[KeithD]

put a top end in a 500ss, set ring gap at.18, sled did not run right would die after warming up and had low compression (90 psi) especially on mag side, thought maybe I had the ring upside down, took it apart and now the ring gap is huge? Like 1/4 inch. Old ring still fits fine, how did I wear down my ring in a few heat cycles and test rides? I’m certainly no engine builder so feel free to explain it to me like I’m 5.

 

[DOOLIFE800]

Did you hone it before you put the ring in it? And if so how coarse? In other words too course may have worn it fast. Is it a cast iron bore or a coating? Maybe look closely at the ring and see if it's wearing excessively somewhere like maybe the exhaust port side. If the cylinder is worn badly especially by the small Port Bridge area where the ring rides I wonder if the exhaust port could just wear it fast as it comes up and it's expanded into those Bridge areas. That's where I see my coated cylinders losing all its crosshatch first. OEM ring? Is it consuming the right amount of oil? In other words if that's not feeding right could be wearing things fast? I'm just throwing stuff out there.

 

[KeithD]

It’s iron not coated. I used a ball home to tidy the cylinder up medium grit. It doesn’t have enough miles on it to know oil consumption but it was working properly before, lol pump was never touched.


Wasn’t excessively course but I guess that could make sense. It was a quick job to try to get back on the trail, the cylinders will go the machine shop now. Probably better to just start with a fresh bore as they have one size left.

 

[Backwoodsriding]

When you are measuring the ring gap are you squaring the ring up in the cylinder using the piston to push it up from underneath?

 

[KeithD]

Yes it’s square in the bore using the piston. Even the pto ring is at the top end of wear spec now, it had about 125 psi before disassembly.

These rings did not look like this 30 minutes of wear ago. I’m not going to devote too much mental energy to this just curious if anyone has had similar.

 

[thinksno]

Ball hones can really cut, hatch will settle down during break in. If hatch was deep then it might be time to measure bore?

 

[skipower]

If the bore is 3" you would have to enlarge the bore about 1/12 inch (.080) to enlarge the gap 1/4 inch. There would be zero compression. There is something else going on I think.

 

[KeithD]

If the bore is 3" you would have to enlarge the bore about 1/12 inch (.080) to enlarge the gap 1/4 inch. There would be zero compression. There is something else going on I think.

The bore is the same size (76.5mm) and the old rings are still within the upper end of spec, these new rings just wore down like absolute crazy. Now it was a real bear to restart and turns out the choke was stuck on, is it plausible that the extra fuel dumping in the cylinder washed all the oil off causing the ring to wear especially fast? The piston coating is almost completely gone which I don’t think should happen with 30 min run time.

 

[nm9stheham]

How did you clean the bore after the honing? If it was not thoroughly cleaned with ATF or a fluid meant for bore cleaning, then the grit left may be a cause. Lots of fuel would cause some piston scuffing, I would think. but if those are good and the bore is good like it sounds, that seems like not an issue.

In your pix, is the light silver edge color on the outer edge of the ring is all gone in the 2nd pix? It is almost like a real thick coat of moly got on the outer edge of that ring and all wore off. Does the ring in the other piston have the silver edging? How do the ring widths compare?

Never have seen anything close to what you show.... That is indeed special ! Never seen this size of gap with auto and truck engines at well over 100,000 miles run on oil crappy Quaker State oil LOL. What does the 'Made in -----' say on the box?

 

[Jetblack3]

2nd pic looks like it had a bad filing job done to it ?? / Nothing squared off. As long as bore is stock whatever pistons and rings that were sent to you should have been in spec right out of the box.

 

[KeithD]

How did you clean the bore after the honing? If it was not thoroughly cleaned with ATF or a fluid meant for bore cleaning, then the grit left may be a cause. Lots of fuel would cause some piston scuffing, I would think. but if those are good and the bore is good like it sounds, that seems like not an issue.

In your pix, is the light silver edge color on the outer edge of the ring is all gone in the 2nd pix? It is almost like a real thick coat of moly got on the outer edge of that ring and all wore off. Does the ring in the other piston have the silver edging? How do the ring widths compare?

Never have seen anything close to what you show.... That is indeed special ! Never seen this size of gap with auto and truck engines at well over 100,000 miles run on oil crappy Quaker State oil LOL. What does the 'Made in -----' say on the box?

Cleaned in hot soaping water. They were pretty spotless going back together and like I said this was a job to try get me on the trail otherwise I would have taken the cylinders in. The pto side ring has similar wear and is over spec now too. Not by nearly as much. I just assume everything is made in China today, they were Pro-x pistons and rings, which I believe are wiseco value line.

2nd pic looks like it had a bad filing job done to it ?? / Nothing squared off. As long as bore is stock whatever pistons and rings that were sent to you should have been in spec right out of the box.

The ring ends do have some marring on them that most certainly wasn’t there on assembly. The pistons that came out were .5mm (.020 over) and that’s what back in.

