325 Classic Touring Car rebuild.

[winx]

Interesting! I ordered my pauper spec gaz golds with the m3 ARB tabs welded on to the strut and haven't got round to sorting the drop links yet. Is there a half decent kit off the shelf or am I best to make something up with rod ends and threading some bar?

[Demlotcrew]

Interesting! I ordered my pauper spec gaz golds with the m3 ARB tabs welded on to the strut and haven't got round to sorting the drop links yet. Is there a half decent kit off the shelf or am I best to make something up with rod ends and threading some bar?

All the kits ive seen were far too heavy (much heavier than the stok items).

So many new BMW's use a plastic drop links reduce weight too.

I used off the shelf rod ends (one left one right) and a turnbuckle joins them both (again with a left thread on one end and a right thread on the other).

The rest of the hardware is sourced from a few different suppliers. Seems to have worked well so far, but are not suited for a road car that sees a lot of salt and water.

HTH

[winx]

Better start having a look at McGill then! My car will only be coming out in the dry unless it is on track or on its way to a track!

[Rav335uk]

I have another question.
Can you use a custom made 24mm rear arb without issuses??
The only issue I see is that it would rub on the rerar floor, correct?

[Demlotcrew]

I've not had any rubbing on the floor, but the differential is very close and when you jack the car the top touches the ARB.

[Rav335uk]

YHPM Andrew.

[Demlotcrew]

You can see how close the ARB really is to the top of the differential casing. Of course the axle is raised about 12mm higher than a stock car, so in many cases it would be a non issue.

[Demlotcrew]

Topic Moved in here

[Paynts]

any news on the car Dan? Ive got an exkumho 325 which has been laid up for a couple of years following the crankshaft damper exploding at bedford autodrome at 7000 rpm ....im getting it up and running fro my stag this summer!!!
Cheers Simon
PS i used to message your dad a bit a year or 2 back when he used to poston E30 zone

[knobstar]

Loving this - wish I had the patience to execute my '72 02 Touring racer to the standards that people like you achieve!

[taylorspug]

Sorry for the super late replies gents! I have been extremely busy in the last couple of months (work, distracted by girls etc) and as such ZERO work has been done on the E30- I've not even so much as logged into here. Poor car is looking very sorry for itself buried under mountains of parts in my garage. However I'm going to kickstart it all back into motion now, have a few new plans regarding the engine which require some radical changes- so expect a few for sale topics in the next day or so! Will keep it all close to my chest for now, as I need to work out the logistics of what I am trying to do before I start harping on about it....

[taylorspug]

Ok so an update on whats happening with the car. I had been slowly but surely working through the planning stage of building up the engine for the car, both in parts I was going to use, and people I was going to use for some of the finer points such as headwork. However I was getting frustrated. There is a serious lack of solid, proven knowledge in this country on head work for the M20 motor when used in naturally aspirated form, and as my engine engine was going to be on the more extreme end of that scale this was a major point that really needed to be right! After speaking with a few people and looking at a few options, I decided the risk was huge in comparison to the reward. Best case for me and my spec, staying at 2.5l, the motor would make 260hp, probably wouldnt be all that useable, and even then there were several major factors out of my control, which if not done right would put me back to square 1! Thats not in any way to discredit anyone who is still working on tuning the M20 in its standard form, its a fine engine and im sure they are getting solid numbers. But I've been around cars long enough now to know I need more than a 'maybe' when it comes to engine numbers.

So solutions. One was just to use a complete engine from another BMW, so S50/S54 etc. Its easy, bolt in power and would far exceed any M20 I could put together realistically. However for most race series in this country it would either make it completely illegal, or put it in the seriously modified classes with things like this:

http://awsmedia2.turbosport.co.uk/2009/ ... CF1423.JPG

Now I'm no pot hunter, I'd prefer a good race and coming 3rd to winning because I'm the only one in the class, however getting blown away every weekend because the car isn't really built for the class its racing in is another matter!

Most of these sets of rules stipulate that the car must retain the engine block it came from the factory with, so in this case it either means an M20, or the 4 cylinder M42 (think thats the right code!). The head meanwhile, has to be from the same manufacturer, but is free.

