Is it a good idea to put some valve grinding compound on the sealing surface where a machined head and new cylinder come together and then rotate the head back and forth on the cylinder by hand?
Or is it better to install these in the motor the way they are?
The cylinders and pistons are new Mahle 97mm 3.3 turbo from a sealed box and the 1976 930 heads were machined some years ago.
Recently I had the small bevel around the combustion chambers that were originally on 95mm cylinders machined by xtreme heads so they would fit the 3.3 liter 97mm cylinders and pistons.
If it's good to hand lap the heads to the cylinders which of these compounds I have be best to use? Or is something else better?
The tube of permatex valve grinding compund is water based and old but it still squeezes out and the can is 150 grit grease based compound.
Here's pics of the grinding compounds I have and the sealing surface of a machined head and new cylinder.
Thanks in advance for opinions on installing them the way they are or should I hand lap the sealing surface to a uniform grey and wash them off first?