I think I’ll just have them bored to 77mm and go to 1 mm oversized pistons, start fresh. Mag side crank seal was leaking too which was nice to catch.

 

[nm9stheham]

Next time.... I'll suggest using ATF to clean the bores, even after the hot wash. Even hot soapy water will not do nearly as good a job of getting fine grit out of the honing 'grooves'.

ATF has a super high level of detergents that makes it work so well. I use it on every bore, even after solvent washes at the shop and hot water washes at home and it's surprising what ATF will pull out. I find that it takes 3-4 passes with ATF soaked paper towels in each bore before the last pass comes out with no more dirt/grit.

 

[KeithD]

Next time.... I'll suggest using ATF to clean the bores, even after the hot wash. Even hot soapy water will not do nearly as good a job of getting fine grit out of the honing 'grooves'.

ATF has a super high level of detergents that makes it work so well. I use it on every bore, even after solvent washes at the shop and hot water washes at home and it's surprising what ATF will pull out. I find that it takes 3-4 passes with ATF soaked paper towels in each bore before the last pass comes out with no more dirt/grit.

Thanks this is a good advice!!

 

[LETMGROW]

A ball hone will leave a rough finish. Like a mini grindstone. When we bored a cylinder, afterward we ran a hard hone through the cylinder but this was in a honing machine with fluid running into the cylinder throughout the whole process. This was done to assure there was no taper in the cylinder from the boring. Next the cylinder got a flex hone and lastly and very importantly the cylinder got a plateau hone run through it to smooth out any sharp edges. Rings didn't need any break in or hardly at all.
Every cylinder or engine block went through the blast cabinet then the cylinder(s) got a through cleaning with a mixture of ATF and Mineral Spirits on a soft cloth.
You won't know it in a 2 cycle engine but there is a significant tell tale sign in a 4 cycle engine. If the cylinders are properly prepped after boring and (or) honing, the engine oil will look clean after draining it the first time. If not properly prepped the oil will turn black from the shaved metal particles and the worn rings.

plateau hone at DuckDuckGo

DuckDuckGo. Privacy, Simplified.

duckduckgo.com

 

[Meat Head]

Ball hone only to de glaze for new rings to seat. Should not need more than 5 down and up motions to complete the process on iron.
I've done a few plated with a ball hone, 2 strokes and done. Run a test on a personal sled several years ago. Still running today with great compression.

 

[Daag44]

From 0.018" to 0.250" that is a lot of wear. Can there be that much wear on a ring without destroying the cylinder and crankshaft bearings?

 

[KeithD]

From 0.018" to 0.250" that is a lot of wear. Can there be that much wear on a ring without destroying the cylinder and crankshaft bearings?

The cylinder looks fine to my eyes, I’ll let a machine shop measure it properly, the crank also appears fine, loads of iso in the bearings which all are smooth and quiet, is there really any other way to check a bearing? The question remains, where did the worn metal go??

 

[Daag44]

The cylinder looks fine to my eyes, I’ll let a machine shop measure it properly, the crank also appears fine, loads of iso in the bearings which all are smooth and quiet, is there really any other way to check a bearing? The question remains, where did the worn metal go??

I am still stuck with how was this even possible??? The only thing that I can think of is if there were high peaks that worn down, but again is this even possible??? It isn't like you are adding material, but rather removing!

I echo skipower in post #7 that something else is going on. How about measuring the width of the ring? To have worn that much it must be a lot more narrow, yet it appears the same in the picture. Since the old ring still fits fine, is one bore smaller? This reminds me of the games to spot the differences in two pictures lol

 

[KeithD]

The offensive ring is approx .4mm smaller in width than the old ring. But I don’t know what the comparative measurement is/was pre install as I didn’t measure the width before so I don’t know how much that indicates.

both cylinders measure at 76.5mm(at the top, with calipers) and ring sizing behaviour is the same in both cylinders for all rings/pistons which says to me the cylinders are the same.

what I’m left with is possible options of
-my ball hone left too rough cylinder
-possibly excess grit left from improper cleaning
-excess fuel from stuck choke washing pre-assembly oil from walls
-possilbly missed the ring locate pin causing ring to spin and wear (it’s tough but I can get the cylinder back on, during diassembly the gap was close to the pin but I can’t say with 100% certainty)
-uncertainty of exact roundness of cylinder
Some or all of these caused the rings to wear excessively fast causing low compression on the mag side.

I am still stuck with how was this even possible??? The only thing that I can think of is if there were high peaks that worn down, but again is this even possible??? It isn't like you are adding material, but rather removing!

I echo skipower in post #7 that something else is going on. How about measuring the width of the ring? To have worn that much it must be a lot more narrow, yet it appears the same in the picture. Since the old ring still fits fine, is one bore smaller? This reminds me of the games to spot the differences in two pictures lol

 

[Daag44]

This may be one of those cases when we are left to grasp what we can to make the best of future rebuilds. At least for me I am having to rethink my own methods and approach. ATF and Mineral Spirits? Like many others I am following and learning. I find myself lucky to have access to such experience on DooTalk.