Using a laterally ported custom CP piston with a C&A .043 top, a .043 second (slightly increased end gap) with a 3/16 oil ring my 582 pulled 205# in every h0le the day it was built, and that was with a fairly big lift Bullet Cam that has a lot of duration on a 112* L/C. After 80 runs it bumped UP 20# to 225# in every cylinder. I run a Moroso 4 vane vacuum pump @ 1:1 that pulls between 13# and 14# at 7800 rpm.

Bob

quote:

Originally posted by Big Steve:

quote:

Originally posted by sr4440:

quote:

Originally posted by wideopen231:
Now with new stuff, I may not go gapless if get a good reason that proves out.

You can do as you like, BUT the reason most people got away from the gapless 2nd ring is because, once the compression gases get pass the top ring, they have nowhere to go and then lift the top ring causing "ring flutter". This is the same reason that ring manufactures are recommending larger 2nd ring gaps.

Joe

^^^THIS^^^
I never understood the gapless 2nd ring for this reason. I always run a wide 2nd ring gap. The 2nd ring is an oil scraper and nothing more. Also if your engine has good vacuum the vacuum will pull from the bottom past the 2nd ring and keep the top ring pulled tight against the ring land preventing any flutter or loss of ring seal

^^^ X3 What Joe & Steve said. No reason to run a gapless 2nd ring.

Got a question about ring flutter. How does one determine if it is happening?

Have heard and read about it in quite a few articles, Yet to see how it was determined to be an issue or more than a theory.

Lost of pan vac and power down track would be a good indicator.

quote:

Originally posted by Big Steve:
Lost of pan vac and power down track would be a good indicator.

I doubt you can pin point ring flutter by power.Now on dyno I guess you could say curve fell off here and can find no other reason so has to be ring flutter.

vac as indicator. Cab see. How do .you know not something else? Really not being smart butt. Just curious as to how anyone ever proved what or when rings flutter. Always been a show me the proof kind of person and inquisitive about all. Yea as kid I was that aggravating as hell. Why did that happen kid.

You will see the vac loss consistently around a certain rpm. Could it be something else? Yes but if you make a change to the rings and it stops, then there ya go.

quote:

Originally posted by CURTIS REED:
You will see the vac loss consistently around a certain rpm. Could it be something else? Yes but if you make a change to the rings and it stops, then there ya go.

Exactly Curtis, when I had a ring seal issue several years ago pan vac would go from minus to positive about 400 ft and car would slow down.
Switched to a different ring package and problem went away. Like I said in my earlier post, loss of pan vac down track is a good indicator

Another fun fact, with my blower motor in TD I monitored pan pressure, obviously no vacuum pump, with clean oil I would see about 1/2 to 3/4 psi positive pressure at the stripe, the more alcohol that got in the oil the higher the pan pressure would be indicating loss of ring seal from the contaminated oil.

I've ran both top gapless and second gapless rings in the past....Both types I had oil control issues. Went back to a standard type ring and issues gone....Right now I run AP steel top, ductile napier second, and low tension oil with a vac pump and dry sump....no more oil burning....

Going to check on extra for noth pistons and rings. If the piston are slightly more makes more sense to go that route since rings should wear before pistons. Guessing maybe two sets of rings to one set of pistons as the baseline?

Guess someone will tell me if wrong. Ok Sure they will. If lateral ports in pistons or rings the resu;t should be same?