Can Detonation Do This????

66sbcduece · 07-02-2007, 09:19 AM

can detonation do this????

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A friend has a bracket car with a 650 H.P. 502 11:1 motor that he runs on VP race fuel. Car would normally run 10.40 and has approx 15 runs on it. Last couple times out he said car was running hotter[maybe 230 by time he was back to pits which was about 30 degrees more than his norm and losing some oil pressure}.Car also slowed down to high 10.70's last couple runs. He ended up pulling a head and found approx a teaspoon full of what looked like glassbead media in each cylinder and exhaust port but was apparently aluminum dust from piston tops or combustion chambers????He then found a bolt loose on his belt drive which showed his cam 10 degrees retarded! Can a retarded cam be the culprit here creating detonation actually leaving aluminum dust in cylinders? I thought just the last 5 seconds idle time would have blown this dust out the exhaust. Spark plugs showed no signs of detonation and cylinders looked good. Just never seen or heard of this before and any responces are appreciated as always. thanks much, AL

07-02-2007, 09:19 AM	#1
66sbcduece Junior Member Join Date: Sep 2005 Location: torrinton , ct. 06790 Posts: 3 Likes: 0 Liked 0 Times in 0 Posts	Can Detonation Do This???? can detonation do this???? -------------------------------------------------------------------------------- A friend has a bracket car with a 650 H.P. 502 11:1 motor that he runs on VP race fuel. Car would normally run 10.40 and has approx 15 runs on it. Last couple times out he said car was running hotter[maybe 230 by time he was back to pits which was about 30 degrees more than his norm and losing some oil pressure}.Car also slowed down to high 10.70's last couple runs. He ended up pulling a head and found approx a teaspoon full of what looked like glassbead media in each cylinder and exhaust port but was apparently aluminum dust from piston tops or combustion chambers????He then found a bolt loose on his belt drive which showed his cam 10 degrees retarded! Can a retarded cam be the culprit here creating detonation actually leaving aluminum dust in cylinders? I thought just the last 5 seconds idle time would have blown this dust out the exhaust. Spark plugs showed no signs of detonation and cylinders looked good. Just never seen or heard of this before and any responces are appreciated as always. thanks much, AL __________________ sbc residential yahoo