M40-M42 Issues, what is this engine?

[Hotjim]

Hi guys i am in need of a little help as i don't know which engine i have here.
I am a relative newbie and decided go ahead and put a m42 into my 318i cab as it's such a straight forward swap. Found an engine up in yorkshire. BTW this is it,

http://cgi.ebay.co.uk/ws/eBayISAPI.dll? ... TQ:GB:1123

The receipt is good.

He took it out of his 318is which was still sitting empty in his garage.

Got all the bits new mounts, coil pack brackets etc.

So getting round to fitting in this weekend and it's all going really well for a walking catastrophe like me. Old one out clean everything and new lump sitting over the engine bay. Then the first road block, the manifold connects to the center section at a completely different angle and a good 4 inches back.

So never mind i'll get a new center section it must have some funky manifold or i didn't read the posts properly on how to do this. Exhaust off carry on until after 2 hours of trying to get the lump onto the gear box. It just wont go. Why? Because the locating pin jobby that sticks out an inch or so from the spline on the box has a dimeter of 15mm the one on the engine less than 12mm!

It was all supposed to be so easy.

What kind of freak engine is this? It dawned on me that it could be the e36 m42 and if it was installed by someone else before the previous owner got the car he wouldn't have known.

Does anyone have any thoughts on what it is? any advice would be great.

I wish i had the all the pics i took but this samsung POS wont give up it's pictures i will have some more today.


Robin

[monkey]

you need a differant spigot bearing in the end if the crankshaft . and i think you will need an m42 exhaust .

[Elecblondie]

^Absolutely right.

The flange on the m42 exhaust manifold is different to the one on the m40 exhaust so it's not a simple modification either.

The old M42 spigot bearing, having quite a small aperture, is awkward to remove, I used a piece of threaded bar welded in place and a slide hammer to remove it but Brian Moore (him of the better answers) has suggested packing it out with grease and hammering a well sized bar in, which sounds better to me.

Next problem for you will be engine mounts, the m42 arms are not the same as the m40's and by the information from the last person that tried they won't go on to the m40 mounts or the m40 arms onto the m42 block (which suprised me). I used e34 m50 mounts and they seem to do the trick. My engine does however sit a little higher than the old m40 so I've ordered some gearbox mounts for the m42 gearbox to bring it inline (I hope). Best bet would obviously be to buy BMW m42 mounts but being fancy hydraulic jobs they cost a fair bit.

It's worth noting that the m42 from the factory used a different radiator but, I think, most people find using the m40 rad to be perfectly fine (I swapped mine anyway as I had one from a broken e36).

It is a simple swap, I did mine in 4 evenings; the only tricky bit is finding all the right bits, it's annoying to find you don't have the plastic insert for the throttle cable to throttle lever arm connection for example .

Good luck with finding an exhaust.

[Hotjim]

Cheers for the replies so soon. So a new spigot bearing it is then is this a new purchase or is one source-able from another block? Or...is the spline/spigot removable as it could quite easily be turned down. Which is more work?

Also yes i already have the funky m42 mounts 50 sheets each but it's going to be in there for the foreseeable future.

And the exhaust, can i get away with just a m42 center section?

Thank you in advance
Robin

[Elecblondie]

Get a new spigot bearing; it's not much money, it's worth replacing anyway and you'd probably cause damage to it removing it. Splines are the same, it's just the shaft diameter that's wrong but it strikes me as crazy to turn down the shaft when you can buy a bearing to fit.

The M42 exhaust is 1/4 inch greater diameter and splits with a flexi joint unlike the m40 one. I'm sure it would be possible to bodge the two together somehow but they won't just mate up properly. I decided on the full exhaust myself.

[Hotjim]

Brilliant thanks for the advice. I need to to go parts hunting again.

[robbo86]

Thankyou in advance
Robin

Dude has stolen my name and my idea!!!

I am the fella Elecblondie was talking about with the m50 solid rubber mounts! They fit perfectly. My exhaust has part of the front section still attached. I spoke to a local vehicle welder who can run a weld round where the back part of the m40 front section will be chopped and slotted into what remains the the front of the m42 front section (if you follow). Also means I get you use my M40 Scorpion exhaust. I keep hitting snag after snag and my current one is working out what route the throttle cable takes and what it looks like all together. See:

http://www.e30zone.net/modules.php?name ... c&t=129668

Hoping Blondie, who has been a real help so far can come through for me on this one.

[robbo86]

Might also be worth taking a glance at:

http://www.e30zone.net/modules.php?name ... 3&start=25

In particular the part at the end about the battery clip. I can see no way the wires that are supposed to come off the positive do in anyway. However if you have a look at the positive clip on one of the other pictures (which shows the positive connection on the old loom) the connection seems to be different. Hopefully you will avoid some pitfalls by reading these!

[RRRR]

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[E30Mark]

Spigot bearings changed size in 09/91.