dear people, i have a 350 - 1972 in my truck with a rattling noise while under acceleration. if i put the truck in park or and rev the engine slowly to say 5000 rpm there is no mishap, but if i put it in gear and use the go fast pedal the engine sounds like i lost a bearing or two. so i replaced all bearings ( checked clearences ) but with the same result, ratling under full load. in then used the pull the plugwire method to find out it was cilinder # 5 that made the noise, when i left that one disconnected there was no noise under acceleration. so i tore the engine apart and found out that the # 5 piston had a very clean top for say half the piston on the sparkplug side while all others where black as you normally see. the block is 0.30 overbored ( TRW forged pistons) and there is no ridge or any other wrong stuff in there other than the skirts of the piston seem a little scratcy i thought it could be the piston pin that would cause the noise, but why doesn`t it make the same noise than if you rev the engine in park, and why is this #5 piston free of carbon ? i am at a loss, please steer me in the right direction. Thank you in advance Dennes
- posted
19 years ago