Author Topic: M42 build for E36 Compact  (Read 106621 times)

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #90 on: June 07, 2014, 05:17:33 AM »
The ECU is detailed here http://motorsport-electronics.co.uk/index.php/catalog/product/view/id/20/s/me442-engine-management-system/#
Yesterday I did a bit more on the engine, ground the head flat.

Refurbed the S50 ITBs, which took for ever! But they've been stripped, ultrasonically cleaned, polished, and then reassembled.

The head was hotwashed (again), scrubbed in the cleaning tank, so I took some loving pics of the port work

Exhaust port

Inlet port

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #91 on: June 15, 2014, 05:45:04 AM »
So now the head is on its time to measure up valve to piston clearance.
Cat Cams give a valve lift value at TDC - for the 1301520 profile I want to run it's 4.30 / 3.70mm

Cometic make various gasket thicknesses, the smallest is 0.040" and the largest I'd want to use is 0.060" as the compression ratios for my engine are:
0.040" gasket - 11.27:1
0.060" gasket - 10.65:1

The higher compression is only just acceptable for a race engine, it really needs to be 12:1 or higher.

Measurements @ TDC:
Inlet 0.040" - 3.51mm
Inlet 0.040" - 4.05mm

Exhaust 0.040" - 2.10mm
Exhaust 0.060" - 2.63mm

Dropping to the lower compression will still not get me the clearance I need and would result in a compression ratio that might be too low for the cams to work properly.

So it looks like I need to take the pistons out and see if they can be pocketed.  At this stage I am wondering if I have enough information in order to buy a set of JE pistons without machined crowns, and get my own crown profile machined from them.


MrPhatBob

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Re: M42 build for E36 Compact
« Reply #92 on: June 19, 2014, 05:26:13 PM »
I need an intermediate engine as I blew mine up at the track today

colin86325

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Re: M42 build for E36 Compact
« Reply #93 on: June 20, 2014, 05:46:20 AM »
Oh crap!  :(
What happened?  how was the car running before it happened?
« Last Edit: June 20, 2014, 05:48:38 AM by colin86325 »

Darky

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Re: M42 build for E36 Compact
« Reply #94 on: June 20, 2014, 07:29:30 AM »
What exactly happened?

wazzu70

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Re: M42 build for E36 Compact
« Reply #95 on: June 20, 2014, 11:01:31 AM »
This just means you need to finish the engine faster so we can see results!

Bummer on the engine failure  >:(
-Nick
91 E30 M42 with VEMS

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #96 on: June 21, 2014, 08:25:59 AM »
The car was running okay, after about an hour laps there was a power loss and some strange noises which I thought was coming from the diff, I noticed smoke out the back of the car so slowed and pulled to the inside line on the track and hoped to limp back to the pits. Suddenly there was the sound of things exiting the engine, total power loss and smoke pouring from the engine and the oil light came on.

The engine spins like the plugs are out, although there was no significant oil loss...

One of the Compact Cup competitors was at the track that evening and I've agreed a purchase of one of his M44 engines as the M42 build is not going to be done any quicker and I love driving that car on the track as it is!

I will be putting my S50 ITBs on the M44 in the meantime, just to get them working and to test that ECU.

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #97 on: July 15, 2014, 03:38:39 PM »
Slow progress, but progress is progress...
I made a fuel rail!

It took forever to do something seemingly that simple, and I think next time I'd be better to do more of it on the lathe, but you live and learn. The Idle air control ports were bunged (in the middle with two tapered grub screws), and with some machined bungs on the outer ports threaded to provide something for the rail to be pulled onto.

For extra points I've scalloped the back of the fuel rail


MrPhatBob

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Re: M42 build for E36 Compact
« Reply #98 on: September 09, 2014, 03:54:17 PM »
Okay... I've pulled the pistons out of the block, measured them up to double check the compression height (31.5mm) and spec the pistons that I need: 7.3cc domed crown, deep piston cutouts...

And I'm getting nowhere with the supplier.

So - where can I get some 86.5mm pistons that will just work with my setup?!?

wazzu70

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Re: M42 build for E36 Compact
« Reply #99 on: September 11, 2014, 02:40:34 PM »
Which supplier are you using? It does not seem like an unusual request!
-Nick
91 E30 M42 with VEMS

jwalton

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Re: M42 build for E36 Compact
« Reply #100 on: September 18, 2014, 04:36:03 PM »
I am pretty interested in this thread, as I am debating on what to do with my m42.  I would be interested to hear your thought process behind the build.

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #101 on: September 25, 2014, 09:39:32 AM »
After talking and looking around, I was told that a bloke by the name of Horst Lems in Germany used Matzinger Performance http://www.matzz.at/ to make his pistons and rods.  I spoke to Berhard there, who replied in perfect english, and suggested I send a piston to him, so that they can machine a set to my specification - as they have the right pocket depth for Horst Lems's cams, and as I am planning on using the same cams I will have exactly what I need.

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #102 on: September 25, 2014, 12:32:55 PM »
I am pretty interested in this thread, as I am debating on what to do with my m42.  I would be interested to hear your thought process behind the build.
Well I think the whole thought process is pretty much detailed throughout the thread - is there anything specific you're interested in?

MrPhatBob

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Re: M42 build for E36 Compact
« Reply #103 on: November 02, 2014, 11:52:48 AM »
Matzinger sent me a snapshot of the pistons they're doing for me


Decent depth of pocket and raised chamber there.

Darky

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Re: M42 build for E36 Compact
« Reply #104 on: November 02, 2014, 04:35:29 PM »
Hi
Any reasons you can't use s50 Pistons us or euro, MM (87) or xrallyparts Pistons (86.5)?
Cheers Rohan