316i m40 to m42 - What do I need?

[stu_316i]

Hi All,

I currently have a G reg 316i that I have been using as my daily driver, but with an upcoming trip to the ring im thinking about doing an m42 conversion to spice it up a bit .

I have looked around this part of the forum but cant seem to find a definitive list of what is actually needed to do this. If people could add anything missing from the following list that would be great:

Engine
Gearbox
Loom
Exhaust manifold
Engine mounts?

My 316i already has a rear disc breaks and ABS, I dont know if this makes any difference to what is needed but I thought I would mention them just incase.

If I am able to get the parts together how long do you guys think it will take to do the conversion, assuming that I have all the necessary tools (a couple of friends that have done lots of engine conversions before ) readily available.

And finally.... is there a guide somewhere for doing this that I have just not been able to find?


Thanks

Stu

[BadDave]

Engine
Gearbox
Loom
Exhaust manifold
Engine mounts?

Couple of other bits to add

Ecu
Coilpack
Poss full exhaust system

[robbo86]

http://www.e30zone.net/modules.php?name ... highlight=

Rough guide but more or less there! Part of the time it took me was that I was converting auto to manual as well. If its already manual it is simply a case of unbolting the slave cylinder and lifting the gearbox away.

[stu_316i]

Thanks for the replys, ill take a much better look into it now and update when ive made a decision . Although I fear a lot of the decision is going to be based on being able to get a good engine and extras within a reasonable distance of where I live.


Is the following everything I need then?

Engine
Gearbox
Loom
Exhaust manifold
Engine mounts?
Ecu
Coilpack
Poss full exhaust system


Thanks

Stu

[robbo86]

Time, Patience, Plentifull supply of tea and custard creams, a wide and varied vocabulary of swearwords for when things go wrong/dont work. Some tools wouldnt go amiss either.

[Scruffymurphy]

You'll also need

Air flow meter
Starter motor

The exhaust is definatley different

As far as I know you can use the M40 gearbox. If you're changing it to the M42 one you'll need to change the prop also as the M42 gearboxes are slightly longer.

The is has ventrd discs so the calipers are different and they have 51mm struts. You can use you 316 brakes and suspension for now though. If your car is a touring it will already have the bigger brakes and struts.

[GrindCulture]

Time wise, I managed my swap in 3 days, not knowing anything about engine swaps with a little help from my ex-girlfriends dad, who also didn't know anything about engine swaps. Do everything methodically. Everything on the M42 goes back in the exactly the same way the M40 comes out. Have fun

[mt1104]

You can use e34 m50 engine mounts as they are far cheaper.

You also need to get the small plastic throttle cable clip as this is different between the m42 and m40 (the bit that connects the cable to the engine).

Source a full exhaust if you can as it'll make life much easier but if worse comes to the worse you can butcher a m42 front section (from an e30 or e36) and connect it to an equally butchered m40 front section.

The m40 gearbox can indeed be used and this will mean you can use the m40 prop that's there already, one thing you may need to watch out though is spigot bearing sizes, as these changed late 1990 and so if the m42 has the wrong one in it'll be annoying. Get the correct one from bmw for the gearbox your using and use that (should change spigot bearings anyway as they wear with the gearbox input shaft).

if your feeling flush might be worth changing the profile gasket and the chain tensioner on the m42 while its out of the car.

Other than that, its all very simple. The prop may fight back a bit but no big deal, just use a bigger hammer.

[jon552]

very simple swap done it start to finnish in 1 day. you do need the exhaust or if you are handy with a welder the down pipe as it slips over the 316I exhaust and you can bodge it on. only other PITA is mounting the coil packs you can either cut them off the donor or make some up out of some sheet steel like i did, but to be honest i would even bother with the m42 swap all you will end up with is an IS with worse brakes/suspention/interiour/ARB's no resale value and more expencive to insure if you are going to do a swap you mite as well go for a m50/m52/m30 to make it worth doing trust me i have been down this road and wished i had just put a 6 pot in to start with.

jon

[stu_316i]

Hey guys,

Thanks for all the input, only just had a chance to check back here, working 12 hour days at the moment

I should have some time at the weekend to make some sort of progress on this