Chevs C60 and C15

[Mike K]

Just my thoughts. The original wartime GM 216 cast iron pistons are somewhat crude , they are heavy and are prone to problems , I have had loose wrist pin bushes and even heard of the top breaking off - they don't like excessive revs ( over 3000 ) for a extended period. Many restorers use the modern Alloy lighter pistons but reading the reports these can cause issues too, it seems that the older brands are more reliable than the modern examples.

I have some NOS wartime pistons and they do look a little rough , the casting of the skirts is not 100%. I will try to take a pic if I can find them.

Some opinions here: https://vccachat.org/ubbthreads.php/...m-pistons.html

With that broken piston , I have some .030" over NOS wartime pistons in sets but I'd hate to part with one piston and leave 5 orphans. First thing to do is measure the bores for wear with a bore gauge.

This might help, or maybe it won't ! https://www.youtube.com/watch?v=pSWZ5aOCPkM I noticed he is using a fibre timing gear, these gears can strip the teeth at any time, leading to a uncertain feeling each time you leave your driveway. I also wish he had not sped up the bit where he is measuring the conrod bores, it's impossible to work out what he is doing.