ring end gap/ how much is too much?

Posted By: volaredon

ring end gap/ how much is too much? - 03/09/15 12:46 PM

putting together a .030 over 360 for a daily driver Ramcharger, LA block, Magnum heads, 4 barrel carb, Speed Pro Hyper pistons,(#405CP)
Mahle Moly ring set. Out of the box, the rings were tight/ .013-.014 was typical, file fit them, instructions with rings said that .016 was minimum allowable, though I had read somewhere (here, I thought) about having to run a larger ring gap with hyper pistons than stock cast.
Got all of them to .022/.023 except for one ring, had my son helping me measure and file, I let him file the last few cylinders' worth of them while I measured, and we have one top ring that he over did a bit, somehow that one wound up at .032. Are we screwed, having to buy another set of rings to replace that one?

Posted By: 70AARcuda

Re: ring end gap/ how much is too much? - 03/09/15 02:57 PM

the larger top ring gap is for KB hyper pistons due to the location of the top ring...as being higher on the pistons...

the speed pro or seal power pistons use standard ring gaps for their bore sizes.

Posted By: Cab_Burge

Re: ring end gap/ how much is too much? - 03/09/15 08:25 PM

I've seen many NOS racers use .050 or larger on top ring gaps with no problems

Is that ring a top or second ring? If second I wouldn't be a bit concerned on it

If it's a top ring put it in the #7 or #8 cylinder, they run the hottests of all the cylinders

Either way it isn't a deal breaker in either location

Posted By: MR_P_BODY

Re: ring end gap/ how much is too much? - 03/09/15 09:17 PM

You can get 1 set if you call the company... .010 is
a bit much on the top ring... if your not in a hurry
to put it together I would call for a single set...
that would put your mind at ease... JMO

Posted By: dvw

Re: ring end gap/ how much is too much? - 03/10/15 01:58 AM

It won't bother a thing. Ring gap is way overrated. If the ring seals to the cylinder wall and the piston groove that is the secret. Hypers need the extra gap to keep the ends from butting(VERY BAD). Educate yourself here: http://www.diagnosticengineers.org/journal_%20articles/Ring%20Gaps%20vs%20Knowledge%20Gaps.php

Doug

Posted By: volaredon

Re: ring end gap/ how much is too much? - 03/10/15 02:24 AM

interesting read. It is a top ring, and according to the box the top rring is "steel" not listed as "cast" like most. 2nd ring is moly in the set.

Posted By: dvw

Re: ring end gap/ how much is too much? - 03/10/15 02:40 AM

Quote:

interesting read. It is a top ring, and according to the box the top rring is "steel" not listed as "cast" like most. 2nd ring is moly in the set.

Most sets will be a moly top, cast second. The moly ring will have a semi shiney silver face, the cast will be dark gray.
Doug

Posted By: volaredon

Re: ring end gap/ how much is too much? - 03/11/15 12:38 AM

Quote:

Quote:

interesting read. It is a top ring, and according to the box the top rring is "steel" not listed as "cast" like most. 2nd ring is moly in the set.

Most sets will be a moly top, cast second. The moly ring will have a semi shiney silver face, the cast will be dark gray.
Doug

Yup when we initially put them in, we switched the 1st and 2nd rings, going by the cross section views provided with them, did not initially see the markings on the box end tabs/ we did get all the dots "up" motor still on stand, short block not quite complete, my son is buying parts as his CC will allow ("student card" not much of a ceiling) between Summit and feebay. just got the cam today via the Brown truck, We are going with a COMP 260H, but I made him spend the extra to buy it "nitrided" because of todays (commonly available) oils.. an off the shelf cam suddenly becomes a "custom" because of 1) the nitride treatment and 2) It's a mopar not a Shivvy or Furd.
Summit carries already nitrided "commonly sold" COMP cams for the other 2 companies but not for Mopar. $180 cam n lifter kit becomes a $330 cam n lifter kit... for Furd and Shivvy it would have been only $30-40 more NOT $150.

Posted By: dvw

Re: ring end gap/ how much is too much? - 03/11/15 03:38 AM

Take it slow. Ask questions. Make sure everything has clearance. Enjoy.
Doug

Posted By: 451Mopar

Re: ring end gap/ how much is too much? - 03/11/15 07:28 AM

Quote:

You can get 1 set if you call the company... .010 is
a bit much on the top ring... if your not in a hurry
to put it together I would call for a single set...
that would put your mind at ease... JMO

Posted By: Stanton

Re: ring end gap/ how much is too much? - 03/11/15 05:53 PM

So you have .006 piston to wall clearance and you've filed the ring .010 too much so the "port" is now .006 by .010 too big. That's like the size of this dot . !! I sure as hell wouldn't lose sleep over it on one piston in a daily driver.

Posted By: Cab_Burge

Re: ring end gap/ how much is too much? - 03/11/15 07:45 PM

Make sure and degree that cam in the motor

I check them on the cam lobes for cam timing and then set a head on with checking springs and check the piston to valve clearances and then check the intake lobe center for advancing the cam to where it is suppose to be

Posted By: Diplomat360

Re: ring end gap/ how much is too much? - 03/14/15 09:40 PM

Similar pistons to what you used, I did the H116CP (which just gets you a slightly higher CR and valve cut-outs)

Rings part #R-9343 25

TOP SECOND
0.020 0.022
0.020 0.022
0.020 0.022
0.020 0.022
0.020 0.022
0.021 0.022
0.022 0.022
0.020 0.022

I used to be worried about oil consumption since I was using a lot of oil..turned out to have been a valve seal (cursed Teflon PC seals) issue. With these gaps, blueprinted 9.8:1 static CR and my Hughes HE3844AL cam I have 175 PSI cranking pressure. All is good...

Posted By: Rapid340

Re: ring end gap/ how much is too much? - 03/17/15 02:50 PM

Pay close attention to installing the second ring correctly, if just one is upside down and everything else is correct, your oil consumption will almost DOUBLE. (I saw this in a test Hastings mfg had published). BTW,a bit more gap on the second ring is actually beneficial.

Don't be too hard on your son, the additional top ring gap on one cylinder will likely cost you under 2HP, maybe less than one on a mild build.