wtf?

 

I have found some brands of pistons need to have more wall clearance because they expand a lot more with heat than other brands even of the same material. It also depends on the design of the piston, where the breakover point it, what kind of taper is in it, etc.

 

so heres what we came up with...

p2w: (.040) .045 max

top:.017
middle:.019


look ok for 800-1000hp on E?

 

I'm assuming one or both of these posts were trolling... If in response to my comment about not being able to hear it over the regular noises of the car then thanks for that.

I wasn't saying if you can't hear it then oh well but my clearances were intentionally selected for gasoline (not ethanol) for intended current and future power levels. I was intending to simply point out that a little loose is better than a little tight. I can tell you with .0065" I can't even hear any slap with a stethoscope cold in my Honda. My 120k Chevy 5.3L clacks like hell every morning and it is perfectly reliable.

If it helps the OP any I ran .0035" P2W on my last motor with 18 top ring gap at 600whp without problems on E85. Adding another 200 whp I would think another 2 thou on top of that would be smart. That is just my opinion though.

 

I do not have my build sheet sitting next to me, but I think that is something along the lines of the clearances I used for my build. Not looking to make as much power as you, but that was what was suggest for me.

 

CP recommends going .004” - .008” bigger than top ring.

 

Yea, the rings cp sent me were huge... When I called them to ask about it, they told me the same thing.... We'll see how it goes once I fire my motor up

 

We shoot for those ring gaps on all our motors.

As far as PTW, maybe shoot on the looser side of things just incase. 5-5.5.

 

I had some rings for my pistons that CP sent. In my cylinder bores before I even did any ring filing some of the measured at around .029". They had really big gaps, I had to order a new set with a different part # so I could actually gap them to where I wanted them.

 

I built my engine knowing that I was only going to be running E85. I run a custom JE piston as well.

My p2w is 0.005
Top ring- 0.020
Bottom ring- 0.024

I was only running 28psi with my 6266 and the engine made 738/530. Didn't have hardly any oil in the catch can after consecutive pulls on the dyno