Fins on back of Valve & Fins pre TB

[Holden202T]

you have to remember though, you forcing air in the inlet pipe is very different to pistons sucking air in through that same inlet tract from the other end of the system.

I don't doubt the difference in distribution you saw just that to really test it properly I think you need to measure from a suction point of view .... but that's hard to do on the whole system as it normally works.... ie. each cylinder opening in order and adding its pulses to the inlet manifold....

[immortality]

Next time it's on the dyno, use a infra-red heat gun to measure the temps of each exhaust port just after the exhaust manifold flange. A difference in temps will indicate different mixtures.

[delcowizzid]

the bellmouth helped low throttle low rpm distribution didnt help WOT distribution just swaps the leaness from back to front LOL.people have cut the top out the bellmouth years ago so its like a tray with sides to get even better distribution and more flow.i can tell you the elbow is a restriction so is the manifold ive flowed both on a head and get about 1 inch of vacum from fitting the manifold with elbow half as much just the manifold itself.series 1 manifold has the runners way down in the bottom of the plenum and is probably better for more even distribution series 2 the runner are at the top of the plenum with air blasting past the ends of the ports.we havnt seen any distribution issues wih series 1 manifold at 450rwhp all plugs the same colour untill we got up over 30psi and the exhaust manifolds started flowing different side to side leaned one side a little or it could of been the fuel rail running out of flow to the 2nd half LOL

[vlad01]

you have to remember though, you forcing air in the inlet pipe is very different to pistons sucking air in through that same inlet tract from the other end of the system.

I don't doubt the difference in distribution you saw just that to really test it properly I think you need to measure from a suction point of view .... but that's hard to do on the whole system as it normally works.... ie. each cylinder opening in order and adding its pulses to the inlet manifold....

yeah Im aware of that. I did mention it wouldn't be quite the same as the engine drawing in rather it being fed in.


Interestingly if I do this same thing to an ecotec manifold, each port flows out the same for or less despite coming in from one side. I do believe the air tumbles in the plenum as 2 vortices

[vlad01]

Next time it's on the dyno, use a infra-red heat gun to measure the temps of each exhaust port just after the exhaust manifold flange. A difference in temps will indicate different mixtures.

thats a good idea. might try that

[immortality]

Next time it's on the dyno, use a infra-red heat gun to measure the temps of each exhaust port just after the exhaust manifold flange. A difference in temps will indicate different mixtures.

thats a good idea. might try that

It's a good way to find a dodgy fuel injector too.

[delcowizzid]

like this might be a good test on the dyno http://i66.photobucket.com/albums/h242/ ... lmouth.jpg

[TdracerTd]

Next time it's on the dyno, use a infra-red heat gun to measure the temps of each exhaust port just after the exhaust manifold flange. A difference in temps will indicate different mixtures.

thats a good idea. might try that

It's a good way to find a dodgy fuel injector too.

Or a bad plug.

Any progress. This subject interests me greatly.

[vlad01]

I just got back from Sydney today, was working there all week and weekends. I haven't had any time to look into it more just yet.

[VL400]

How about this for a custom intake manifold .. http://www.racecar-engineering.com/arti ... of-racing/

It would be done with a powder type 3D printer rather than the extrusion type.