HEAD FLOW

[daveo]

How well dose a m20 cylinder head flow if i was to get the head ported and poslished how much of a power increase would i see.

tia

dave

[maxfield]

Depends what other mods you do also.

Cam?
BBTB or ITBs?
6 Branch?

All these would help increase power with porting and polishing.

[ed325i]

Bigger valves ?

[daveo]

im going to using a mild cam with a 6 branch manifold.

[ed325i]

It still depends on who and how the head is ported.
2 to 4 bhp extra I would think on its own.

[daveo]

so what you are going to gain over standard its not really worth it.

[davecave]

Will you really gain anything for all the work it will take mate????

[maxfield]

Will you really gain anything for all the work it will take mate????

Depends how much power he's aiming for.

If with BBTB, 6 branch and a decent cam then it will probably make a significant difference.

[ed325i]

Who is going to port the head ?
You need a flow bench to make sure each port is flowing the same.
I wouldnt polish the inlet side but go for nice polished exhaust ports.

[e21Jason]

Hi

The 885 head flows pretty well from the box about 20% over the small port head. The real only gain is to run bigger valves and bigger throats, but the m52 heads flow about 30% more than a 885 another reason for an engine swap.

My mate is runing a load of tests on m20 heads on his flowbench at work so i hope to have real data soon.

The intake system is going to give more restance than the head, MS is probably going to gain more than head work.

Jason

[ed325i]

The intake system is going to give more restance than the head

Could an inlet manifold be made that flows better ?
What would be the best design ?

[Turbo-Brown]

Throttle bodies should flow better than the cast inlet

[reggid]

The intake system is going to give more restance than the head

Could an inlet manifold be made that flows better ?
What would be the best design ?

i am looking into doing a extrude hone + gasket match and clean up aroung the ports on my intake manifold in the coming months and i have heard 20% flow increases but thats definately not a 20% power increases. Its an expensive exercise (~250 pounds) but i'll be doing before and after dyno runs for all to see.

[Turbo-Brown]

Would be cool if you can do that in isolation without any other mods reggid

[reggid]

Would be cool if you can do that in isolation without any other mods reggid

thats the plan but it may take a few months for things to happen

[Turbo-Brown]

Good things to those who wait

[e21Jason]

Hi

With out going to ITB's a log style manfold with a big throttle body would flow better something like this.

http://sdsefi.com/techinta.htm

The GT power simulation for the m20 shows up a decent pressure drop across the standard manifold

http://www.gtisoft.com/broch_gtpower.html

Check out the US fourms like rev3 or e30tech for the opinons on the extrude hone.

Ditch the AFM and go to alpha-n will give the best result for least spanner work. That's why it is very popular on s14's, even better if you go to stand alone.

Jason

[ed325i]

a log style manfold with a big throttle body would flow better something like this.

http://sdsefi.com/techinta.htm

Thats more like it.

[ed325i]

I have been looking at building ITB's using suzuki gsxr 600 T/B's like the bloke on e30tech.

[Turbo-Brown]

Just make sure you don't point No.6 cylinder's intake straight at the servo like whoever made that has done!