Ever since I read those rules the idea had been lurking in my mind to build a twin cam, 24v M20 motor, so at this stage with my uncertainty over the M20 motor as a whole, I decided to stop being a bit of a girl and get it done. When I get it to work it will cruise past the figures of the M20 engine in 12v form, and hopefully make the car a genuine contender to something like a well driven E30 M3. Problems like lack of information remain, mainly because I don't think anyone has actually done this before. However its all under my control now, I know what will work and what won't from an engineering standpoint, I have good people to do the machining work for me, so all I need to do is actually solve all the problems for this to get built.

I have been quiet on this for a while as I am actually a decent way into the project, to the point where alot of the apparent issues are already solved and machining on various parts has commenced. I also have a spec list that I will post up a bit later, which you will be pleased to know uses nearly exclusively BMW OE parts, not one major engine part is a 1 off in any way. I have to shoot out soon for work so I will get involved in the details a bit later on today, as I want to explain why I have gone in certain directions from a practical and engineering standpoint.

[Demlotcrew]

Project sounds good!

Back in the day Racing Dynamics did a 24v head for the M20, it could be a good reference to start from.



HTH

Andrew

[taylorspug]

Andrew,

I'd seen the Racing Dynamics head posted around while I was searching for information- mainly on topics with people asking how hard doing a 24v M20 would be! Those topics generally resulted in people getting a bit scared and fitting a complete M50/S50 engine instead. Obviously thats not an option for me. Ironically neither would one of the Racing Dynamics heads tbh- they weren't made by BMW so technically no use to me. Plus lets not kid myself, I'm never going to find one, and I think I read somewhere that they were all destroyed when the project was canned. If only life was that simple eh?!

So the start of the plan, I had to decide what head I was going to use to hybrid with an M20. Obvious choice here is an early M50, non vanos. I did a bit of reading, took a few measurements from a spare head at a friends workshop, and decided it would basically bolt onto the M20 block fine, and a decent amount of the oil/waterways would line up. However there was alot of random drain holes at the back of the head that looked like they could cause issues, and require alot of work having externals drains fitted. In any case it was certainly do-able. My concern was either an M50 or 52 head would maybe need some work in the ports to get the sort of figures I was after.

Then was measuring up some things in the workshop one day, and noticed the S50B30 throttle bodies I have sitting on the bench. Immediately wondered if that head would be suitable, as it would be a far better candidate with the fact it runs on a much larger capacity engine so probably had the flow right out the box to support my needs. Again more pictures were looked at, pages of text poured over, and wat do you know- the S50 heads are actually a better fit on an M20 block than an M50/52 would be! Pretty much all the oil and waterways line up exactly, to the point where I could even use an M20 head gasket. This was a major breakthrough, and pretty much cemented the plan to go ahead with this.

The next issue was going to be the real meat of this project though. An M20 is cambelt driven as I'm sure you are all aware. An S50 is chain driven, so either the block or the head was going to have to be converted to run one or the other. After much thought, my father suggested the best thing to do was get an entire S50 engine, and then I could physically see what was going to work and what wasn't. I also had an idea that I could use the S50B30 pistons too, as the series rules I was building to allowed me to go anything up to 400cc over the cars original capacity, and still stay within the class I was aiming for.

So I decided to sell my freshly bored M20B20 block, and get hold of a B25 block so I could safely go out to 86mm. Byron (Maggspower) bought the block and now redundant 12v head, and was kind enough to donate an ETA block free of charge once I explained what I was trying to do. I'm assuming pity was involved in this, as he is well aware of the size of the task I am undertaking!

With that sorted I put a wanted up on here for an S50, and within an afternoon I had something sorted! Ajay had a pretty much complete but nut and bolt stripped S50B30 engine in one of his lockups, all it was missing was an oil filter housing (didn't think I would need this), and the throttle bodies (have some already). Super helpful and friendly guy, ran up to his place in the city one Saturday and I had an S50 in my possession!

S50 head dumped on M20 block (had to be done ):





Now the real benefits of buying a complete engine would become apparent, as I had a S50 block to measure up and compare to the M20, as I attempted to fit everything in....

[Demlotcrew]

A very ambitious project, looking forward to seeing some of the solutions to the inherent problems of the two blocks.

I guess an S14 turbo is out side of the regs?

