E36 3.0 ITB Race Build

[f0xy]

Re: E36 Track Day Hack (v2)

Unlucky on the engine mate Nothing worse than taking it out just after you've bolted it in!

How'd your brake ducts fare? Work well?

Brakes felt much better yeah, probably better than they have ever been. Might be a combination of new discs and calipers too though!


So after pulling the old engine out, I swapped various bits over to the old engine. Gearbox, Clutch, Flywheel, Exhaust Manifolds, Oil Filter Housing... list goes on. Short while later the old one was back in and the new one on the stand once again. I wanted the old engine back in for a couple of reasons, more on that later. Not so difficult once you've done it a few times, had it all swapped within the day on my own.

A few issues I noticed with the new engine/since Oulton Park. Both gearbox rubber mounts have sheared off. Not sure when this happened, but they were fine when the new engine went in..

When I removed the clutch/flywheel, the pilot bearing was just sat there, loose. When it should be pressed into the end of the crank.. Unsure why.

I got the 'new' engine on the stand again. And noticed the carbon buildup on Cyl1 (the bad cylinder) is a different colour to the other 5..

Also, on the inlet side of the block there seemed to be oil leaking/running down from the headgasket area. Near the 'M' of the BMW casting..

..and running down from the Cyl1 area, above the oil filter housing location..

Hopefully it will make more sense when the head comes off.

 

[Ade T]

Re: E36 Track Day Hack (v2)

This is an awesome build! Shame about the new engine but keep at it!

You've inspired me to look for a e36 m3

 

[f0xy]

Re: E36 Track Day Hack (v2)

Old engine is fully done now, back in and driving. All OK it seems so far.

I considered an E36 M3 before this (and my other 328), but when I factored in the cost of all the additional work I've done on this, the total build cost would be twice the price with the purchase price being much higher in the first place. Depends what you plan to use it for I guess!

 

[f0xy]

Re: E36 Track Day Hack (v2)

So I needed to re-fit the old engine to get the car to Le Mans this year, as it had been planned for a while, plus taking the diesel daily isn't any fun. Once it was back in and running I made a new baffled catch tank to try and help with the blowby out of the crankcase breather, it seemed to help a bit. Everything must have gone together fine as nearly 1200 miles later in the space of a week it made it there and back - not the most comfortable journey in fixed buckets mind!

Another thing I noticed on the journey was the 'old' engine runs much cooler, oil temperature wise. Normal motorway driving never sees anything north of 95-97C. The new engine used to sit at over 103-105C on the motorway, now whether its irrelevant or there has been a problem since it was built I'm not sure! The new engine needs pulling apart to see what the problem is! :clown:

 

[f0xy]

Re: E36 Track Day Hack (v2)

Took the head off yesterday, nothing unusual found though.

Head bolts were of equal torque, head gasket looks fine, no damage to the bore or cylinder head. Did a quick leak down test in the chamber of cylinder one and still well sealed as are the rest. No mixing of oil/coolant anywhere.

There was a bit of oil running down the block on the inlet side, from the head gasket, which I'm unsure about. Maybe its a poor quality or bad gasket.

I've not had chance to take the sump off yet and take the piston out of cylinder one, as it may reveal a broken ring or ring land. Although, if its not that I'm pretty stumped!

 

[MG cup]

Re: E36 Track Day Hack (v2)

What's the actual problem?

That colouring on the piston (timing side) doesn't look right mate, I'm guessing its where the fuel mix is entering the cylinders but it appears a lot cleaner than the other 5 from that pics.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Well it ran in without issue (500-600mi) and then had an oil change. Then took it to Oulton a couple of weeks back and took a hammering all day, felt fine. Late in the afternoon and on the way home it had a missfire at low RPM, but drove back OK.

Swapped out coil and spark plug, no change. Swapped out injector, no change. Compression tested it and five cylinders had 13bar+, the first cylinder (timing end) only had 5-6bar. Compression did not increase with a wet test.

The engine seemed to run much hotter too, oil temperature wise (but that could be the cast iron block vs the OEM alu block). This is all the time, since the engine was fitted. Coolant temperature always OK.

Maybe cylinder one was running lean for whatever reason, hence the different colour on the exhaust port carbon buildup and the piston top? Not sure. All the pistons have the marking, but cylinder one is different as you say...

