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Ring gap Orientation

Started by Flyingbroke, February 12, 2018, 09:49:41 AM

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Flyingbroke

February 12, 2018, 09:49:41 AM Last Edit: February 12, 2018, 11:08:46 AM by FSG
doing a s&s 110 install and question is S&S has this for gap placement which is different from shop manual and fuel motto videos is one way better than other .sorry no handy pic of other way . Installed already per s&S instructions waiting on heads just asking.   

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koko3052

Just asking.....just done... it's good to go!
As long as they are orientated about 90 degrees from each other for break in, they will turn while running.

Ohio HD

That's the positions that I use. And as mentioned, they can move anyway.

Hillside Motorcycle

If you pull the engine down at say 2500 miles, as an example, those rings will not be in the same location whatsoever.
Otto Knowbetter sez, "Even a fish wouldn't get caught if he kept his mouth shut"

jsachs1

Quote from: Scott P on February 12, 2018, 01:22:08 PM
If you pull the engine down at say 2500 miles, as an example, those rings will not be in the same location whatsoever.
:agree:  even a lot less than 2500 miles.
John

No Cents

   kd can tell you how fast the rings move on the pistons.
His bike was heat cycled and put on the dyno and he had them line up. That's how fast it can happen...even when installed correctly.
08 FLHX my grocery getter, 124ci, wfolarry 110" heads, Burns pipe, 158/152 sae

kd

Thanks for that reminder Ray   :banghead:  I heat cycled with a known base tune for my exact engine component recipe, and ran it up 2 times to full temp for approximately 10 miles each to ensure no leaks or other problems before loading it on the trailer to the tuner. After about 1/2 to 1 hour on the drum we noticed black smoke out the pipe that could not be tuned out with AFR adjustments. When doing a compression test and leakdown to trouble shoot the engine pools of oil was noticed in the rear intake runner. Eventual removal of the rear barrel found every ring (all of them including the oil ring scrapers :dgust:) were lined up absolutely perfect. The rings WERE installed correctly at 180* from each other and I clearly remember where each one was. It was reassembled and never reoccurred.  BTW this was with the factory cross hatch in 120R cylinders. I blueprinted everything on assembly and the barrels measured WELL within spec and were close to perfect.   :scratch:   :nix:

This all happened in less than 2 hrs on the tach. Maybe if there wasn't 2 people in the booth it might not have been noticed and could have corrected itself. We'll never know now. 
KD

Pirsch Fire Wagon

I've often wondered why there are no Ring Stops. Just makes you go Hmmmmm.
Tom

kd

There are ring stops in 2 strokes to prevent a ring end from snagging into a port on the cylinder wall as the rings rotate. In those engines rings are prevented from rotating.
KD

Pirsch Fire Wagon

Quote from: kd on February 12, 2018, 04:25:51 PM
There are ring stops in 2 strokes to prevent a ring end from snagging into a port on the cylinder wall as the rings rotate. In those engines rings are prevented from rotating.

Just wondering why they don't use them on these Engines. These things rotate like helicopters. Like rolling Die, sooner or later you're going to Roll Snake Eyes.
Tom

Ohio HD

As well the port in the cylinder tries to induce ring movement on 2 cycle motors, hence the pins in some pistons.

Pirsch Fire Wagon

Quote from: Ohio HD on February 12, 2018, 04:43:28 PM
As well the port in the cylinder tries to induce ring movement on 2 cycle motors, hence the pins in some pistons.

I get it.

Just seems to me if there were ring stops we wouldn't have this issue. That's all.

How many Engines have been tore down because Rings have aligned? I've done at least 50 in 20 years. EVO's TC's, and Sportsters. No discrimination. They all do it. They sell Pistons with Stops for High Performance Race Builds. Why not just make them Stock Equipment?

Heck, It happened to me on I-95 about 10 years ago with only 20k miles on my Ultra. My Wife and Kids were following me in our Van. It was covered in Oil. I wouldn't have noticed it had she not went crazy with the Horn and Lights Flashing. When i looked in the Mirror, It literally  looked like a James Bond Movie using a Smoke Screen and Oil Slick escaping an Assassin.

Tom

PoorUB

I have never worried much about where the ring gaps were as long as they were staggered, never had an issue.
As for the piston ring stops my guess is the engine will live longer if the rings are lowed to rotate, other wise you could end up with a wear pattern from the ring gap.

The chances of them lining up are slim, but obviously it happens.
I am an adult?? When did that happen, and how do I make it stop?!

