TS Ring End Gap

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RoadScholar

RoadScholar

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During the measurments phase in pre-assembly I came up with .022 end gap for the top ring, which is a conventional ring, and .023 for the gapless two piece second ring, I didn't measure the rail.

These rings are going on JE forged pistons (.020 oversize) which have a .0052 clearance with the bore.

Using the factor supplied by TS multiplied by the bore the ring gap should be .013, but they also say .015 at a minumim, a bit confusing to say the least.

Many of you have had experience with TS rings and rings in general; my intention is to bolt this engine together once.

Your thoughts please.

RS
 
Never used gapless rings but FWIW current engine building thought for "normal" rings is for the the top ring gap to be WIDER then the 2nd ring gap (and piston rings installed dry in the bores - at most just a smear of oil on the piston skirts). It has been found to eliminate ring flutter - a common cause of poor sealing/excessive oil use and make break in virtually instantaneous. Lot of data about this from ring manufacturers for anyone interested in searching.

When I rebuilt my 850 last year the above was the process I used. Nothing blew up! :)

Sorry, I realize that doesn't address the question but thought it might be of interest.
 
RS, ring gap is a concern to hi heating Ms Peel as well as best compromise of proper set up internals. There are formula's for ring gap by the bore and type of rings as well as the rpm and heat/pressure loads. I'm not sure if I lost my files on ring gaps but will start reviewing this for my own needs and let ya known if useful for non extreme set ups. I've called TotalSeal on this in past so you might also to get scope of variables to set your gaps to. Basically lower stress > lessor gaps, higher stress - bigger gaps, same with piston clearance too. If you come across useful references before someone else please share it here. Anyone can turn a wrench but real mechanics know how much to twist and what to set clearances too. I'm still working up to think of myself as much more than monkey with a tool kit.
 
Thanks Hobot!
Your words mirror the instrucion sheet and are detailed as well...The manufacturer has supplied the formula (street, strip, circle) which in my case is: bore x .0045 Top ring, bore x .0035 Second ring, and Oil ring = min .015.; My bore, according to Leo goff is 2.8973 (both sides), doing the math my top ring should be .013 end gap; it has a .023 gap, the second ring should be .010; is has a .024 gap, I haven't measured the oil control rings.

TS adds in bold lettering at the top of their page: "Caution... These Are File-To-Fit Rings!!! I'd be inclined to purchase the 3rd oversize rings and file them down, but the arcs should/would be all wrong.

This is an area where the experienced tuner/builder rules, possible a "black"art; I'm good, but my resume wouldn't get me an interview with any professional racing organization. I don't need this engine to win races to eat I just don't want it to look like a misquito fogger...

RS
 
RS, No, thank you for actual formula vs my blurry over view. I don't know how to file less gap in a ring ugh. Blow by, oil contamination and less power increase with too much gap- duh. TS likely has proper same OD rings with no-nil gap to supply so DIY can follow their instructions. Be sure that you are not confusing instructions for water jacket engines vs non written special instructions because you asked for rings for air cooled engine and they knew what to supply. More hassle to have TS tech staff check this out and replace rings it need be. Peace of mind and good fit is part the reason we get so intimate with out Commandos.
They get pestered by Nortoneers for decades now so bet ya they are aware, but why guess. I once read up on how to best file ring gap but forgot as just using out the box rings on plain Trixie but Peel is using Schimdts kit - so I will apply the formula then add the rule of thumb fudging of gap for boosted air cooled to see if wise to open her gaps more. I should call them any way might learn me stuff like you.
 
Bill, I wouldn't be concerned about the extra clearance on the second ring but the top ring is a bit too wide for my liking. You can definitely file down the next oversize ring to get the correct clearance. Total seal tends to make their rings on the short side when your setting clearance for forged pistons in a Norton. Jim
 
comnoz said:
Bill, I wouldn't be concerned about the extra clearance on the second ring but the top ring is a bit too wide for my liking. You can definitely file down the next oversize ring to get the correct clearance. Total seal tends to make their rings on the short side when your setting clearance for forged pistons in a Norton. Jim
Click to expand...


Thats because the pistons are not sized correctly for a standard bore, were the ring are,your bores are nearly 0.003'' oversize,this is something that I feel JS should be addressing, the problem with the standard NORTON rings is they use an imperial ring in a metric bore, if you can find a 73mm +0.30'' ring that fits ,your bores are already half way there.
 
