Rings: Buying Time, or Buying Headaches?

ah, yes. I spent the better part of the weekend tearing into the Galaxie to make way for new cam, lifters and manifold. I'm at a crossroads at the moment in that the heads are just sitting there waiting to be popped off- think I might have a couple of leaky valves- so I'm puzzling over whether it makes sense to borrow a ridge reamer and a hone and re-ring the ol' bastard.

she's an old and tired FE 390 and my wallet won't let me do the right thing and send the block off for a bore and new pistons.

my question is this: on an engine with fair-to-middling compression and about 120,00 miles, is it worth the gamble to put in new rings?

hmmmm?

 

I'm cheap so take this with a grain of salt

if it's not burning oil, you got good oil pressure and its not knocking I'd leave the bottom end alone otherwise you might shake your confidence in the ole engine, pull the heads and fix up them leaky valve problem and call it done

 

Found myself in the same delemma with an ol 428 once. Did the heads blah blah...big cam 510 lift 290 dur, adjustable rockers, duel quad intake. doug thorley headers..ran that engine 10 more years in a bunch of rides...no smoke no foul..oh an it ran like a scalded cat. Im with the cheapo on this one. save yer bucks for dingleballs...LOL..

 

The last time I bought a set of rings it turned out to be a bunch of headaches but we've stayed together through 30 years as of last Tuesday. She's put up with a lot of race cars, harleys and hot rods, not to mention all the beer that goes along with 'em.

 

A lot of good sence has been spoken.
If the General Health ( compression, oil consumption) is good, I'd leave it alone.
Once you open it up, your going to find all kinds of things that are going to make you say "HHmmmmmmmm?!"
Then you'll be doing a complete rebuild........

 

oh, she loves oil. STP, too. probably should have mentioned that earlier.

 

It was explained to me that when you grind the valves and valve seats, you increase the compression which will be wasted, blowing past old rings. In other words, do the valves and new rings. You must hone the glaze outa the cylinders first. You are 'freshening' the engine, not rebuilding it, but you still get out cheap. and.........ya know, if you put in new rod and main bearings.....you will be good for a long time. Do all you can while you are doing.

 

I think rings would buy you some time, but you might as well replace the Rod and Main Bearings while you're in there.

Several years ago, I had one that was burning oil, but otherwise ran good. I ground the valves and seats, cut the ring groove out, Honed the cylinders, replaced the Rings, installed new Rod and Main bearings, and got about two more years out of the motor.

 

I replaced the connecting rod bearings a year back, might take your advice and do the mains this time.

I think I'm going to go ahead and do rings....unless the Machine Shop Fairy leaves a .030 over freshly-bored block and a set of hypereutectic pistons under my pillow. thanks for the advice.

 

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The last time I bought a set of rings it turned out to be a bunch of headaches but we've stayed together through 30 years as of last Tuesday. She's put up with a lot of race cars, harleys and hot rods, not to mention all the beer that goes along with 'em.

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Amen, brother, Amen. It's only been 3 years for me tho.

Jay

 

I have to second the motion, when you do the top end only, you likely blow out the bottom (rings just won't handle the extra compression). So good chance it will still smoke.

When cylinder bores wear out, they get a taper, larger bore at the top, smaller at the bottom. A hone and moly rings will work, but they ovbiously won't last as long. The rings wear faster because they are constantly expanding and contracting, traveling through that tapered bore.

But if they last 2 or 3 years, what the heck, that might be enough time to save up for the complete rebuild later.

 

I know I did a bunch of head work on an old 62 galaxie, didn't last long till it blew the rings out, smoked like a train. Throw some rings in it while you are there, thats my 2 cents...

 

sadness....

I pulled the heads, found a couple problem valves. one exhaust has a chunk missing about 1/4 by 1/16, another's so garked up with carbon it's not quite seating.

but the big bad news is I miked the bores.....book sez .005 is acceptable taper. I've got .012. da-a-a-mn.

the ugly reality sets in...

 

If I were going that deep in the engine, I would pull the pan and pop a main/rod cap to see how the bearings are going... no sense dropping in some cash if its gonna eat its self...

 

[ QUOTE ]
If I were going that deep in the engine, I would pull the pan and pop a main/rod cap to see how the bearings are going... no sense dropping in some cash if its gonna eat its self...



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those look good but it's of no consequence now as the thing needs to come out and be stripped down. it needs machining.....when I can afford to do so.

just wish I had something to drop in there in the meantime.