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BMW M50 or M52 Engine?
randombloke - 7/11/11 at 04:01 PM

Hello Everyone

Been lurking on Locostbuilders for a while, learning lots of interesting build info, but this is my first post.

I am planning to build a sevenesque roadster using a BMW E36 as a donor and wanted to get some advice as to which engine to choose.

The 325 uses the M50 engine which produces 190BHP but weighs in at 198KG, on the other hand the 328 has the M52 engine which also produces 190BHP but due to the aluminium block is 170KG.

Seems a simple choice, especially when you consider that by swapping the M52 inlet manifold with one from the M50 engine you can increase the power to about 210BHP; however I have been warned that the more modern electronics on the M52 can be more difficult to get working.

Has anyone had any experience of using the 2.8Lt M52 engine in a locost? as I would be really interested to know what the pitfall are to watch out for?


Thanks in advance,


DixieTheKid - 7/11/11 at 04:04 PM

M52 with a M50 325 inlet manifold and S52 cams!

[Edited on 7/11/11 by DixieTheKid]


jossey - 7/11/11 at 04:37 PM

m52 is better has the longer stroke which is worth the extra money for the extra displacement.


Nickp - 7/11/11 at 05:15 PM

I'm in the very early stages of fitting an M52 into a Haynes Roadster.
It fits, just, with some chassis chopping- http://www.ppc-mag.co.uk/forum/viewtopic.php?f=7&t=9383&sid=cbcfbf228a5688c7e0a5bee7d3edfc9f
I haven't given the electrics much thought, but figured if I can't get it to run I'll just Megasquirt it.


sdh2903 - 7/11/11 at 05:20 PM

Have a word with rodgling on here, he has been down the 2.8 route then subsequently the m3 lump. (in a gkd)


jambojeef - 7/11/11 at 06:12 PM

I am breaking a whole 528i manual with engine and gearbox out ready to go - all other parts available too.



£250 for engine and box, all other parts cheap and in ex working order - PM if you like, wont be putting on ebay for a little while.

Geoff


SteveWallace - 7/11/11 at 07:16 PM

If you search for my various threads you will see the progress that I have been making putting a 2.8 into a Viento. The main issue is the bulge in the side of the sump which needs to be cut off to fit between the chassis rails. It is also quite a high engine. I reckon that I have 10mm clearance under the bonnet with a 80mm ground clearance, but I don't know how this would translate into a smaller 7.

I've just started on the electrics and there are a LOT of wires in the BMW loom - most of which will not be needed. By the time that you get to that point, I should have more constructive advice for you. Also, I have found a download of the wiring diagram thats much more detailed than the one in the Haynes manual so I can send this across to you when you are ready.

Steve


rodgling - 7/11/11 at 09:36 PM

I had the 328 originally. It's a good choice in terms of being lighter, it has lots of power (as in, I don't notice the difference 0-60 against the M3 because both are traction-limited on T1Rs), it's cheap, etc, etc.

There are two big downsides to the 328. These are the redline - 6200 is just rubbish in a sports car, and the questionable durability of the aluminium block... the consensus on the BMW forums seems to be that HGF is quite likely to result in stripping the threads for the head bolts. That said, the redline is only slightly better on the M50.

Apparently a frankenstein combination of the M50 block / M52 head / M54 crank & pistons is possible giving a 3.0L engine if you wanted to go that route... but then you might as well just get an S50.

Height is a bit of an issue, but I've ended up with about 100 mm sump clearance (with a bonnet scoop to let the throttle mechanism poke out the top).

The gearbox and diff should be very strong, diff is pretty heavy but that's possibly a good thing with that much torque.

TBH if doing it again I'd go for an M3 as it's very strong and reliable (compared to the 328) and can be made to rev to silly RPMs. But it is very expensive compared to the 328 route.


Nickp - 8/11/11 at 07:36 AM

quote:
Originally posted by rodgling
There are two big downsides to the 328. These are the redline - 6200 is just rubbish in a sports car, and the questionable durability of the aluminium block... the consensus on the BMW forums seems to be that HGF is quite likely to result in stripping the threads for the head bolts. That said, the redline is only slightly better on the M50.



