slappo
New Member
I have an older edelebrock on my 318 poly (sitting on weiand high rise manifold). I'm wondering if if would be better to rebuild this one, update to a newer edelbrock or switch to a holly.
NOW . . . how much time will be spent at those elevated rpm levels? Primaries sized at or below 1.69" are fine for a small motor, by observation. Almost perfect for a 360CID motor, and a bit less so for a 400CID motor. On the primaries, "size" for a 3000rpm cruise and let the WOT stuff happen as it might for the carb size.A stock 318 poly max safe RPM is 6000, correct? According to the CFM formula, the most air it can swallow is 552CFM. Add 10% for to cover any carb marketing BS and its 607cfm. Add a little more for those crazy times you go above 6000 rpm and I'd say a 650 would be perfect...Who's with me!
Thanks Cbody67. Whoops....I was in racing engine mode. Old stock engine VE commonly top out at 80%, so the most air that 318 can swallow at 6000rpm is 442CFM. Thanks for catching that.NOW . . . how much time will be spent at those elevated rpm levels? Primaries sized at or below 1.69" are fine for a small motor, by observation. Almost perfect for a 360CID motor, and a bit less so for a 400CID motor. On the primaries, "size" for a 3000rpm cruise and let the WOT stuff happen as it might for the carb size.
So, the famed 0-3310 780cfm Holley, with 1.69" throttle plates, would be about 400cfm on the primaries alone. Might be too big in the total aspect, but not too big for a 3000rpm cruise, in any A or LA motor I suspect. Then tune the spring pressure for the secondaries to open only as much as needed, which they will mostly do anyway, to not over-carb the motor at WOT.
In the above CID air quantities, what level of Volumetric Efficiency is being used in that formula?
Just some thoughts,
CBODY67