M52 b28 or the m54 b30?
Moderator: martauto
I’m going to do an M54 swap because with a clean sheet of paper it seemed to me to be the best engine to use and the easiest to get hold of good ones with E36s now getting scarce in their own right, however if I already had a M52 I’m not sure I would do the swap.
Going M54 you are adding in a lot of complexity and losing engine bay room if you are keeping DISA, dual Vanos and ms43 ECU.
The more I look into it I’m not sure a good m52 swap with the older intake and manual throttle wold not be the better swap.
The M54 seems to pull head bolt threads if overheated (but can’t see the m52 being any different) it has poor design oil control rings (can be swapped with M52) and the M54B30 has a bad crank harmonic at high revs that can chew through crank vibration dampers, and shake a few things loose.
With dual Vanos and DISA it has V8-like low down torque so not sure of the need for high revs anyway, but if you are tracking the car regularly at high revs something to keep in mind.
I asked for this section to discuss these things, when I get a bit of time I’ll put some better thoughts down on a swap.
Going M54 you are adding in a lot of complexity and losing engine bay room if you are keeping DISA, dual Vanos and ms43 ECU.
The more I look into it I’m not sure a good m52 swap with the older intake and manual throttle wold not be the better swap.
The M54 seems to pull head bolt threads if overheated (but can’t see the m52 being any different) it has poor design oil control rings (can be swapped with M52) and the M54B30 has a bad crank harmonic at high revs that can chew through crank vibration dampers, and shake a few things loose.
With dual Vanos and DISA it has V8-like low down torque so not sure of the need for high revs anyway, but if you are tracking the car regularly at high revs something to keep in mind.
I asked for this section to discuss these things, when I get a bit of time I’ll put some better thoughts down on a swap.
the best thing about the m54 is it's crank/rods and pistons
an m52 b30 stroker has more bhp and torque than the 231 bhp m54
an m52 b30 stroker has more bhp and torque than the 231 bhp m54

m52 b30 stroker 6-speed 318is Galvanizer
m42 touring
+ a yard full of scrap turds
Hi Dan, yes I did the original conversion 5 ish years ago had your loom and ews delete.
Annoyingly my water pump failed on a track day and killed the engine. I have another and have bought cooler thermostat aluminium housing plus a bigger radiator. So I think I will stick to the m52.
Annoyingly my water pump failed on a track day and killed the engine. I have another and have bought cooler thermostat aluminium housing plus a bigger radiator. So I think I will stick to the m52.
Not many (if any) really successful M54 swaps, let alone people going FI). Would look at E46 forums for the problems of blowing the M54 it seems it is no stronger than the previous and still pulls threads lifts and heads with boost
Trouble is you are using the one bit of the M54 that worries me.
Out of interest Dan what makes it better than the M50 or M54 Are you talking about steel block or alloy? I'm a bit confused as to which M52 has what.
Personally I'm not trying to get the fastest or more powerful E30, plenty of other engines for that, and I know the S50/S54 quite well. It is just I did over 50k in a 330i sport and loved it. Always thought it would go well in an E30 both for power, weight and sound.
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DanThe
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M50 - early 90's cast iron
M52 - mid 90's aluminium
M52tu/M54 - late 90's/early 2000's aluminium
Comparing out the box engines, the M52 is a light engine, an easy 220hp & 200lbft by fitting the correct intake manifold, rev well, relatively simple design, fantastic management system, easy to diagnose, reliable and will last for many 100's of 1000's of miles, the M50 has a much lesser management system, cannot trim fuel mixture half as well, much heavier pistons/connecting rods and of course the whole thing is a good 25-30kg heavier
M54 is ok but they are renowned for sensors that fail much too early, the head is restrictive and dont forget these engines were designed to meet the new emissions regulations that were coming in, so you have a situation where emissions are having an influence on power/reliability, they are not easy/cheap to modify because of how complicated the intake system is, Alpina never used an M54 as a base engine which says something
M52 - mid 90's aluminium
M52tu/M54 - late 90's/early 2000's aluminium
Comparing out the box engines, the M52 is a light engine, an easy 220hp & 200lbft by fitting the correct intake manifold, rev well, relatively simple design, fantastic management system, easy to diagnose, reliable and will last for many 100's of 1000's of miles, the M50 has a much lesser management system, cannot trim fuel mixture half as well, much heavier pistons/connecting rods and of course the whole thing is a good 25-30kg heavier
M54 is ok but they are renowned for sensors that fail much too early, the head is restrictive and dont forget these engines were designed to meet the new emissions regulations that were coming in, so you have a situation where emissions are having an influence on power/reliability, they are not easy/cheap to modify because of how complicated the intake system is, Alpina never used an M54 as a base engine which says something
Cheers for the explanation, It is why I wanted an M54 section to thrash this sort of thing out before starting a lot of work.
