out of the turbo end but the block end is very awkward to get at because you can’t see it from any angle and the access is tight because the bolt sits virtually under the downpipe. Good luck! When you’re struggling to put it back on after changing the turbo don’t forget the gasket. Also this pipe is apparently common for leaking because the bolt doesn’t get put in sufficiently tightly or the gasket gets damaged during reassembly. I’ve highlighted this below in red.

6. The coolant hard line on top of the turbo needs to be removed which leaves an open rubber hose end. An M8 bolt fits perfectly to block this and stop coolant pouring out over everything so have one to hand before you take it off.

7. Carefully check the boost control hoses – apparently these commonly crack and certainly in my case they were quite degraded around the turbo. You can buy the proper replacement VW part if you wish but it may be cheaper to just order some 5mm vacuum hose and put a run in. In my case I didn’t notice the damage until I started taking it apart and managed to get a random bit from a friend. His wasn’t the common stuff it was thin walled and reinforced so the standard clamps didn’t fit but luckily with some persuasion I managed to fit the thin hose into an offcut of the original one. When combined with a suitable hose clip it’s working fine and has been for ages – that said I do not recommend this option!

Damaged section of hose in red above. The image below shows the hose I replaced marked in red going from the turbo housing back to the boost control solenoid and then the second similar line from the solenoid to the wastegate actuator marked in green.

Unfortunately as I mentioned earlier I didn’t take extensive photos of this replacement but I hope these few points help someone out there!

Good luck!

RX8 Project – Part 18, Resurfacing Cylinder Heads the Cheap Way!

As ever do this at your own risk. For most people you’re better off just getting heads machined by a specialist but if you’re reading this blog you’re probably already aware that’s not always the way I do it!

So this idea came from me wondering how I could easily clean up the cylinder heads on the V6 without additional machining. The heads were generally in good condition so I just wanted a fresh surface for the new head gaskets to seal well on rather than trying to remove any surface damage or warping. If you have this sort of damage this method is not for you.

When I came up against this problem I decided to do some research and found quite a few people online saying you could just do it with suitable abrasive paper and a sanding block. Now I get the idea but the engineer in me sees a good possibility of some part getting ground back more than another actually increasing the issues with the head that we’re trying to remove in the first place. Around this time I spoke with a few different people who have experience with engines and they all said much the same thing – machine skimming is safest and easiest but with enough care it should be possible to do a perfectly good job by hand, the problem is getting the whole thing completely flat which is very difficult by hand. Most people who had done this seemed to have done it on engines with small cylinder heads such as single cylinder machine engines which being small are easier to get flat by hand.

The problem was absolutely one of getting something suitably flat that would cover the whole head to get the whole thing even so I started looking into what might work. I was already aware of engineers surface tables which are used for checking flatness but these are large, heavy and very expensive as they’re often made of stone or tool steel. I then looked at getting some surface ground steel plate (where a thick steel place is ground to a precision flatness) but again this seemed to be expensive and awkward. After a bit of thought I had an idea…

£4 eBay coffee table


Ok, so at first glance this seems like a daft idea but stick with me! The cheapest and most rigid precisely flat surface I could find was a piece of toughened float glass. Specifically toughened because it is created in such as way as to pre-stress the surface which makes it both stronger and stiffer but also much more brittle – this is the glass that breaks down into granules when broken rather than shards. Initially my plan was to just order a decent sized bit but that seemed rather wasteful so I thought about it and realised second hand furniture included quite sizeable bits of the glass. I began searching eBay and Facebook marketplace to see if I could find something suitable as cheaply as possible and after a week or so found this coffee table. It was nearby and listed as local collection only with some damage to the wood veneer and scratches on top surface of the glass (so the price was unlikely to go high) and 99p no reserve starting. Couple days later I was the proud owner of a £4 coffee table!

Now you may be wondering why we aren’t bothered about the surface scratches on the glass which is likely to be a problem with any similar furniture. The reason is twofold, firstly due to this being toughened glass any scratches are likely to only be very minor and secondly the glass has a whole other side which is unlikely to have any scratches anyway so we’re going to use the underside.

I took the table apart carefully removing the top and to give additional support I placed it flat on a 19mm (3/4″) thick bit of chip board carefully screwing an section of baton at each end to stop the glass sliding about while we’re working. This assembly when then placed on my carpet which is just very hard office carpet tiles on concrete so shouldn’t allow any appreciable movement so hopefully with that stack of support the glass should be perfectly flat even with a cylinder head on it! The abrasive I will be using is wet and dry paper in a range of coarseness, get a pack of each grade you plan to use, it will take a lot of it! I made sure the wet and dry would stay in place by spraying the back of it with spray mount adhesive and putting it in place. Spray mount should also peel off relatively easily when we need to change the paper. I used 3 sheets to create an area larger than the head face in both length and width.

Glass coffee table refinishing rig


So now we have our setup we need to prepare the cylinder head for this. When it came off the engine it was quite grimy as you might expect so this needed addressing.

Head with worst of gasket scraped off


So here you can see how it was when it was (almost) fresh off the engine but with the residual head gasket material scraped off. You can see the amount of grime isn’t too bad, I have already wiped some off the top half but the bottom is a bit more representative. You can also clearly see the outline marks from the head gasket that we’re looking to remove later. This step basically involved soaking the mating face in a de-greaser then wiping it all off carefully.

