Simple piston ring installation?

[wmjinman]

It's not over yet!! They "say" they're gonna do right by me....

But I've dealt with these guys before, several times, and I think they're honest. On occasion, I might doubt their competence for awhile, but things always manage to end up ok - so far, at least.

I'm usually not too thrilled at how much I end up paying for what gets done, but then, it's the same with anyone else - - - mechanical repairs are just expensive.

[user removed]

Whew I probably should not step into this one . I never liked the idea of a hone and re-ring. You have a wear pattern with the ridge at the top of the cylinder and cylinders do not wear in a circular pattern, more oval with the least wear where the wrist pins slide into the piston. I have seen pistons burned down the sides from a hone a re-ring. New rings like to break fairly quickly when the now new top of the ring meets the ridge in the block.

The best way to check is to see if the ring end gap is still in specs. If not you need to do a thorough check over and probably bore the block. Why not since you are already there with most of the stuff removed already.

Warped heads due to overheating, or burnt valves and a lot of miles are all reasons to bore that block.

I never heard of a bent cam, at least in Nissans, but I have heard about a warped head that was surfaced and then it broke the camshaft in half a short time later. Most reputable machine shops know this and they will try to heat the head and get most of the bend out. then machine out the rest, but for cam in head engines the tolerances are low.

Another thing is to keep the old head gasket and match it to the new one, as well as the block, and head. You want to make sure there are no blocked passages with the new gasket. Sloppy work and debris can really kill this job very quickly.

regards
Mech

[wmjinman]

Thanks Mech. That makes a lot of sense. The mechanic insists the thing shouldn't need rings. No smoking apparent, smooth cylinder walls, VERY minimal "lip"....

And then when I suggested the "quickie re-ring" I'd read about, he said we'd really need to take the whole thing to the machine shop and "do it right". Then he repeated how nice the cylinders looked....

One question I have is why the oil seems to get black so soon. Could it have been from the out of tolerance valve guides, or does it mean soot & crud are getting past the rings? Or could it mean something else?

By "getting black soon", I mean well before I do the oil change (at 5000 miles). The oil in the other cars I've owned (newer cars in good shape) would be a bit dirty and definitely no longer "clear" by 5000 miles, but not "black". With this thing, the oil is actually BLACK.

edit:
PS: The thought of a head gasket problem blocking the oil to the cam occurred to me. The bearings on one end were ok, but the ones on the other end were screwed up. Dunno if that means anything. But with other engines, I've heard of getting the wrong gasket or putting in on backwards, or...

[MTXA]

Originally Posted by wmjinman

One question I have is why the oil seems to get black so soon. Could it have been from the out of tolerance valve guides, or does it mean soot & crud are getting past the rings? Or could it mean something else?

Worn out valve guides will cause oil contamination. If there is no indication of excessive bore wear, the fresh head by itself may slow the discoloration down.

I'm with Old mechanic 100% on doing a ring job properly. A car can become a money pit pretty quick by doing stop gap repairs.

[Miller88]

Oil will turn black as it cleans, or just from every day usage. Is it possible your engine is hard on oil? Or did it have previous sludge problems? I really wouldn't be concerned about an engine turning the oil dark quickly.

Get a used oil analysis done ... that will let you know if you have a problem.

[wmjinman]

I don't know if it had a sludge problem, as it already had 70,000 +/- miles on it when I got it. But the mechanic said there was no sludge under the valve cover or anything like that. The oil was black when I got it, however, so I did an oil change soon.

I had been thinking maybe this engine had higher loads, since it is small and presumably needs to "work harder". I really like my 5000 mile oil change interval, because it's so easy to keep track on the odometer "without thinking", but maybe I need to shorten it up to 3000 or something.

Maybe when and if I ever get it running again, I'll pay attention to how it looks at 3000. And with a newly reconditioned head on it, maybe it'll stay cleaner longer, too.

[wmjinman]

I guess a little "epilogue" wouldn't hurt. Turns out the head was not repairable, so we needed to look for another one. After a few days of dead ends and false starts, my mechanic LITERALLY stumbled over another complete engine, EXACT same version as mine except a year newer, in a local wrecking yard.

The story is it had been sitting there for 10 years. The car, a 2000, a year newer than mine, got rear-ended and totalled with only 7000 miles on it. For that whole time, I guess the engine had just been sitting there waiting for me.

So as of today, my '99 Swift has a 2000 engine with 7000 miles, a new clutch, new timing belt, water pump, alternator, & new axles. I drove it home and was very pleased. Good pep, quiet, smooth clutch, and 41+ MPG on the trip home (about 5 miles in mixed city/hwy driving).

So all's well that ends well.

PS: Oh, and also - the mechanic "took care of" the whole engine swap after the head repair went south. .... didn't ask for another dime.

To be fair to him, I volunteered to pay for a couple "extra" things that weren't part of the original deal (aka rebuilt head). That is, I got a new clutch & motor mounts, which I would have wanted had the original deal been to pull the engine, so I told him I'd pay for that.

[Frank Lee]

That should be a nice heart transplant.

[wmjinman]

I described it to someone as being like a 65 year old person getting a heart & lung transplant from an 18 year old!!!

[user removed]

Sort of like my 1994 VX that was hit in the rear end at 27,492 miles. Mine was inside an insurance training institute, so it was preserved almost to perfection. I drove it 10k miles on the original tires when they were 15 years old in 2008. Never got as good mileage after I replaced those tires. Sound like you have a great mechanic, personally I would give him some kind of gratuity.

regards
Mech