1FSTRK

Quote from: kd on February 12, 2018, 03:54:06 PM
Thanks for that reminder Ray   :banghead:  I heat cycled with a known base tune for my exact engine component recipe, and ran it up 2 times to full temp for approximately 10 miles each to ensure no leaks or other problems before loading it on the trailer to the tuner. After about 1/2 to 1 hour on the drum we noticed black smoke out the pipe that could not be tuned out with AFR adjustments. When doing a compression test and leakdown to trouble shoot the engine pools of oil was noticed in the rear intake runner. Eventual removal of the rear barrel found every ring (all of them including the oil ring scrapers :dgust:) were lined up absolutely perfect. The rings WERE installed correctly at 180* from each other and I clearly remember where each one was. It was reassembled and never reoccurred.  BTW this was with the factory cross hatch in 120R cylinders. I blueprinted everything on assembly and the barrels measured WELL within spec and were close to perfect.   :scratch:   :nix:

This all happened in less than 2 hrs on the tach. Maybe if there wasn't 2 people in the booth it might not have been noticed and could have corrected itself. We'll never know now.

I think we all agree the rings are always rotating. It has been my experience that if they self align the gaps while running the only way to un-align them is to disassemble and turn them by hand. It seems that once the cylinder pressure is blowing by the aligned ring gaps it is enough to stall the turning motion. We have theorized that even if they start to rotate during the non pressure strokes the compression and power stroke blow them right back to alignment because they cannot achieve enough stagger on their own in one stroke.

I have shared here before (this is my own personal experience/observations and in No way a judgment on KD's experience) that the single common denominator in properly staged rings aligning themselves is Heat. It can be lack of cooling, running lean, too much ring heat during break-in but in ever case on the engine dyno, bike dyno, or on the street we found that even brief over heating was involved. This does not say that if an engine gets hot the rings always align, only that in every case where rings were aligned we could either see signs of high heat or look back to conditions that would have produced high heat. This held true on both water cooled and air cooled engines ranging from stock rebuild to blown or sprayed race engines.
I, like KD, personally installed the rings correctly on a V-8 only to have it blow by on the dyno so bad we pulled it back down and found 6 of the 8 cylinders perfectly aligned and the other 2 were within about 15 degrees of perfect. I post this for your consideration, your experiences may vary.
"Never hang on to a mistake just because you spent time or money making it."

kd

February 13, 2018, 05:29:13 AM #14 Last Edit: February 13, 2018, 05:37:33 AM by kd
Quote from: 1FSTRK on February 13, 2018, 04:48:04 AM
Quote from: kd on February 12, 2018, 03:54:06 PM
Thanks for that reminder Ray   :banghead:  I heat cycled with a known base tune for my exact engine component recipe, and ran it up 2 times to full temp for approximately 10 miles each to ensure no leaks or other problems before loading it on the trailer to the tuner. After about 1/2 to 1 hour on the drum we noticed black smoke out the pipe that could not be tuned out with AFR adjustments. When doing a compression test and leakdown to trouble shoot the engine pools of oil was noticed in the rear intake runner. Eventual removal of the rear barrel found every ring (all of them including the oil ring scrapers :dgust:) were lined up absolutely perfect. The rings WERE installed correctly at 180* from each other and I clearly remember where each one was. It was reassembled and never reoccurred.  BTW this was with the factory cross hatch in 120R cylinders. I blueprinted everything on assembly and the barrels measured WELL within spec and were close to perfect.   :scratch:   :nix:

This all happened in less than 2 hrs on the tach. Maybe if there wasn't 2 people in the booth it might not have been noticed and could have corrected itself. We'll never know now.

I think we all agree the rings are always rotating. It has been my experience that if they self align the gaps while running the only way to un-align them is to disassemble and turn them by hand. It seems that once the cylinder pressure is blowing by the aligned ring gaps it is enough to stall the turning motion. We have theorized that even if they start to rotate during the non pressure strokes the compression and power stroke blow them right back to alignment because they cannot achieve enough stagger on their own in one stroke.

I have shared here before (this is my own personal experience/observations and in No way a judgment on KD's experience) that the single common denominator in properly staged rings aligning themselves is Heat. It can be lack of cooling, running lean, too much ring heat during break-in but in ever case on the engine dyno, bike dyno, or on the street we found that even brief over heating was involved. This does not say that if an engine gets hot the rings always align, only that in every case where rings were aligned we could either see signs of high heat or look back to conditions that would have produced high heat. This held true on both water cooled and air cooled engines ranging from stock rebuild to blown or sprayed race engines.
I, like KD, personally installed the rings correctly on a V-8 only to have it blow by on the dyno so bad we pulled it back down and found 6 of the 8 cylinders perfectly aligned and the other 2 were within about 15 degrees of perfect. I post this for your consideration, your experiences may vary.