Head during degreasing
Head after degreasing but before refinishing


It’s not perfect but it’s a huge improvement on where we started. The combustion chambers are considerably better. There’s some residual on the face but its more staining than anything else and will be removed by the refacing. So now we’re ready to go.

First cover the wet and dry with your chosen lubricant – water should work but I found WD40 seemed to work better as it helped the head ‘glide’ more. A light oil like 3in1 would probably be even better as it’s a little thicker again and WD40 tends to dissolve the spray adhesive as you work making the wet&dry come loose. Take the head and place it on the wet and dry (I started at 120 grit) holding both sides lightly start to slide it across the surface. There are different approaches to this where you can angle the head first one way then the other to give a crosshatch pattern. In my case I generally moved it in a long oval and this seemed to give a nice even finish but as ever your mileage may vary!

Cylinder head sat on DIY refinishing setup

You will find that as you work the oil and metal shavings will spread so I suggest doing it somewhere you don’t mind the mess!

This will take some time and effort. If the wet and dry wears down replace it. when you’re happy with the initial surface being clean of all the minor marks and debris you can go up to increasingly fine levels of grit for a better finish.

On the subject of finishes when I was doing this work I found the following information which relates the abrasive rating with the achieved resulting surface roughness – if anyone knows where this is from please let me know as I can’t seem to find out.

US GritUK Grit Ra µmRa µinch
 P1203125
 P180285
80 1.6570
 P2401.550
 P3200.7530
180 0.6225
240 0.4518
 P5000.415
320 0.2510
Comparison of grits vs achieved surface finish

So in the context of this I’m working in UK grit. Unfortunately the only information I could find on the required surface finishes for head gaskets came from the US so is in Ra µinch (Ra being the roughness average of the surface) but luckily this table equates everything. Generally normal gaskets seem to need a surface finish of about 50-60 Ra µinch, modern multi layer steel head gaskets require 30 Ra µinch or smoother so we need to finish at a minimum of P320. I actually went up to P400 to be safe.

Comparison between not touched and work in progress cylinder head


This is the comparison of the untouched head and the one with the first couple of grits done and so not quite finished but you can see the massive improvement made here.

Head surface reflection

I know judging by eye isn’t accurate but it’s clearly doing something good!

Keep going until you do all the grits you need and when you’re done then you need to check the flatness. I did this with an engineers straight edge (as opposed to a builders straight edge which is a big ruler) which cost £25 off ebay. This is a bit of steel that has been precision ground to be completely straight in one plane so is often only a couple mm thick but 70mm wide or more. You check the flatness by putting the straight edge perpendicular to the head (so it sticks up) and trying to slide a feeler gauge under the mid point (or as close as possible) of the area you’re checking. You need to check the width, length and both diagonals but also check across all the bores. The head should have no more than 0.075 mm off flat over the longest span on an iron head, or 0.05 mm off flat on an aluminium head on a V6. In my case the smallest feeler I have is 0.04mm so that proved it was good enough but to check it further I got some thin foil, checked the thickness with a digital micrometer which came out as 0.01mm and placed the foil on one of the central bridges of the head and put the straight edge on and it rocked on the foil. I then redid the test with the foil at the ends and the same again in other directions. Each time the straight edge was clearly resting on the foil first so the head must be flat to <0.01mm across the whole head. Unfortunately I neglected to take any photos of this stage but there’s plenty of information online.

That’s about as good as it gets so our £4 coffee table looks like a success. Plus I still own a coffee table – albeit with a few new scratches!

RX8 Project – Part 17, Changing to a concentric clutch slave.

To preface this I’ve not actually run the car with this setup yet so please make your own decision if you give it a go. This was done on the gearbox from a 2006 year RX8 5 speed box so may not be applicable to others. It looks like it should work but that’s only my opinion – your mileage may vary!

So this is a bit of an odd problem which depending on the engine you’re swapping in may not be and issue but in my case I decided a V6 was a good idea and unfortunately the standard clutch slave on the RX8 gearbox is on the top offset to one side which lines up perfectly with one of the cylinder heads on my V6. Add to this if you made the better decision mentioned earlier and made the adapter thicker you may be able to avoid this as well. But since I’m largely making this up as I go along here we are!

Now I did look into whether anyone offered a concentric slave conversion for this car but it seems that was never a thing anyone did so I set to work building my own. Luckily there was one thing I knew which would help this process quite a bit – the input shaft on the gearbox is the same diameter/spline as most Ford patterns and so a Ford part should be exactly the right clearance. Add to that I’m actually using a Ford clutch if I get the depth right everything should just match up ok.

So that’s the good news, the bad news is the RX8 gearbox was never intended to be used in this way so mounting a cylinder could be an issue. Now on the RX8 there’s a flanged sleeve mounted which the original release bearing slides on the outside of. This is held on by four bolts into the back of the bellhousing and so this appeared to be essentially the only option. The tube itself can’t stay because the new concentric slave is the same ID and so clashes with it but I thought why don’t I just unbolt the tube at the flange and bolt a suitable adapter there and we’re good to go? Well it’s never that easy is it. Under that flange is a location lip which not only keeps it concentric to the gearbox input shaft but it turns out it also the height of the shoulder accurately holds the input bearing in place behind it so if I just remove that whole part the bearing will move out of position and that will very likely result in it not having enough support and rapidly removing itself from the gearbox in small pieces.

