That's what I was going to say.... check that top wring gap. Also, no matter what the top end gap is... quit cheesing out on the fuel. You'll pay for it in the long run. Mixing fuel is not a linear equation. 1 + 1 does not equal 2 in the cases of mixing octane. The only true way to know where you were at is to octane test your batch.

I still believe that you burned down a wring. I run a RWR advance cdi on my 13.5:1 HPR piston and run a 25 shot. I HAVE to use straight 110 or better. I probably should be running 112. Viper, make sure that you get your cylinder honed and re-nicked. Groves are never good, especially if you can feel them with the end of your fingernail or a feeler guage. If you need a new cylinder, let me know.

Good luck and keep us up on what's doin'

BD

 

Thanks for the words Doctorturbo. Coming from you, that means a lot[img]i/expressions/face-icon-small-wink.gif[/img]

One thing that really perplexes me is the fact that the damage to the cylinder isn't worse than it is for how bad a shape the rings are in. If those rings butted ends on a 30 shot or they bent and cracked and warped out of place due to preignition, I would expect that cylinder to look like hell!..............yet it doesn't. Also, if there was enough detonation to force the ring out and down, you sure would think it would apear on the edge of the piston.

I am imagining that is an HPR 12:1 with nikasil coated rings? What is the NOS gap on stock bore? .025 - .027?

I really don't want to jump in too much but one thing I learned about nikasil is if you can feel the scratch, it is through the nikasil and will end up being a compression liability.

Was that 100 octane the oxygenated designer fuel or just the 100 octane unleaded race fuel? 12:1 compression, 32 deg of advance, 30 shot of NOS on 100 octane............even at 5000 ft, I think you figured it out already[img]i/expressions/face-icon-small-wink.gif[/img]

One more thing, I can hear detonation on these single cylinders when I am running all motor. Since I haven't run NOS before, can you hear detonation when you are on the button?

 

Thats terrible Jed... But not as bad as it could have been.


The cold thin air probly leaned it out, and after you drank a few cold ones you decided to go spray the nos???LOL Hope you get that pig runnin soon keep us posted. But if your running BOSS system doesnt it compensate for the cold air? If so then you did it on all motor. I thougth the boss would add the extra fuel?

 

Mario,

Thats a good question and Im happy to answer. The NOSS system simply takes care of itself, as far as being on the button. Since the air (N20) is regulated, the fuel can be the same. HOWEVER, that being said, if your carbs are off, then the whole system will be off. If the air drops 30-40 degrees, and re-jetting has not been done, you will still have a lean issue, on or off NOSS. Yes, you can compensate with the MFM, but if you dont know there is a problem with DET, then you wont know to raise the fuel level on the MFM. And since the MFM only controls fuel while on the button, its simply best to "old school tune your carb" when these dramatic temp issues emerge. Further, the NOSS system can be perfect, but if your carbs are not, and you run NOSS, it can accentuate the problem. Just depends on how rich or lean your NOSS system is. In Jed's case, he was actually rich on the NOSS side.

So, you simply treat your motor like you would any other time. If you need to rejet then you rejet. The NOSS system does not need to be rejetted.

Marky

 

You know, I hate to say this....but, I didnt recheck the gaps on the rings. They were predone at Hpr, but I would bet just for motor. Now that has been said, I guess I will have another motor to tear down to recheck gap. That would definitly describe why the end of the ring left an impression on the cylinder.

Detonation can be heard on nitrous as well. But like on all motor, it depends on how severe its happening. When it occurs on motor, you get that loady sound to it, like its not running clean. You get that with nitrous as well, but only if you are getting it severe. Running lean does not give that sound. The bike sounded good, both on and off the bottle. But I am now willing to guess, that the ring expanded, butted ends, spun in the cylinder, and the one edge that is cracked caught on one of the grooves and bent the ring lands. Since there is no other sign of deto, it makes the most sence. I would bet I still had deto though.

The rings were gapped at I believe 22 thousandths.

Big D. I dont know what to say about the Ron Woods box. The one I borrowed came from one of the motors I put together with 12-1 comp, and he is running my old BD setup with a 20 shot, on the same mix of fuel. So I dont think its all the boxes fault, but more of a combo of them all. More importantly mine, one for running to low of octane, and two for not checking my build like I should have.

I will be needing another cylinder though, as I have already got some calls out for one. Give me a pm if you got one you would like to get rid of.

I have spoken with Eric about this. I will be sending my piston back to him for him to evaluate as well. I am also sending my vortex in to get the rpms limit rasied. Over the phone we came to the conclusion as most others did that I ran too little octane. But we didnt talk about the ring gaps!

 

Sorry to hear the news Jed. I will say I had the same problem and it was ring problems only on the turbo bike. Smoked alot more when off the throttle. I also had noticeble crank case pressure causing the seals to leak especially around the front sprocket. Alot of oil out the blow-by also.

 

Ouch!! Sorry to hear this 650Viper! BTW good meeting you last week!

Crackerjack, what did you find out on the DS motor you had with you that day we met? Is the piston toast?

 

It will be torn down by the end of today. I will let you know.

 

Hightower, it was great to meet you as well. Sorry I wasnt much for company, I was trying to get the bike to run, eventhough I didnt have all the parts I needed to make it happen. Next year I will catch you in Idaho and runs some bowls.

Justin, it sucks. I had it running good on friday. I cut a little less octane in it and it drops in temps and poof, smoke. All so sudden. But wait till you ride the thing. Holy crap. I have got to get the suspension setup better to handle the speed. It flat halls the mail though. I should have it back together in a couple weeks, so it shouldnt be down too long.

 

Jed er shoud I call ya tight wallet Napoleon?,

Anyways, I will give ya a holler later this eve, I have a few ideas. Seen this before.