Dual plane manifolds......OK, or NO way

[Dr. Righteous]

Stock low profile intakes manifolds are of a dual plane design and the most popular (affordable) after market intakes are dual plane also. I notices that almost nobody is using these when they build an EFI port injection setup. Is there a good reason why? I know they are not used generally in max power application because there is no benefit to longer runners at higher RPMs. But for general use if the builder is after improved driveability and mileage; why not a dual plane?

[Bernard Fife]

Dr.R,

You can use a dual plane, in theory. The reason most don't is that the ports are at different angles (and hence heights) at the head flange, and this makes positioning the fuel injectors for a common rail per bank much more difficult.

Also, the biggest advantage of a dual plane is that each plane draws from only 1/2 the throttles butterflies. This can mean a faster peak velocity through a carb, and hence better fuel metering and atomization (often referred to as a 'better signal'). With EFI, fuel metering and atomization is independent of peak air velocity in the throttle, so the gains aren't nearly the same as with a carb.

Lance.

[patrickbrown]

If you already have the dual plane then go ahead and use it. Although if you plan to modify it for port injection I probably wouldn't go to the trouble and expense. Start with a single plane for that.

[Dr. Righteous]

If you already have the dual plane then go ahead and use it. Although if you plan to modify it for port injection I probably wouldn't go to the trouble and expense. Start with a single plane for that.

Actually I have a stack of 'em. And they are readily available and generally cheaper for MoPars.
I'm sure single plane design manifolds are cheaper to produce but since they are consider more of a race piece the price is higher.

[convertables_10]

Ive got a dual plane performer rpm on mine. I can tell a difference between it and the single plane torker 2 I had on it. I gained low rpm power but traded off a little high rpm power. Im tbi though.