Ive seen these pistons split both direction . usally they split with the wrist pin one split the oppisite of the pin I will try and get some picks to show you . Also there were no signs of Detonation . Running race blend . I have also noticed JE has changes the build of the piston 3x that I know of and increased the lenght of the pin 3x . Dont you just love being a R&D lab .

 

Do you really think if he sends the piston to JE they're going to say "Looks like our piston is a poor design and it's our fault". NO! They're going to say "You did something wrong. Here's a piston, now go away". That's what they did with me when I sent them Sam's piston ( in the second set of pics). I wanted to send the piston to Ross but JE never sent it back to me.

I think what happens is the top of the piston is to thin and flexes and you all know what happens when you bend aluminum back and forth, IT CRACKS.

Those of you that say you see detonation please point out just what it is you see that makes you say that, because I sure don't see it. The pic of the head looks like oil and carbon baked on to the head, I see no pitting on the head or piston.

On Sam's piston the hole was over a 1/2" away from the plug and looks about the same on wshrdskins first.

 

I have a 13:1 coming hopefully it doesn't turn out like these [img]i/expressions/face-icon-small-shocked.gif[/img]

 

Just out of curiousity... what kind/heat range of plug is everyone running that has been having problems with this?? Just a thought.... might be something..... might not. Anyone experimented with a different heat range of plug?

 

I run 1 shade colder than stock and have been for well over a year. I went too a colder plug when I heard detonation using my stock bore 11/1 JE on pump gas. No way a rider will not hear detonation on the Raptor....very loud and very distinct.
Gary

 

My Raptor leaks some oil out of the K&N breather filter. Not pouring out, but enough to make sand cake to it. Also, my oil is black after like three minutes of running. I can only assume that this is not normal. Would I be better off running straight race gas when I'm spraying?

 

dude check your piston cuz those are the signs of a hole in the piston, you dont want anything that cakes up coming out of the breather filter....

 

I talked at length on the phone with someone the other night who also had 2 failures identacle to Wshrdskins, he is not on the internet and didnt get pictures so no one on here knows of him. JE did replace them both. So I have read or heard of about 1/2 dozen similar failures now, they sell alot of pistons though! I bet it was a bad batch.

The 12:1 has more meat up top

Also I dont think at this point you can go by what the plug looks like to determine the failure, there was a hole in the piston..

 

I thought it was common knowledge to run at least 107 octane with the JE 11:1 ?

Sure, it says 11:1, but its actually much higher compression in the motor. I can only
speak from what my builder, Bob Craycraft , recommends. And he recommends at
least 107 octane in the 11:1. AKA - VP Red straight ! Or similar. I sure wouldnt put
in 91, or 94, or a mix to get it near 100. I run straight VP Red.

Too low of octane causes detonation right ?

 

I run 93 on my 11:1 Ross. Nothing more nothing less.