3D model of the RX8 gearbox input bearing retainer
Unfortunately I can’t find a photo of it but the part looked like this!

Ok so I can’t just remove the flanged tube and stick an adapter plate on but how about cutting the tube down to the flange to leave a flat face above the bearing retainer and just using some longer bolts to keep it all in place. After some very careful trimming I was left with this:

Modified RX8 bearing retainer

Next was picking a suitable concentric slave from the Ford range. After a bit of poking about and trying to find something I could make fit I found the Teckmarx TMCS00047 which is a 3rd party part number for a 2001-2007 Mk3 Mondeo/Cougar among others which as you might have read earlier was also available with this same V6 engine I am using and this model has a few advantages firstly that both in and out hydraulics are in one direction so if I make that line up with the original position of the clutch fork I should have easy access and also that they’re threaded the standard M10x1 brake fitting thread so I can direct connect hoses or hardline as I need to make it work. another major advantage is they’re used on loads of versions of the car so they’re widely available and very cheap at under £25 delivered. It also seems that the RX8 also has almost same clutch master cylinder bore as the Mondeo (18mm vs 19mm) which should mean pedal travel is still sensible.

Mondeo mk3 concentric clutch slave

3D model of Mk3 Mondeo Clutch slave

Now with the clutch slave accurately 3D modelled I could measure the 4 bolt flange from the gearbox bearing retainer and by overlaying the two bolt patterns aligned on the centre of the input shaft I could design an adapter which I could index the relative rotational angle of the bolt patterns in the software until the fluid connections where in the right place for the hole in the bellhousing. The resulting first version was this :

3D design of first adapter design

Initially I transferred this to a bit of scrap plastic to make sure I hadn’t made any stupid mistakes before spending much more time cutting a proper steel adapter plate.

Plastic prototype RX8 clutch slave adapter

So with all that checked out and nothing apparently an issue I moved onto the steel one. I did make a mistake here if you can spot it…

To make the adapter I did the same as I had done with the plastic where I printed out the design at 100% scale, stuck it to the steel and then used a centre punch to mark the centre of all the drill positions. I admit this isn’t the most accurate method but it seems to work quite well!

Clutch slave adapter Mk1 in steel

This is the initial adapter, the four larger holes are M8 clearance holes. on the original RX8 flanged retainer they’re 9.4mm but I think I did them 8.5mm as that’s the drill I had available and tightening up the tolerance was probably a good thing. This actually turned out to be less of a problem in the end but that’s another story. The centre hole is larger than the original design to allow for the location feature I’d overlooked on the new slave (which is 42mm OD) to sit within it.

Clutch slave adapter trial fitted to the gearbox

So it fits, I called this good progress but it should come as absolute no surprise that it wasn’t quite that simple…

Clutch slave unit fitted to adapter plate

As soon as I tried to add the clutch slave all the issues become apparent as it just clashed with everything. This told me that I’d need to change the adapter to countersunk bolts so the slave didn’t foul them. I could have changed the rotation but I wanted to avoid having lengths of pipe in the bell housing if I could. Plus I’d already made this steel adapter and didn’t want to do it again!

The other thing I noticed is that the cast webs off the original pivot point actually clashed with the adapter plate preventing it from quite sitting flat so I decided to remove some of the plate to correct this minor issue.

Now the adapter sits flat and at the same time I countersunk all the adapter bolt holes and replaced the bolts.

It all fits more or less where I wanted it but when I tried to bolt up the gearbox I saw another problem. With the bearing retainer plate, a sensible thickness for an adapter plate and the height of the concentric slave itself the slave was already almost fully pressed down so that which it may have worked initially as the clutch wore the slave would prevent the clutch from fully re-engaging. Clearly not ideal so we need to get more radical. First off the back of the clutch slave had a lip similar to the one on the RX8 flanged plate which initially I was just going to leave on and sit on top of the bearing retainer plate as it was slightly thicker than the adapter plate but that just wasn’t an option any more. Below you can the way the slave is totally compressed. Also note how close the hydraulic connection point is to the original pivot point casting.

Stack height issues in the new clutch assembly

This lip was adding a couple mm of stack height we needed to remove so I proceeded to carefully file the lip off down on the slave such that it would sit full within the adapter plate and ideally totally flush to the back of the plate.

On trying to refit this in its new position I realised I’d created another problem that I glossed over earlier – that I’d need to remove some of the original gearbox casting to make the new slave sit flat in the orientation I needed as the original clutch fork pivot point clashed with the location where I wanted the hydraulic connections on the new slave. The best method I found was a drill bit larger than the feature and just drill the top of it away until it clears the new slave.

