180 na horse ?

[bmwman91]

Haha...180WHP NA from a M42 is a tall order. If one is OK with an engine that measures its life in track-hours, it is doable.

[carnurd]

Haha...180WHP NA from a M42 is a tall order. If one is OK with an engine that measures its life in track-hours, it is doable.

That's basically the path I'm going to take with my m42... Then again I was getting 142rwhp(dynojet) @ 2100' elevation on a stock bottom end and unported head with cams and valves. Lightweight pistons and rods with more compression, removal of dampner, solid lifters and ITBs are my next steps. With good tuning and good headwork I don't see a reason to not be able to make 180rwhp. Then again I'm also planning to spin 2krpm more than the factory redline..

[benz-tech]

GOOD headwork and cams! 180 at the flywheel is 100bhp/L. Not an easy figure with an M42. At least you're prepared to spin it.

[Massimo]

That's basically the path I'm going to take with my m42... Then again I was getting 142rwhp(dynojet) @ 2100' elevation on a stock bottom end and unported head with cams and valves. Lightweight pistons and rods with more compression, removal of dampner, solid lifters and ITBs are my next steps. With good tuning and good headwork I don't see a reason to not be able to make 180rwhp. Then again I'm also planning to spin 2krpm more than the factory redline..

That is what my plan is. To spin it higher on the stock crank. I have been wondering if it could handle 9000rpm.

If you compare the M42 to a F20C then the M42 has a shorter stroke but a shorter rod. Also the M42 main journals are larger while the rod journals are smaller. The problem here is larger journals create a larger surface area, while this is good for strength its negative impact is it can lead to quicker wear. Not that that would be a problem in an engine like this as you would not be driving it every day.

I see 4 issues with running upto 9000rpm.

What will the result be of the compression stroke with light weight rods and pistons?

Can the stock oil pump handle the rpm?

High rpm vibration damper, can the damper work thought out the rev range?

Getting enough flow from the M42 head.

Ithor way I do not see why something like 200whp to 230whp is not possible, people need to stop thinking hp/lt and start thinking hp/lt/rpm.

Once I finishing doing up my house the project will start and will see where it gose I supose.

[JonnyOg]

See thats the thing. You said NA so I assume strictly NA which simply isnt that cost effective at all.

For 1k ish you can do a pretty simple turbo m42 running on stock motronic and make over 200hp.

Its been done several times. Danny, a member here did it. He later went MS but thats beside the point

Duuuude thats all I want. A nice reliable 200 crank horse. What else does it require to run on stock montronic? What kind of tune? Whats a good thread to learn from?