here's what I'm up to


any suggestions?

Looks great!

But still, the old problem of yanking the air/fuel mixture on a 90% turn right after it leaves the carb...

How about a side-draft carb (or a couple of them)?

-Mac

I know that this is posted in the fuel injection section, but is this manifold for two carbs or throttle bodies?

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The old white brick

I was throwing around the idea of dual throttle bodies for better flow.
the manifold wont actually be port injection, more like runner injection because the injectors will be on the back of the manifold pointed directly at the intake runners through the plenum.

You can find 60mm stock throttle bodies in junkyards, I don't think you'd need more flow then that. Two of them complicates linkages. Pressure (or the lack thereof) will be the same across the whole manifold, won't it? Since your not running liquid through the throttle bore I don't think there will be flow problems, which brings me to...

The injector setup you describe is a bit different. One advantage of having mpfi is that its a dry manifold, avoids condensation on manifold walls when cold. Why aren't you putting them in the runners?

Nice ute - she looks great! Good luck with your project.

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What about 1 large throttle body in front?

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

I didn't want to put the injectors in the runners because it's an additional operation that I would have to make a fixture for, but I might end up doing it anyway.
The flanges already have a section 3-d machined to make a nice even transition from the rectangular intake inlet to the round runners that I plan on running.
I was also throwing around the idea of running a round plenum w/the throttle body on the front. But this causes a clearance problem for my truck. I would just about have to do a direct 90deg. turn to avoid the radiator. (I have a A-100 truck) Normally this wouldn't be a problem for cars.

round plenum???

also part of my idea of having the injectors inthe back of the manifold is to create a refridgerating effect in the runners to chill the fuel. condensation on the runners might happen but I think it'll be unlikely because of the proximity of the exaust runners.

For one, I'd recommend velocity stacks around each runner entry. Second, I don't think you'll clear even manual brakes with the plenum.

Mike

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Recognized by US Federal Courts as a Fuel Economy Expert!

Could I have the runners go furthur into the plenum to act like stacks?

lol.0 on my truck the brakes aren't even remotely close to my intake. If I make one for someone's car I'll probably have to find someone local with a slant 6 car that's willing to experiment.

You are looking for a tapered and rounded entry into the ports. I doubt poking the runners further into the intake will accomplish that.

I'm on dial-up. I noticed the A-100 after I made my post.

Mike

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Recognized by US Federal Courts as a Fuel Economy Expert!

If you have clearance at the back, you could parrallelgram the runners and plenum shifting the plenum back giving more room for the throttle up front.

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

Don't know if it matters, but from an airflow perspective, airflow might be more even if the runners are all the same distance apart on the plenum side (angle the runners a bit so 3 & 4 are the same distance apart as the rest of them).......

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Ed
64 Valiant 225 / 904 / 42:1 manual steering / 9" drum brakes

How Far along are you on this project? Have you built anything yet? It looks like a great plan for a dry flow system, which would involve putting injector bungs near each intake port. Pardon me if I misunderstand your intention here. It is my understanding that turns in the flow don;t mean much if there is no gasoline mist to fall out of suspension at the turns. How hard would it be to add the bungs for the injectors? You are going to such great lengths to design such a nice manifold, it seems a shame not to go all the way with it. Yours looks much like some of the more trick looking custom manifolds in some of the books I have read on EFI. Which ever way you go, I wish you success with this, and hope you keep us posted.
Sam

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