M20 engine in a E36 ?

[Pork_n_Beem]

I am looking to put a M20 325i engine in a E36 Compact.

Noticed that the sumps on E36 tend to be at the back of the engine but on M20 they are at the front.

Has anyone converted an M20 so that the sump and pick up are off the back of the engine.

Any help appreciated

[PJR]

I've been seriously tempted to do a similar conversion. Although im tempted to use an E46 3.0 lump if its possible.

I'll be very interested to know how you get on.

P,

[ShropshireMike]

Pork_n_Beem said:

I am looking to put a M20 325i engine in a E36 Compact.

Noticed that the sumps on E36 tend to be at the back of the engine but on M20 they are at the front.

Has anyone converted an M20 so that the sump and pick up are off the back of the engine.

Any help appreciated

I guess you're interested as you already have the engine? Or can get it very cheap? If not, have you considered the later M52 6-cyl engine? The reason I say is that BMW already did that conversion themselves.
If you knew this already, apologies

[PJR]

ShropshireMike said:

Pork_n_Beem said:

I am looking to put a M20 325i engine in a E36 Compact.

Noticed that the sumps on E36 tend to be at the back of the engine but on M20 they are at the front.

Has anyone converted an M20 so that the sump and pick up are off the back of the engine.

Any help appreciated

I guess you're interested as you already have the engine? Or can get it very cheap? If not, have you considered the later M52 6-cyl engine? The reason I say is that BMW already did that conversion themselves.
If you knew this already, apologies

Im not familiar with all the engine codes, but would you be referring to the E36 323i compact that was available in some other parts of europe?

P,

[ShropshireMike]

PJR said:

ShropshireMike said:

Pork_n_Beem said:

I am looking to put a M20 325i engine in a E36 Compact.

Noticed that the sumps on E36 tend to be at the back of the engine but on M20 they are at the front.

Has anyone converted an M20 so that the sump and pick up are off the back of the engine.

Any help appreciated

I guess you're interested as you already have the engine? Or can get it very cheap? If not, have you considered the later M52 6-cyl engine? The reason I say is that BMW already did that conversion themselves.
If you knew this already, apologies

Im not familiar with all the engine codes, but would you be referring to the E36 323i compact that was available in some other parts of europe?

P,

Exactly right, the 323ti. I only mentioned it in case the OP wasn't aware of the model's existence

[Marquis_Rex]

Pork_n_Beem said:

I am looking to put a M20 325i engine in a E36 Compact.

Noticed that the sumps on E36 tend to be at the back of the engine but on M20 they are at the front.

Has anyone converted an M20 so that the sump and pick up are off the back of the engine.

Any help appreciated

I'm not quite sure what the goal would be here. An M52 engined 323ti is sold in germany and all teh bits are more readily availiable for this.
As regards the sump design, I know that people who fit either the M50 or S50 (M version) 24 valvers into E30s or E21s use the sump from an E34 5 series which is similarly biassed toward the front of the car.
I was going to suggest that in a similar manner the sump of the E36 M50 24 valvers could be used onto an M20- however further examination of part numbers shows that totally different sump gaskets were used M20 to M50. This infers that the sump designs are of a totally different design.

[Mustard]

Slightly off Topic Marquis but M20 related

Now I know the 2.7ltr M20 conversion is popular with E30's by getting a 525e Bottom end, but how would one go about such a conversion rather arse about face ie Making an 525e Fly!

Now obviously I already have the bottom end what 'top end' components are needed, from what i've read (but may have misunderstood) the actual head would stay, but would require a 325i Cam plus inlet manifold? 190bhp is a realistic figure without too much work

Please correct me if i'm wrong on my thoughts

Other crazy ideas included a 3.0/3.2 E36 M3 lump or E34 3.6/3.8 Lump

Edited by Mustard on Wednesday 16th May 18:30

[Marquis_Rex]

Mustard said:

Slightly off Topic Marquis but M20 related

Now I know the 2.7ltr M20 conversion is popular with E30's by getting a 525e Bottom end, but how would one go about such a conversion rather arse about face ie Making an 525e Fly!

