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Walt Fricke Walt Fricke is offline
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Join Date: May 2004
Location: Boulder, Colorado
Posts: 4,949
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Josh

If you plan this 2.8 to be anytning other than a mild street motor with a conservative redline, like 7,200 or so on a pre-3.2 crank, and lower on the 3.2, you are flat out nuts if you don't use Raceware or ARP rod bolts. They are significantly stronger than stock - 220,000 psi steels. Additionally, they can usually be reused several times before they are stretched too far. That is a good thing for a race motor, because those tend to need to come apart more often than motors used in less stressed applications. Less of a consideration in a street motor you hope to run for 100,000 or more miles before.

I sure wish bolts of this sort were available when I built my 2.3 motor, because a stock rod bolt failure (not clear if the fried bearing was cause or effect here) destroyed it. Equally bad problems with the 2.7 (I think that was the piston that pulled in half) that had Racewares left me with a bent end cap, and of course two bent rod bolts, but the bolts prevented the big end from getting loose.

I doubt you will find any of the guys who make a living doing this using stock rod bolts in engines built to anything other than stock specs.

I don't know what bolts Porsche used on their 2.8 race motors, but those motors got torn down between races typically and stock bolts I suspect are up to that number of fatigue cycles.

Walt Fricke
Old 09-09-2005, 10:30 AM
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