Just goes to show what I and others have said.

Dual plane kicks a single planes *** in any engine under 65-6800.

 

That was some good testing..but remember it's only a 360" motor. More cubes can skew things the other way. We did a 400" recently with tests of the Dart air gap style dual plane and a Weiand Team G single plane. The avg power from 3000 to 6300 WAS about 4 HP better with the dual plane, but the avg from 5000-6300 rpm was 8HP better with the single plane. The crossover point for the single plane was at 4800 rpm and by 6300 rpm the single plane was up 20 HP and it just kept hanging on. At 6500 rpm it had only dropped 4 HP.

The point is that unless you have a REAL tight converter and no gear, WOT at 3000 RPM and below doesn't mean a whole lot. You're running around at part throttle at those speeds. Once you stuff your foot in it you're above 4000 RPM in a nano-second and it doesn't usually drop below that if you shift in the 6500 or so range.

Don't get me wrong, the new dual planes are great and run killer, but there is still a place for a good single plane on the street.

JIM

 

More cubes can skew things the other way.

Yes sir! The sbc intakes were designed around 350's, and bbc intakes were designed around 454's or less. Throw some cubes beyond that, and those dual planes are choking them. Those motors need to breathe.

 

Not completely true Walter.

Many 496-505's run with a dual plane and make big power and are definitely not being choked.


Just curious what times have you run in your 69?