850 Cylinder wear
- Thread starter MS850
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If you do have the rings that came with the pistons, just for the heck of it measure the depths and compare.
Also, in the two pics of the expanders, the Hepolite from Danno appears to be the far better piece compared to the Hastings. Much more prominent and sharper ridges at the inner circumference would more positively located the scrapers I would think. I wonder if the Hastings unit were setting up some sort of a "flutter" because of poor scraper to expander relationship? How does the other cylinder compare?
Also, in the two pics of the expanders, the Hepolite from Danno appears to be the far better piece compared to the Hastings. Much more prominent and sharper ridges at the inner circumference would more positively located the scrapers I would think. I wonder if the Hastings unit were setting up some sort of a "flutter" because of poor scraper to expander relationship? How does the other cylinder compare?
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Biscuit said:
The wear pattern on MS850's cylinder walls are from the fact that the expander puts pressure on the backside of the rail slightly unevenly.
The initial wear is at the points where the pressure from the expander is the greatest.
We are talking about wear that is visible -but so small it is virtually un-measurable. Just shiney spots.
As the rings and bores break-in the wear pattern will become even and you will no longer see the streaks.
I have seen this pattern before with some types of rings and yes I do prefer the original Hepolite ring set.
But give it a few thousand miles, instead of two thousand miles and they will look great. Jim
Danno said:For Bill; 750 Norton Hepolite 3-piece oil ring spacer. Should I mail it to you so you can examine it more closely?
I thinks YOU should look at your 750 3 PIECE OIL RING EXPANDER very closely, assemble it up and see how it works, better still cut 1'' off the ends and assemble your engine with it.
I reckon the the hone patterns to coarse and chattery, the white discolouration is has come from the oil control rail finish, used to be chrome type of finish, cooking itself to the bores, you didn't submit to the dry ring start terrorists by any chance did you ?
no need to mail it as dances has already pointed out to you and as i have tried to show you the vertical tabs on the inside circumference is where the rails receive there outward pressure.
Danno said:For Bill; 750 Norton Hepolite 3-piece oil ring spacer. Should I mail it to you so you can examine it more closely?
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splatt said:Danno said:For Bill; 750 Norton Hepolite 3-piece oil ring spacer. Should I mail it to you so you can examine it more closely?
I thinks YOU should look at your 750 3 PIECE OIL RING EXPANDER very closely, assemble it up and see how it works, better still cut 1'' off the ends and assemble your engine with it.
I reckon the the hone patterns to coarse and chattery, the white discolouration is has come from the oil control rail finish, used to be chrome type of finish, cooking itself to the bores, you didn't submit to the dry ring start terrorists by any chance did you ?
I don't have a 750 any more, just leftover parts from an old top-end overhaul. My 850, which got top-ended more than 20 years ago is running just fine and I never advocated cutting anything. I think YOU should read the individual posts as you are mixing them up. And maybe YOU should do the spring scale pull test and actually prove or disprove what you are probably just repeating from the words of someone else. Which you also may have gotten mixed up.
Danno said:
Don't know how one would accomplish this as the expander also does indeed has a duty to positively locate the scrapers on the roof and floor of the oil groove. Without an expander they would just fold up. The part in question does two things I suppose.
It keeps the scrapers located (separated) so it's a separator.
It exerts pressure to the scrapers by expanding them outward so it's an expander.
It's an expanderator. Or maybe a seporander.
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I don't think spring steel scrapers would fold up. They'd just slip to the top land of the oil ring groove and stay there as long as the spring scale kept pulling on the wristpin. There's enough outward tension to keep the whatchamacallit snug against the inside edges of the scrapers, but I'd bet anyone here a case of beer it's like the fly bending the steel bar; not enough to measure. Do the test and prove me wrong and I'll buy you a case of your favorite beverage. Show no measureable difference and you owe me one. Put your beer money where your mouth is.
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