Speaking to wiseco they said 2.5 thou as measured off the coating on the skirt. this seems very tight to me for a 500-650 whp build. also since the rings come already gapped i guess i have to go with what ever the gap is once PTW is set. any way i was thinking 3 or 3.5 thou would be ideal. and what is a ideal ring gap range for the same power level.

 

want me to just build it for you

 

that would make it much easier. im thrashing to get this together and tuned all within the next few days. im just used to using file to fit rings and these already have the rings all installed so when i have the machine shop set the PTW they also have to adjust the ring gap if needed so i dont have to remove them again to do it. the issue i see is when i call wiseco i get told one thing and after searching and asking around i get a few more specs, i figure a once and for all thread to settle all the confusion will be a huge help for future searchers.

 

Did you tell them you'd be making 650whp? There is no way in hell I'd build a 650whp b-series with 2.5 thou p2w, and I'd definitely not use a pre-gapped ring either.

 

2.5 is a little on the tight side

 

yeah unless some one knows something i dont about these pistons i will be going for a 3 - 3.5 thou gap,, and yes i told them i was making 650 currently and thats why they sai di have to order the upgraded wrist pins.

 

i went with 3.5 thou on my wiescos. all is good. only making 300 hp though.

 

was they coated?

 

.0025 holy **** for that power i would do .0045 - .005

Thats just my opinion.

 

We ran 2.5 thou on our old shop race car. It was making over 700HP and after quite a few passes we pulled the motor to inspect it and there was 0 cylinder scarring. This was a LS/VTEC 11.5:1 compression revved to 10K with AFRs of 12.8:1 on full boost about 28-30PSI.

 

they were weisco pistons too

 

yes, mine are coated.