 

[MG cup]

Re: E36 Track Day Hack (v2)

No1 bore shiny?

From everything you have said and with your findings I would hazard a guess at cyl1 over fuelling, bore washing and things snowballing from there.

The damage was already done on the track day so you were never going to stop that misfire I would say. The excess heat might be ring blow by or as you say just a difference of the cast iron block. The soot is from burning excess fuel.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Its not shiny, just the same as the others. Fresh hone marks still clearly visible on all of them etc. Its pretty weird.

Maybe a bad headgasket? Causing the cylinder/mixture to not burn properly?

Oil temperature was a good 10-15C hotter than the old engine on track, using the same sensor/gauge in the same location, with the same cooler setup

The old engine suffers from severe blowby (200k+ miles and a Nikasil block, with only 9/10bar compression). It puts a lot of oil vapour past the crankcase breather, which I cycle into a catch tank then return to sump (with an atmosphere vent). On the new engine this was not required, crankcase breather was completely dry, so was looped back to the inlet (as stock) and the inlet remained dry for running in and the track day.

All the exhaust ports had soot, but the other 5 were properly black as I would expect. Cylinder 1 was like a light grey colour...

 

[matt_132]

Re: E36 Track Day Hack (v2)

Which piston did you swap out,if you did at all, vaguely remember you not being happy with one of them?

The missfire I've been hunting for months is looking more and more like lack of compression, doing a test tomorrow.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Could be any of them now they were removed from the M52 Aluminium block, then fitted into the M50 Iron block in whatever order I picked them up in. Didn't really matter, as I checked the ring gaps again, and they were all new rings / good pistons etc.

It was the gudgeon pin that was stiff, so that rod/piston/pin was left to one side (still on the bench) and I chose one of my six good spares as the replacement

Yeah, see what you get back from it!

 

[MG cup]

Re: E36 Track Day Hack (v2)

I don't know how a bad HG would affect the cylinder burn and especially in one cylinder although was there any water being used as you say it had light grey soot.

The difference between the old and new engine is that one had 6 dodgy cylinders and the new only has one so it may not be enough to cause heavy breathing. Your going to have to take the pistons out anyway as if the bore isn't the cause for lack of compression then its the rings, valves or if none of those then the HG.

Valves are straight? Tested the head with petrol?

 

[f0xy]

Re: E36 Track Day Hack (v2)

I don't know how a bad HG would affect the cylinder burn and especially in one cylinder although was there any water being used as you say it had light grey soot.

The difference between the old and new engine is that one had 6 dodgy cylinders and the new only has one so it may not be enough to cause heavy breathing. Your going to have to take the pistons out anyway as if the bore isn't the cause for lack of compression then its the rings, valves or if none of those then the HG.

Valves are straight? Tested the head with petrol?

Valves are all OK. Tested all six with petrol, left for 20min+, no leakdown..

Took a closer look at the head side of the headgasket, which revealed some marking around the chamber. I originally thought it was dirt, but its not..

Onto the relative part of the head which may have created the above marking..

There is quite a defined drop in the two surfaces that you can feel with your nail, when all the other cylinders are completely smooth/flat as they should be..

Not sure whats happened but the inlet side of cylinder 1 was completely flat when skimmed..

Its been suggested on some of the BMW forums that the head gasket might have been the wrong bore (not that I'd notice when assembling as it was purchased as M52) in the first place, but either way there is definately a problem with the inlet side of the chamber on cylinder one, but what has caused it I'm not sure...

 

[welshname]

Re: E36 Track Day Hack (v2)

Got any further into resolving the headgasket issue?

 

[f0xy]

Re: E36 Track Day Hack (v2)

Not really, no one seems to be able to pinpoint what it is to be honest. Not much of a response on the UK forums, US have been much more help but no one can really definitely say whats caused it. Head is damaged though.

I've had piston one out, rings + piston are fine

I stripped down my spare cylinder head so its bare, and its been in the boot of the Passat since. Just not had time to pass the machine shop to get it tested/checked/skimmed. If its all good I will bolt it back together with a new (genuine this time) head gasket and bolts and swap it back over. Hopefully that will be it and the cause was a headgasket/head issue, which is the most favoured suggestion.