Modifying the M54 is not really something I'm looking to do. I just want to get it running as well as it can and leave it at that. Although the intake is complicated when the dual vanos and DISA are working well, I love the way it drives.
The car is low miles and I've done a lot of them so it is a known engine, it is running OK but using oil, I'd like to check that it is rings not bores, replace the oil rings with the 52TU ones. The only mod I am thinking of is deleting the CCV but if i cure the oil use it should be less of a problem anyway.
If I had not got a 330i sitting here I would maybe go M52
Have you had much thread problems in the alloy blocks? If you have it stripped would you timesert it anyway?
Modifying the M54 is not really something I'm looking to do. I just want to get it running as well as it can and leave it at that. Although the intake is complicated when the dual vanos and DISA are working well, I love the way it drives.
The car is low miles and I've done a lot of them so it is a known engine, it is running OK but using oil, I'd like to check that it is rings not bores, replace the oil rings with the 52TU ones. The only mod I am thinking of is deleting the CCV but if i cure the oil use it should be less of a problem anyway.
If I had not got a 330i sitting here I would maybe go M52
Have you had much thread problems in the alloy blocks? If you have it stripped would you timesert it anyway?
- TurtleDesignTech
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Interesting stuff. Thanks DanDanThe wrote: ↑Sun Aug 04, 2019 3:11 pmM50 - early 90's cast iron
M52 - mid 90's aluminium
M52tu/M54 - late 90's/early 2000's aluminium
Comparing out the box engines, the M52 is a light engine, an easy 220hp & 200lbft by fitting the correct intake manifold, rev well, relatively simple design, fantastic management system, easy to diagnose, reliable and will last for many 100's of 1000's of miles, the M50 has a much lesser management system, cannot trim fuel mixture half as well, much heavier pistons/connecting rods and of course the whole thing is a good 25-30kg heavier
M54 is ok but they are renowned for sensors that fail much too early, the head is restrictive and dont forget these engines were designed to meet the new emissions regulations that were coming in, so you have a situation where emissions are having an influence on power/reliability, they are not easy/cheap to modify because of how complicated the intake system is, Alpina never used an M54 as a base engine which says something
What are your thoughts on M52tu vs M52?
Did Alpina ever use the M52 alloy block or were they using the M50 iron for the 2.8/3.0/3.2L engines? they appear to be 86mm bore are people using the alloy block that big of a bore?
i like the m54 it has proper vanos and is a fair bit gruntier compared to m52b28 but the complexity makes it less ideal to tinker with if you're that way inclined as sometimes the simplicity of an engine is an advantage. The M54 still has a fair bit of potential without opening up the bottom end but its probably better suited to keeping pretty much stock overall.
i like the m54 it has proper vanos and is a fair bit gruntier compared to m52b28 but the complexity makes it less ideal to tinker with if you're that way inclined as sometimes the simplicity of an engine is an advantage. The M54 still has a fair bit of potential without opening up the bottom end but its probably better suited to keeping pretty much stock overall.
E30 325is with M20B31
I think this is what was causing my confusion. There are M52 cast iron blocks around but from what I gather only for the US market. Alpina obviously sourced those blocks. I don't think any others came to the UK.
It is a difficult one for me. I like the weight of the alloy block especially in the E30, but there are too many people pulling threads on engines that it is doubtful have ever overheated.
I am sorely tempted to do something to the block when the head is off anyway. Timesert, 11mm studs etc are all used it is just deciding what is worth doing.
The plan is to keep it pretty much stock but if there are easy things that can be done while rebuilding I'll do them. Other than cams I have not heard of much that can be done to the M54 what were you thinking of?
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DanThe
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In all the years ive been messing with M52's ive probably only pulled threads on 3 or 4 engines, I say "ive" pulled the threads,,, they were actually already pulled by the head when it warped that much due to overheating the bolts were lifted. The other problem you can have with threads is when they are not cleaned properly or the bolts are not oiled.
I heli-coiled the first 3.0 M52 engine build I did just as a safety precaution and that engine did 50+ track days in my track car before being retired to an E34, never had an issue with it I just wanted to be safe as it was a scrap yard £40 engine
I heli-coiled the first 3.0 M52 engine build I did just as a safety precaution and that engine did 50+ track days in my track car before being retired to an E34, never had an issue with it I just wanted to be safe as it was a scrap yard £40 engine



