Topic: plastigage ?
in Forum: C3 Engines
Rebuilding motor, had crank polished and they mared two of the serfaces, so i took it back and they had to polish it some more to get them out. So when i put the crank in I plastigage it, one of the mains they nicked gages .003 now, is this acceptable? what is ideal, what are the limits.
Lifetime MemberModerator
#s 2-3-4 should spec at .0010" - .0023"
and the #5 main should spec at .0017" - .0033"
So, it kinda depends on which journal you have the issue with. You can get oversized bearings, and "polish" them with a scotch-brite pad, if needed. Not the way I would recommend, but it is an alternative. Otherwise, I think I would look into having the machine shop FIX their screw-up with either re-machining the crank and supplying new bearings, if possible, or replacing it.
oh, and it's kstyer(Ken) that Scott was referring to.
Joel Adams
C3VR Lifetime Member #56 
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"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
The main at .003 is #1. Here is the whole deal, I took my block and crank to napa mech. shop. They bore the cylinders 30 over and check crank, they said crank good and just polished it. they tell me I can order parts. bring parts ($270 summit), they press pistons on to rods, cam bearings, freeze plugs, bore, crank $400. Heres what i get. Scored cylinder wall and mared crank. they said they will fix. What should i do?
Lifetime MemberModerator
If you're not comfortable with the shop, and we can all understand why/if you're not, at this point, then the only other option you have is to take it to a different place for the machine work. Believe me, I've been thru the the same crap too many times in the past...machine shops with Bubba working the equipment...
It's your call, but I think I would be looking for a new machinist, as much as it sux to have to lay out more $$$.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Lifetime MemberModerator
Can the block be bored to fix it, or is that out of the question, considering the added expense of new pistons/rings?
Man...that whole situation sux a big one.
Joel Adams
C3VR Lifetime Member #56
My Link
(click for Texas-sized view!) NCRS
"Money can't buy happiness -- but somehow it's more comforting to cry in a CORVETTE than in a Kia"
Yes the cylinders were standard bore so they took them to 30 over and then yes the money for the pistons, rings, main bearings, and I guess the cam bearings need to be replaced again, wont they get messed up while boring? Man if I can just get my money back on all, yes this does suck @I$#.