Not really been in a rush as had nothing booked for it etc!

 

[welshname]

Re: E36 Track Day Hack (v2)

Ah fair enough. Does seem a strange issue tbh especially seeing as you had everything skimmed and tested first time round, the only variable is the head gasket really.

Fingers crossed anyway.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Yeah, hopefully just a bad gasket. It was just a generic 'OEM' gasket, as part of a headset. Never had an issue with them in the past on other engines, but you never know.

I could use an MLS gasket, but then you need ARP studs to do it properly. Not usually stocked in the UK, and for the both its over £500 before you've even started. The ARPs are reusable, but I dont plan on pulling it apart again! A stock genuine gasket and standard bolts are under £70... so thats all its worth really!

 

[jhot80]

Re: E36 Track Day Hack (v2)

Took the head off yesterday, nothing unusual found though.

Head bolts were of equal torque, head gasket looks fine, no damage to the bore or cylinder head. Did a quick leak down test in the chamber of cylinder one and still well sealed as are the rest. No mixing of oil/coolant anywhere.

There was a bit of oil running down the block on the inlet side, from the head gasket, which I'm unsure about. Maybe its a poor quality or bad gasket.

I've not had chance to take the sump off yet and take the piston out of cylinder one, as it may reveal a broken ring or ring land. Although, if its not that I'm pretty stumped!

Did you have all the dowels to tie the head and block together in and were they in good condition. Looks like the head has been moving and damaged the head gasket. Same reason K Series engines fail.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Yeah both dowels were in place and good condition - I chose the best pair from the various M50/2 blocks that I had at the time. No one seems to really know what the cause is for sure, but obviously the HG has been damaged and the head has moved/cracked/got damaged because of it... I'm hoping my spare head is 'good' after a skim and then I might get chance to build it back up..

 

[Ph1 Tom]

Re: E36 Track Day Hack (v2)

Can you get MLS gaskets for them instead?

 

[f0xy]

Re: E36 Track Day Hack (v2)

Yeah, you can buy them from the US (people run them when turbo/charging them). Problem is they are not cheap after shipping + duty.

Places in the UK list them for sale, but they just order in from the US on your behalf. Its recommended you run head studs with them also (ARP) instead of the traditional head bolts, as people usually have issues with the M50/2 when using an MLS with stock bolts.

Its about $530 in parts and shipping, then an extra £70 in duty once landed in the UK. Soon adds up considering its a stock engine!

 

[f0xy]

Re: E36 Track Day Hack (v2)

So, I finally got somewhere. Started with a new head. Didn't trust the old one, nor my spare.

Skimmed, pressure tested, valve seats/bowls checked, valves lapped, new stem seals, etc. Also has the second port on the side of the head for an additional coolant temperature sensor, so I can run a proper gauge instead of the cr*p stock one from now on.

Changing a few other things on the engine internally now also... more on that over the weekend.

 

[f0xy]

Re: E36 Track Day Hack (v2)

With the engine being in pieces and the next outing only in a good few months I decided to make some other changes to the engine. I came across a cheap M54B30, which originally came in E39 530i, E46 330i, X5 3.0, etc. The internals are interchangeable with M50 and M52 engines. I wanted the engine for the full rotating assembly (Crank, Pistons and Rods), essentially creating an M50/2 'stroker' giving 3.0L capacity.

The E36 M3 uses 86mm pistons, whereas the M54 retains 84mm pistons like the M50/M52 engines have, which is why they fit straight into the engine. The M52B28 (328i) has 84mm pistons, and 84mm stroke on the crank. The M54B30 (330i) uses 84mm pistons with a 89.5mm stroke. Crank bearings, seals, flywheel mounting, and everything else is the same.

M54B30 on the left, M52B28 on the right:

M54B30 crank:

The M52 uses a 228deg duration, 9.0mm lift inlet cam, with the same spec on the exhaust.

Whereas the M54 uses a 240deg duration, 9.7mm inlet cam, with a 228deg duration, 9.0mm lift exhaust cam.

