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Topic Review (Newest First)
01-21-2013 04:20 PM
cobalt327 That and the KB ring gap recommendations are in the link at post #13.

This thread was resurrected by HSDropout, it's not still from '09.
01-21-2013 10:40 AM
BuzzLOL .. Actually, there is another difference in rings, some are thicker and the grooves in the pistons are deeper for those rings... ran into that problem one day with rings which wouldn't go down into the grooves far enough...
01-21-2013 09:50 AM
sbc 350 piston rings?

Man, hope the rest of my day does better than answering this 2009 thread!
01-21-2013 09:45 AM
sbc 350 piston rings?

What is the part# of the pistons you bought? The only thing that makes a difference is if the piston uses 1/16,1/16,3/16 rings or 5/64,5/64,3/16 rings. Post the part# of the pistons.
01-21-2013 06:21 AM
BuzzLOL .. KB hypereutectic pistons use top rings gaps up to double what used to be recommended, depending on your overall setup/power adders/usage...

.. Pre-sized "drop in" rings can have the gaps filed bigger, if needed... usually, the gap needed is never smaller than what the drop in rings will already have...
01-18-2013 04:22 PM
Originally Posted by bwomp969 View Post
my engines over bored 0.60"... ...overbore size 0.45" or 0.65" not 0.60"...
Not to nit pick- and I know what you are saying- but for your own benefit, get the decimal places correct. You mean to type 0.060", 0.045", etc.

...would work except that the pistons I got are meant for 11:1 c/r and the rings are meant for 10.5 to 1 c/r...
There is- generally speaking- no difference in the rings used between these different those two compression ratios.

Now, there may be a different ring called for if the engine will be run at an exceptionally high rpm (generally thinner), and sometimes they'll be made from a different material (if nitrous or super-/turbocharging is to be used), and there are different ring tensions used for different applications, but generally rings will be the same regardless of the CR, all else being equal.
01-18-2013 03:37 PM
HSDropout Thanks for the review info, much appreciated.
Clean and check everything.

By the way.......I did get all "A"s in auto shop and art.
01-18-2013 03:23 PM
1Gary Remember to follow the piston manufactures spec when using any power adders.Normally you need a bigger gap.
01-18-2013 03:11 PM
Originally Posted by HSDropout View Post
Is it unrealistic to think that the gap can be checked and hand filed as needed ? Anyone know if the filing machine is available as a loaner tool at any of the auto parts stores? Thanks.
I got all my parts back from machine shop, ready to build......trying to stay calm but all the fresh new parts have got me wound up pretty good.
Welcome to Hotrodders.

Rings can be measured/hand fit to the cylinders of an engine if you're willing to do the work w/a hand file. But you have to be careful to keep the ends square. Only file one end, leave the other alone. When the gap's right, any sharp edges need to be removed from the end you filed.

You measure the gap by placing a ring into the cylinder its to be fit to, then the ring is squared in the bore. You can use a ring-less piston upside down to press the ring in the cylinder with to square it. Then carefully use feelers to gauge the gap.

If you're using moly rings, you need to be careful to not chip the moly. My recommendation is to use a ring filer machine for this (I know of no 'loaners'), but it can be done by hand w/care.

All that said, there's little advantage in jumping through all the hoops. Just by a normal-fit ring set in the correct size. Check the end gaps as described above. A short page w/ring info is here.

Good luck.
01-18-2013 12:36 PM
Mr. P-Body Yes, rings are EVERYWHERE for the 4" bore. Whoever told you Total Seal was the "only" one, well, NEVER ASK HIM AGAIN! Gapless rings were a good idea, they just didn't "work". That is, while they DO seal the cylinder and generate better "numbers" in a leakage test, they don't make any more power or use less oil (often, more) than "conventional" rings. Gapless rings also tend to taper the cylinder quite rapidly. The Sealed Power E-251K mentioned is a very good ring. If the bores aren't "fresh", though, I'd opt for the E-251X instead (ductile iron). The "K" series are "moly" rings and may have trouble seating in a "used" bore. I haven't seen Perfect Circle available in a LONG time. We use SP as said, Speed Pro (EXCELLENT race ring) and Hastings. We've used Grant in the past with success, as well.

"File fit" rings are among the more used and abused products among DIY engine builders. When building a RACE engine ("custom" specs), one must "fit" everything. Generally, standard clearance (piston-to-wall) is inadequate for racing. As a result, the bore size may increase as much as .005-.006". The "file fit" ring allows you to do this without ending up with too much ring gap. Aside from that, there is no "advantage" to a file-fit ring. We use "drop-in" rings in the majority of our builds.

01-18-2013 12:34 PM
MouseFink Sorry, my error, plasma moly rings, hone with a Sunnen 625 stone (280 grit) and finish with a Sunnen 820 stone (400 grit). The Sunnen numbers is not the "grit". Use Sunnen MAN845 honing oil. Season with ATF before installing pistons.
01-18-2013 12:25 PM
HSDropout Oh, sorry if I may have butted in but my questions seemed to relate to original posting subject. My bore is 4.060" also.
01-18-2013 11:35 AM
MouseFink PISTONS: Speed Pro L2256F forged + O.S. , .0025" - .0035" cyl. wall clearance

RINGS: 5/64", 5./64", 3/16", plasma moly (60% porosity) ductile iron top, ductile iron second, SS oil.

CYLINDER WALLS: hone 625 grit, finish hone with 3 strokes 820 grit, season with ATF

SEATING: instantly, rings will seat before you can adjust time timing advance.

BREAK IN: Make a full pass or go get some beer.
01-18-2013 10:04 AM
HSDropout Is it unrealistic to think that the gap can be checked and hand filed as needed ? Anyone know if the filing machine is available as a loaner tool at any of the auto parts stores? Thanks.
I got all my parts back from machine shop, ready to build......trying to stay calm but all the fresh new parts have got me wound up pretty good.
07-21-2009 09:33 AM

Sealed power E251k. Everybody and there brother sells them, .060" over is a stocking item.

I even have them in stock.

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