Around this time I realised really I needed to remove the original flanged bearing retainer plate as it alone added about 4mm to the stack height so I engaged in the type of butchery that makes engineers wince. I took the flanged retainer and trimmed the flange off it. Yes I specifically mean that – if you cut through the bearing retainer ring it will reduce the height such that the bearing is no longer held tightly so you need to carefully trim off just the flange plate leaving a ring the right height fill the gap between the bearing and where the retaining plate face would be. because the new slave retaining face was now flush with the adapter plate this ring will now be held in place by that. Removing this plate now meant I had to drill yet more out of the pivot casting to prevent it clashing but that’s easy.

Final fitment of the concentric slave conversion from the original fork position

Now everything is in place and the hydraulics are accessible through the original clutch fork hole.

RX8 gearbox refitted to the car

And all back in the car…

For anyone who may want it here’s the PDF drawing for the adapter :

Start of 2020 Update

Apologies to anyone who’s been waiting for an update on any of the projects I’ve put on here – I’ve had a lot going on over the last year and writing up all of this information takes me a lot of time so has taken a bit of a back seat. None of that information has been lost and I hope to start catching up on all of this over the next few months.

Where we are right now :

V6 Mazda RX8

The V6 engine has been fully rebuilt and has been sat in my living room next to an engine crane for about 8 months now, Partly this is due to me not currently having a garage to work in and it being winter and partly due to being very busy last summer. But yes, the project is still ongoing and hopefully will make good progress this year.

Six million dollar welder

Is still on my workbench awaiting the last couple of bits. I’ve had to swap out 24V PSU’s a couple times as they couldn’t deal with the current of the new feed motor. It now works but needs the relays mounted to the panel so I need to remember to find 4″ of DIN rail.

DL180 Server

Is still working beautifully after the Arduino fan controller mod. It’s been hosting this blog ever since so something like 12 months now without a problem. It also provides the storage for my CCTV system.

Hikvision CCTV

I’ve got a couple of updates to write about expanding the system beyond the original one camera setup I wrote up last year. Using multiple cameras with network storage seems to be poorly documented and have a few interesting quirks but after some work I got it working fine. The biggest problem I’ve had since is when the local police asked for my footage following a nearby break-in I had to supply them on a 1 Tb hard drive! High resolution digital video takes up a lot of space!

Other Projects

I’ve had various other projects going on as well. I’ve started looking into using NodeMCU WiFi microcontrollers as sensor nodes with their own web servers around my house with NodeRed requesting the page and parsing the HTML to return the information I want. I can read the temperature sensor connected to the nodes and control the LED on the MCU from NodeRed. Currently the data is not stored because I ran out of time trying to get MySQL setup. I’ll write this all up at some point

Raspberry Pi’s – I seem to have collected a selection of Raspberry Pi’s somewhere along the way. I have a Zero, a ZeroW, 1B (which in a different life I turned into a PoE CCTV camera), 2B and 3B plus I think somewhere there’s another 2B. I really should do something cool with them!

Wooden storage box – I started restoring a large wooden box some time ago. The box used to be in my granddad’s workshop as a toolbox for many years and before that I gather it belonged to his uncle so it’s been around for a long time and has suffered a bit with use and age with some areas with woodworm damage and the rope handles badly degraded. It has also been painted brown at some stage so I’ll need to get that cleaned up as well. I intend to restore it to a ‘usable’ condition so rather than trying to make it as new just tidy it up, repair the damage and make it solid enough not to degrade further but still look like the well used item it is.

Subwoofer project – Has been in constant use for ages despite never being technically finished. I really need to actually finish it and write this up!

There will be more but I think that’s enough update for now – rest assured I’ve not stopped! Especially since this morning another turbo arrived in the post, the fourth I now have here….

Living with a Scirocco 1.4 TSI 160 (118kW)

So recently I finally decided it was time to retire my previous long suffering car – a 2003 1.4L Mk1 Seat Leon I’ve had for 10 years! When I bought the car in 2009 it had 62,000 miles on the clock, now it has 198,000 miles on it and needs to be run on 10W40 rather than the specified 5W30 just to stop the engine rattling. The Seat did well but it had a hard life including 3 years commuting 400 miles a week and had got to the point where I was fully expecting it to fail sooner or later and wanted something that wasn’t as underpowered.

So I started looking about for another car and the new style Scirocco caught my eye. After looking for a while I found a decent condition version with reasonable mileage, service history and not reaching a high bid. Detail on this car was a little lacking as it was just described as a 1.4 TSI but the car had no engine/spec badges (a factory option from VW) so I wasn’t sure which version it actually was but on the basis it wasn’t advertised as the higher power option it would be the lower power turbo only 122 bhp model. So I went for it and got it for a decent price. When I arrived to collect it having never actually seen it before I checked it and found the identifying sticker in the boot which showed the power as 118kW, this is 160bhp so I’d got the more powerful one.

Image of a 2010 Scirocco
Something like this one.

This is both a blessing and a curse because while obviously it goes better the 160bhp version also have a reputation for unexpectedly experiencing catastrophic engine failure.

That said always take forum posts on the internet with a pinch of salt – people rarely take to the internet as much when their car works perfectly.

