There ya go!!! Lets go out and flog the hell out of a motor that needs race fuel on pump gas.

 

Interesting turn of events.

Your actually kinda lucky that in this case the head gasket was the weak link (aside from you). Most high compression motors would have siezed the piston. And that really messes up the cylinder walls. And in some cases they can't be honed out. You learned a very expensive lesson for sure. Trust me I've learned the hard way many a time myself. What ever you do though. Don't tell others that a CDI caused your pain. If you had run at least 110 you would not have detonation / the pinging. Your CDI didn't cause that. The low octane fuel did. That would have evenually siezed the piston or blew a hole in the top of it. Your head gasket gave way first. Hope it didn't get to hot. But Im sure Gary checked it for warpage.

 

sorry, still don't buy the head gasket blowing out due to timing. Detonation or not, the head gasket should not have failed. Yes, the piston and rings would have been a real mess, and yes he is lucky.... but pre-detonation doesn't eqal pressure and pressure is the only thing that should have made a new gasket fail.

I'm not trying to lean on TVI, they can do what ever they want..... and I'm not trying to be a "BREEZE" here. It just doesn't equate. The only way possible for this to happen would be for the metal ring on the head gasket to fail before the piston. The piston which is directly below the spark should have been first. I realize that rings also go bad in these conditions as well, but they are under load and much hotter temp wise than the gasket.

 

[img]i/expressions/face-icon-small-confused.gif[/img]

Anytime you fire on the upstroke your building a lot of pressure???

 

I would think the pre-detonation would produce more pressure then normal.

Please correct me if I am wrong with my reasoning.

During pre-detonation, the piston is still traveling up to TDC and before it reaches TDC the gasses ignite which would push down on the piston but instead, the piston is still traveling towards TDC compressing the mixture even more making even more pressure.

Under a normal ignition sequence the mixture is ignited and the piston heads towards BDC which would relieve the pressure quickly.

On a side note, if you were happy with the RWR cdi then I wouldn't of wasted my $$$ on the MSD. If you truly thought the RWR cdi was at fault then I would of reverted back to the stock CDI to prove it wasn't the CDI. I am sure the RWR cdi compounded the issue of running too low of octane. I would think with the proper octane you could run any cdi currently on the market with no problems.

 

Yes, pre-detonation is a big problem and I do agree that more pressure is built by the early ignition. But the early ignition that we are talking about is not the ignition that is sending the piston back down. It's little itty-bitty ingitions just enough to pit pistions and put hole i them. We're not talking about big explotions that blow gaskets out. O-ring'd blocks (or jugs in this case) are put there to help seal the block that will experience very high pressures. We used to have to o-ring our blown motors in our race boats all the time, becuase to the forced induction via the 1471 sitting on top.

The poor guy doesn't have a leg to stand on. Gary told him to stop running the sled, told him to use race fuel..... sent the motor out to be used in a certain fashion. I don't disagree with anything up until the fact that the RWR CDI caused the failure. While speculation is nice, this exact scenario can't be proven. And to ignore past problems such as leaky cylinders/heads and put this completely on the CDI would be a mistake in my humble opinion.

Agree with most of what Duneme and Sand said. Just know that when anyone says "always", "Forever", "Never"....... I tend to be causious. Absolutes are rarely 100% accurate.

 

If pre-ingition can take out con-rod bearing as it has in several cases on the fourm lately,it sure can make a head gasket leak! Broke rings and hammered valve seats!As I stated in letter to CC Co. I have pictures....

 

Bigboo good luck. If you were to do it all over again get a HPR730. I rode BigDaddy's 730 and it was a monstrous improvement over the 720 that I previously have had. His bike impressed the hell out of me and pulled with power to spare everywhere. I secretly didn't want to return his bike back to him. Anyone considering a bigbore kit don't waste your time get an HPR kit. My 720 leaked coolant as well and never saw any serious gains. More money for the HPR but you get what you pay for.

 

Thanks for the props Dave. I agree that it's all BAD...... my point is, lets not forget about the problems that are out there with leaking head gaskets from sleeved BB kits form just about everywhere. It's not my intent to hang Gary or all TVI stuff. My intent is to clear up the point that the RWR CDI is not the culprit for the head leak. I said earlier that if it was the CDI than I'm short. If it where the CDI's fault, many of us would have blown head gaskets for appearently no reason at all. I have a RWR CDI and have 13:1 and run NOS - no head gasket issues. As I said earlier, this guy really doesn't have a leg to stand on...... but let's not blame the CDI.

Lot's of CDI talk lately, and I don't want to put the RWR unit on the chopping block for no reason at all.

I'm done - no more comments from the gallary (me that is).

Good luck with your motor.

I think that Entomber hit the nail on the head......

 

I have a question for you guys......on the pred motors that get built by doug(only performance builder i know)......he puts time on the motor by using a quad without a motor in it......this way he knows it will run correctly, and he can tune it.....


Do other builders not do this?? I think I'd do it if I was a builder......and I'd want it done if it were my motor.....otherwise, too many liabilities.