1FSTRK, here's another observation for your list. In my case I had measured the cylinders (granted , without torque plates) every inch at 4 - 45* lines down the barrels. The front cylinder was dead nuts at .0000 in all positions repeated at least 3 times. The rear cylinder had a very minor, almost immeasurable  deviation that formed a barrel shape with a slight oval to the cross mounted position. The aligned rings were at the center of the oval position on the right side of the engine when the barrels were slid off. There is a thread on here with the pic  of them undisturbed and another one with my measurements and the diagram to where the variance was. I believe (as did Tman and Steve Cole) that was the problem. We whisker honed to take the edge off the crosshatch and reringed .... problem gone.
KD

rbabos

Quote from: PIRSCH FIRE WAGON on February 12, 2018, 03:55:37 PM
I've often wondered why there are no Ring Stops. Just makes you go Hmmmmm.
Sometimes it's better if they move around a bit. Keeps the gap from making a wear line in the cyl.
Ron

1FSTRK

Quote from: kd on February 13, 2018, 05:29:13 AM
Quote from: 1FSTRK on February 13, 2018, 04:48:04 AM
Quote from: kd on February 12, 2018, 03:54:06 PM
Thanks for that reminder Ray   :banghead:  I heat cycled with a known base tune for my exact engine component recipe, and ran it up 2 times to full temp for approximately 10 miles each to ensure no leaks or other problems before loading it on the trailer to the tuner. After about 1/2 to 1 hour on the drum we noticed black smoke out the pipe that could not be tuned out with AFR adjustments. When doing a compression test and leakdown to trouble shoot the engine pools of oil was noticed in the rear intake runner. Eventual removal of the rear barrel found every ring (all of them including the oil ring scrapers :dgust:) were lined up absolutely perfect. The rings WERE installed correctly at 180* from each other and I clearly remember where each one was. It was reassembled and never reoccurred.  BTW this was with the factory cross hatch in 120R cylinders. I blueprinted everything on assembly and the barrels measured WELL within spec and were close to perfect.   :scratch:   :nix:

This all happened in less than 2 hrs on the tach. Maybe if there wasn't 2 people in the booth it might not have been noticed and could have corrected itself. We'll never know now.

I think we all agree the rings are always rotating. It has been my experience that if they self align the gaps while running the only way to un-align them is to disassemble and turn them by hand. It seems that once the cylinder pressure is blowing by the aligned ring gaps it is enough to stall the turning motion. We have theorized that even if they start to rotate during the non pressure strokes the compression and power stroke blow them right back to alignment because they cannot achieve enough stagger on their own in one stroke.

I have shared here before (this is my own personal experience/observations and in No way a judgment on KD's experience) that the single common denominator in properly staged rings aligning themselves is Heat. It can be lack of cooling, running lean, too much ring heat during break-in but in ever case on the engine dyno, bike dyno, or on the street we found that even brief over heating was involved. This does not say that if an engine gets hot the rings always align, only that in every case where rings were aligned we could either see signs of high heat or look back to conditions that would have produced high heat. This held true on both water cooled and air cooled engines ranging from stock rebuild to blown or sprayed race engines.
I, like KD, personally installed the rings correctly on a V-8 only to have it blow by on the dyno so bad we pulled it back down and found 6 of the 8 cylinders perfectly aligned and the other 2 were within about 15 degrees of perfect. I post this for your consideration, your experiences may vary.



1FSTRK, here's another observation for your list. In my case I had measured the cylinders (granted , without torque plates) every inch at 4 - 45* lines down the barrels. The front cylinder was dead nuts at .0000 in all positions repeated at least 3 times. The rear cylinder had a very minor, almost immeasurable  deviation that formed a barrel shape with a slight oval to the cross mounted position. The aligned rings were at the center of the oval position on the right side of the engine when the barrels were slid off. There is a thread on here with the pic  of them undisturbed and another one with my measurements and the diagram to where the variance was. I believe (as did Tman and Steve Cole) that was the problem. We whisker honed to take the edge off the crosshatch and reringed .... problem gone.

Great info.
I would offer this not as a contradiction but as an observation. I have seen many poorly bored or honed cylinders, some visibly bad others that showed when measured or were disassembled for various reasons, and have not seen any pattern of ring alignment with bad or out of round cylinders. One set of sleeved cylinders used in testing would go out of round when run to the point they could not be honed with a ridged hone (.003 oval) and never once were the rings aligned when disassembled.
I will definitely note your experience and theory to keep in mind  for the future but with so many bad bores out there I would think we would see more examples if it was the root cause. 
Thankfully you are past it and are running fine.
"Never hang on to a mistake just because you spent time or money making it."