By this point its too late to back out so I’m now the owner of a Scirocco with a 1.4L engine! So now I start looking into things I need to watch out for. The engine is the first interesting thing here as it’s both supercharged and turbocharged to give a much better low down grunt than expected from such a small engine with supercharger boost while still having a wider power curve by the turbo taking over at about 3000 rpm and working higher up. The engine peaks out at about 1.5 Bar of boost (22 PSI) from the factory. This system obviously adds complexity and potential points of failure with various valves and clutches to make it all work so a number of things to keep an eye on.

VW Technical guide to this engine available here

Clearly we’re playing with a fairly highly strung engine so my first thought is what the maintenance schedule on these was like. People tend to ignore their cars so long as they keep working and from my previous 1.4 VW engine in my Seat I’m aware they have some issues with oil consumption. On my first look at some of the reports of damage online most seemed to mention failures that could easily be a result of oil starvation. Again, something to keep an eye on.

Moving beyond the engine that car itself is fairly advanced as well. These cars come as standard with adaptive suspension designed to react to road conditions. It has four sports seats which are very comfortable and the boot is quite reasonable for this type of car. Internally the Scirocco is very similar (depending on model year) to either a mark 5 or mark 6 Golf but is a bit less practical due to the style of the vehicle and lower roof line. That said I’ve had four full grown adults in mine and while it’s not hugely roomy it’s comfortable enough.

Now for the the but – I think mine was cheap partly because it has none of the extras. It doesn’t have cruise control, it doesn’t have HID headlights, it doesn’t have the more common 18″ ‘turbine’ wheels (I have the 17″ shown above), no DAB radio and no bluetooth. Other than the twincharged engine its a basic model and for most people that would be all there is to it but that’s not how I work. I will improve it as I go along and hopefully record how I do it all on here!

RX8 Project – Part 16, Fitting Piston Cooling Oil Jets

These are something I hadn’t really come across until I started working on this project. While I was researching the work Noble had done developing their twin turbo engines I found the installation of piston cooling oil jets noted as one of the modifications undertaken. On the basis they found it was fine to use the stock pistons but did this mod I started doing research into what exactly they were and why they were used.

The usage of these jets seems to be almost exclusively related to turbocharged engines, both diesel and petrol due to the amount of energy released in these engines. This increased release of energy caused by burning more fuel in pressurised air generates much higher temperatures inside the engine and while the block and head are actively cooled most normal engines rely on incidental oil spray to keep the piston cool. Once you start getting the piston considerably hotter you have a couple options. Either use a piston material which will cope with much higher temperatures without degrading (either due to the temperature affecting the material properties or due to thermal expansion) or somehow cool the piston. Various materials have been used for high performance pistons to help negate the material strength and thermal expansion problems with varying degrees of success but these are generally very expensive made to order parts and well beyond the range of most. This is where the jets come in.

The jet is usually some sort of nozzle drilled into an oil gallery in the block which directs a stream of oil at the underside of each piston. This both cools and lubricates the piston and rod small end/pin.
The original Noble modification is known to have some issues but this was more of a problem with the implementation. Take a look at this : http://noblecars.org/engine.html

The basic problem of the original Noble method is that with such large drillings (probably about 4mm diameter) the cooling will be very effective because the flow rate will be high but the overall engine oil pressure will likely be very low, particularly around the main bearings because that is where they are drilled into the oil supply. Clearly the one place you don’t want low oil pressure!

So me being me I decided to improve on the situation! Firstly I found that most cars that have these fitted (unsurprisingly) use considerably smaller jets, the best example I found was a NASCAR engine using a jet of 0.75mm (I have since tried to find this page again with no luck). Not wanting to risk trying to drill a hole of such a small diameter freehand at the bottom of the cylinder bore from the top I took a slightly different approach and started looking for suitable nozzle inserts that I could use that were available easily and cheap. After a lengthy search trying to find something intended for the purpose (from either a suitable production vehicle or something) I gave up and started just trying to work out what I actually needed and realised that with the rise of home 3D printing small nozzles were actually easy to get – specifically the extruder nozzles used on these printers. These nozzles are usually brass, have an M6 thread and are available in a range of hole sizes, for me the 0.8mm version looked like a good match.

3d printer nozzle

I bought a pack of four nozzles off eBay for a few pounds and decided I should see what sort of spray I actually got from them – I wanted them to produce a fine jet at the normal engine oil pressure rather than a mist as this would assure the oil reached the piston rather than most of it just hitting the inside of the cylinder bore which would achieve nothing. Because I’d decided on the M6 thread it made a test jig quite simple, just a normal M6 nut welded on the end of a bit of 12mm tube. When welding anything threaded it’s a good idea (particularly on smaller threads) to put a suitable mating part in to prevent distortion if you can. In this case I used a standard M6 bolt. After welding the nut the bolt can simply be unscrewed again but if you don’t do this the heat will often distort the thread enough that it is unusable after welding. The 12mm tube just happened to be about right for the nut but also a good size to allow a normal garden hose to fit over it. Water pressure in the UK is nominally about 3 Bar which is at least in about the right area to represent an oil pressure. Also there is the question of viscosity but my logic told me that oil being more viscous than water should not form a mist as easily, so if it worked with water oil should be fine. The test showed a solid jet out to about a meter from the nozzle and beyond that a tight stream of droplets another meter or so. This should certainly be good enough for what I need!

