Quote:
Originally Posted by BRENT in 10-uh-C
While I definitely will yield to your wisdom regarding not up to specs, surely you would agree that many, and I mean MANY were subjected to competition and racing without failure, so how do you argue that point? Additionally, many AA trucks were outfitted with OHV heads that often doubled the original horsepower. These trucks were subjected to much more intense loads, -often at the same RPMs as a racing engine, and they lived.
I am curious on the SCAT cranks that failed, was the drilling for pressure done by SCAT during the manufacturing process, or by the engine rebuilder?
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Brent,
I would guess that the "double HP figure" would be 80-100 HP. And you are right, many lived at those power levels. By today's standards, this would be a hot street motor, not a competition motor. To fully understand what a competition motor is capable of you need to look towards Bonneville as the speeds are averaged over a mile run so not only does it have to make power, it has to stay there for awhile. My run this last year was under 21 seconds for the final mile, at about 6500 rpm.
The "C" crank besides the counterweights has approximately 1.6 times the cross section on the rod journals. This in itself is a huge difference in strength, not to mention drilling for oil feed. There are a few shortcomings in the "C" crank, with proper work can be used to make ~200 HP.
The two broken SCAT cranks were strokers, "A" rod journals and yes, drilled at factory. I know that one let go about 6000 rpm, the other probably close to that, one block survived. I have no idea why.
John