Flyingbroke

Thank you all for the info now wont loose sleep over original placement but will have ring movement in mind wish would have paid close attention to stock piston ring orientation when removed just for an example.have done lots of two stroke pistons in dirt bikes and snowmobile and agree there should be ring pins . 

04 SE Deuce

I wouldn't think seeing signs of heat unusual with all ring gaps lined up. 
Oil contamination in the combustion chamber and combustion/compression heat/pressure going down the side of the piston.

1FSTRK

Quote from: 04 SE DEUCE on February 13, 2018, 10:00:12 AM
I wouldn't think seeing signs of heat unusual with all ring gaps lined up. 
Oil contamination in the combustion chamber and combustion/compression heat/pressure going down the side of the piston.

This is not a chicken or the egg scenario as is possible when you are looking at one engine and search for a root cause. This is information compiled from a half dozen or more engine builders and as many dyno tuners over the last 30 years. As I said I am only passing on the knowledge, but rest assured these guys get paid to pay attention to details. Even at this level things happen. Heat cycling an V-8 on the Superflow with the EGTs not yet hooked only to find that in all the haste the wrong jets were put in the carb. That was my job, I'll own that one. Hooked them up and saw the problem but it was too late. CCP and leak down confirmed it so pull it down and found the 6 cylinders with the rings perfectly aligned. This one story alone means nothing but in every case even on high mileage engines methodical practice and records leads back to a heat related cause.
As I said do not take this as a know it all claim, take it as food for thought then keep it in mind if and when you see the next piston pop out with the ring gaps aligned.
"Never hang on to a mistake just because you spent time or money making it."

TJAH

kd,
what did the leak down show when the rings were aligned and did it happen on both cylinders ?


Quote from: kd on February 12, 2018, 03:54:06 PM
Thanks for that reminder Ray   :banghead:  I heat cycled with a known base tune for my exact engine component recipe, and ran it up 2 times to full temp for approximately 10 miles each to ensure no leaks or other problems before loading it on the trailer to the tuner. After about 1/2 to 1 hour on the drum we noticed black smoke out the pipe that could not be tuned out with AFR adjustments. When doing a compression test and leakdown to trouble shoot the engine pools of oil was noticed in the rear intake runner. Eventual removal of the rear barrel found every ring (all of them including the oil ring scrapers :dgust:) were lined up absolutely perfect. The rings WERE installed correctly at 180* from each other and I clearly remember where each one was. It was reassembled and never reoccurred.  BTW this was with the factory cross hatch in 120R cylinders. I blueprinted everything on assembly and the barrels measured WELL within spec and were close to perfect.   :scratch:   :nix:

This all happened in less than 2 hrs on the tach. Maybe if there wasn't 2 people in the booth it might not have been noticed and could have corrected itself. We'll never know now.

kd

Quote from: TJAH on February 13, 2018, 05:12:51 PM
kd,
what did the leak down show when the rings were aligned and did it happen on both cylinders ?


Quote from: kd on February 12, 2018, 03:54:06 PM
Thanks for that reminder Ray   :banghead:  I heat cycled with a known base tune for my exact engine component recipe, and ran it up 2 times to full temp for approximately 10 miles each to ensure no leaks or other problems before loading it on the trailer to the tuner. After about 1/2 to 1 hour on the drum we noticed black smoke out the pipe that could not be tuned out with AFR adjustments. When doing a compression test and leakdown to trouble shoot the engine pools of oil was noticed in the rear intake runner. Eventual removal of the rear barrel found every ring (all of them including the oil ring scrapers :dgust:) were lined up absolutely perfect. The rings WERE installed correctly at 180* from each other and I clearly remember where each one was. It was reassembled and never reoccurred.  BTW this was with the factory cross hatch in 120R cylinders. I blueprinted everything on assembly and the barrels measured WELL within spec and were close to perfect.   :scratch:   :nix:

This all happened in less than 2 hrs on the tach. Maybe if there wasn't 2 people in the booth it might not have been noticed and could have corrected itself. We'll never know now.



The compression on both cylinders was a tic over 200 PSI EACH and both leaked at almost 3%. The problem with the ring alignment was definitely not obvious in those 2 tests. If not for the oil pooling in the intake it would have been a tough find.  Here's a couple of links to the measurements and a pic of the piston and rings seconds after the barrel was slid off. The front was checked and OK. The difference in the barrel measurements and where the rinks ended up indexing to seemed to be related to the out of round to us.

Eric, here's a pic of the piston (2nd link) but not the skirt. You can see by the measurements of the barrels (1st link) and why we decided the shape was likely the culprit and/or a harsh cross hatch so we light whisker honed and re-ringed.  If you blow up the pic and look at the piston and ring faces they are (or appear to be) perfect for the amount of running time the engine had on it.


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KD