Metal in the Oil

[carl hinkson]

Originally Posted by magnumv8

I am going to throw something out for you to check.....if you are running a timing chain and the block hasn't been align bored when you start your reassembly use a new timing gear and chain set....it almost looks like the timing set you had was "short" putting excess pressure on the bottom of your front cam bearing.....


D L Rambo.....

If a block is being line bored the operator should not be cutting the journals on the block side but only the caps, On performance engines the blocks should be finished with aling hone and not an align bore as most line boring machines can not cut all 5 journals with one set up.

As far as cam to crank center to center distance they are all over the place with GM OEM blocks we had pne a few years ago that was off .016.

When GM machine their blocks the cam tunnels can be off as they line bore with the cam bearings installed to correct to bad machining.

Try to by a GM OEM block with out cam bearings.

On the BBC we take and drill another hole appox. .3:30 grove the OD of the cam bearing between the 2 holes as we try to create another oil wedge before the load area. Make sure your using a performance cam bearings.

The edge loading on the main bearing maybe from tapered journal do to over polishing.