Who's hitting 4000 rpm with their model a b engines? I guess it's not too tough, that's about 80 mph with stock 4.11 gears 28" tires. How bout 5000? Where ya at on the spectrum?
I've hit 4k with mine on occassion, though I prefer not to too often. I'm still running an A crank - though counterweighted - and I'm only too aware of how small my journals are! Not had my engine dyno'd yet but I know the power is dropping off by then anyway.
I shift at 4000 from second to high gear and at the last hillclimb it hit about 3600 at the end which was 59 MPH. 2 years ago at the Antique Nationals I hit 78 which would be about 3700 with 4.11's. When I ran "A" cranks they seemed to break when we pushed 4000, both broke at #4 rod throw. Both were counterbalanced and drilled for pressure Now I use harmonic balancers. My wife said that she hit 5000 playing at El mirage one day. I had told her to see if it would hit 4000 and she came back and said"It went way past 4000, at least 5000." This was in 1 st. gear of course. Back to the "A" cranks, one was with a chopped "A" flywheel and the other was with a Al. flathead v8 flywheel. Also, my rear tire diameter is 29.5
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