70 engine noise

[Bob in Mi.]

I have a 70 standard with fiarly loud engine knock. My first guess was rod. So I pulled the pan checked in the bottom for pieces- none. Don't see any shavings or much in the way of silver color. Rods all seem to good and tight. Not a lot of end play in crank. Can see what appears to be copper colered bushing edge (?) near front of motor on crank. Wires on main bolts, coter pins in rod caps. Any thoughts?

 

[Anonymous-0]

wrist pin? maybe

 

[J. Wondergem]

I had a 49 Chevy truck once that had a broken motor mount, and I thought it was a rod. It would knock only when the revs went up.

 

[Anonymous-0]

I just tore my 70 apart as well. I wasnt planning on it but my bushings for the wrist pins were shot. The guy i took it to asked if the motor was making any noise. I said no. He said well then it was just about to as loose as the piston was on the rod.

So im thinking thats whats wrong with yours. I got bushings for about $100. Might as well check you rings while youve got the pistons out. Why not the bearings to?? Turns out on mine I have to do all 3 that i just mentioned!!! Turning out to be an expensive project!

 

[Brian Jasper co. Ia]

I just rebuilt a 60 that knocked a little. Crank and rods were not that bad. The wrist pins were in real bad shape. Better pop the pistons out and check them.

 

[hoader]

If you do pull the pistons, You may as well check the rod and main bearing clearance. Just clean the inserts and the caps and use some plastiguage to measure clearance.
George.