Hi people
I am just in the process of rebuilding a grey motor at 40thou over. My holden manual is missing the engine specs page and I am unsure of what gap to file the rings to. The motor is a 138 taken out to 40thou.I am using hastings rings. The rings alone cost $200.00 so I dont want to make a mistake when setting the gap.If anyone out there has any knowledge I would greatly appreciate it.
G'day pat1961,
From memory the end gap should be .004-.007 thou per inch of piston.Hopefully someone can confirm this for you.
Have you tried contacting the the supplier of the rings?
Regards roto
.005 per inch of bore is nice and safe. going bigger is better than too tight. the difference in 015 gap to 020 gap makes no difference in performance or blowby at all. even up to 030 is ok on a 4in bore, theres alot of hype and bullcrap about ring gaps, bore finish and type of ring is far more important, been there done that