Even though the M54 uses dual VANOS, the inlet side of the system is the same design as the M52, making the inlet cam interchangeable. It also times up exactly the same with the same tools. I'm going to run the M54 inlet cam, with the M52 exhaust cam, essentially creating an engine thats the same specification as a US 3.0 M3 (US models never ran ITBs or any of the same bits as the Euro models). All that would be left to do is flash the correct map and it should make a nice engine :clown:

 

[welshname]

Re: E36 Track Day Hack (v2)

Well played. Should be fun when completed!

 

[Ph1 Tom]

Re: E36 Track Day Hack (v2)

Nice! Hopefully you'll have more luck this time.

 

[matt_132]

Re: E36 Track Day Hack (v2)

Bit advanced that mate! Do you think you may find some problems along the way like the m50/52 baffle and oil pump?

 

[f0xy]

Re: E36 Track Day Hack (v2)

The M54 block is pretty much the same, as is the oil pump and chain to the crank (all the same M50/2 sprockets/hardware fit the M54 crank). The baffle plate is exactly the same as the M52 item, but I don't use either. I use a modified M50 item as I'm using the iron M50 block (Iron vs Alu block uses different baffle), so having already modified it there won't be anything to do. Il put the same oil pump on also.

Most of the M5x series engines are identical, the M54 has slightly different cooling setup and casting but internally very similar. Things changed a lot when they moved to the N5x series stuff.

 

[f0xy]

Re: E36 Track Day Hack (v2)

For anyone interested, here are some comparisons of M50/M52/M54 components, which hopefully will lay to rest any 'internet myths' that I've come across when researching these parts. The details below are only really accurate for Euro models only, where US internal components are the same, the blocks can differ (usually all Steel/Iron). Other variants of each range are the same block, with usually a different crank/rod/piston combination.

M50B25 (2.5L Petrol, 1990-1996, E36 325i and E34 525i) - Steel/Iron Block, 84mm Bore, 75mm Stroke - 189hp, 181lbft.
M52B28 (2.8L Petrol, 1992-2001, E36 328i, E39 528i, E38 728i, Z3 2.8) - Aluminium Block, 84mm Bore, 84mm Stroke - 190hp, 210lbft.
M54B30 (3.0L Petrol, 2000-2006, E46 330i, E39 530i, E60 530i, X3/5 3.0, Z4 3.0) - Aluminium Block, 84mm Bore, 89.6mm Stroke - 230hp, 220lbft.

All the internal components are interchangeable between blocks, with the most common swap to use a Steel/Iron block due to the Aluminium blocks having issues with head bolt threads pulling out (as per my issues!).

So the common mod for power gain is to fit the M50B25 inlet manifold onto your E36 328i, which releases up to 20hp, but loosing a bit of torque low down, not really noticeable. Nearly all components (external) are interchangeable between the M50/M52, considering the blocks are the same. Some things even share parts with the M20 (E30 range), like the flywheel that I use etc.

Essentially using these three engine series you are creating an affordable 3.0L, with very good performance for the cost, compared to going out buying an S50/2 engine (which are very expensive in comparison). The S50/2 cannot really be compared to this method, as they run a slightly different valvetrain, a better balanced/designed crank, and a few other changes to allow them to rev so high. This does not apply so much to the US variants, which don't have ITBs, or create as much power as the Euro models. They run a Steel/Iron block from factory, and an M50 inlet manifold instead. The euro models use an Aluminium block. Even with the different specifications, they share an 86mm bore, instead of the M50/2/4 84mm, and a different stroke. The M54 components swap is a good way to create a 3.0L without increasing the bore, as you are retaining the 84mm of the M50/2.

The M54B30 uses the exact same rod as the M52B28, 135mm in length (on the right). The M50B25 uses a different rod, which is 140mm long (on the left).

The pistons between all three are somewhat different. The gudgeon pin locations are different also. M54B30 uses much thinner rings, and the piston is the smallest of all three.

If you are going down the 3.0L 'stroker' route, the 'correct' thing to do is use the full M54 rotating assembly (Crank, Rods, Pistons). If you can only get hold of the Pistons, M52B28 rods can be used instead.