Andrew

[taylorspug]

Measuring up started! I wanted to start from the ground up, so stuck the M20 and S50 blocks side by side and measured their height. From rough measuring, the S50 block was 276mm tall overall, which is 10mm more than an M20. However it appeared that the crank centreline to deck measurement didnt run quite true to this, as the S50 was 216mm, and the M20 ETA 205.5mm. Again all of these are rough measurements, but it gives me a decent idea and meant I could start working out compression ratios with an S50 head and pistons when they are only compressing just over 2.5l of charge rather than 3l. I really wanted to use the 140mm M52 rods I have with the 75mm M20 crank, as it gives a really very nice rod/stroke ratio. I was concerned they just physically weren't going to fit into the shorter block with the S50 pistons though.

Here is an M52 rod fitted with an S50 piston.



The little ends are 1mm smaller in the S50 pistons, so I would have to get the rods re-bushed if I was to use them. Obviously I will need to add on 0.5mm to any crown height measurements before this is done to account for the slack when its in the bore! The M52 rods are a very nice lightweight design, and these are the non cracked big end type, so have a uniform mating surface and positive locating dowels for the caps like the M20 rods do.

Anyway after a bit of measuring using the piston and rod in the S50 block with an M20 crank (obviously doesn't fit in the M20 block at the moment as the bore isnt big enough!), and transferring the measurements over, I was really very happy to see it would all fit, albeit with a gasket thats about 1mm thicker than standard (2.7mm roughly). What I didnt realise before I had a set sitting in front of me is that the S50 rods are 142mm, id assumed they would be the general standard 135mm that BMW seem to like! I also didnt realise they had a 5mm bigger big end than an M20/50/52- so running S50 rods requires an S50 crank! Obviously no immediate bother to me, but it does allow some interesting future developments with regard to capacity though (offset ground understroked S50 crank...?! ).

This pretty much made my mind up on pistons and rods- S50 pistons and M52 rods. The pistons will need some work, as the engine will 'only' be displacing 2,619.02cc with an 86mm bore and 75mm stroke, so will need to intrude into the combustion chambers to reach my target compression ratio of 12:1. I will leave the details of this alone for now, as I have more fundamental parts of the build to decide on. Suffice to say I'm happy its do-able with modified standard S50 pistons though.

So with that done and some more encouragement it was time to start on the major job I mentioned in my last post- the head and specifically cam drive method....

[taylorspug]

A very ambitious project, looking forward to seeing some of the solutions to the inherent problems of the two blocks.

I guess an S14 turbo is out side of the regs?

Andrew

Thankyou- I'm sure you are already aware of some of the issues, and I think I am on top of the more fundamental ones already, including a couple of little stinkers that could easliy slip through the net....!

Yes unfortunately turbos generally move you up into a silly class, especially if the car was not turbocharged as standard! Its all a balancing act tbh, building an all out car with the best of everything doesn't always work in your favour.

[taylorspug]

Ok, so the head issue. An M20 has a cambelt, an S50 has a cam chain, but more importantly the cam pulleys and chain are in an integral casing which shares oil with the head, and drains back to the block. After a quick look/think, I was 75% sure I wanted to convert the head to run a cambelt, but as I had all the necessary parts for the cam chain too, thought it would be silly not to mock that up and see how it went.





Firstly I fitted an M52B25 crank I have, which has the longer nose to house the front oil/chain casing. Then fitted the front case up. Straight away it was obvious every bolt hole would need redrilling, and that the case itself would have to be slimmed down to fit the M20 block, which is fundamentally a different shape due to different locations for the oil and water pumps. The water pump I knew would have to be moved, however it became apparent that the oil pump too would not be able to stay in the original M20 position. The casing covered half of the drive stub, and even if this was modified, it then ran slap bang into the location of one of the chain tensioners. Add to this the need for a totally different sump to the baffled one I already had for an M20, aswell as having to make all the mounting posts for the chain guides and tensioners, as well as the fact that the head would still need to be slightly modified to work with the M20 block- it was a no go. I did think maybe it was more of an option right up until the need for external oil and water pumps became apparent!

So that idea was out, sort of a shame as the cambelt option was do-able, but required me to take some extra strength bravery pills with one particular part...

