intake port molds

[LGAFF]

Originally Posted by tpepmeie

The housings.... well appear to be a dud. Lost a ton of airflow and couldn't repeat the previous numbers for some reason, not even close. More work to do for sure. It would be an absolute shame to cork up these heads with weak injector housings.

stay tuned.

So are you saying that the 35MM is not enough? Been reading up on Sean Hyland's(Another Damn Canadian) work on Cobra DOHC NA motors, looks like they have 37MM runners on the 5.4s producing 500hp. Cam timing is interesting also. Our intake to exhaust valve ratio seems alittle on the high side in comparison too.

Seems Cobra motors have secondaries also

[Polo-1]

Yes, it looks like they are lost.

For those who did not see, or hear.

Todd's heads out flowed me by a good margin in my book. same bench, same operator.

Todd tiny port vs Kevin Big Dogs



These are one of the biggest ports GVD has done.

[tpepmeie]

Originally Posted by LGAFF

So are you saying that the 35MM is not enough?

Dunno. Probably will go bigger at least at the entry and also the injector bosses can be cut down a lot more.

Even the best ported housing is still gonna lose a little. Can only wish we had the next-Gen LT5 setup, with the nice straight shot runners. Or more hood clearance and some individual throttles and trumpets!

[flyin ryan]

As I said in the 'lost' post's, not to poke my nose into your guys' business, but please, PLEASE don't live & die by 'Dry' bench alone. Todd, your guy (C.B.) didn't do your heads wicked then get stupid on the Injector housings. The 'Dry' flow bench will lie to you if you let it,...Believe it! Just don't want to see you guys, & everyone else out there, get tripped up . Put it together, it'll haul the mail

[Paul Workman]

From a scientific point of view, I too would be curious to see what your setup would do "as-is", being that you can always go bigger on the IHs later (but it is harder to add metal once it is gone). In addition to flow characteristics, the resonance frequency (a la rpm vs. torque) will shift upward as the diameter of the Helmholtz tube...er...IH increases.

Although Mr Ryan is being cagey - at least on this open forum - I agree there is sooo much more at play that a flow bench does not reveal. It would be very interesting to see some dyno curves with your IHs and then with some slightly bigger (like mine). I'd be willing to lend my IHs/plenum to ya to do just that, but there would be the transition between my 36.xs to your heads' 35s to figure out (epoxy?).

It is always interesting to compare the calculated design to actual. One thing some flow treatments do NOT do is consider is surface area of the intake runners; I'm speaking of programs that only deal with cross sectional area and not consider the barrier zone on the surface of runners. Point being, if it is a dual runner the cross sectional area can be made the same as a single runner, but the surface area (and resonance characteristics too!) are significantly different. There is significant wiggle room if the treatment is overly simplified and in the end what works best...works best (regardless of the model predictions).

As for the "Big Dogs" not flowing as well as Todd's, (assuming all else being equal in the test) there's got to be some turbulence being developed in their design that is creating some kind of standing wave(s) - effectively pinching off the air flow...would be my guess. Wanna really see a reduction? epoxy a flat surface on the knife-edge of the divider in the head, so that the flat surface is no wider than the septum, but perpendicular to the flow. (Same principal - when a big runner couples with a smaller runner w/o any taper in the transition!)

P.

[flyin ryan]

Originally Posted by Paul Workman

As for the "Big Dogs" not flowing as well as Todd's, (assuming all else being equal in the test) there's got to be some turbulence being developed in their design that is creating some kind of standing wave(s) - effectively pinching off the air flow...would be my guess.

Good post Paul. If the above was/is the case, the flow bench would get very loud, call it dirty air. As far as that goes, can have two ports/heads that 'Dry' flow the exact same, but if one of the two is very loud, it's dirty/turbulant air, & that one will not run with the good 'Clean' one in the car or on the track.

[flyin ryan]

Originally Posted by Paul Workman

It is always interesting to compare the calculated design to actual.

I always refer to Warren Johnson on this one. He will say, 'When fact's dis-prove theory, believe the fact's & get a new theory!'.

[Pete]

Originally Posted by LGAFF

So are you saying that the 35MM is not enough? Been reading up on Sean Hyland's(Another Damn Canadian) work on Cobra DOHC NA motors, looks like they have 37MM runners on the 5.4s producing 500hp. Cam timing is interesting also. Our intake to exhaust valve ratio seems alittle on the high side in comparison too.

Seems Cobra motors have secondaries also

Lee, where is the info
Went to his site couldn't find it.

Pete

[scholtmj]

Speaking of dry flow benches, doesn't Dart wet flow their heads now? I heard they developed wet flow technology but have not heard anything recently. I suppose you would still dry flow the IHs but wet flow the heads.

[flyin ryan]

Originally Posted by scholtmj

Speaking of dry flow benches, doesn't Dart wet flow their heads now? I heard they developed wet flow technology but have not heard anything recently. I suppose you would still dry flow the IHs but wet flow the heads.

Yes, Richard Maskin had Joe Mondello build them a wet flow bench, I believe it cost around 60K. Flow everything on the wet bench, Everything!, Including IH's. Mixture is going in both directions, like a mini tornado when an engine is running. I 'Hate' Dry benches, personally .