The M54B30 uses dual variable valve timing (VANOS), where the M50B25 and M52B28 use single. The hardware/gears on the inlet camshaft is the same between all three, just the M54 has an additional VANOS unit on the exhaust cam. The M54B30 inlet camshaft has a slightly more aggressive profile than the other two, being 240deg duration and 9.7mm lift, whereas the others are 228deg duration and 9.0mm lift. As you can see, they are very similar:

It will time up with the standard timing tools, which lock onto the blocks at the end of the camshafts. It will also drop straight into the M52B28 camshaft trays without issue. Even though the VANOS hardware is the same, the M54 uses a slightly longer engagement spline, so to allow use on an M52 unit it has to be machined by 4mm. M52 on the left, M54 on the right:

With the 4mm shaven off the front, it is a direct fit as the standard cams would be. The best compromise is to retain the standard M52B28 exhaust camshaft (228deg duration, 9.0mm lift) and everything will work fine. If on the rare occasion you can find a US M3 3.0 Exhaust camshaft (240deg duration, 9.7mm lift) you will have a matching set, but they are very hard to come by. I hope the above clears up some confusion for someone along the line...


So over the weekend I spent some time sorting out the best combination of parts to be used on the engine and cleaning things. The six best M54B30 pistons, rods, cam trays/caps and mains caps were all cleaned and checked. Surprising whats possible without a parts washer or dishwasher...

After that I decided to sort out all my spares, various sets of pistons/rods, one M50B25 set, M52 random spares and M54s. Ended up with a complete set of M54B30 pistons/rods spare, hopefully never needed though!

With the M54 piston rings being completely different to the M52, I got hold of some during the week. I also dropped off my spare Steel/Iron M50 block at the machine shop to be skimmed and honed. Hopefully get round to building it up in the coming weeks!

 

[Eddie.]

Re: E36 Track Day Hack (v2)

Awesome post, cheers Jord.

 

[daveski]

Re: E36 Track Day Hack (v2)

Great work as always Jord.

 

[Martin.]

Re: E36 Track Day Hack (v2)

Awesome post. I wish I had a 1/10 of your knowledge.

 

[Jon.G]

Re: E36 Track Day Hack (v2)

Actually some really interesting information there. Nice to know what the differences are between the bunch.

 

[jhot80]

Re: E36 Track Day Hack (v2)

For anyone interested, here are some comparisons of M50/M52/M54 components, which hopefully will lay to rest any 'internet myths' that I've come across when researching these parts. The details below are only really accurate for Euro models only, where US internal components are the same, the blocks can differ (usually all Steel/Iron). Other variants of each range are the same block, with usually a different crank/rod/piston combination.

M50B25 (2.5L Petrol, 1990-1996, E36 325i and E34 525i) - Steel/Iron Block, 84mm Bore, 75mm Stroke - 189hp, 181lbft.
M52B28 (2.8L Petrol, 1992-2001, E36 328i, E39 528i, E38 728i, Z3 2.8) - Aluminium Block, 84mm Bore, 84mm Stroke - 190hp, 210lbft.
M54B30 (3.0L Petrol, 2000-2006, E46 330i, E39 530i, E60 530i, X3/5 3.0, Z4 3.0) - Aluminium Block, 84mm Bore, 89.6mm Stroke - 230hp, 220lbft.

All the internal components are interchangeable between blocks, with the most common swap to use a Steel/Iron block due to the Aluminium blocks having issues with head bolt threads pulling out (as per my issues!).

So the common mod for power gain is to fit the M50B25 inlet manifold onto your E36 328i, which releases up to 20hp, but loosing a bit of torque low down, not really noticeable. Nearly all components (external) are interchangeable between the M50/M52, considering the blocks are the same. Some things even share parts with the M20 (E30 range), like the flywheel that I use etc.

Essentially using these three engine series you are creating an affordable 3.0L, with very good performance for the cost, compared to going out buying an S50/2 engine (which are very expensive in comparison). The S50/2 cannot really be compared to this method, as they run a slightly different valvetrain, a better balanced/designed crank, and a few other changes to allow them to rev so high. This does not apply so much to the US variants, which don't have ITBs, or create as much power as the Euro models. They run a Steel/Iron block from factory, and an M50 inlet manifold instead. The euro models use an Aluminium block. Even with the different specifications, they share an 86mm bore, instead of the M50/2/4 84mm, and a different stroke. The M54 components swap is a good way to create a 3.0L without increasing the bore, as you are retaining the 84mm of the M50/2.

