<HR style="BACKGROUND-COLOR: #e5e5e5; COLOR: #e5e5e5" SIZE=1> <!-- / icon and ***le --> <!-- message -->Getting my 401 built for my 65 riv, when heads were pulled off the top outer edge of 3 pistons were broke off, builder says prob caused by detnation. He wants to take my compression down from 10.25 to around 9.50 so i can run on standard pump gas, others are telling me that i shouldnt worry bout 10.25 that it should be fine? Just hoping to hear some suggestions. Thanks. <!-- / message --><!-- sig -->__________________
I have a 65 Riv that I bought in 1994. It only had 55,000 miles on it and I think it had been driven very conservatively resulting in a lot of carbon build up. It would ping easily even on a blend of premium and anti knock additive. I finally got the cylinders cleaned out by running fairly hard for short distances to blow some of the carbon out and then treated with a product called BG 44K or something like that name. Now I can run premium 91 octane with no problems pinging. The detonation results on your pistons may also have resulted from someone burning regular gas as prices increased. Ie. "why put premium in an old car that gets lousy mileage anyway?" 9.5 pistons will give you plenty of room for variations in gas quality and peace of mind but the 10.25 original equivalents will give you more power. Jerome
Yes carbon is a problem. the risers in the cast iron in the head will also cause a problem. polish the "domes" of your heads. works great!
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