From digest.v6.n44 Fri Jan 10 19:13:54 1997
From: Land Shark <lndshrk_at_>
Date: Fri, 10 Jan 1997 10:27:57 -0700
Subject: RE: Upgrading an M42 motor
>I am looking for some info and procedures (Jim C, where are you?)
I'm right here .. have been outta town for a bit
>upgrading an M42 motor DTM-style-- I know that this process will cost ALOT of
>$$$, but that will not be a problem. I did some research (well, a little) and
>talked to the BILLET SOURCE a while ago, and they recommended to upgrade the
>valves, valvesprings, connecting rods to titanium alloy ($$$), and to replace
>the head retaining bolts w/ raceware bolts to begin with, along with upgrading
>the ECU, fuel pump, oil cooler, and other stuff.
Umm ..STOP... HOLD ON..
First off .. decide what you need to do to make the motor BREATHE..
Since you will need a CUSTOM intake manifold (ala E30 M3) to do what you
want.. the plenum manifold of the M42 will NOT do!!!
So, FIRST, find out the best flowing valves you can get and figure out
the optimum intake runner/Throttle body size... and plenum volume
At some RPM, even that is going to stop breathing and there is NO reason
to spin the motor any higher.. there is your rev limit
From the rev limit comes the materials needed for the bottom end
Then the ECU, the stock DME will not run over about 9000 rpms
Don't forget the custom vibration dampener for the front of the crank
since the stock one comes apart at 7200!!
This all gets DESIGNED before you buy ONE part!!
(it's called ENGINEERING <grin>)
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