E30 M42 + Manual conversion

[Shaun14 30]

Hi all,
 

I’ve just acquired a mint automatic E30 318 facelift coupe with a very ticky M40 and am wanting to swap in a m42 and Getrag 240 out of an E36 318. I understand the engine and gearbox bolt up to the M40 engine mounts/arms and I can use the loom and ECU from the E36. My question is regarding the prop-shaft and diff – Will either the e30 or e36 prop-shaft bolt in or will I need to source an E30 manual prop-shaft and am I correct in assuming that the E36 diff would be preferable? 
 

I’ve also read that I will need a E30is (M42) exhaust manifold – can anyone confirm if this is the case?
 

 I am also looking to do a coil on plug conversion from an M52, a AFM to MAF Conversion from an M44 and a single mass flywheel from an M20 as well as some sort of chip which is yet to be decided.
 

If anyone has done this conversion and can offer some advice or knows of a donor car for sale that would be greatly appreciated.

Cheers,
Shaun.

[turbolizard 38]

I have an e30 with which I put an M42 into so might be able to help with some of your questions.  However my conversion was a bit simpler in a lot of ways.

The car was originally M40 manual so the driveshaft was already correct for the Getrag 240 I had - the automatic one is the wrong length (I think it is too short).  I did use an M20 flywheel, which was lightened and material was removed where clearance may be an issue on your M42 block.  The engine arms are the same for M40 and M42 so no problems there.  Exhaust I used an M44 header and had no clearance issues around the steering (manual steering for me).  This will be easier to find than M42is manifold and looks like it might work better too (not tested).

My engine has ITBs off an MR2, with wasted spark ignition and a Link computer.  I made a custom wiring harness for the Link  by hacking up an old M40 e30 harness to tie into the car as plug and play (I wanted to be able to put the old engine back).  If you need help with the pin-outs for the C101 etc I have that info somewhere.  It was pretty easy but time consuming.

If i could give some advice it is make absolutely sure you invest the time to do the wiring to a really decent standard so you don't have to chase hard to find faults in the future.  My car has been raced like this for three years and I have had no issues at all.  I have raced cars and boats and proper wiring is critical for reliability (and sanity).

[alisterh 26]

If you haven't already seen my thread have a look, It should cover most of the general stuff. I would try and find an M40 manual conversion first it will make it much easier, then just find and m42 from an auto.

I used the 318is manifold as I knew it would fit 100% like OEM, I have also heard that that the M44 will fit but I have never seen photos of it installed.

This is the guide I used for COP http://bmwz3diys.weebly.com/coil-on-plug-conversion.html, I may also have a spare COP bracket for cheap.

Your stock diff will work but RPMs will be higher, the ratio you need will depend on the gearbox you go with, a 4.1 is  good with a E30 m40 gearbox. AFM to MAF is not going to happen unless you go aftermarket ECU. Most M40 flywheels are already single mass and will install without modification.

I would look for a crashed car from turners or manheim. Even running a driving 318ti's are worth bugger all.

 

 

Edited May 3, 2018 by alisterh

[Shaun14 30]

Hi Guys, 

Thanks for the info! 
Sounds like I'm on the hunt for a manual conversion and a donor car! 

14 hours ago, turbolizard said:

 Exhaust I used an M44 header and had no clearance issues around the steering (manual steering for me).  This will be easier to find than M42is manifold and looks like it might work better too (not tested).

My engine has ITBs off an MR2, with wasted spark ignition and a Link computer.  I made a custom wiring harness for the Link  by hacking up an old M40 e30 harness to tie into the car as plug and play (I wanted to be able to put the old engine back).  If you need help with the pin-outs for the C101 etc I have that info somewhere.  It was pretty easy but time consuming.

If i could give some advice it is make absolutely sure you invest the time to do the wiring to a really decent standard so you don't have to chase hard to find faults in the future.  My car has been raced like this for three years and I have had no issues at all.  I have raced cars and boats and proper wiring is critical for reliability (and sanity).

The M44 header sounds like a great option. 

Sounds like a beasty little motor! 

I'll definitely take my my time on the wiring - electrical gremlins have left me on the side of the track more than a few times!

2 hours ago, alisterh said:

If you haven't already seen my thread have a look, It should cover most of the general stuff. I would try and find an M40 manual conversion first it will make it much easier, then just find and m42 from an auto.

I used the 318is manifold as I knew it would fit 100% like OEM, I have also heard that that the M44 will fit but I have never seen photos of it installed.

This is the guide I used for COP http://bmwz3diys.weebly.com/coil-on-plug-conversion.html, I may also have a spare COP bracket for cheap.

Your stock diff will work but RPMs will be higher, the ratio you need will depend on the gearbox you go with, a 4.1 is  good with a E30 m40 gearbox. AFM to MAF is not going to happen unless you go aftermarket ECU. Most M40 flywheels are already single mass and will install without modification.

I would look for a crashed car from turners or manheim. Even running a driving 318ti's are worth bugger all.

 

 

Thanks for the link it will definitely come in handy! Sounds like M40s with ticky tappets are not uncommon. 

If you do have a COP bracket for sale that would be great!
I'll stick with the AFM in that case but good to know about the M40 flywheel! 

 

I'm keeping an eye on the auction sites - hopefully something pops up! 

Cheers,
Shaun 

[dirtydoogle 383]

I have an m44 header I could sell.

Have an m44 motor with a rebuilt head (all tested, decked and seats cut) 

M40 lifter tick is one of two things usually, 

First is the upper sump gasket perishing internally creating an air leak in the oil pick up, delivers aerated oil to your engine.

the second is a mixture of poor servicing and also poor materials, the oil spray bar on the head gunks up and you run the cam surfaces with less oil than needed, they then wear through the hardening and destroy the cam, rockers, rocker pads and lifters 

I have a full bmw history e36 316 that had worn the cam at 180km, cost me around 400 nzd to replace the cam/rockers/lifters 

[Shaun14 30]

10 hours ago, dirtydoogle said:

I have an m44 header I could sell.

 

Hey Mate, 

That would be great - Let me know if you do decide to sell it. 

Cheers

[Shaun14 30]

Managed to track down a manual conversion for the m40 and have had the box rebuilt. Bought an m44 header too. Now I just need to find a good low kms engine conversion and COP bracket.