Post by stepthrutuner on Oct 26, 2010 11:19:17 GMT -5
You are probably aware of these 'rules of thumb', but here they are.
The closer the baffle center point to the piston skirt the higher the rpm at which the pipe hits.
The more volume the entire headpipe and chamber encompass the more bottom end torque the engine will have.
A tapered-wall headpipe is superior to a straight-walled headpipe.
The smaller the I.D. of the stinger the more baffle action (mixture restuffing effect), but the higher the cylinder temperatures (not good especially on a/c cylinders).
A longer stinger has the same effect as a smaller I.D. stinger but probably not to as an much extent.
And, of course, the more shallow the tapers of the divergent or convergent sections the wider the rpm range of the power band.
There can be unintended consequences of pipe action such as lean spots or even near complete shut down of fuel release at the carb venturi due to reverse or stagnant flow through the transfer ports.
In summary.... you really won't know what you will have until you build and run the pipe. You'll just have a pretty good idea of the predicted performance based on the above general guidelines.
