So you guys are sayin that these pistons are crackin cause people are using to low of octane and the pre detonation is makin them screw up? If thats the case then these people deserve that for there own stupidity! Also what are these "TRUE" pistons your talkin bout? I got my JE 12:1 piston w/ heat coatings a few months ago from Bob...That thing better not screw up cause I don't have that kind of money to buy another one of those *****! Will this type of thing be covered by JE? Or are they sayin it's not their problem?

 

A TRUE 11:1 piston is something bob told me about, because I wanted to run 93 pump gas. You would have to talk to him about it.

 

The TRUE comp. ratio. JE 12:1 actually comes out closer to a 13.3:1, the 10.75:1 is higher than that but I'm not sure how much more on that one. There may not be a problem with them but I would run a little rich and plenty of octane.

 

I have a wiseco 11:1. I havent seen many people running this piston but i havent heard anything bad about it either. Its stock bore with a stage1 cam and exhaust and filter. I was told by many many raptor owners that I could run 93 premium pump gas with this setup. Was I mistaken? Do I need to worry about these problems surfacing if I use 93 even with my std bore 11:1 wiseco?

 

ive been running a JE piston for a long time now and havent had the slightest problem.....knock on wood!

 

I used one in my raptor and it died after two races. My father in law says it was the piston that broke. I am trying to decide what to put in it but i may go with stock because I was going to us a j.e. but now i don't kkknow about that.

 

I think allot of the pistons cracking are due to detonation, and not necessarily the owners fault! JE is offering pistons that are ADVERTISED as 11/1 and 12/1 comp ratios, but the 12/1 with a stock head is actually like 13.3-5/1 and the 11/1 with the stock head is actually 12.1-3/1, this is causing allot of problems with people not running the right octane fuel exceptionally ( spelling? ) with the 11/1 piston. Someone buys it thinking they can run on the edge with pump gas but in reality its going to cause detonation under hard loads. Wisco seems to run much closer to there advertised numbers and probably is why we aren't seeing the same problems! If they were to advertise real compression numbers with the stock head I'm sure we wouldn't be hearing as much about this!

 

If what you say is true and i had an j.e. 11/1 piston what octane should i run?

 

It depends on other things as well (IE: cam, type of riding, chamber mods, ect....) but somewhere around 100 to be safe. IMO

 

Measure the wrist pin and make sure its the right one. ALot of the cracks are around the wrist pin area from underneith and if I remember right they did have a run of short pins that can walk