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rod · 05-02-2012, 04:01 PM

sometime back i posted about shortening a pin. this is a forged TRW piston with a 3" Chevy pin.
what i want to do is place 2 .042" Tru-Arc lock rings on each side of the piston. i have now done some serious measuring and i find that there, for whatever reason, is a large amount of end play between the pin and the OEM single lock ring groove, .029" to be exact.
so, if i widen the original groove to the outside by .0275" i can get the 4 lock rings in, and not have to shorten the pin.
this leads to a whole new question. there will be approx. .0875" of material remaining between the outside of the lock ring and the flat face area [on the outside] of the piston.
the question then , is .0875" enough material to hold the ring in place and not be hammered out? currently, in unmodified form there is .111" of material.
.111"-.0275" = .0875"

thanks rod in AZ

05-02-2012, 04:01 PM	#1
rod Member Join Date: Dec 2009 Location: Kingman, NW AZ. in the middle of the longest stretch of Route 66 Posts: 315 Likes: 0 Liked 20 Times in 15 Posts	2nd. piston pin ? sometime back i posted about shortening a pin. this is a forged TRW piston with a 3" Chevy pin. what i want to do is place 2 .042" Tru-Arc lock rings on each side of the piston. i have now done some serious measuring and i find that there, for whatever reason, is a large amount of end play between the pin and the OEM single lock ring groove, .029" to be exact. so, if i widen the original groove to the outside by .0275" i can get the 4 lock rings in, and not have to shorten the pin. this leads to a whole new question. there will be approx. .0875" of material remaining between the outside of the lock ring and the flat face area [on the outside] of the piston. the question then , is .0875" enough material to hold the ring in place and not be hammered out? currently, in unmodified form there is .111" of material. .111"-.0275" = .0875" thanks rod in AZ