. X 2... I think most are building 350-450 HP truck engines... a high rise airgap dual plane to boost mid RPMs torque would be great...

. Don't know why the spacer plates cost more than an intake...

 

. Sounds kinda like those old dual level port Offenhauser intakes... they gave about 350 HP from a 500 HP engine... LOL!

. Might be better to have a dual plane with a 3500 RPM valve that opens and gives a shortcut from the plenum for high RPMs power... like some of the new EFI engines use...

 

Same concept, but completely different. The old offy dual ports are two single planes on top of one another with the primary bore going strait through the front of the secondaries plenum. My design uses a small dual plane and a single plane on top with the primary bores wrapping around the upper secondary plenum (the primaries entering the lower plenum from the sides, not the top). The valves your talking about are the secondary blades, the shortcut is the single plane (think mini tunnel ram) on top. Also offy split the port, primary on bottom and secondary on the top, my design has the primaries on the short side of the port and the secondaries on the long side. Split vertical, not horizontal like the offey. Tall narrow ports flow better than flat wide ports is my thinking. Ideally I would use a small metal insert in the manifold port to direct the port flow "split", right at the valve guide. Offy really screwed the pouch on this manifold. For the primaries they use a single plane, we all know dual planes are better for low end, Offy fails. They used a single plane for the secondaries, good, BUT they put a huge obstruction in the plenum, again Offy fails. It's like they purposely tried to make it a horrid manifold, I guess its more profitable to sell two manifolds instead of one. The Tri-plane design uses a tiny dual plane for the primaries, good, with a unobstructed plenum and a large single plane fed by the secondaries, again good. Look at an SP2P intake, tell me their isn't room to drop a single plane on top of that!

 

plenty of room for a secondary port.




see how the primaries go strait thru the upper plenum for the secondaries, starving the front four cyl for air/fuel? Wrap the primaries around the upper plenum is my solution.




split side ways, I would split it up and down. Compare these ports with the SP2P ports.

 

. As soon as you split the port either way, I suspect you're losing 25% of max airflow... that's just fluid dynamics... a single large port can flow much more air than two smaller ports of same total cross-sectional area over long lengths...

. It's not "dual plane" or "single plane" that makes the performance characteristics difference... it's the length of the ports... dual planes get longer ports in a compact space... low/medium rise single planes give too short of runners in a compact space...

. A dual quad tunnel ram is a single plane that gives more torque and HP than either one... but... of course... doesn't fit under most hoods... and its runners still compromised somewhat toward longer or shorter... street or race versions...


. An EFI 'barrel shaped intake' is an attempt to get a tunnel ram single plane under a hood... and is the currently favored design... of course, the curved runners don't flow quite as well as straighter ones... then 8 valves can be opened to shorten the same runners to tune for higher RPMs...

. Another system on 4 valve heads is to use one intake valve at low RPMs and both at high RPMs... and may also add runner length changing...


. The SP2 looks like it might boost torque on a stock or stockish 400... although the multiple radius curves may damage the 'ram' effects... and may get fuel pooling in the lower runners...
.

 

Hard to compare MPI and carb manifolds as you can twist and turn an MPI port more since you don't have to worry about fuel dropout. So, they are getting quite creative on MPI manifolds, as I saw recently on a Modular V8.

 

One word "resonance", but Ok, forget I mentioned it. Still would prefer a single plane with a removable divider plate.

 

I'd pay $400 to $500 for a single plane with cast in efi bungs.

 

. Maybe CHI can supply this one with the bungs... or weld them on...

 

Tim, I'm running a Torker with Price spacers and 4V heads. I'd be interested in a E.P. RPM Air Gap type intake specifically for a 400. I'm willing to put up a deposit if this gets off the ground.

 

Although I would love a single plane with a divider plate, I would have to concede that a RPM style dual plane would be more marketable. The 351C single plane availability is amazing, and the added cost for spacers is peanuts in the overall cost of an engine build, when one takes into account the money spent in a engine to take advantage of said single planes. A RPM style dual plane for the 400 would fit the builds most commonly found in these forums and therefore, I believe, would sell more units. I would trade off not getting the "best" manifold for my application, for a better manifold than the two we have now. Just my two cents.


P.S. If Tim can pull off the manifold, I would LOVE a aftermarket 400 block with siamesed cylinders and a 4.125 bore. I mean, one has to have goals and after succesfully pulling off pistons, splayed mains, stroker kits, oiling mods and a manifold, whats really left?

 

. Ford has already supplied a '400 Cleveland ' without need of 4 1/8" bore...


. If want a '400' small block with 4.125" bore, swap in a Chevy... if want a '400' small block with 4.351" bore, swap in an Olds 403"...




. Did that fit a 400? Are the molds and tooling still available?


. I vote for a street/strip dual quad tunnel ram for a 400... if only for eye-candy that out does EFI when opening the hood...
.

 

Sorry there is no aftermarket Cleveland block with the 400 deck height, mains and a BBF bell pattern, let alone one with a 4.125 bore. OR I WOULD BUY ONE! I'm talking 428 ci or 454 to 460 ci with a 4.25"stroke not 400ci. And why in the F would I put a Chevy or a goddamn Olds in my Ford? The 403 olds had such small coolant passages it had over heating problems and it has weak *** windowed mains. The 400 Chevy has a laughable rod to stroke ratio let alone the fact ITS A CHEVY. Just try droping a 4.25 stroke in one of those turds and keep a respectable rod too stroke ratio, let alone trying to bolt a chevy or olds engine in a 78 bronco. Things like accessories, headers, tranies and such. I would drop in one of those boat anchor 460 ford strokers first! My god man, that has to be the gayest thing I've read all day. Lol. None the less, the blue thunder takes adapters and are we not talking about a new manifold that wouldn't take adapters?

 

This would also work nicely for EFI if the injector bung bosses were there.

Ditto on the deposit (if it has injector bungs)

 

feeble, you make a great point. If Tim is going to tool up for a new intake, he might as well maximize his customer base. I just installed a FAST EZ EFI on my 400 and would love to go to port injection in the future. A ready made intake with injector bungs would be a huge help and should put the injectors in a much better location than what I will have if I add injectors to my Torker/PMI spacer combo.