E30 Zone

i have been thinking about fitting an m50 into my is . i understand that some of you have used m42 gearboxes , so could i keep the prop , gearlinkage and diff . is it as simple as taking the m42 out and an e34 m50 bolted up to the box with e36 alloy mounts with e34 mounting bushes or will it sit too far forward or would the mounts not line up correctly ?

Use your prop/gearbox with an M20 flywheel/clutch/starter...
M50 engine
E36 mounting arms
M50 or E28 M5 rubbers
M52 manifolds
Golf or Clio servo

Thats the main list

Not sure how long the small case diff would last wit the M50 bolted to it.

What would you do with your M42 once you've done the swap? Sell it complete or break the morsels out?

Use a 3.91 diff

I put a m50 in my 318is, I had to use a 325 prop with the m42 box, keep the linkage as you dont need to bend it, and i will go with eko on the 3.91 diff. I have a 3.91 lsd on mine and its fooking quick to 100. There are some pictures in the photo gallery

thanks eko , not too worried about the rest of the swap as i helped do one last year but we used the 525 box and cut the props up to make one the right lengh with the right ends on it for the box and diff . that was a lot of time wasted if i dont need to . the gear ratios where s**t aswell . Sam i would take out the cams and fit the standard ones back in then sell the engine on . her indoors wants the cams for her e36 . the diff would only be temporary anyway .

BigBavarian wrote:I put a m50 in my 318is, I had to use a 325 prop with the m42 box, keep the linkage as you dont need to bend it, and i will go with eko on the 3.91 diff. I have a 3.91 lsd on mine and its fooking quick to 100. There are some pictures in the photo gallery

thanks i have seen the pics of your car very good work there , nice car

I'd say a 3.64 is better on the m42's box thats what I use and although it does make 5th more of an over drive gear you have to remember the m50's create power over a wider band than any "factory" e30 engine

I have a 3.71 with my IS box. It's really good, a nice blend of acceleration and cruising ability I get about 30mpg from it....

Ive not tried working my mpg out yet, im a little scared to be honest!

BigBavarian wrote:Ive not tried working my mpg out yet, im a little scared to be honest!

So was I - I made sure I did it when "she" wasn't around!!

I used this:

http://www.torquecars.com/tools/uk-mpg-calculator.php

mines useless I got 9mpg at oulton roughly, and the 2.5 would return 18mpg but it did overfuel....

Bob_S wrote:mines useless I got 9mpg at oulton roughly, and the 2.5 would return 18mpg but it did overfuel....

"In Oulton" is they key to your 9mpg, I doubt you were driving economically!

i now have most of the parts that i need . i have a pair of e36 alloy engine mounts , m52 exhaust manifolds , e36 325 rad , clio 2 servo , electric fan , m20 flywheel & starter on the way and a 2.5 m50 still in a 525 auto . will it cause me any problems with the engine coming from an auto ? will an m20 2.5 exhaust be up to the job ?

Just make sure you fit a spigot bearing of the right size for the gearbox you choose

monkey wrote:i now have most of the parts that i need . i have a pair of e36 alloy engine mounts , m52 exhaust manifolds , e36 325 rad , clio 2 servo , electric fan , m20 flywheel & starter on the way and a 2.5 m50 still in a 525 auto . will it cause me any problems with the engine coming from an auto ? will an m20 2.5 exhaust be up to the job ?

As Dan said above get a spigot bearing that matches the gearbox your using.
M20 exhaust is fine

thanks boys . i will get a spigot bearing when i get the clutch . i think there is two sizes of bearing so i will get both . is the auto loom going to give any bother ?

monkey wrote: is the auto loom going to give any bother ?

None whatsoever!

thans brian so all i need do is swap the wiring plug over for an e30 one

I'm using an M42 box, lightened M20 flywheel, E21 323 release bearing and M20 clutch kit.

Dunno if that's any help at all for you!

Daf318is wrote:I'm using an M42 box, lightened M20 flywheel, E21 323 release bearing and M20 clutch kit.

Dunno if that's any help at all for you!

why did you use a e21 release bearing? also what did you do with the gear linkage just shorten and get welded or plate and bolt it ?