After this test I decided to go for it, so I ordered another set of four nozzles and started trying to work out how to actually machine the block to make them fit. Due to the position the jets need to be installed the oil feeds need to be drilled from the crank bearing housing 60° either side of the centre line to match the cylinder bore angle and also at a slight angle forward or backward (depending on which cylinder it is) so they actually come out into the shoulder at the bottom of the bores rather than just continuing between the cylinders.
First off I marked up the 60° line for each bore so I had something to line the drill up with for the angle and the starting point for the drilling. Next I found a drill bit that nicely fitted into the groove in the bearing housing so as to avoid reducing the supporting area for the bearing which as it turns out is a 3.2mm. This is the area that apparently will crack on the Noble engines – they use a significantly larger drill hole here which breaks into the bearing support lands and I suspect this is part of the issue but that’s purely speculation. There is also no issue with restricting the flow to the jets here because the jets are now significantly smaller than drilling. The next important thing is this involves drilling quite a long, narrow diameter hole through aluminium and that can be quite problematic!

First off let me say this is next bit is a bad idea all round, you either have to be very confident in your abilities with a hand drill or not care if you ruin an engine block. Ideally you want to be both! If not you will want to talk to a machine shop to do this!

Before you start remember to remove the bearing shell itself and put it somewhere safe! Aluminium is a soft material and will stick to drill bits and tend to generate heat due to friction, if it gets hot enough it can actually seize onto the drill bit causing it to break. Firstly a normal length 3.2mm drill won’t be long enough for this job, it will work to an extent but the flutes will eventually be covered by the sides of the drilled hole when you get deeper and there’s nowhere for the chips of aluminium to go. My advice is to buy a long series drill bit and use it. Start the hole with a normal bit because long bits are more flexible and can be harder to get and accurate start with but once you have a dimple that will hold the bit in place swap to the long series. Use plenty of lubricant (go on, guess how I found that out!). You can use WD40 but it can get quite expensive if you have a few holes to do as it tends to vaporise off during cutting. Thicker oils tend to protect the cutting edge more but make cutting slower but in this case aluminium is soft and so drills quickly anyway plus we’re only making a small hole so it will make little difference. Personally I used 3in1 on mine with works well and helps flush the chips out but you will need to reapply the oil to the hole regularly during the process to make sure the drill is well lubricated. You could also use engine oil or even gearbox oil but these would probably slow the process a little more. Go slowly and let the tool do the work, if you push too hard there is a serious risk of flexing the drill bit which at best will give you a hole that wanders and at worst a serious risk of snapping the drill bit.
Once the 3.2mm hole comes through into the shoulder at the bottom of the bore we need to make the M6 nozzle fit, this means tapping a suitable thread into the bore end of the drilling. First clean out all the swarf (drilling debris) from the new hole. At this stage this is just to make sure we get a nice clean thread cut. Now we have the interesting bit, to tap M6 we need a 5mm pilot drill, so we have to drill out the cylinder end of the 3.2mm drilling to 5mm with enough depth for the nozzle to screw in but the only way to do this is to do it from the top of the bore with a really long drill! I went on eBay again and bought and extra long series 5mm drill for the job. This thing is 250mm long and looks absolutely ridiculous in a cordless hand drill.

Extra long Series Drill

It actually looks more like it should be used on masonry but these have the normal tip and are actually for metal. If the one you buy has a flat ceramic insert in the tip you’ve bought the wrong one! 5mm Drill Jet

I suggest you mark the depth you need to drill to accommodate the nozzle thread (with a little extra room for tapping) on the drill bit. The actual depth here isn’t critical as long as there’s enough depth for the nozzle threads at a minimum. Again plenty of lubricant and drill with slow speed and light pressure and be very careful to keep the drill loaded straight otherwise at best your hole will be at a funny angle but at worst you may snap the drill and damage the bore surface.

5mm Drilled hole

Next clean the swarf out again so we can get a good thread tapped. Tapping the holes is another slightly awkward problem for the same reason as drilling the pilot hole, we need to do it from the top of the bore. I suggest going on eBay (or any of a thousand other places online) again and looking for an extra long ratchet tap wrench. These are available under any number of brands but I suspect they’re largely all from the same place. They are available in a small version, which is 250mm long and will tap M3-M10 or a large version which is 300mm long but taps M5-M12. I went for the smaller one because the smaller chuck should allow tapping tighter to the cylinder wall without damaging it and this is likely to be tight for this task. Expect this to be about £10. While you’re at it buy an M6x1 plug (bottoming) tap!

Tapping the Jets

Again proceed slowly with a well lubricated tap, many people will say you need to use proper cutting compound but for a small hole in a soft material this isn’t necessary, 3in1 will be fine. Try to cut forward a bit (maybe a turn at a time or so) and then back the tool off until you feel it turn smoothly. This will help prevent the tap from clogging up and either seizing up or damaging the new thread by material being forced against it. It may be necessary to back the tap out entirely to clean the removed metal from the threads because this is effectively a blind hole. Be careful not to keep going once the tap bottoms out. If you aren’t careful it’s comparatively easy to strip the threads in the aluminium with such a small tap and then it would be awkward to repair. If you’re not confident this really isn’t an ideal job for anyone new to tapping because it relies on having a degree of ‘feel’ about what you need to do and when to stop.

