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Old 10-09-2012, 04:21 PM
cdminter59 cdminter59 is offline
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tapping noise at 1500 rpms.

Originally Posted by Monte84 View Post
I have a sbc 383 with the same problem. I've reajusted rockers,and new plugs, but still have tapping noise at 1500 rpms. Noise sounds like in the area of 1 or 2 cylinder any suggestions?
Is this a new rebuilt engine, if not how many miles is on it. Did you check the rod bearings on #1 and #2 with plastic guage after hearing the tapping noise? It could be a wrist pin or piston slap. I remember the first time I rebuilt a 383 I took my block in to the machine shop and told them to check the block and bore it if needed. They told me It was fine just needed honing. I had just rebuilt this motor as a 350 and read about the 383 in a magazine. It ran fine with no tapping noise. I had the 400 crank turned and the block prepped by the machine shop. I had the old TRW 11.1 pistons. I even had my heads shave to give me more compression. Well when I got it running the first thing I heard was a faint tapping noise coming from the passenger side. I pulled the oil pan first checked all the bearings one at a time and retorqued. Rods were not hitting the bottom of the cylinders or oil pan rail. ??? I drove it a couple of times but the tapping was getting on my nerves. I pulled the heads and no valves were hitting, so I pulled the motor and disassembled it to take the block and pistons back to the machine shop. I knew the guy that waited on me and told him what was happening. He called the next day told me that # 2 cylinder and piston were out of round. Well what happened to checking the block to see if it needed boring. Ended up putting a sleeve in that cylinder and new piston. Sorry about the long story!!!
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