The M54B30 uses the exact same rod as the M52B28, 135mm in length (on the right). The M50B25 uses a different rod, which is 140mm long (on the left).

The pistons between all three are somewhat different. The gudgeon pin locations are different also. M54B30 uses much thinner rings, and the piston is the smallest of all three.

If you are going down the 3.0L 'stroker' route, the 'correct' thing to do is use the full M54 rotating assembly (Crank, Rods, Pistons). If you can only get hold of the Pistons, M52B28 rods can be used instead.

The M54B30 uses dual variable valve timing (VANOS), where the M50B25 and M52B28 use single. The hardware/gears on the inlet camshaft is the same between all three, just the M54 has an additional VANOS unit on the exhaust cam. The M54B30 inlet camshaft has a slightly more aggressive profile than the other two, being 240deg duration and 9.7mm lift, whereas the others are 228deg duration and 9.0mm lift. As you can see, they are very similar:

It will time up with the standard timing tools, which lock onto the blocks at the end of the camshafts. It will also drop straight into the M52B28 camshaft trays without issue. Even though the VANOS hardware is the same, the M54 uses a slightly longer engagement spline, so to allow use on an M52 unit it has to be machined by 4mm. M52 on the left, M54 on the right:

With the 4mm shaven off the front, it is a direct fit as the standard cams would be. The best compromise is to retain the standard M52B28 exhaust camshaft (228deg duration, 9.0mm lift) and everything will work fine. If on the rare occasion you can find a US M3 3.0 Exhaust camshaft (240deg duration, 9.7mm lift) you will have a matching set, but they are very hard to come by. I hope the above clears up some confusion for someone along the line...


So over the weekend I spent some time sorting out the best combination of parts to be used on the engine and cleaning things. The six best M54B30 pistons, rods, cam trays/caps and mains caps were all cleaned and checked. Surprising whats possible without a parts washer or dishwasher...

After that I decided to sort out all my spares, various sets of pistons/rods, one M50B25 set, M52 random spares and M54s. Ended up with a complete set of M54B30 pistons/rods spare, hopefully never needed though!

With the M54 piston rings being completely different to the M52, I got hold of some during the week. I also dropped off my spare Steel/Iron M50 block at the machine shop to be skimmed and honed. Hopefully get round to building it up in the coming weeks!

Do you know what the difference is between them all for compression ratio? I assume compression ratio is what drives the different overall piston heights.

Do you know which ones give the lowest piston and rod weight? Given its going to spend most of its life at 5k+rpm and that they all have the same bore the lowest weight and inertia assembly would be the best for your application. For both durability and more rev happy nature especially as it will be a very under square engine making it much lazier engine.

Are you going to have it live mapped?

 

[Chi]

Re: E36 Track Day Hack (v2)

Legend!

 

[f0xy]

Re: E36 Track Day Hack (v2)

M50B25 - 10.0:1
M52B28 - 10.2:1
M54B30 - 10.2:1

The M54 pistons/rods stop around ~1.8mm from the top of the block by design (all three blocks have the same deck height) I'm using a standard thickness HG (1.75mm), with a skimmed block + head so id imagine it to be ever so slightly higher than the stock 10.2:1. Also the M54B30 makes peak power at 5900rpm, whereas the M52B28 makes it at 5300rpm, better for me.

The M52/M54 rods are significantly lighter than the M50 items, then with the M54 pistons being the smallest overall of the three they are the lightest also. I might weigh all three later and see what the real difference actually is..

I'm going to have my spare ECU flashed with a US S50B30 map, which will pretty much be identical to the spec of the engine. These use the same 'Pink Top' injectors as the M52B28, which is what I will have fitted. No one really offers true 'live' mapping, due to the way the ECU stores the CAL. Usually its trial and error, make adjustment, write the CAL, then dyno, and repeat. There is quite a broad range of 'self adjustment' with the maps, to account for a large range of different fuels (91RON>102RON) but I know someone with the ability to tune the map to get it exactly right/safe. Its recommended to run a 3.5" MAF from a 540i/740i to release that bit more, but its not a requirement for decent results.