Rinse and repeat five more times and congratulations you now have six neatly drilled and tapped jet positions! Before doing anything else clean everything again, I used a combination of brake clean, compressed air and a scribe. You need to make sure there is no swarf left in the drillings so you don’t risk that jet becoming clogged. Once clean you need to fit the jets. The jets I selected have an external hexagon and so can be tightened up with a socket wrench but you will need sufficient extension to reach the bottom of the cylinder bore with an appropriate sized socket. Clean all the jets with brake clean to degrease them – technically this is not necessary but it helps remove any other grime that has become stuck to the jets in manufacture/transit. Next I recommend you apply a small dab of a suitable thread locker to the jet threads, specifically I went for Loctite 243 which is a medium strength thread locker which will resist oil. You can use others but if you go for anything stronger you’ll need a blowtorch to get it out and trying to do that down a cylinder bore could be interesting! Once you have the dab of Loctite on the jet you need to screw it into the newly tapped hole – I found it easiest to do this carefully from the crank side of the block by fingertip but your mileage may vary! Once you have it in enough to keep it in place tighten it in with the socket wrench. The jets will only need to be nipped up for two important reasons; firstly they are thread locked and so will not vibrate loose and second they are small and made of brass so any more force will likely strip the hex.

Piston Jets Fitted
That’s it, one new set of shiny piston cooling oil jets! More on this project coming soon!

RX8 Project – Part 15, Engine Strip #2

So having removed the timing chain and tensioners (see part 1) next we need to start looking at removing some more major parts of the engine.

Having already removed the cam covers already you should be looking at something like this:

Jag Cams

Thanks to the Jag Motor Project for the image – hopefully they don’t mind me borrowing it! It seems I have misplaced my own photo of this!

You need to remove the cam bearing housings because the design of this engine has the head bolts directly under the cam making it impossible to remove the head with the cams still in place. This is worth remembering and is at least part of the reason stretch bolts are used for the head – it is impossible the re-torque them after an interval of use without removing all the timing gear. As you can see in the photo these are three smaller housings and one larger one at the front each held on with two small bolts. Basically you just need to carefully remove these bearing housings in order. I suggest marking the direction and its position on each one before removal. The position could be achieved by putting each into a small tub which is numbered. However you do this you need to know which is which and which way round they go. Remove them carefully and make sure you don’t drop any bits! Once you have removed the housings you’ll see this:

S-Type V6 Cams Removed

Now we have clear access to the head bolts which as you can see in the photo there are eight of. These are fairly easily removed except for one thing – the bolts are set well down into the head and there is very little room in the recess to put in a socket. You will need a 15mm socket for these bolts and a small breaker bar (or an impact gun) as they will be quite tight.

These bolts are not reusable – I mean you can but it’s a terrible idea particularly in such a critical location because odds are high it will not be up to the job. This is because “stretch” bolts rely on the material of the bolt reaching the yield point of the material at which it begins to exhibit a fairly constant elastic stretch. In effect once they start to deform they behave a bit like a very stiff spring and so if tightened correctly will hold a very accurate load without loosening and so do not need to be re-tightened after a run in period. That said hang onto them for now so you know what to order to replace them!

S-type V6 Head bolt removal

You can see how tight the casting is around the socket! Once all the bolts are gone you can lift the head away. It might take a little persuasion with a mallet. Make sure you have a suitable clear space to put it on once you remove it.

Now you should have this level of grime:

S-type V6 Head removed

Obviously you can just pull off the head gasket now to improve the situation quite a bit and you can have a good look at the state of the engine:

S-type V6 Factory Hone

Here you can see the cylinder bore actually looks in very good condition and even still has the factory honing marks on the bores which is a good sign it’s been working well and shouldn’t have suffered wear issues.

Now do all of that again for the other head and you should have something that looks a bit like this:

S-type V6 Heads Removed

Congratulations now you have an engine with no heads but since my plan was to upgrade the rods I still needed to remove more so flip the engine over and we can get to it.

S-type Oil Pump

In the picture you can see the oil pump is just held on by four small black bolts. I put the crank bolt back in place just so I didn’t lose it but you would have removed this a long time ago. Once the four small bolts are out the oil pump can just be slid off the crank and put aside.

S-type V6 Front Oil Pump Removed

 

Next we need to remove the con rod bolts and this is where having the crank bolt comes in because you can put it back in finger tight and once it snugs up a bit you can turn over the engine to get access to all the rod bolts. Mark up each rod with a cylinder number and arrow for the front of the engine. I put sharpie marks across the split line of the rod to make it easier to match them up later. I had to use something to knock the piston out of the bore use something non metallic otherwise you will likely damage a surface you don’t want to damage. I used a length of wooden dowel. Do these carefully unbolting and removing one at a time. When knocking the piston out don’t forget to catch it before it falls on the floor!

