re-ringing a short block, cast or moly rings?

Posted By: patrick

re-ringing a short block, cast or moly rings? - 07/06/09 04:50 PM

short block in question is a 1986 vintage 318, 76k miles on it.

there is no ridge detectable with a fingernail, and you can still see the cross hatching

I wasn't really planning on even touching the rings, but last year I sold the '302 heads off the motor, and apparently I didn't do a super job cleaning things up after I took them off and there was a little bit of coolant sitting in the #4 and #6 cyls. I can't feel anything with my finger/fingernail, but there is some slight discoloration in the cylinders, that's why I'm thinking of tossing new rings in.

should I leave it as is, or toss some new rings in it while I have it apart?

I have one of those 3 finger, spring loaded hone/deglazers that I can run through the bores to clean it up, or I know someone with a ball hone that I can borrow. which would be better? also, if I toss new rings in, should I get plain cast, or plasma moly coated?

thanks in advance.

Posted By: MoparforLife

Re: re-ringing a short block, cast or moly rings? - 07/06/09 05:11 PM

For the amount of miles these engiens will get I would run a deglazing hone through the bores and put a fresh cross hatch in and new rod bearings and a set of less expensive cast rings and be don with it.

Posted By: HealthServices

Re: re-ringing a short block, cast or moly rings? - 07/06/09 05:17 PM

If you are not re boring the holes with new pistons get the plain iron. It will seat easier.

Posted By: patrick

Re: re-ringing a short block, cast or moly rings? - 07/06/09 06:12 PM

Quote:

For the amount of miles these engiens will get I would run a deglazing hone through the bores and put a fresh cross hatch in and new rod bearings and a set of less expensive cast rings and be don with it.

I'm going to pull the pan and check the rod/main bearings. last time we tore apart one of these was back in high school, my dad's '85 5th ave had 150k miles on it, we pulled it out to fix some oil leaks, popped the main and rod caps and checked them, all were still within spec.

Posted By: patrick

Re: re-ringing a short block, cast or moly rings? - 07/08/09 01:21 AM

question #2 get stock bore 3.91" rings, or 3.915" rings (.040 over 283 chev rings)and file fit them? they're about the same price

Posted By: RapidRobert

Re: re-ringing a short block, cast or moly rings? - 07/08/09 01:27 AM

Quote:

question #2 get stock bore 3.91" rings, or 3.915" rings (.040 over 283 chev rings)and file fit them? they're about the same price

good idea & I am in the minority on this but I would not hone it & get plasma moly and read "breakin secrets" @ www.mototuneusa.com

Posted By: patrick

Re: re-ringing a short block, cast or moly rings? - 07/08/09 01:45 AM

well, I spent some time in the garage tonight looking at it closer, and there are some pits in the 2 cyls, so I'm definitely going to clean them up and put new rings in...hopefully they'll clean up, as I really don't want to afford new pistons and a bore job....

the wife won't like it if I have to bore w/pistons

Posted By: DaytonaTurbo

Re: re-ringing a short block, cast or moly rings? - 07/08/09 04:26 AM

Quote:

good idea & I am in the minority on this but I would not hone it & get plasma moly

I've heard you and a few people on other websites say to do this as well, but I have yet to actually hear from someone who's put moly rings in a glazed, shiney cylinder. Until we can hear some real-world results, I'll have to say to stick with the cast rings and a drill hone job. They say cast rings do a better job of sealing to a worn cylinder, although if the factory crosshatching is still visible that's not your problem(also why I would not bother with file fit rings in your application). Anyway the cast rings with a drill hone are a proven time and again way of doing it.

Posted By: Bill MeLater

Re: re-ringing a short block, cast or moly rings? - 07/08/09 03:39 PM

Quote:

Quote:

good idea & I am in the minority on this but I would not hone it & get plasma moly

I've heard you and a few people on other websites say to do this as well, but I have yet to actually hear from someone who's put moly rings in a glazed, shiney cylinder. Until we can hear some real-world results, I'll have to say to stick with the cast rings and a drill hone job. They say cast rings do a better job of sealing to a worn cylinder, although if the factory crosshatching is still visible that's not your problem(also why I would not bother with file fit rings in your application). Anyway the cast rings with a drill hone are a proven time and again way of doing it.

Here's a pic of mine round 500 miles on it. Ball honed stock bore w/speed pro moly file fits. Seated real quick. I was gonna go w/iron but couldn't find file fits. Bores were nice and round but had .002-.0025 taper so standard ring set end gaps would have been stupid. Ran great untill I holed the radiator, overheated it and hung a couple of valves. Minimal damage though, should be up again by this weekend.

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