E30 M42 swap infomation

[ade36]

With a bit of jiggling I've managed to get my M42 in... Now just a case of screwing on the bell housing and adding the ancilleries. It seems to have gone onto the M40 gearbox but now I've suddenly started worrying about the spline on the input shaft; hasn't it been said that this is different on the M40 gearbox? Should I have changed something or will it work on a completely stock M40 gearbox? Sorry if it seems I'm just re-wording questions that other people have asked but I'm just trying to get things straight in my mind...

[zimmerkid]

my car has no problems with the gear box! i swapped the m40 flywheel and clutch assembly on to the m42 engine though! But when i tried the m42 clutch assembly on the output shaft for the gearbox the splines were correct I changed because there was a very noticable weight difference!
HTH

[ade36]

That's all I wanted to hear... I'll finish bolting it all back together now!

[rix313]

Also e30 wiring loom needs modding to accomadate for the knock sensors and such on the e36 engine! HTH

I never had to do that on mine

[buzz6353]

JBH is selling a full conversion
Engine .Box. Prop. diff .and all the electrics if anyone is interested

[jbh]

JBH is selling a full conversion
Engine .Box. Prop. diff .and all the electrics if anyone is interested

http://www.e30zone.net/modules.php?name ... 42#1844142

[ade36]

Also e30 wiring loom needs modding to accomadate for the knock sensors and such on the e36 engine! HTH

I never had to do that on mine

So you used an E36 loom on an E30 M42 engine/ecu/fusebox etc with no worries?

Also, excuse my ignorance here but what part do the knock sensors play? Is it an extra cable on the loom that goes somewhere or what? Assume I have no idea what you are talking about...

[zimmerkid]

when i did my conversion i used a e36 is engine with the ecu and an e30 engine loom, e36 engine had knocksensors on it and the e30 engine loom doesnt have the provisions for these so i butchered the e36 engine loom to get the wires out and fit them to the e30 loom

[rix313]

So you used an E36 loom on an E30 M42 engine/ecu/fusebox etc with no worries?

Also, excuse my ignorance here but what part do the knock sensors play? Is it an extra cable on the loom that goes somewhere or what? Assume I have no idea what you are talking about...

Hi mate,

Other way round 1995 E36 M42 engine with E30 loom

Knock sensor detects whether the engine is 'knocking'. Knock is an 'explosion' in the engine when it shouldn't be, left over air/ fuel ignites after the spark and main explosion. the knock sensor detects this and and adjusts the ignition to stop it from doing so.


Is this the part you're refering to Zimmer?

[zimmerkid]

thats the one!! although there's two of them one for cyl 1&2 and one for 3&4! could perhaps get away with not using them but thought I had better put them in to be safe!!

[rix313]

Hmm, that's the only one on mine but there was a plug in my loom for it.

[ade36]

If i used my E36 loom on my E30 engine could i just leave the knock sensor bit of the loom unplugged? And run it on an E30 ecu? I know it probably would be easier to get an E30 loom but having trouble getting hold of one and I have a perfectly good E36 loom in my garage...

[mc_hawkings24]

Dont see why you cant leave the knock sensors off as they just detect knocks, bangs, detonation pinking and the engines still going to run fine.

[rix313]

It wont for long if those conditions continue but plenty of E30 engines run ok with out it.

[mc_hawkings24]

But other engines dont have them and they manage but if your engine isnt pinking to begin with should be ok shouldnt it?

[tunnel]

Hi guys,

Currently converting my 318i using an m42 from an 36. Had a quick glance through this section as i am having some difficulties getting the engine fit right.

everything has lined up except from the engine on the mounts. Iam using:

36 m42 engine
m40 gearbox
m40 prop

Should i use e30 engine mounts or e36? Currently on the 318i engine mounts.

Cheers Ross

[rix313]

E30 engine mounts are what you need. Got any pics of how it isn'tlining up? Have you changed the sump on the E36 engine?

