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goinbroke2 · 02-28-2009, 05:53 PM

Bruce Fulper did a story a few years ago with regards to engine rpm and how quick an engine rev's etc.
It was with pontiac's (of course) but the gist of it was, a bigblock or long stroke/heavy rotating assembly engine rev's up slower than a lighter small block/short stroke/etc. A bigblock that prefers to spin up at 600rpm per second would be quicker with a glide due to less parasitic losses (spinning up the assembly) than a 3spd which would require 900 rpm per sec. A small block however that loves 900 rpm per sec would be slower (or at least not faster) with a glide because it doesn't have the reserve torque.

Veh weight the same, gearing the same, all else the same, a slow reving (reving up) big block is quicker using torque where a quick reving smallblock needs more gears/closer ratio.

More coming back to me...two 455's on a dyno, the newer one with an extra 20hp was actually slower because it was tested at 600rpm per sec and the gearing of the car and the old 455 was set up for 900rpm per sec. The new motor couldn't spin up as fast and was therefore slower on the track.

Speaking of Bruce..anybody heard from him lately? Reading some old BracketRacingUSA mags the other day and came across a couple other of his stories.

02-28-2009, 05:53 PM	#1
goinbroke2 Senior Member Join Date: Mar 2002 Location: NS CANADA Posts: 898 Likes: 1,670 Liked 396 Times in 155 Posts	Re: 1960 283 chevy Bruce Fulper did a story a few years ago with regards to engine rpm and how quick an engine rev's etc. It was with pontiac's (of course) but the gist of it was, a bigblock or long stroke/heavy rotating assembly engine rev's up slower than a lighter small block/short stroke/etc. A bigblock that prefers to spin up at 600rpm per second would be quicker with a glide due to less parasitic losses (spinning up the assembly) than a 3spd which would require 900 rpm per sec. A small block however that loves 900 rpm per sec would be slower (or at least not faster) with a glide because it doesn't have the reserve torque. Veh weight the same, gearing the same, all else the same, a slow reving (reving up) big block is quicker using torque where a quick reving smallblock needs more gears/closer ratio. More coming back to me...two 455's on a dyno, the newer one with an extra 20hp was actually slower because it was tested at 600rpm per sec and the gearing of the car and the old 455 was set up for 900rpm per sec. The new motor couldn't spin up as fast and was therefore slower on the track. Speaking of Bruce..anybody heard from him lately? Reading some old BracketRacingUSA mags the other day and came across a couple other of his stories.