New SBC Manifold with tooling

[SchmidtMotorWorks]

How far away from the fore and rear plenum box walls should the end port openings be. Make those end walls longer. How much gap between the end port openings and plenum box wall to avoid the port entrance being "coupled" to the plenum wall? ½" ? 1"?...

0.5 Runner diameter is reasonable but that is dead space, not desirable on a carbureted manifold.
This is one of the reasons that manifolds usually have an X shape rather than H.

Another reason is runner length.

[67RS502]

Who recalls the distribution problems contestants encountered in the 2012 BLP Carb Shootout with single carbs on the tunnel ram type intake that had a long rectangular box plenum with parallel 90 deg. equally spaced runner entries, as opposed to the "X" layout of the Victor type intakes. The contestants supplied their own carb mounting plates that attached to the rectangular plenum with the carb situated in the center over the center four ports. The contestants using nearly flat lids had fuel distribution issues with the end cylinders lean and the center cylinders rich. The two contestants who used the same pyramid shaped lid had much better distribution and were the two top contestants in that portion of the shootout.

This is well said, and explains the issue that some see between the center 4 and outer 4 runners.
How much better would a pyramid lid be compared to a flat lid be? Is that the only change needed?
I remember the vid that Kaase had with a transparent tunnel ram, its crazy what actually goes on in a plenum and runners.
It makes sense that the outer runners would be leaner on this design.
So how can Joe solve this issue with this casting?

[paulzig]

What about a version with with EFi bungs?

If you have distribution issues just use sequential injection with individual cylinder correction...

[F-BIRD'88]

How far away from the fore and rear plenum box walls should the end port openings be. Make those end walls longer. How much gap between the end port openings and plenum box wall to avoid the port entrance being "coupled" to the plenum wall? ½" ? 1"?...

0.5 Runner diameter is reasonable but that is dead space, not desirable on a carbureted manifold.
This is one of the reasons that manifolds usually have an X shape rather than H.

Another reason is runner length.

Was thinking more in reference to a tunnel ram, like his second manifold.
I get the hows and whys of the curved runner X 4 bbl intakes.

[Tuner]

https://www.yellowbullet.com/forum/show ... count=1692

[Warp Speed]

What about a version with with EFi bungs?

If you have distribution issues just use sequential injection with individual cylinder correction...

You can fix fuel distribution issues with efi, but it will do nothing for the inherent air distribution issues in the single 4 version.

[engineguyBill]

Joe, you are off to a great start on your head/manifold package. It will probably need some tweeking to get optimum results but your efforts so far are very positive, in my opinion.

[F-BIRD'88]

https://www.yellowbullet.com/forum/show ... count=1692

Off topic.. This is the general shape form of the 2x4 to 1x4 carb adapter. And the 6 venturi carb scheme to 1x4 bbl adapter. Nice and tall like this for a good transitiion.

[Ericnova]

How far away from the fore and rear plenum box walls should the end port openings be. Make those end walls longer. How much gap between the end port openings and plenum box wall to avoid the port entrance being "coupled" to the plenum wall? ½" ? 1"?...

0.5 Runner diameter is reasonable but that is dead space, not desirable on a carbureted manifold.
This is one of the reasons that manifolds usually have an X shape rather than H.

Another reason is runner length.

Fix the end wall to runner opening situation, and cast the top with flanges for a Split Dominator....basically make a dual 2-Barrel deal out of it, might show some real promise.

[SchmidtMotorWorks]

How far away from the fore and rear plenum box walls should the end port openings be. Make those end walls longer. How much gap between the end port openings and plenum box wall to avoid the port entrance being "coupled" to the plenum wall? ½" ? 1"?...

0.5 Runner diameter is reasonable but that is dead space, not desirable on a carbureted manifold.
This is one of the reasons that manifolds usually have an X shape rather than H.

Another reason is runner length.

Fix the end wall to runner opening situation, and cast the top with flanges for a Split Dominator....basically make a dual 2-Barrel deal out of it, might show some real promise.

Not with those short runners or large combustion chambers.

[gmrocket]

if you chopped off the four outer runners, it would be an X pattern ,like a normal intake. except the inner runners do seem to have an extreme taper to them... which effectively will make them work as a shorter runner. That's odd since the outers appear really long and straight in comparison

if you look at an intake like the Indy 440-3X, it's an X pattern, meant for up to 600 cubes and 500 plus cfm heads. I know it's made way over 1000hp.

It's not far off the Chevy port pattern either..

[Newold1]

I think I know why but it always makes me wonder why back in the earlier days of aftermarket performance and racing cylinder heads why more SBC heads were not designed and built that utilized symmetrical port layout instead of perpetuating the poor design of a siamesed port head and then perfecting intake manifolds that crutched the poor heads with an intake that would slightly improve overall performance of these aftermarket heads.

The real answer, it was cheaper to design and build manifolds than design and build new better heads!

[SchmidtMotorWorks]

I think I know why but it always makes me wonder why back in the earlier days of aftermarket performance and racing cylinder heads why more SBC heads were not designed and built that utilized symmetrical port layout instead of perpetuating the poor design of a siamesed port head and then perfecting intake manifolds that crutched the poor heads with an intake that would slightly improve overall performance of these aftermarket heads.

The real answer, it was cheaper to design and build manifolds than design and build new better heads!

The headbolt pattern on an SBC is not compatible with a symmetrical port layout.
Even if it were, that would require compatible cam and headers. From a marketing standpoint that is a nonstarter.
It is very difficult the achieve ROI on head or manifold casting, making it less accessible to some means that it is unlikely to break-even.

[F-BIRD'88]

If you look at the Chrysler Indy ModMan intake manifolds you may see some of the distribution issues this intake will likely have with a single 4 bbl carb in the center.
2x split dominators, one on each end directly inline with the port entries will likely be better.
Possible Tri Power using the split dominators.

The Modman is also a H pattern intake.

[BradH]

I can add nothing re whether the design is viable or not... but it's cool to see something go from concept to product (even if only in prototype phase).