Onto the cambelt option! First I mocked up the block with all the basic parts an M20 would have on it. So M20 crank, front cover, oil pump sprocket, alternator, cam tensioner, crank sensor etc. First issue was the water pump catching the head:



This was a minor issue as you will see. Basically to fit cam pulleys I was going to have to perform MAJOR surgery to the front of the head. At the moment its integral with all the oil galleries in the head itself as part of the large front casting which houses the cam gears and the Vanos bridge etc. So this needed sealing off. My plan was basically to cut the front casting off of the head, and then machine a bolt of 'motor plate' for the front of the head. This plate would seal off the front of the head, house an oil drain back to the sump, and have 2 cam seals in it which would pick up on the 6 bolt Vanos hub mountings.

I did ALOT of measuring to make sure what I was about to do was going to be able to work! Then went from this:



To this:





So thats me committing to that then! Now I had room for the head to miss the waterpump which was great, and also room to fit cam pulleys. My plan with these had always been to use 2 M20 vernier pulleys, and then find a suitable belt/tensioner/idler setup. However a problem became immediately apparent with that too. An M20 cam pulley is 124mm in diameter, and the S50 cam jounals are only 118mm apart centre to centre- so the pulleys wouldn't fit side by side! This meant I realistically needed to find a pair of pulleys which were no wider than 115mm to give me clearance. I soon found something closer to home than I thought:



These are a standard pair of cam pulleys from a Peugeot 106 Gti/Saxo VTS. They are 113.7mm OD, so will fit easily side by side on the S50 head, and as an added bonus they are a standard 3 bolt vernier pulley, something that is quite common on PSA group engines of this era.

This means I will need to get the crank pulley machined down so it has an OD of 56.85mm. I considered getting a 106 Gti one of those to fit, but the M20 one has the hub on it for the timing ring/alternator pulley integral with it, so its going to be far easier to get a machine shop with gear cutting capabilities to just machine the M20 one down.

Next I could start to realistically look at the cambelt routing. The first thing that became apparent is the water pump is massive, and right in the way! To get a belt on with the standard M20 waterpump in place, it was going to have to follow the standard M20 route, but just be longer to accommodate 2 cams. I didnt much like this idea, as it left no room for an idler pulley (just the standard M20 belt tensioner), and it meant the belt entered the exhaust pulley at a very steep angle, and would have been wrapped around very little of the inlet pulley before it diverted off to the oil pump pulley. So the standard waterpump will be deleted, and an electric pump remotely fitted instead. This gives me a ton of room to fit a proper idler and tensioner, and means I can run the belt up the exhaust side of the block to the exhaust cam pulley. It also gives room to fit a better oil drain to the front plate of the head. I will control the water pump via a proper controller, so will have no need for a thermostat. This solves a small problem in itself, as the thermostat housing for the S50 head mates up to the S50 waterpump- so is completely useless for me! I had been considering just running without a thermostat full stop which I wasn't too keen on.

So that was the next piece of the puzzle in place, and maybe the biggest issue tackled to the point where I knew where I was going. Next up was mounting the cam pulleys on the correct centreline with the crank pulley, and making adaptors to fit them to the S50 cams without modification... Oh and the one small but major difference between the mating of an M20 block and an S50 head....

[Demlotcrew]

Love this project, so much to think through and fabricate

[jmc330i]

Love this project, so much to think through and fabricate

Cutting up an S50 head, that's commitment

Definitely a great project

[taylorspug]

Thanks chaps, it is indeed alot of work, but I like the fact the limit of it is what I can come up with to solve problems, rather than work someone else will have to do with no input from me. My machinist Nick is a very clever guy, so basically any idea/solution I come up with he can make happen. I'd do all the machining myself, but I don't have the machines lol.

Cutting the front off that S50 head was probably one of the most nervous times in my 10+ years in cars! Obviously its going to be milled flat, and probably have some mounting lugs welded into it so I cut it well short of where it needed to be. But its still an expensive head! I did look at getting an S54 head, but cutting up a £400 head on a 'voyage of discovery' engine just wasn't ever going to happen!

[rix313]

Really interesting to see something like this. Looking forward to more updates!

[taylorspug]

Really interesting to see something like this. Looking forward to more updates!