Now obviously I already have the bottom end what 'top end' components are needed, from what i've read (but may have misunderstood) the actual head would stay, but would require a 325i Cam plus inlet manifold? 190bhp is a realistic figure without too much work

Please correct me if i'm wrong on my thoughts

Other crazy ideas included a 3.0/3.2 E36 M3 lump or E34 3.6/3.8 Lump

Edited by Mustard on Wednesday 16th May 18:30

Hi ya mate, you're pretty much spot on.
There are lots of ways of doing this.
I would keep your block and cylinder head, as you correctly say, and try to either get hold of an "eta" crankshaft and rods and pistons also.
Some say that the con rods of the eta are too short for the 81mm stroke length, and indeed years ago I went to the bother of using the longer 325i rods and going to the expense of specially forged pistons. In practice 5mm of extra rod length wont make a huge different to friction or piston side loading.
If you go for the "eta" pistons- try to get the earlier 11:1 Compression ratio ones, as with your bigger chambered 325i head this will drop down nicely to a 10.4:1 which is just right! The other complaint about using the eta engine pistons is that they have a flat crown edge and are slightly mismatched in terms of "squish" to your 325i cyl.head- in practice, do you really want to go to the bother of copying the crown shape of your current pistons with custom pistons to get a big more turbulence in the combustion chamber (like I once did)? Not sure it's worth it. You could keep your existing camshaft or go for a Schrick 284 duration cam- in my opinion this is a mod worth going for! It will give the engine nice top end breathing but you'll still have plenty of low speed and much more than a 2.5 litre.
With the above and the high 10.4 CR, and STOCK cams I would expect about 180 to 190 Bhp, with the schrick cam, perhaps 200 Bhp plus.

The other option is that you could use a crankshaft from a 328i M52- this gives you extra capacity from an 84mm stroke, but as this engine is chain driven- a spacer on the nose of the crank would be needed to adapt to the belt drive- and I dont recall what piston types are best to use and I think the intermediate shaft that drives the oil pump may be have to be clearanced for the bigger wipe line of the counterweights.

My current plans are to stretch the M20 right out to 3.1 litres, using an M3 crank shaft and adapting, designing my own cam, using S50 port throttles, forged pictons and forged rocker arms that are good for 8000 rpm. We'll see how this goes, if i dont change my mind!

[Mustard]

Now this may be me being thick but I thought the 525e was 'eta'

Wouldnt be doing the work myself, but do have a very reasonble / experienced BMW mechanic whos used to motorspot fabricating

[Marquis_Rex]

Yeah the 525e is the "eta" I speak of, but it is ALSO possible to fit the crankshaft of M52 24 vavle 328is and 330is with some modifications for an even greater capacity hike! However this is NOT as straight forward!

[mustard]

Marquis_Rex said:

Yeah the 525e is the "eta" I speak of, but it is ALSO possible to fit the crankshaft of M52 24 vavle 328is and 330is with some modifications for an even greater capacity hike! However this is NOT as straight forward!

Think the confusion lies in your thinking I'm modifying the 325i conv, but this would be actually modifying the 525e that I have

[Marquis_Rex]

Mustard said:

Slightly off Topic Marquis but M20 related

Now I know the 2.7ltr M20 conversion is popular with E30's by getting a 525e Bottom end, but how would one go about such a conversion rather arse about face ie Making an 525e Fly!

Now obviously I already have the bottom end what 'top end' components are needed, from what i've read (but may have misunderstood) the actual head would stay, but would require a 325i Cam plus inlet manifold? 190bhp is a realistic figure without too much work

Please correct me if i'm wrong on my thoughts

Other crazy ideas included a 3.0/3.2 E36 M3 lump or E34 3.6/3.8 Lump

Edited by Mustard on Wednesday 16th May 18:30

Hi Phil, sorry for the misunderstanding.
The problem with retaining the 525e cylinder head is that the ports are very small for the capacity (the casting of teh cylinder head is identical to the old E21 323i which was only a 2.3 litre, the E30s all moved on to better flowing heads)- if you want the engine to rev- so it can't flow enough and the gas velocities become too high.
The second problem with that cylinder head is that it was designed to run cams with only 4 bearings for lower friction- where as the 320i, 323i and 325i all run cams with 7 bearings. You could drill extra oil ways into the cylinder head supports - it's not as difficult as it sounds and then you'd be free to use the 325i camshaft- however with the other issues I've already mentioned you'd have an engine that "chokes" at top end revs.
None of this is a criticism of the 525e head which is well suited for that low revving economy engine.

190 Bhp would be very optimistic retaining that cylinder head. Even if it were ported (very expensive- and then still probably inferior to the excellent 325i head) and an inlet manifold with shorter inlet tract lengths were used- it would still be hard pushed!

Good luck!

[Pork_n_Beem]

Thanks for the replies guys.

Yes, you have guessed right, i have all the bits to build a pretty powerful M20 engine will only cost me a gasket set.

I was aware of a 2.5l compact but thought the engine was an M50.

The problem as i see it is that the oil pump on an M20 is fed from a rod off the intermediate shaft and has a need for a sump with a pan at the front of the engine.

All the 6cyl engines i have looked at fitted to e36 cars have the pan at the back. So to fit the M20 engine in i think i need some form of modified oil pump and pick up at least.

Someone recently told me the oil pumps on the M50 and 52 engines are chain driven ?