Thats because the pistons are not sized correctly for a standard bore, were the ring are,your bores are nearly 0.003'' oversize,this is something that I feel JS should be addressing, the problem with the standard NORTON rings is they use an imperial ring in a metric bore, if you can find a 73mm +0.30'' ring that fits ,your bores are already half way there.[/quote]

That is right, it's because JE says their piston can be fit at about .0025 clearance. I know people who have tried them at .0025 and the result was instant seizure on the first startup. Anything less than .005 is seizure and you better be careful from .005 to .006. I fit them at .006. Jim
 
Remember that you cannot buy a set of the next larger size rings and file them to fit; it won't work. Rings designed to be filed to the proper gap (the best way to do it) are made for the size bore involved and are simply longer. For example, if your bore is .020 over and you buy a set of rings for an .030 oversize bore, planning to file them for the correct end gap,, they will not seal properly because they are made for a different circumference - they will not seal against the bore all the way around.
 
mike996 said:
Remember that you cannot buy a set of the next larger size rings and file them to fit; it won't work. Rings designed to be filed to the proper gap (the best way to do it) are made for the size bore involved and are simply longer. For example, if your bore is .020 over and you buy a set of rings for an .030 oversize bore, planning to file them for the correct end gap,, they will not seal properly because they are made for a different circumference - they will not seal against the bore all the way around.
Click to expand...

I have asked this question of Total seal. They said file fitting .010 oversize was fine and .020 was marginal. They did not recommend file fitting rings designed for more than .020 over the bore size.

I have seen it done with rings that were .060 oversize with no apparent problems but i wouldn't recommend it. Jim
 
Well, I wouldn't argue the point with a ring manufacturer but I don't see how a "perfect seal" could possibly occur between two circular items that are of different diameter. Basically, you are going to get a seal at two points but I guess they have found it works sufficiently well. But maybe the should call the rings "Good Enough Seal" instead of "Perfect Seal." :)
 
I suspect the rings are flexible enough to handle the slight change in geometry. I have file fit .010 oversize rings regularly for many years after talking to them and had very good results.

The oil ring is a different story. I would not attempt to use an oil ring designed for a larger bore. Jim
 
mike996 said:
Well, I wouldn't argue the point with a ring manufacturer but I don't see how a "perfect seal" could possibly occur between two circular items that are of different diameter. Basically, you are going to get a seal at two points but I guess they have found it works sufficiently well. But maybe the should call the rings "Good Enough Seal" instead of "Perfect Seal." :)
Click to expand...

The actual combustion pressure acting on the top ring is very significant and will deform the ring to the bore somewhat, but on top of that the bore will not be round during the combustion process either.... so yes good enough is the best way of looking at it!!
 
I spoke with Jim Schmidt about this earlier in the week; he pointed out that he runs the same set-up in his street bike and has had no issues and highlights the fact that leak-down is considerably extended (over non-TS rings) and that he had made calls, on my behalf, to Total Seal whose Tech section pointed out that the end gap (mine at .023--top ring) was within SAE guidelines. I just got and e-mail from Jim (super customer service and thanks Jim for the follow-up!!) on the subject:

"I had a customer in Canada who had the same ring end gap clearance concern. He also had gapless totalseal rings. When the build was complete he was very happy with the results - seal was tight. Regardless - I will be making changes in the Future to tighten the end gap clearance.

Jim"

Time will tell and so will I, so stay tuned. My next, obvious, question is that if all is well with a .023 end gap why tighten it? Sometimes being an "Early Adopter" is an adventure in and of itself...

RS

PS: There are a few members who have installed Jim's kit with TS rings---Where are you???
 
RoadScholar said:
I spoke with Jim Schmidt about this earlier in the week; he pointed out that he runs the same set-up in his street bike and has had no issues and highlights the fact that leak-down is considerably extended (over non-TS rings) and that he had made calls, on my behalf, to Total Seal whose Tech section pointed out that the end gap (mine at .023--top ring) was within SAE guidelines. I just got and e-mail from Jim (super customer service and thanks Jim for the follow-up!!) on the subject:

"I had a customer in Canada who had the same ring end gap clearance concern. He also had gapless totalseal rings. When the build was complete he was very happy with the results - seal was tight. Regardless - I will be making changes in the Future to tighten the end gap clearance.

Jim"

Time will tell and so will I, so stay tuned. My next, obvious, question is that if all is well with a .023 end gap why tighten it? Sometimes being an "Early Adopter" is an adventure in and of itself...

RS

PS: There are a few members who have installed Jim's kit with TS rings---Where are you???
Click to expand...

Yes, I put the last set together with .023 ring gap. Kenny didn't know it till now. It is not a problem. Jim
 
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