390 rebilt

[elvis67]

HI guys I search the forum for this cant find answer
I bought silvolite piston 1130 020 for my 390 and hastings rings. in the box there a paper that says hypereutectic piston require an increase in ring end gap of 40% more than original on top ring only ? Im in my first enging built a newbe is anyone know anyting about this?? see pic please
any help would be much appreciate thank you
ps search on google the only thing I saw is the say that the top ring on hypereutectic piston is closer to the top and heat more that s why they want more gap in top ring. but the distance of the top ring on my original piston is the same height see pic tanks

[Lee]

Hum,..... I am running the same pistons in my 390 except there 060 over.

I rebuilt the engine back in 2005,... and can't remember the ring gap issue you mention ... sorry.... but ,.... I would probably lean towards whatever the manufacture recommends.

I have 45k heavy towing miles on my rebuild without issue so I must have done something right.
Lee

[elvis67]

Thanks for your reply Lee
Finally got a answer from uem piston
They say if there a H after my number on the box it is hypereutectic pistons
And mine is 1130.020 so it is not. there are standard piston the gap of the ring is really .016 minimum Thank you