T
The squish design is not focaling heat to the middle, it's using a wider larger trapping area to quench more of the piston.
Explain this ring failure,
Explain this ring failure,
Follow along with the video below to see how to install our site as a web app on your home screen.
Note: This feature may not be available in some browsers.
So you're saying that the wide quench area is used to cool? the piston?? Under compression that would mean. Are you sure?? That seems like a long shot. Explanation?? Not trying to bash
Ring explanation...
Took the head off the other day because the motor was down on compression. It was down nearly equally on both holes. Figured I would take it apart and have a peak at it. I have an engine tech head. Domes are modified a bit. Turned on a lathe, altered quench angle because piston crown is different on 08 and 09 pistons. Head was designed originally with 08 pistons, angle needed altered for use with 09 pistons. The sled gets run really hard, its jetted lean and runs hard when it runs. (A bit inconsistent) What I found when I lifted the head was a few hundred ping marks on the piston and head, the pings match each other. Not ping marks caused by detonation, but marks caused from pieces. Where the pin in the piston, the cylinder is scored. The ring broke at the end and went up through the edge of the piston. That sent piston and ring pieces loose throughout the chamber...thats the theory anyway. I havent disassembled the rest of the way yet. I got megasick. The pin possibly could be trying to back out. Not sure yet.
Any ideas are much appreciated. I am going back to the stock head. I have to get a handle on the parts breakage and try again.
No, the ring never turned. The end just came off. The motor ran fine, it just was down on compression. Both cylinders, same failure. Mag side slightly more ping marks
Ya the funny part is the only other time we have seen this was on chevy too. For the same reason, the ring touched. The odd part to me was that I have ran a bunch more compression on this same motor and worked it harder than I had worked these pistons and it never broke. Now it grenades with lowered compression. I really dont get it. The only thing I have done is narrow the quench area slightly, and loosen the squish by about 15 thou.
Kinda what I was thinkin. It ate the cylinder, both slugs and head. I can save the head if I want. Thinkin I may go back and just mill the stocker and run it. I just dont understand why this thing is so finicky about its head. The dome design I have is far superior to factory dome for output. We developed this dome on a YZ125 that will beat up on ported, piped 250f's. It works well, and it built good power on this sled until it broke.
Now I have a question for all you big bore boys...trying to decide on either a carls 860 or a turbo for my dragon..would enjoy hearing your thoughts if you have ridden with em....
Hey TNT... how did that T 860 go after you "fixed: it. sj
Yes it does! ,,,I,ll be on my backup sled tomorrow, Have the Raves out for a little work on the 880.....Sucks!IT RIPS!!! Watch out bob! LOL.![]()
Dam, already making excuses lmao.Yes it does! ,,,I,ll be on my backup sled tomorrow, Have the Raves out for a little work on the 880.....Sucks!
I have done a dragon, and to be honest I talked the customer out of doing 860, the cylinders are so thin that if you should get it hot, I don't think it will survive.
Now I did a aggresive trail port with twins and it's strong running sled, less money then a BB and very reliable and not finicky like most twins seem to be.
Just food for thought!
Someone posted that the 09 is off the clock at 3 hours, They posted copy of the page right out of the manual.Dam, already making excuses lmao.
Be interesting how well it runs after 10hrs.