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[snowrider13]

I have always set my 2nd ring end gap a couple of thou more than top ring. I see that is what HD has called for also. Looking at my service manual suppliment for my 110 it shows just the opposite, with the top ring being more than the 2nd. Is this a misprint? Chime in folks. Also seeing increased measurements for piston pin fit, and skirt clearances. What do the builders on this site do? I generally go for a snug fit, and a gentle controlled break-in, (longer life-quieter). Thanks

[HILLSIDECYCLE.COM]

Standard thumb of rule is .004-.005" per inch of bore, minimum, unless otherwise specified by the piston manufacturer.
Too snug can result in issues.
Scott

[HD Street Performance]

Carry on as you planned.

[snowrider13]

Standard thumb of rule is .004-.005" per inch of bore, minimum, unless otherwise specified by the piston manufacturer.
Too snug can result in issues.
Scott

This part I get. Why the difference between the 103 and the 110 as far as ring end gap stagger between the 2 compression rings?

[HD Street Performance]

Add .003 gap to ring #2 from what you gapped #1 at.

[snowrider13]

Add .003 gap to ring #2 from what you gapped #1 at.

This makes sense to me. Thanks

[sadunbar]

This part I get. Why the difference between the 103 and the 110 as far as ring end gap stagger between the 2 compression rings?

Whether it's bikes or cars, I've never gapped the top ring more than the second ring, and never seen a spec that called for it.  Just a guess, but I'd suspect a misprint.  If it's not a misprint, I'd love to hear the engineering explanation as to why...

[CVODON]

Unless you are using a Dykes or different width 2nd ring I just see no reason for gap to be different. I have done a bunch and they were the same, and I had no problems with them.

[HILLSIDECYCLE.COM]

Are Dykes rings what Bruce Jenner uses?
Scott

[snowrider13]

Are Dykes rings what Bruce Jenner uses?
Scott

I don't care who you are...that's funny...

[HD Street Performance]

Unless you are using a Dykes or different width 2nd ring I just see no reason for gap to be different. I have done a bunch and they were the same, and I had no problems with them.

If there are "no problems" does that mean we have achieved the optimum setup?
The reason for a slightly larger gap on ring 2 is to relieve trapped pressure between rings 1 and 2 to prevent flutter and effectively have better sealing and conduction of heat
Cite: Keith Jones Total Seal Ring  Co.

[sadunbar]

If there are "no problems" does that mean we have achieved the optimum setup?
The reason for a slightly larger gap on ring 2 is to relieve trapped pressure between rings 1 and 2 to prevent flutter and effectively have better sealing and conduction of heat
Cite: Keith Jones Total Seal Ring  Co.

 

[snowrider13]

I understand the reason for the difference. W
hat I don't understand is why HD is asking for a LARGER top ring end gap than the 2nd on the 110.

[HD Street Performance]

Are they always right?
What they state will work and not fail. We are splitting hairs, nuances not mountain peaks.

[wfolarry]

I understand the reason for the difference. W
hat I don't understand is why HD is asking for a LARGER top ring end gap than the 2nd on the 110.

Because the top ring is getting hot closing up the gap. Similar to what KB pistons recommends because of their higher ring placement.