[tunnel]

Got it all in! swapped the e36 mounts on the engine with the m40 engine mounts!

Next problem is the wiring. Tried butchering the e36 loom and attempted joining it to the e30 connector coming out of the fuse box, had no luck

after reading this thread i guess i am going to have to go with the e30 loom? will it run with the e36 coil pack, ecu, engine???

Cheers

[mc_hawkings24]

Anyone know if the m40 water pump fits the m42? i've fitted a new one on the m40 last month so could reuse it

[rix313]

I would suspect so as the blocks are the same. Best way to check is go on realOEM or BMWfans and cross ref the part numbers.

[MrWhite]

Coming back to the gearbox...
This thread mentioned somewhere that the M40 box has different ratios to the M42 box. Is this correct? I've read other places that the 240 box is exactly the same for both except for the output flange being longer on the M42 box. Does anybody know why the gearbox for the M42 has a longer output flange?

The reason I'm asking this is that I'm going to put my M42 into a 316i touring. The iS gearbox was a little noisy and I need a prop shaft for it. However, I have a perfectly good gearbox and prop I just took out of the touring. The prop is the thicker type (because it is a late model perhaps?) and if the M40 gearbox has the same ratios as the M42 box I'll just use this combination instead of trying to source a replacement M42 box and prop.

Is there a specification or a thread on here stating the ratios of the two variants of the Getrag 240 box?

Thanks

[Touring Whore]

I've just looked up a few tables and they only have one listing for the 240 box, so I'm guessing they're both the same. I was of the opinion they were both the same when I did my 316i touring/m42, which is why I kept the original box and prop.

Depending on what you plan to use the car for, you might want to ditch the 316i touring diff (4.27) for something a bit longer. As a daily driver I find the 4.27 too short, making it a noisy revvy drive.

[rix313]

Both boxes are the same bar the rear flanges.

[MrWhite]

Thanks for the replies. I'll probably just keep my 316i box and prop then. I'll be using a 4.10 LSD for the back end so the 4.27 will be getting launched... unless anybody wants it of course.

[blademankiller]

hi there
ok i have a m42 engine from a e36 and i am puting it in my e30 need to chage the sump yes.

can i use my old sump from my 318i engine or do i have to get a e30 m42 smup.

nice one all
simon

[ade36]

As far as I know the e30 M40 and e30 M42 sumps are the same...

[MrWhite]

^^ Second that. The M40 upper and lower sump are the same as for the E30 M42.

[blademankiller]

ok cool nice one man will let you know


simon

[blademankiller]

ok next one..... will my exhaust from my e30 318i fit the e36 m42 engine????

[MrWhite]

No, you will need a full E30 318iS system. The manifold is different too.

[blademankiller]

nooooooooooooooo not good noooooooooooo
s@~t f@?k dam god dam it just get a new full exhaust system...on my e30 318i !!!
there can i get a e30 m42 engine manifold from then can you help ?
will just have to custom fit the rest of the exhaust



simon
ps]
i have f@~k my 318i engine this is y i have got a m42 engine from a e36.

[MrWhite]

Look for somebody breaking an M42 engine in the parts for sale section, or put up a wanted ad. You should be able to get one for £30-£40.

I'm no exhaust expert but I think you'll have a hard job modding the M40 system to match the M42 manifold. As above, post in the wanted section that you need a full M42 system, there are enough of them around and, depending on condition, not too expensive. Then sell your M40 system.

[MrWhite]

Here's a good place to start:

http://www.e30zone.net/modules.php?name ... c&t=175772

[mc_hawkings24]

Depends well actually i must be a genius as i cannibalized my m40 downpipe well actually two to make one m42 downpipe. Still i've got the proper downpipe now as the one i made hangs a tad lower.

Ive got an m42 manifold 45quid including packing has new studs and number 4 ports been welded up but then they all crack in time no matter what

[blademankiller]

hi there i have a 318i manifold can i not use this on my m42 engine????in my e30

simon