How much did that bearing cost Dafs?

Did you fit a new clutch? How does it feel?

You dont want to know how much that bearing was think it was about£65 from BMW.

Brand new clutch feels fine. Perfect pedal position

I used the E21 bearing because I was running an M20 flywheel on my M42. I have a picture somewhere, I'll try and find it!

M20 release bearing and E21 323 bearing:


M42 flywheel clutch and bearing alongside M20 flywheel clutch and bearing

Look at those new clutch spring levers compared to the old!

The old is off the 4 pot wrongness - there wasn't enough torque in the M42 to need much better to be honest

I take it that you never ran it on V-Power?

If you thought I was going to spend an extra 8p per litre to squeeze one extra horse from a 110K mile engine........!

On the swaps my father has done since August, 1992, we've used standard E30 325i Getrag 260's with anywhere from 3,46 to 4,45 rearends [typ 188], depending on the engine and vehicle setup. This includes M50's from 2,5 to 3,2 displacement, some with compressors. The 260 trans is stout, and can take a lot of beating as long as you have the proper clutch and pressure plate setup, and maintain the gearbox oil level [rear seal on 260's like to drip.]

The Getrag 240 nor typ 168 differentials are a good idea in my opinion, the components are weak, and do not hold to the rigors of track duty with even a non-VANOS 2.5.

As for M50's in 318is's; we've had great success with them! Our first M50 swap was a non-VANOS 2.5L in an '84 318i (finished in August 1992) that did 13.9s in the 1/4 mile and blasted many-a-2.5L E30 M3 at trackdays; and the E36 M3 couldn't quite catch it in a striaght-line drag. : ) With air-conditioning, the car weighed 2480, including interior and standard daily-driving amenities. For comparison, a U.S. market 325i weighs about 2820. : ) Our 3.0L 318is weighs 2620 with full vinyl trim and U.S. market accessories, and though we havn't run it in the 1/4 mile, it does 8.501s in the 1/8 mile and wipes out 6-throttle E36's in straight line pulls. : )

Lots of fun, is the 318/6

StuMc316is wrote: Our first M50 swap was a non-VANOS 2.5L in an '84 318i (finished in August 1992) that did 13.9s in the 1/4 mile and blasted many-a-2.5L E30 M3 at trackdays

So how did you manage that? Stopwatch timing gear?

14.8 was my best with a NV 2.5, 2.8's aren't 13.9 fast!

DanThe wrote:

StuMc316is wrote: Our first M50 swap was a non-VANOS 2.5L in an '84 318i (finished in August 1992) that did 13.9s in the 1/4 mile and blasted many-a-2.5L E30 M3 at trackdays

So how did you manage that? Stopwatch timing gear?

14.8 was my best with a NV 2.5, 2.8's aren't 13.9 fast!

it'll be the uber short diff he used.

I wouldnt have thought that possible, nearly a second quicker with different gear ratios?

All you BMW boys need to realise the brilliance of short diffs. They make the car feel relentlous(spel?). They are brilliantly cack when it comes to long drives on motorways though.

Jon_Bmw wrote:All you BMW boys need to realise the brilliance of short diffs. They make the car feel relentlous(spel?). They are brilliantly cack when it comes to long drives on motorways though.

24v are relentless!

DanThe wrote:

StuMc316is wrote: Our first M50 swap was a non-VANOS 2.5L in an '84 318i (finished in August 1992) that did 13.9s in the 1/4 mile and blasted many-a-2.5L E30 M3 at trackdays

So how did you manage that? Stopwatch timing gear?

14.8 was my best with a NV 2.5, 2.8's aren't 13.9 fast!

Haha, no not a stopwatch. ; )

That car didn't use a 260 box, it had a Sport dogleg with a 3.64 rear gear and the car was under 2500 pounds. The engine was relatively stock (Heck the M50 had just come out a year earlier!) but the cylinder head was massaged some and it used a chip designed by one of BMW NA's electrical engineers that proved to be very potent due to an extremely aggressive timing curve.

[PS] - I've tried to contact the person who bought that car from us 15 years ago, though it's changed hands again since then. I'd love to have that car back one day.