Let's see how much m20 heads suck.

[AlphaE]

any more info on this?? FF????? Digger??

[digger]

in the real world i suspect extrude honing the manifold alone would offer little peak hp (without addressing the head) but perhaps the power wouldn't nose over so quickly because of the increased size of the runners.

[rogue38]

I have said it before. For now, the manifold already flows more than needed and any change to the manifold did not help flow at the valve. The valve/bowl is the restriction in a stock m20 setup. A few more CFM and the valve coefficient will be reached

Duh, went back and reread. Must have misconstrued something. Sorry about that.

[ForcedFirebird]

I have said it before. For now, the manifold already flows more than needed and any change to the manifold did not help flow at the valve. The valve/bowl is the restriction in a stock m20 setup. A few more CFM and the valve coefficient will be reached.

[rogue38]

Interesting numbers. How do you think extrude honing the intake and the ports would effect the numbers, being the runners and ports would be so smooth.

[ForcedFirebird]

Here you see real numbers and percent of gain over stock.

http://wot-tech.com/pdf/885%20Port%20Testing%201.pdf

[ForcedFirebird]

You can't port a head and expect solid results unless you have access to a flow bench.

Will be posting numbers here shortly, but we have gained as much as 20CFM in a few high lift areas. It's getting interesting now. 17 flow tests with removing material in between and flowing for results.

[Exodus_2pt0]

Leave the heads and manifolds alone, all the "ported" stuff we tested either was same as stock or worse. Even if your "ported" head flows the same as stock, you are ruining velocity.

And to think I was attacked for asking someone on these forums for flow bench numbers on their head.

[digger]

http://www.maxracesoftware.com/PIPE36-1.pdf

this shows an example of the recommended port size to attain the best airspeed as measured on flow bench @ 28" to target a specific goal

[AlphaE]

CHECK THIS OUT!

http://www.camaroz28.com/forums/adva...-heads-282255/

very interesting!

[rogue38]

Been watching this thread and found it interesting. I have always looked forward to seeing Forced Firebird's opinion on engine stuff. Seen him on a few of the firebird forums I go to.

Got to thinking of the flows and velocities and it reminded me of one of the systems on an aircraft model I work. It uses cabin pressurization exiting the aircraft to cool components. Problem is as the velocity of the air approaches Mach, it creates a back pressure and loss of cooling effect. So a restriction had to be put into the tubing to suppress the flow to sub-Mach speeds.

This may have some of the same principles with a balance of volume of flow and the velocity of the flow through the manifold and head.

[AlphaE]

i ment #s for the seta head, but then i saw the link to your site... thanks

What was done to the e mani to get it to flow as well? the pdf on your website shows drastic differences in flow from e to i. Is that w the i tb and ported to match a 885 head?

is there way to get the air velocities along w the cfm? how big a differnece does velocity make? CFM if per minute right? so a minute is a minute. if it flows more PER minute than thats more right? Does it make a difference in relation to valve lift and the cam lobes design? or is it a total design of head and manis that work together to create a system that achievs a sum cfm greater then the individual peices, due to the velocity that actually creates/enables greater air movement? Basically why is velocity important?
sorry if these are lame questions..

[ForcedFirebird]

so FF, the i cam w the eta ported intake on a 885 head? I forget, the runners are longer on the eta intake right? im curious why you say the Super eta intake is junk. Wouldnt it be an in between intake? Not a big as i and not as long as e. Therefore a good compromise on air velocity and volume?

I really wanna see #s on this stuff.

I posted numbers ;)

The seta manifold flowed worse than the eta, proved it on my flow bench. The eta manifold barely flowed worse than an "i" manifold, almost dead even with an "i" throttle body (both on 885 heads).

Digger, I meant that the "i" cam would be a limiting factor on getting the b25 to see b27 torque.

[AlphaE]

so FF, the i cam w the eta ported intake on a 885 head? I forget, the runners are longer on the eta intake right? im curious why you say the Super eta intake is junk. Wouldnt it be an in between intake? Not a big as i and not as long as e. Therefore a good compromise on air velocity and volume?

I really wanna see #s on this stuff.

[digger]

I'd love to see what an MM/Korman head/mani combo looks like on your bench - sorry I don't have $5k to pick one up and send it your way for examination.

probably not as good as you might expect;)