6200rpm? Is that right? Doesn't sound a lot. Is that due to some mechanical limitation or just what the factory rev limit happens to be set to? My M52B25 apparently has a 'chipped' ECU to make the most of fitting the earlier M50 inlet manifold and I was expecting the rev limiter to be raised also. I was certainly intending revving it higher than 6200rpm, don't know how long for though But at the price and availability of these engines they're pretty much disposable anyway


rodgling - 8/11/11 at 09:44 AM

Yup, really limited to 6200 :-( I don't know how high it can safely be revved if de-limited.


franky - 8/11/11 at 11:55 AM

As dave said, if you forget about the low red line they're amazing engines for the cash. When he had a 328 engine it was very very quick.


Nickp - 8/11/11 at 12:07 PM

Think I'll megasqirt it and see how she revs!!


rodgling - 8/11/11 at 12:23 PM

A quick google suggests that 7k is fairly safe, but if you go much beyond this you are likely to run into problems with the valve train.


franky - 8/11/11 at 12:26 PM

quote:
Originally posted by Nickp
Think I'll megasqirt it and see how she revs!!


or save money and use the standard ecu and have a map that cost £££££'s to develop?


Nickp - 8/11/11 at 12:28 PM

7k sounds more like it for a modern-ish 4 valve motor. There'd be no gain of going beyond that on std cams anyway, just nice to know you can hang onto a gear if required on track.


Nickp - 8/11/11 at 12:48 PM

quote:
Originally posted by franky
quote:
Originally posted by Nickp
Think I'll megasqirt it and see how she revs!!


or save money and use the standard ecu and have a map that cost £££££'s to develop?


I'll be trying to get it running on the chipped ecu first. Is the original key required?


rodgling - 8/11/11 at 04:08 PM

The chip from the original key is required, though this is easily swappable between keys if you wanted to change the ignition barrel. You'll also need the EWS (immobiliser) box, plus a little "key amplifier" box which sits between ignition barrel and EWS and sends the info in the chip to the EWS. All E36 328s had EWS II AFAIK, so you won't find an ECU which doesn't need an immobiliser.

I don't think it's possible to get the 328 ECU de-immobilised - I spoke to several chipping companies who said they can't do it. However, mine has been reliable once I got it working and it's probably good for insurance purposes to have it.


rodgling - 11/11/11 at 09:53 AM

This is interesting: http://www.bmwowner.com/forum/viewtopic.php?f=27&t=208191&sid=2e5aa080e0c2c3aa508abebb1d18c822

Some bloke is selling a 328 ECU with a 7k rev limit and (he claims) no EWS required for £100. I'd snap that up quick if I were you.


Nickp - 11/11/11 at 10:28 AM

quote:
Originally posted by rodgling
This is interesting: http://www.bmwowner.com/forum/viewtopic.php?f=27&t=208191&sid=2e5aa080e0c2c3aa508abebb1d18c822

Some bloke is selling a 328 ECU with a 7k rev limit and (he claims) no EWS required for £100. I'd snap that up quick if I were you.


Cheers for that, mine's a 325 and I'm not sure if they're the same. Anyway I've U2U'd the guy I got my engine off and he's sending me the rest of the bits - EWS module, key etc etc I suppose it'll be more complicated to include the EWS but hopefully should be do-able if I've got all the required bits.


randombloke - 13/11/11 at 06:50 PM

Thanks everyone for your replies.

I have decided I am going to use the M52 2.8 for my build. I will buy a complete car, rather than just an engine so I know I have all the electronics.

As for the size, especially the height, I am not too worried as I am designing my own chassis to fit it in.

A couple of people mentioned the S52 cams. I did some research on this and it seems the S52 engine to be US only, are there suppliers in the UK that can supply the S52 cams?

[Edited on 14/11/11 by randombloke]


Bare - 17/11/11 at 05:24 PM

Yikes 198Kgs!? Anchor from the Titanic comes to mind.
Sure it may accelerate.. but even so nowhere as near a well as a Hyabusa or most any litre plus Bike engine unit will.
That's some serious mass to try to bend into a corner.
Don't think the chairman would have approved :-)


DixieTheKid - 17/11/11 at 06:28 PM

quote:
Originally posted by randombloke
Thanks everyone for your replies.

I have decided I am going to use the M52 2.8 for my build. I will buy a complete car, rather than just an engine so I know I have all the electronics.

As for the size, especially the height, I am not too worried as I am designing my own chassis to fit it in.

A couple of people mentioned the S52 cams. I did some research on this and it seems the S52 engine to be US only, are there suppliers in the UK that can supply the S52 cams?

