I'd like to see what Ross has to say about the piston. I can already tell you what JE is gonna say, but you'll probably get a piston out of them. Or you could send it to Ross first and then to JE.[img]i/expressions/face-icon-small-smile.gif[/img]

 

No, it wouldn't run long enough. Have you ever seen a heat stain on a burnt piston?
On some of our long run high HP turbo engines we will see the total underside turn black (even with piston oil squirts to cool it) We ended up going to Cosworth in England to get an alloy that would tolerate this much heat. But that's another story!!
I'm gona sign off now, it's 12:30 am here and race season is just around the corner so I'll be at the shop from 7am to 10 or 11 pm tomorrow night. I don't have time to check my "E" mail at the shop so my next reply won't be until I get home.
Ray

 

Hey dynoray is the discoloration a electrochemical reaction?

 

Sam's ran for half a day of hard dune riding with blowby out of the breather from the crack in his and was still running when we tore it down..

 

I ran my stock bore 10.75/1 JE on pump gas with no problems. My new 686 with another 10.75/1 JE is working fine on pump gas as well. Anything more is a waste IMO.

 

My Builder is putting a 12:1 JE is my 686. Should i tell him to go 11:1 before it is too late? I'm getting scared now. I ride everything from Dunes to trails and, i just wanted more power to keep up w/ my buddies Bansheees. I'm nothing close to a mechanic and, these problems explained above would prolly cost me 1k per time i needed the piston replaced by a Local Stealer.

So what is the true recomended Octane to run in a 11:1 and, for 12:1 pistons? IF it is 93 for 11:1 will 100 octane hurt anything? Or, Vise versa.

While on the subject of higher compression = how are starters holding up for you guys? Is 12:1 gonna make my starter crap out? I really can't afford nor, repair these types of problems. I'm starting to wish i'd have stayed piped! OUCH!

Please advise, i got "Butterfly's" now!

 

I have over 40 hours on a 11:1 JE and NO problems, first ride was pump gas, then went to race gas and it runs MUCH smoother, I race it ALOT if that tells you anything.

 

My first piston I'd guess 40 hours plus and the 2nd piston I'd say I doubled that.

Also, the first piston I ran it with a crack or start of a hole for the entire 2 weeks I was in LS Utah/St Anthonys, Idaho/Montana. It was gradualy getting worse with the oil out the crank case breather and then it was rode for a weekend at Pismo until it was more than obvious I had a problem, but it wasa still running.

This time there was no blow by to indicate a problem until while going up the hill it died, I looked down and saw oil dripping on the swing arm/back of motor and I knew what had happened.

I'll get it straitend out one way or another.

 

Me too, most of the time, but it makes it sweet when Banshee riders or anyone else comes up to you and asks what you have done to your quad etc. The last one, on the day of the carnage said, after I said my piston blew a hole in it, and I quote "Good, I was tired of getting beat by you" He was ported, domed and some other stuff. Of course he wasn't serious about being happy that my quad broke but it still almost makes it all worth while.

 

Piston is on it's way, you will see it thursday, in time for the weekend...hope it works out, ill be ready in a few weeks i hope, everything is coming together..