Piston wall clearance

[DSM_Rastafari]

Does anyone know the recommeneded clearance for JE pistons? 8 8 1 compressoon model, tried to look on the website but no luck

also any of you go away from the recommendation?

 

[BogusSVO]

PTW is cut into the piston from the factory.

Read this...

http://www.dsmtuners.com/forums/cyl...824-how-measure-mic-piston.html#post152953026


Yes, some engine builders will loosen the PTW depending on what the engine will be used for.

 

[Fehrion_sit]

agreed^^^ it should say on your box ... .003-.005 if i remember correctly from engine machining class for boosted or NOS motors ...

 

[DSM_Rastafari]

well i bought mine used with .20 over, thanks for the the link, but nowhere near a shop to buy those measuring tools

 

[briank]

How much power do you plan to make? Clearance would be different from 200hp to 400hp.

 

[BogusSVO]

What excatly are you trying to do?

If you do not have the tools to measure with, how do you plan to figure the PTW?

 

[DSM_Rastafari]

I seriously though that the manufacturer would have a recommended sepc for them, goals are 300hp, i'm actually on vacation just came to my mind about the PTW for my pistons, (rebuilding motor), thought it was a standard measurement i can right down and remember

 

[BogusSVO]

PTW is cut into the piston from the factory.

This tells you.... ^^^^^^^^

So I can walk you thu the math, we will use an engine that has a STD bore of 85mm or 3.346

Now add the .5mm or .020 for the over size.

The target finished bore should be 3.366

Now when you mic the pistons, you will see that they are smaller, appox 3.363 to 3.3625

That works out to be .003-.0035 of PTW