Strange Engine Noise - Rod Knock?

Anyone experience the same pushrod interference issues?
When reassembled, I will definitely turn the motor over, fingers on the rockers to test for interference.

I got 40 minutes into the teardown and 2+ hours in cleaning the sealer off the cases/barrel.
Previous mechanic used threebond/yamabond type sealer on the base gasket. Not a good idea. A pain to clean between the studs and not get sealer/gasket particles into the case. Used the rear nuts to separate the barrel from the case.
 
I would check the piston to bore clearance before you put it back together.

Pushrod to head rubbing is fairly common. Use a carbide bur to remove some material from the head where it was rubbing.

I do not think that was the source of your noise.
 
Anyone experience the same pushrod interference issues?
When reassembled, I will definitely turn the motor over, fingers on the rockers to test for interference.

I got 40 minutes into the teardown and 2+ hours in cleaning the sealer off the cases/barrel.
Previous mechanic used threebond/yamabond type sealer on the base gasket. Not a good idea. A pain to clean between the studs and not get sealer/gasket particles into the case. Used the rear nuts to separate the barrel from the case.
Have you solved the problem?.
Ciao
Piero
 
Yes. Pistons were very worn out and were installed reversed from their normal wear pattern. Loose piston caused the noise. From memory, clearance was around .008 and .010!

For amusement, I turned the pistons around and the noise is almost gone. For now.

Looking for a NOS set of Atlas dished pistons.
 
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