[Edited on 14/11/11 by randombloke]


The S52 was used in the 3.2l Evo's

I really...... REALLY REALLY miss mine. Still some bloke from Northampton is happy

[Edited on 17/11/11 by DixieTheKid]


rodgling - 17/11/11 at 07:26 PM

quote:

The S52 was used in the 3.2l Evo's



No, the 3.2 Evo was the S50B32 (and the M3 3.0 was S50B30). S52 is US-only, more similar to the 328 than the European M3 engines.

quote:

Yikes 198Kgs!? Anchor from the Titanic comes to mind.
Sure it may accelerate.. but even so nowhere as near a well as a Hyabusa or most any litre plus Bike engine unit will.



You'd be surprised. It weighs an extra 100 kg, sure, but also has 210 lb-ft (260 for an M3 EVO) vs, say, 130 lb-ft from a BEC. Torque-per-ton, which is what mainly influences acceleration, is way up over a BEC.


DixieTheKid - 17/11/11 at 07:33 PM

aaarrrgghhhh yes yes yes... B32 sorry thats where im getting confuse because the std M3 was the B30. Hands up... im a nobber!


franky - 17/11/11 at 08:00 PM

quote:
Originally posted by Bare
Yikes 198Kgs!? Anchor from the Titanic comes to mind.
Sure it may accelerate.. but even so nowhere as near a well as a Hyabusa or most any litre plus Bike engine unit will.
That's some serious mass to try to bend into a corner.
Don't think the chairman would have approved :-)


Less than 198kgs, and it'll go much better than just about every bike engine


ftaffy - 8/12/11 at 09:34 PM

Hey Guys,

I was looking at using the M50/M52 BMW engines, but ended up with a M44 (318IS E36) as that fell in at the right price when i was looking to buy.
Currently in the middle of stripping it down, hopefully will pull the engine this Sat and get to sit it in my old chassis to get a better feel for its size.

I have designed a chassis to suit (with high enough stiffness aim was 6000Nn/deg) hopefully the BMW 4 and 6's, though it will need some refining. Used alot of the linton thesis mods and ended up at around 136kg as per the below SS.



Loved the look of the GKD roll hoop but doubt it will make it the final build. Also have a standard hoop designed for it.

Be interested in sharing ideas as it goes along as everything apart from actual engine will be basically the same.

My Build log is located on the Aussie clubman site, though you have to register to see it. Might start one on here if there is movement on doing a few BMW based builds.
http://www.ozclubbies.com.au/index.php?/topic/3383-taffys-tf7i-build/

One note for those looking at doing this. Go for the M42 engines over the M44 as there ODB-I which means there plug and play with the chip tuning.

Also thoughts on running a dry sump? I found a few that sell them online but not cheap! Might need to find an ally welder to cut mine down as there damn deep.

Cheers,
Taffy


matt_gsxr - 8/12/11 at 10:33 PM

136kg sounds a bit heavy to me.

I managed to move my chassis with the wishbones on alone and I am not that strong (Phoenix which is same as striker).
I think a striker chassis is about 62kg and they can take decent power although it would be a bit smaller than yours.


randombloke - 11/12/11 at 09:20 AM

quote:
Originally posted by ftaffy

I was looking at using the M50/M52 BMW engines, but ended up with a M44 (318IS E36) as that fell in at the right price when i was looking to buy.




Really funny because I started looking at the weight of the engines and the m44 has much better power to weight ratio than the m52. Then last week I got offered a complete 318is with 80k on the clock, no tax or mot for £250 that I really couldn't say no to.

I too am designing my own chassis to fit and now I have the donor I can start removing bits and measuring then so I can finish the design.


ftaffy - 11/12/11 at 07:16 PM

Hey Random,

Congrats on the M44/318is.

Would be interested to see what you come up with in terms of a chassis design.

Are you CAD modeling the parts? If so what program?

I am loosely model items in solidworks.

Pulled the engine on Sat, tips:
A/C compressor has 3 hex nuts that hold it on, two lower and 1 at the top. Remove the steering rack before getting to the last one.

I just cut the P/S lines to the rack as i am going to attempt to use it depowered

Engine +gearbox will come out as 1 unit, remove radiator etc.

Driveshaft is a PITA to undo, suggest you just until the middle joint using a pipe wrench to get it started and then by hand.
You will then have half a driveshaft attached to your engine but i spent a while underthere and the damn things wont budge.
You will need to leave an axle stand to support the rear section.

