question about ring end gap

[elimination]

I am wondering what the end gap on a 4.31 bore with a hyp. piston should be. The rings are the plasma moly race rings (file to fit) made by Speed Pro. I was told that it should be .024 but that seems too tight for the top ring.Any help would be appreciated

[GofastRacer]

The paper work that came with the rings will tell what gap to use for what bore you have!.. :)

[Moneypitt]

Are those hypereutectic pistons? If they are you MUST gap your top ring according to the PISTON instructions.(larger than normal ring gap) If you don't, you'll burn um up. The .024 sounds about right. As a general rule of thumb is .004 per inch of bore. So 4.3 would be about .017 with a normal forged piston. I think you'll see the 2nd ring groove is a ways down the piston from the top, the casting method of the new type piston dictates that SOME gases get past the first ring, this is the reason for the large top ring gap. If your pistons are not the cast hypereutectic, then .024 would be a little on the loose side. Hope this helps.....Moneypitt

[FastTimmy]

Hey elimination,
If it is a N/A application I would say .005 for every 1.00" of bore. That would be 4.31x.005=.0215
If it is a Blower application I would say .0065/.007 for every 1.00" of bore. That would be 4.31x.0065=.028 or 4.31x.007=.030
Just me .02
Timmy

[Kindsvater Flat]

I just put my 440 together and had to call. I'm running the same rings. .024 was what I was told.

[Moneypitt]

What PISTONS?????

[058]

Hypereutectic pistons require more end gap. Go by the piston manufacture's recommendation. It can be as much as .030" to .032"

[LeE ss13]

Replace the second rings with Childs & Alberts ZGS (Zero Gap Second) Taper Faced rings. No filing necessary and good for a few more HP.