S-Type V6 Oil Pump Removed

So all we have left is the crank. If all you wanted to do was straight swap the rods this is as far as you need to get. Well I wanted to do a few other while I was at it (more on this in another post) so I carried on to remove the crank. This is actually pretty simple at this point, you just take out the 16  main bolts holding the lower block to the upper block along the bearings. The other thing you can see in the picture are the engine mounts, the rubbers here aren’t stock s-type, they’re actually from a V8 Land Rover (Discovery among many others). The reason for this is they’re very strong, extremely cheap (£7 a pair delivered from eBay) and have a stud each side which will fit straight onto the factory cast aluminium mounting arms and also make mounting onto the car really easy when we get to that stage!

S-type V6 Lower Block

It’s worth noting in the above picture not all the bolts are the same. This is because some have small studs on the top to allow the windage plate to be mounted (blue). Note which goes where so this can be put back later! Next you also need to remove the 6 outer bolts (red) before the block will separate.

S-Type V6 Lower Block Bolts

Once all the bolts are out again you might need a gentle tap with a mallet and/or a scraper to get the block apart. Don’t drop the crank bearings!

If you’ve done all of this you should have something a bit like this in front of you:

S-type Stripped 2.5 Block

And a heap of bits you just removed:

S-type Engine Parts

More to come on this project in my next post!

RX8 Project – Part 14, Engine Strip #1

After deciding to turbo the engine (see earlier posts) is became apparent I would have to upgrade the piston rods to make sure the engine wasn’t in danger of these failing and ruining the engine. This meant I needed to extract these from the engine Now bear in mind that this was the first time I’d ever taken the head off and engine before let alone removed a crank so it was likely to be quite a long and delicate process! Also accept that I was making this up as I went along, things may be in a strange order but it seemed to work!

First things first mount the engine to a suitable stand:

Here it is, it’s already upside down but that doesn’t matter! First off I took off the sump. On this engine it’s a cast alloy unit with a large front bulge which makes working around the front of the engine more awkward so I got it out the way early on.

V6 Windage tray

Take off the oil pick up pipe (2xM6 bolts) to get room for the windage tray. The tray is held on by 5 nuts on some special studs on this engine, these are M10 one side to hold the lower block to the upper block but i think M5 on the top just to hold the windage tray.

Duratec V6 Bottom

Now we have exposed the moving parts of the engine and get the first look at the bits we are replacing but there’s a lot more before we get them all out. An interesting thing to note here is the absence of crank bearing caps. On this engine the block is formed in two cast pieces which joint along the crank centre line so the crank bearings are held in place by the substantial cast ribs you can see in the picture and each bearing has four M10 bolts to keep it in place with additional bolts around the outside of the casting.

Next move to the front of the engine and disconnect the hose from the block to  the water pump then unbolt the water pump. On the Ford version of this engine the water pump is driven directly off one of the cams but on this Jaguar one it is a separate unit driven from the back side of the accessory belt and is held on by three small M6 bolts. Next up remove the crank bolt, there are a variety of ways to do this (the easiest probably being a decent impact gun but at this point in the project I’d not yet bought it) but the method I chose was to block the rotation of the crank using a block of wood. This is done by finding a suitable block that fits between the crank and the housing such that as the crank counterweight rotates round it is stopped by the wood. Just remember that the crank bolt undoes anticlockwise so make sure you put the block on the correct side(the bottom in the above image)!

S type V6 front

Now you can flip the engine back up the correct way because we’re moving on to the heads This is because the cam covers need removing to take off the front engine cover.

S-type V6 Black Cam Cover

This bit is again very simple, remove the bolts holding each coil unit in place. Again this being the Jaguar version of the engine is came from the factory with coil on plug. Next remove all the bolts around the cam cover and lift the cover away. Sometimes these get refitted with instant gasket to fix a failed cover gasket cheaply and quickly and so it may require some persuasion, I usually use a putty knife or a wallpaper scraper for this job but it can be easy to damage the faces if you’re not very careful. Alternatively plastic trim removal tools can work well. Obviously repeat the process for the other cover.

Next up we need to remove the front engine cover. This involves removing the bolts all the way round the edge, you can’t miss them, there’s loads and they’re all the same! Make sure you get them all, I think there’s 17 of them but don’t quote me on that, one is under the belt tensioner by the crank! This cover again might require a little help coming away due to the gasket but should be relatively easy. If it isn’t then you’ve missed a bolt so stop prying it!

S-Type V6 No Front Cover

It should look something like this! Now you can see the other feature these jag engines have – variable valve timing on the intake cams. An important point here is the crank timing wheel (the notched wheel on the crank). These have two key positions but only one is correct so carefully mark which position lines up with the key on the crank when you take it off. I recommend something permanent so when you clean all the oil residue off the mark is still visible, a centre punch mark should do it.

Next you need to remove the timing chain tensioners. These are small hydraulic cylinders that use engine oil pressure to maintain tension in the timing chain. They are held on by two bolts each. Just undo the bolts and carefully remove the tensioners from the tension arms.

S-type V6 Timing Tensioner

Once the tension cylinders have been removed the tension arms can be lifted off their dowels and removed as well and then the chains can be lifted off and you should have something that looks a bit like this:

S-type V6 removed tensioner

Now all that is clear the chain runners can be removed. These also hold the VVT solenoids and so are quite a complex bit of metal but are easily removed. I also took of the water hoses at this point just to simplicity.

Now you should be at this stage:

S-type timing gear removed

In the next part the engine strip will continue…