 

[jhot80]

Re: E36 Track Day Hack (v2)

M50B25 - 10.0:1
M52B28 - 10.2:1
M54B30 - 10.2:1

The M54 pistons/rods stop around ~1.8mm from the top of the block by design (all three blocks have the same deck height) I'm using a standard thickness HG (1.75mm), with a skimmed block + head so id imagine it to be ever so slightly higher than the stock 10.2:1. Also the M54B30 makes peak power at 5900rpm, whereas the M52B28 makes it at 5300rpm, better for me.

The M52/M54 rods are significantly lighter than the M50 items, then with the M54 pistons being the smallest overall of the three they are the lightest also. I might weigh all three later and see what the real difference actually is..

I'm going to have my spare ECU flashed with a US S50B30 map, which will pretty much be identical to the spec of the engine. These use the same 'Pink Top' injectors as the M52B28, which is what I will have fitted. No one really offers true 'live' mapping, due to the way the ECU stores the CAL. Usually its trial and error, make adjustment, write the CAL, then dyno, and repeat. There is quite a broad range of 'self adjustment' with the maps, to account for a large range of different fuels (91RON>102RON) but I know someone with the ability to tune the map to get it exactly right/safe. Its recommended to run a 3.5" MAF from a 540i/740i to release that bit more, but its not a requirement for decent results.

You do have the opportunity to increase the compression further by using the M52B28 pistons and rods or mix in between before risking piston to value contact.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Unfortunately using an M52B28 piston with the M54B30 crank does not work (rods being the same), the piston comes out of the block..

Other available BMW 84mm pistons, whilst they fit in the block, the skirts are too long for the stroke with the B30 crank, or come out of the block too far etc. You could probably skim the block more, but using a slightly higher lift cam on the inlet I'm not sure how close things would get. Aftermarket pistons can be bought in a huge range of options for these, so you could get whatever spec you want really, but I'm just working with whats commonly available really..

 

[f0xy]

Re: E36 Track Day Hack (v2)

Quickly compared them earlier:

M50B25

M50B25 Rod - 631.5g
M50B25 Piston - 452.0g (344.5g w/o Pin)
M50B25 Assembly - 1083.5g (6501.0g Total)

M52B28

M52B28 Rod - 603.0g
M52B28 Piston - 428.0g (320.5g w/o Pin)
M52B28 Assembly - 1031.0g (6186.0g Total)

M54B30

M54B30 Rod (Same as M52B28) - 603.0g
M54B30 Piston - 399.0g (291.5g w/o Pin)
M54B30 Assembly - 1002.0g (6012.0g Total)


So with the M54B30 parts, you're saving 174.0g over the M52B28, and 489.0g over the M50B25.

 

[jhot80]

Re: E36 Track Day Hack (v2)

Thats good drop in the assembly.

So you have 2 rod lengths and 3 different piston heights. Are the pistons and rod interchangable i.e. same piston pin dia? You have a deck height of ~1.8mm to play with. The engine in my XR2 has a deck height of 0.2mm. The best way to find out is to put it all together on a stand fill the Combustion chamber with playdoe spin it over and it will tell you how much clearance you have to play with. Number of spares you have you could prob do it in 1 build with the varying parts.

Wheres the fun in just buying aftermarket bits to fit. Its much more interesting to do this.

 

[f0xy]

Re: E36 Track Day Hack (v2)

Yeah the pin is the same for all three. The height of the pin on the piston (relative to the top) is different on all three mind. The M52B28 comes pretty much flush when assembled in stock form. There is probably another 84mm piston that would work out right from a different BMW engine, problem is with the long stroke the piston/skirt need to be short for the rod to clear.. I've seen people skim the top of the piston in some builds when using different ones, but its a guessing game as to how much they took off. Yeah I agree, spending lots of money buying aftermarket shiny bits is the easy way.... I'd rather work out what fits..

I picked the spare block up from the machine shop on the way back from work earlier - I gave him the timing cover this time to skim when the block was, so its completely flush and everything is square.

Didn't do this last time, maybe it was one of the factors of a head gasket issue on cylinder one? The head gasket goes all round the timing chain/cover area.

Anyway the bores were checked top and bottom, all good with no wear. I was worried about them possibly being oval, but I had that checked also and they are fine. Hopefully start building it up soon.