M40 or M42 on an E30 318 I

Author Topic: M40 or M42 on an E30 318 I  (Read 2319 times)

MAKAROV000

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M40 or M42 on an E30 318 I
« on: December 17, 2013, 07:46:50 AM »
I brought an E30 318 I
It’s engine is corrupted
I’m going to replace it with a new one
What would you recommend usage of m42 or m40 engine?
The original engine of the car is m40
In case I decided to replace it with an m42
What are the parts required to be replaced along with the engine
The gearbox? the differential…?
Should they also be replaced?


Darky

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Re: M40 or M42 on an E30 318 I
« Reply #1 on: February 12, 2014, 05:26:59 AM »
Corrupted?
The m42 has a lot more go and room to grow!
Also your diff and gearbox are essentially the same, may have slightly different gearing in gearbox!
Most of the ancillarys ie power steering, Aircon, alternator change over, providing you stay e30 m42.
E36 m42 have the v belt that goes everywhere and the dipstick moved back.

DesktopDave

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Re: M40 or M42 on an E30 318 I
« Reply #2 on: February 12, 2014, 03:04:19 PM »
I'm pretty sure those two motors share the block. You could possibly swap the head from an M42 onto the M40. It'd be easier to swap the whole motor.

The detail differences are what you need to look out for - different exhaust manifolds, different engine electronics, etc.

We didn't get any M40 over here in the USA, so I can't be sure. I can tell you a lot about the M42 though.
'08 Karmesinrot 128i 6MT
'86 Zinnoberrot 635CSi (M30B32/G265/3.46 torsen LSD)

Sold: '97 Montrealblau 318iS, '91 Brilliantrot 318i, '91 Brilliantrot 318iS