Thread: What do you engine guys see here?

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KD Tools makes a ring fileing tool part # 870. This is the one that I've used. They can be had for about $70.00 or so. You'll also need to get a ring squareing tool to put rings squaely in bore for accurate measurements. Also if you havn't done this before, I suggest practicing on some used rings before cutting on your new rings.

Steve, he (and I ) are a little bummed about having to pull the body off and build a new motor, but it is what it is. I think you guys are right about tight rings breaking, and maybe in the next week or so we will have it torn down for a looksee.

sbcguy, that KD tool is exactly what I am looking for, and will pick up the squaring tool as well......good advice. Sure beats the hand file and using a piston to square them up as I have always done.

Don

Those ring filers are pretty slick. Found the KD one mentioned above here for around 58 bucks, hope this helps.
Save on KD Tools 870 at ToolTopia.com

I would tear it apart before anything else to see what happened. I've used plasma ceramic rings with good success.

Every set of pistons I ever used when checked would be around +/- .002" varience in diameter. For example a set of 4" pistons lets say +.030 over would actually measure in a set of eight from 4.029" to 4.031". Sometimes the varience in diameter was more. Too much more and we would order other pistons and send back the ones too far out of spec. Basically make up our own set of pistons within .002" tolerance. This is why we used to bore the block to fit the pistons and file fit the rings to get the correct gap.

Heres a chart from Sealed Power / Speed Pro giving reccomended end gaps per application.

RING END GAP RECOMMENDATION GUIDE (FOR 4.000 INCH BORE)
Speed Pro Top Rings
(ductile iron, 4" bore) 4.000" Example Minimum Gap Factor
Moderate Performance .016 - .018 (.004 per inch of bore diameter)
Drag Racing, Oval Track .018 - .020 (.0045 per inch of bore diameter)
Nitrous Oxide - Street .020 - .022 (.005 per inch of bore diameter)
Nitrous Oxide - Drag .028 - .030 (.007 per inch of bore diameter)
Supercharged .024 - .026 (.006 per inch of bore diameter)

Speed Pro 2nd Rings
(cast Iron, 4" bore) 4.000" Example Minimum Gap Factor
Moderate Performance .020 - .022 (.005 per inch of bore diameter)
Drag Racing, Oval Track .022 - .024 (.0055 per inch of bore diameter)
Nitrous Oxide - Street .024 - .026 (.006 per inch of bore diameter)
Nitrous Oxide - Drag .028 - .030 (.007 per inch of bore diameter)
Supercharged .024 - .026 (.006 per inch of bore diameter)

Notice: Most of the second ring gap recommendations are larger than the top rings. Recent testing has proven that a
larger second gap increases the top ring's ability to seal combustion. This larger "escape" path prevents inter-ring
pressure from building up and lifting the top ring off the piston allowing combustion to get by. Many engine builders
have reported lower blow-by and horsepower gains at the upper RPM ranges with wider second ring gaps. Also,
almost every new car made is using this inter-ring pressure reduction method to lower blow-by and emissions and to
increase engine output

Don i've used one of these Speedway type for years without any problems.

This one works good, i also have the electric version.

Precision Piston Ring Filer - Speedway Motors, America's Oldest Speed Shop