Thanks, hoped it might at least provide some different reading from the usual engine projects! I'm nearly up to date now with progress, I'm just waiting for some things to come back from being machined and I can start some dry assembly.

[taylorspug]

So onto the next stage, and what I had decided was the first part that needed to be finalised and machined so I could lead onto everything else. The cam pulleys needed an adaptor made to convert from the 6 bolt flange on the S50 cams to a single bolt hub on the 106 pulleys. I was keen to keep the cams unmodified, mainly because if I end up buying a set of expensive aftermarket S50 cams, I dont want to start machining them so they only fit in this engine, it leaves me free to sell them on if I need to. Also the 6 bolt hub will act as a good register for an oil seal in the front plate for the head.

Firstly I needed to find some way of solidly holding the pulleys so I could accurately measure and make sure they were in line with the crank/oil pump pulley.



Came up with this, the bolt slots nicely into the drilling in the exhaust cam, then used the nut as a stop and adjuster so I could hold the pulley in a solid position to measure.



This was the correct position. Measured it off of the oil pump pulley which was 1mm narrower than the cam pulley, so using a long straight edge held against the outside of the oil pump pulley, I needed 0.5mm overlap onto the cam pulley. After subtracting the depth of the small depression in the centre of the cam so the measurement was effectively taken from the hub face, I ended up needing an 18.2mm spacer. Just big enough to have the centre bolt hole blind, as the cams are oil fed and I dont want oil leaking out the centre of the cam pulleys!

Anyway these measurements are now with my machinist, along with a cam and pulley so he can make 2 up. Hes going to do the bolting face for the cam at the same diameter as the cam is to give a wider seat for the oil seal. Once these are back and the crank pulley is turned down I can decide on a cambelt, and then design the front plate for the head.

Now onto the sneaky little problem with fitting the head to the block. Apart from having to slightly eek out some of the oil drain holes in the head which will be half shaded by the M20 head gasket, the blocks are pretty much identical with regard to waterways etc. However the pressure oil feed, which comes up through the S50 block into the centre of the head is different! The feed itself is the same shape etc as the M20 one, but it comes up through the block on the inlet side, where its on the exhaust (ie oil filter) side of the M20. This means I am going to have to do an external drilling on the block, and run oil pipes up to the head to tap into the oil supply galleries.

At first I thought this would be a slight headache, but now I think I have identified that the oil is supplied to the S50 head through 2 gallery rails which run front to back. Handily these galleries have external grub screws which can be removed, presumably giving access for the head to be thoroughly cleaned. So my plan is to tap into either the block to pick up the standard oil feed to the head or maybe the oil cooler sandwich plate, then feed both of these oil galleries from the rear of the head. I am aware that the S50 has a problem with retaining oil in some way when its on track which can make it smoke a bit, but I plan to look at this in full once the basics of the engine being bolted together are sorted. Obviously I will have key differences to a full S50, different oil pump, no oil spray bars under the pistons, no front gallery on the head etc. Plus I also have the option to use the big M20 oil drain on the inlet side of the block if need be.

Anyway, thats me pretty much up to date now, more will follow once I have the cam spacers back.

[Demlotcrew]

Have you found seal the exact size needed for the cams? you might find that the spacer needs to be machined for the seal you can source rather than the cam flange.

Although im sure you are aware of that

[taylorspug]

Great minds! That was my plan! Once I have the spacers back, I will source the cam seals themselves, then machine the plate to fit them.

[Motorhole]

Awesome undertaking, brave man! And top work. Subscribed

[Eddie25]

Awesome undertaking, brave man! And top work. Subscribed

+1

[Bump]

Blimey. I worry about fitting a new rear badge..

[Paynts]

hi Dan

I'm just at the coffee and computer stage of getting my ex Kumho car out of storage ...(Again!)
Your build looks amazing is it finished? I wanted to ask what the regs are for Classic touring car? can you run throttle bodies and aftermarket ECU? and can you run outboard coil overs on the back?
Cheers
Paynts

[Paynts]

Dan I now see because my computer has finally loaded the last years worth of your posts!! that you ve gone off the deep end with the engine!!!! Will thiscar run classic touring car or is it track day?

