Warsteiner, Wazzu70 and bmwman91 convince Norm he can build a smoking M42

[Warsteiner]

Yes Sion the head is ported. The big thing with flow and valves is when you get into the higher rpm ranges and higher lift cams. It will move the entire power band upward but will make more power. I was only building a bullet proof street motor. There can be a lot of power gained before moving up in valve size. I'm not sure where the cut off is.
The anti drain back valve is called a non-return valve and is located between cyl 2 and 3.
http://www.realoem.com/bmw/enUS/showparts?id=AF91-EUR-02_1989_E30_BMW_318is&diagId=11_4380#11111734667

Cheers,
~Ralph

[1998ccc]

Great work Ralph. 

If u r bored, throw the stock exhaust back on and report back with the dyno results. 

[Warsteiner]

Hey 1998ccc,

That won't happen.LOL Too much time, effort and money invested in the M3 exhaust and the car is now tuned.

Cheers,
~Ralph

[sh123]

Yes Vince... that is is exactly what I meant about the close ratio and the differential. It will probably be too short for a stroker and everyday driving.  Almost like using an E30 gearbox with a 4.45 diff. or the M10 4 speed days on the highway. Hahahaha

Cheers,
~Ralph
PS...ok! another pic....

Was having a look through this thread and saw your post warsteiner. Im considering sticking a cop conversion on my engine before it goes on. Any reason why you haven't?  (Im hoping the image of your engine is attached to your quote)

Also what itbs are these?

Sion

[Warsteiner]

Sion,

Yes I have the COP kit on my car from Rob.

Those are Dbilas 45mm ITB's.

Cheers,
~Ralph

[sh123]

ah right ok.

the pic of the engine in the post I quoted had an engine with yellow plug leads?

I think  i may aswell go for cop, everyone else seems to.

cheers
Sion