Need help on M40 to M42 IS swap

Fri Mar 13, 2009 10:14 am

Guys

I am thinking of swapping my M401.6L to a M42 1.8L IS engine.

Think its not a straight fwd swap - some mounting etc needs to be changed etc?

Can anyone advised all the parts from the M42 I will need?

I am sure there is a well documented thread on this swap with detailed pics - can a kind soul provide this link?

thks in advance

Fri Mar 13, 2009 1:49 pm

As long as you get an E30 engine complete with loom, mounts, inlet gubbins and all of the exhaust system, it's easy as pie to swap over. Just a case of plug and play. An E36 item will fit but will need an E30 M40/M42 sump, oil pickup and dipstick, E30 M42 exhaust, the E36 inlet manifold will work but the E30 item is deemed as being better, and E30 mounts. You'll need the E30 gearbox and prop too, although I'm sure the M40 item will work fine (as long as you use the corresponding propshaft.) Also, the E36 loom will need rearranging into the E30 plug.

It really is a simple swap to do, just take your time and make sure you disconnect everything before you rip the old M40 out. Any questions feel free to drop me a PM. I went into my swap fairly blind, it was my first big job involving cars and I managed it in a few days.

Fri Mar 13, 2009 1:52 pm

Oh, and unless you're going for a coil on plug setup, the coil pack bracket will need to be welded to the O/S wing.

Mon Mar 16, 2009 5:35 am

Thanks Mate

Do u happen to know a link where there is a detailed write-up (pics woul dbe ideal) where I can be guided along as I suck at things mechanical....

cheers

Mon Mar 16, 2009 5:44 pm

Take a peak at Baz666's iS cabby build, not sure how comprehensive it is but there's some useful info on there. I wish I'd done a writeup when I did mine, as it would have been some help to some people I'm sure.

Tue Mar 17, 2009 12:27 am

I am undertaking one right now. You might be worth reading through this one. Its at an advanced stage from the start of this post, but should be fairly plug and play. Might help you avoid a few pitfalls I have hit.

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

Once I have finshed it I will do a write up. be much easier for you as yours is a manual.

Tue Mar 17, 2009 12:34 am

What gearbox are you going to use? If you are planning to use your current box you will need to replace the spigot bearing with an m40 one. As you mentioned you need engine mounts, I used e34 m50 mounts, they do the job. You will need to buy anything that's missing such as the clip between the throttle cable and throttle lever. the M42 rad is bigger and is the same as e36 m50 rads, you can buy the bracket for it cheaply at the dealer; the original m40 fan cowling will not slot onto the proper rad. You will need to buy to coil bracket or sort a COP setup. There's a few little things to be thinking about.

Tue Mar 17, 2009 2:22 am

robbo86 wrote:I am undertaking one right now. You might be worth reading through this one. Its at an advanced stage from the start of this post, but should be fairly plug and play. Might help you avoid a few pitfalls I have hit.

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

Once I have finshed it I will do a write up. be much easier for you as yours is a manual.

Thanks Mate!

looking fwd to it

Tue Mar 17, 2009 7:12 pm

Although the M42 rad is bigger the M40 one works fine. I'm running the M40 rad with no issues what so ever, just needed to modify the length of one of the coolent pipes a little.