[Demlotcrew]

Any updates on this

[kimbo]

Hi, I thought I'd post a quick reply on Dans behalf, as I doubt he's been on the forum for months.
The build has stalled at the moment, I'll let Dan fill in the detail when he resumes, but a combination of trying to kick start a business, sloth from suppliers and changes in personal life have combined to slow things down. It's still very much 'work in progress' though - so watch this space.

@ Paynts (Simon?) Hello again. Regarding your questions, I'm not fully up to speed on their current regs, but certainly they never used to allow ITB's unless originally fitted to the vehicle in the pre '93 series. So on your M20 lump, they're a no no. I think the coilovers are OK, as you're using the original mounting points - you may or may not have to put a light 'helper' spring in the original position as well - some regs do require this, but I don't remember.
Dans car (and yours, if you're on ITB's) would be eligeable for CTCRC 'Classic Thunder' series, but there's some serious stuff in that, or at least there was when I last looked.
He's building his to the sort of generic 'Tin Top' regs which require original block but everything else is free, so in this neck of the woods it's the BARC QMN series, or BARC SE Tin Tops.
He's also got an eye on 'Speed' events - sprints and hillclimbs, which also spec original block but pretty much free on anything else, as above.
What are you thinking of doing with yours? If you're not going to race it, why not try hillclimb or sprint- I marshal at Gurston Down pretty much every meeting and it's a great atmosphere. Your car would slot into Mod Prod I reckon. Tbh you wouldn't be ultra competitive up against scoobies and evo's, but its a great way to test yourself and the car.
You dont need to do the ARDS thing just filll in the form, send the money and you've got a license.
Anyway, as usual I'm going on, so I'll go away now.

Kim (Dans dad, for my sins!!)
It runs in the family!!!

[Paynts]

Hi Kim! Good to hear from you again, Sorry to hear Dans car is stalled but then this is the norm for "projects" I reckon

.in answer to what to do with the car I've got a M52 crank on order(S/H ) and some shorter Rods. together we my existing Hi comp pistons I can build a high compression 2.8. (10.8 to 1 ish) Im hoping for a lot more torque and possibly 205 hp. The Weber Alpha system has proved to be a good engine management system even tho its old and for a non stroker car the engine now feels very strong
I've looked in the Kumho series 2014 regs and the car would be eligible with thw 2.8 crank stroker. Kumho organisers use a car mounted accelerometer or some such thing and with the car Weighed you then go into a Class A B C depending on your displacement and hp/ tonne figure, ITBs are OK as are Rear Coilover dampers
My plan is to get the car up and running again, track day it this summer and then see if anyone wants to buy it to race in Kumho, since I don't want a fortune for it I think it would represent a bargain, if no one will give me 4 k or there abouts I'll keep it.
your hill climb / sprint idea sounds great fun that could be a plan!
Out of interest if you look at a post I put in the m20 section about dyno figures on a 2.5 with ITBs you'll see the before and after figures. it's no wonder the car wasn't competitive, it was in drivable in the wet and had so little torque at 3000- 4000 that it couldnt pull skin off a rice pudding and with a standard sport box it was just not getting into the power band quick enough between 2nd and 3rd and 3rd 4th
regards Simon

[rix313]

but certainly they never used to allow ITB's unless originally fitted to the vehicle in the pre '93 series. So on your M20 lump, they're a no no

This is indeed true, you can however convert to carbs.

I think the coilovers are OK, as you're using the original mounting points

Most certainly are. In any championship seeing as upgraded suspension is a fundamental part of building a competition car.

Dans car (and yours, if you're on ITB's) would be eligeable for CTCRC 'Classic Thunder' series, but there's some serious stuff in that

When you start changing big stuff with the engine (heads, ITB's, capacity etc) the only series/championships you can enter are those that allow a wider variation of car and spec. What inherently comes with that, is as you mention, being put up against some pretty powerful machines.



I've just had a look over the Kumho regs and they have changed some what from when I used to run a car in it. Having said they they seemed to rewrite it every year haha. I was interested in class D as I run an M42 but when I was looking at which championship to enter a year or so ago the E30 wasn't eligible. It seems they've opened it right up to allow E30 and every Z3 with M42 into it. Kumho is a bit of a money pit though with the guys in Class A and to an extent, B, throwing a lot of money at engines and suspension.