Cheers,
Taffy


randombloke - 13/12/11 at 12:35 AM

Thanks for the tips Taffy.

I am using Autodesk Inventor to design the chassis and yes I will be modelling the parts. I want to have a CAD model of the chassis, suspension, engine and gearbox mounts; and diff placement before I start fabricating the chassis.

I will post some pics of the chassis soon.


Nickp - 13/12/11 at 07:13 AM

The M44's a good choice, especially at £250 for a whole car!!
Have you considered making the car LHD? I've just fitted an M52 that leans the same way and it'd be a lot easier with the column and master cylinders on the other side.
As for power to weight ratio. The M44 may be better on its own but once installed in a chassis the 2.8 M52 has a potential to make an extra 100BHP so doubt the 1.8 will touch it TBH Horses for courses though.


randombloke - 13/12/11 at 05:32 PM

quote:
Originally posted by Nickp
As for power to weight ratio. The M44 may be better on its own but once installed in a chassis the 2.8 M52 has a potential to make an extra 100BHP so doubt the 1.8 will touch it TBH Horses for courses though.


The M52 is nearly 80Kg heavier than the M44 and as I hope to get near to 200BHP from it, the acceleration should be goooood.

I also think that a lighter engine is much more in line with the Lotus design philosophy


rodgling - 13/12/11 at 05:38 PM

The M52 does have the advantage that you can drop an M3 lump (320 bhp) straight in when you need more power... plus it sounds more interesting than an inline 4.


daniel mason - 13/12/11 at 05:48 PM

some inline 4's maybe!


Nickp - 13/12/11 at 08:40 PM

quote:
Originally posted by randombloke
quote:
Originally posted by Nickp
As for power to weight ratio. The M44 may be better on its own but once installed in a chassis the 2.8 M52 has a potential to make an extra 100BHP so doubt the 1.8 will touch it TBH Horses for courses though.


The M52 is nearly 80Kg heavier than the M44 and as I hope to get near to 200BHP from it, the acceleration should be goooood.

I also think that a lighter engine is much more in line with the Lotus design philosophy


I agree with the lightweight philosophy also, but the 'bang for buck' ethos made the M52 the 1st choice for me
A 200BHP M44 sounds great. I presume your talking fairly lairy cams, plenty of headwork and ITBs or bike carbs? I'm hoping my £150 2.5 M52 with just an M50 manifold should make about the same. And when I get bored I can slot in a 2.8 or M3 lump. I also suggested making your chassis LHD so you can easily fit a turbo down that side of the engine. Now that would have good power-weight ratio


ftaffy - 13/12/11 at 08:40 PM

If you make your chassis long enough in the engine bay you should actually be able to swap a M44 for the S50 (E36 M3 engine) as the gearbox mating should be the same i believe - it works for M42,M44, M50, M52...
Its also easier if you just get the electric fan model when you looking around, BMW seemed to be 1000 minds when putting the fans onto these cars - electric in front, electric behind, infront and behind or clutch/belt in front.... bah!

As i said before the M44 is less tuneable then the M42 due to unable to change the chip easily (which was an easy ~20hp and 500rpm on the redline).
Though the best performance upgrade (M44) is (From google reading, no exp here) to put an M20 flywheel on, that will give you big low end performance boost and combine that with a diff swap for a nice accel upgrade. - doubt i will bother with anything until i get the car running. KISS!

My M44 engine and box


an M44 engine is approx: 440mm long, and 620mm between the mounts.
The gearbox from bellhousing to shifter is approx 760mm long.
Not put it on the scales yet but have to move it tonight so i can get the old chassis out so might pull them out and check what the lump is less the A/C and powersteering pump.

On the car strip down, the biggest problem i am now facing is the fight with the steering column. Should have googled first but you need to cut into the bolts/studs to give you a head to rotate them. Interesting i will be able to keep the tilt adjust in my column.

Cheers,
Taffy


rodgling - 13/12/11 at 09:03 PM

quote:

If you make your chassis long enough in the engine bay you should actually be able to swap a M44 for the S50 (E36 M3 engine) as the gearbox mating should be the same i believe - it works for M42,M44, M50, M52...



That's true about the gearbox end, I think, but I was also thinking about the exhaust - all the straight sixes have identical exhaust manifolds which means they're straight swaps (along with ECU I suppose).