- Joined
- March 13, 2005
- Messages
- 7,262
- Reaction score
- 22
- City, State
- Martinsburg WV
- Year, Model & Trim Level
- 84 BII "Li'l Samson"
Sorry I stand by every word I said. Single plane are for large fuel drops into that large area. Then you start getting into runner lengths also. But that's for anothe day. He's building a trail/dd not a 1320 wheel standing high revving engine. One other thing if he runs a single plane he'd better consult a cam builder to get that low end torque from a manifold meant for higher RPMs. night. BTW I did pick my own cams and even told them what lift, duration and with that allmighty split overlap I wanted and they ground to my specs. Granted these were no trail rigs but all out drag cars. Even as far back as the late sixties I ran one of the first truly big single plane manifolds... the Tunnel Ram. Topped with two big Hollys. Hold 6000 RPMs on that small block and slip your foot off the clutch. What a ride. That manifold looked like a mail box with runners coming off the bottom. The single planes come into their own when your twisting the engine. Then the dynamics of the exhaust gases exiting through your propely sized header tubes creates a scavaging effect at high RPMs when the exhuast pulses hit the atmospheric pressure at the end of the header tube. And that only works when your running enough split ovelap to keep the intake and exhaust valves off their seats at the same time. Now your going to get a free charge of air through your intake ports before the piston ever starts down to draw a vacuume. For this to work you need the large area of the single plane with plenty of gas. And that is why you don't run a single plane on a engine that's creeping along at 1000 RPMs about ready to roll down a hill. Now I know people do run them, but for my money I would stay with a dual plane for his build.