Quote:
Originally Posted by johnneilson
No dog in this hunt, just a couple observations;
The "A" crank journal sizes are not up to spec for a Hot motor, definitely not a competition motor. Cross drilling the crank to oil the rods makes the situation even worst, you are removing up to about 9% of the cross section on a journal that is too small already.
Personally not seen a broken Burlington crank, after seeing one up close I declined to attempt for a customer's hot motor. I have seen the aftermath of two broken SCAT cranks, they were stroked with "A" rod throw diameters and cross drilled. Both broke along the oiling hole on the #4 rod.
It really depends on the application and the loose nut behind the steering wheel.
J
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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?