M42 Head Gasket Blown, Project Thread

[e30if]

Saw a Craigslist ad while I was browsing for random e30 parts locally, he's got a couple M42 harnesses and random other parts if you haven't already sourced a harness: https://seattle.craigslist.org/est/p...234061958.html

[bmwman91]

Thanks, I may end up bugging this guy since the r3v'ers with harnesses have not gotten back to me.

[digger]

Thanks, I may end up bugging this guy since the r3v'ers with harnesses have not gotten back to me.

Don't you just need a patch harness or de-pin the factory connector and re-pin to the LINK connectors ?

[bmwman91]

The Link ECU uses the same 88 pin connector, so I could just depin the plug & move stuff around as needed. But, I am planning to add all sorts of features and rewire some stuff, so I want to do all of that on a spare harness. Then I can keep my stock ECU and the harness I just rebuilt together (to keep the car running now, and to swap in if I need to), and build a separate one for the Link ECU. I have a thread going for the ECU project now.

https://www.r3vlimited.com/board/forum/e30-technical-forums/engine-drivetrain/alternative-tuning-w-a-r-megasquirt-etc/9961647-m42-ecu-conversion-link-g4x-e36x

[e30sh]

C’mon dont be afraid, find Dynojet

Ha, yeah I need to just go get on it already. There are a few shops in the area with dynos.

l.

You have had a year. Did I miss the report?

[bmwman91]

Nah, have not gotten around to it. COVID messed a bunch of stuff up, and now I am about the tear the car apart for a full repaint lol. Thereafter I will be finishing up my Link E36X ECU conversion. At that point dyno time will be unavoidable lol. I have a thread going in the engine management section about that, but it's on hold until the paint job is done.

[e30sh]

Don't you want a before and after to see if all that engine management change was worth it? Around here it's $75 for 3 pulls.

Shoot for 70 degrees (early morning or later in the day in a few weeks) to help with correction factors and use the same mode as ForecedFirebird. Maybe you can get some repeatable ad comparable data.

[bmwman91]

Haha, if I was concerned with HP per dollar, I would have chucked the M42 and done an S52 swap instead (or maybe an aluminum block M52). The ECU conversion is purely for fun, and while it may help me to pick up some power, and fuel economy, it is just for the fun of the challenge really. But, yes it would be cool to have some preliminary numbers. I'll look around the area for dyno shops to see who is open and can get me in for a few pulls. I guess it's something I could almost do on a lunch break if there is a local shop.

[onesecond]

I'm stoked to see what MM Engine makes to the wheels!

[e30sh]

I'm stoked to see what MM Engine makes to the wheels!

My guess is 165 wheel HP.

[roguetoaster]

My guess is 165 wheel HP.

Ahem, you mean 123kW? It is a metric engine after all...

[digger]

It should make 175whp on paper with a dynojet if the claims are true.
For the purposes of a power run i wouldn't waste my $$$ on any other type of dyno as its a lottery and almost completely meaningless in isolation. Go for the tried and true DJ