hey i have an 88 duke and when i rev it up to about 2k rpms i get a knocking noise. could this be because i have 10w40 oil and not 5w30? THanks for the help.
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06:46 PM
PFF
System Bot
TopNotch Member
Posts: 3537 From: Lawrenceville, GA USA Registered: Feb 2009
Once a bearing starts Knocking, I've never seen it where the crank was NOT hurt. count on turning the crank, it's the only CORRECT way. Otherwise you are only buying a short time. ( I know , somewhere theres someone who just put in bearings & it ran another 20 years)
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12:28 AM
katatak Member
Posts: 7136 From: Omaha, NE USA Registered: Apr 2008
Although I have never done this on a Duke, I have done it on many straight 6 Chevys. Drop the pan, locate the bad bearing(s), remove the rod cap and inspect. If there are no deep gouges in the crank, you can fix it right there. The last one I did had a bad bearing that had left bearing material stuck to the crank. This motor was siezed tight on the one bearing. I got some emory cloth and polished the Journal. Measure the journal - you may get by with a standard bearing but oversized bearings can be bought. I di this to a 260 in a 51 Chevy truck and put another 35k on it before I sold the truck. It is still running today with over 80k since I did the work to the crank. If it is not a "race" motor, you can get away with a lot of "fix's" that many people would not think works. It's worth a shot and you will only be out some time, a pan gasket, some emory cloth and oil. Good luck.
