Bought a set of NOS pistons for a 54 302, nice looking pistons, however they have 4 rings, 3 compression and 1 oil ring. Wondering if they need 3 compression rings ? Modern pistons have 2 compression rings, is it a case where the modern rings are better quality? Can they be installed with 2 rings rather than than 3?
Why would engineers go to the trouble to design a 4 ring piston, and produce rings for it, if it wasn't necessary? Actually, that third "compression" ring is a "scraper" ring that seals compression on the upstroke, and flexes to catch any oil that the main oil control ring misses on the downstroke. Of course, those engines were designed to work for a living, not ride a trailer to a car show a couple of times a month! Jerry
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I installed a set of 1950 Chrysler pistons in my 216 with the 235 crank and rods. They had 3 compression rings and an oil ring. There were no markings on the compression rings indicating which way was up, indicating they were symmetrical and could be installed either direction.
Kevin 1951 Chevy 3100 work truck Follow this saga in Project Journal Photos 1929 Ford pickup restored from the ground up. | 1929 Ford Special Coupe (First car) Busting rust since the mid-60's If you're smart enough to take it apart, you darn well better be smart enough to put it back together.
Dave - Not sure if the 1955-59 GMC Shop Manual info is the same as your '54 302 (?), but I found the below diagram on the 4 ring setup that might offer more info on your question. The diagram and the details of piston ring fitting can be found on Page 387 of the 1955-59 GMC Shop Manual which covers models 100-500 and the 302 engine.
~ Dan 1951 Chevy 3 window 3100 Follow this story in the DITY Gallery "My Grandpa Carl's Truck and How it Became Mine" 1966 Chevelle (Wife's Hot Rod) | 2013 Chevy Silverado (Current daily driver) US Army MSG Retired (1977-1998) | Com Fac Maint Lead Tech Retired (1998-2021)
Bought a set of NOS pistons for a 54 302, nice looking pistons, however they have 4 rings, 3 compression and 1 oil ring. Wondering if they need 3 compression rings ? Modern pistons have 2 compression rings, is it a case where the modern rings are better quality? Can they be installed with 2 rings rather than than 3?
where did you get them, if i may ask? i've been looking for a set, i believe my block is std. bore but would like a .010 or over set. Jay D.
