does anyone have clearance sheets for wiseco pistons? i called wiseco and they said they didnt have a clearance sheet!!! Im planning on running 30+ psi on e85. The rep told me that the min should be .003, but reccomended .004 for around 30psi. Ill post piston # and kit #s when i get out of work. PLEASE HELPPPP!

 

Bump

 

DOUBLE BUMP! this is important!

 

bump

 

Are you looking for ring gap or piston to wall clearance?

 

piston to wall

 

0.0040" is what recommend to me and what I used.

 

They told you what you should do....run .003" unless you're running more boost (30psi+) which requires about .004". That sound correct to me, but if you're not sure just call Wiseco. Ask for Brian Nutter.

 

Are you building the car yourself?

What i know is that if you want to run higher than 30psi you need to run more open than the reccomended in the box...

 

im running .003 on wiseco's, I stayed a bit on the tight side, hopefully its enough for 30psi+ on race fuel. I probably should have went with .0035 - .004 though. lol

 

Wiseco pistons need to be on the loose side of what they recommend. They use 4032 which expands a little different than 2618 (JE, CP, Ross, etc.) which is the normal usage. It should also be based on power not boost as the expansion has nothing to do with boost.

I would go no less than 4 thou on piston to wall. If its going to be a 500+ whp monster I'd think about 4.5 thou. For comparison on my motor (expecting 700-750whp) I went 5.5 thou.

 

should i be worried with my wiseco's at .003? Making the power in my sig, havent been tuned for race gas/high boost yet. Wiseco recommend .0025 as a starting point iirc.

 

I run Wisecos at about 0.0005" PTW clearance. I've tried 3 and 4 thou and usually get just a little side wall scuffing. 5 thou is perfect for the 300-500 HP engine not spraying nitrous. If nitrous, add another thou or two.

 

originally i had decided on .0035 but i will go with .004 as per wiseco's instructions. my goal is650 whp/600wtq on e-85. do you think this is reasonble?

 

What is the downside of too much clearance? Too little seems fairly obvious to me, but I'm curious what happens if I build with .005" or so with an intent to make more power much later. Personally I'm running JE pistons.