Thread: I blew IT! :) 56k don't do it!

could have been the crank flexing at those high rpms and caused the pistons to hit the oil squirters?? are you using the 8 or 4 counterweight crank?

8cw DE crank. I don't think it was flex though. Sure the pistons will move a little further down when under full load, but it isn't much.

fuel cut limiters ARE the devil. But I tried searching google for anyone else getting detonation at fuel cut, and most people are saying you won't det. But then again, most of those guys aren't pushing much power.

I've thought the same thing for a while now, but you know that.

With TunerCode, I can program the rev limiter to operate pretty much any way you like, in terms of fuel cut and/or timing retard. I don't think you want timing cut and fuel cut because I believe you would still want whatever fuel is in the cylinder to burn there, rather than in the exhaust system. Ignition cut only rev limiters bother me a little because of cylinder wash-down and lots of raw unburnt fuel in the exhaust system.

Maybe we should start another thread to discuss proper rev limit design?

Dave

I learned this little tip from my hardcore rotary roomate...seems that those engines don't like fuel cut rev limiters. I watched his motor explode lol. but he wouldn't make that mistake on his new motor he made sure to get an ignition type rev limiter.

Honestly when I do hit the rev limiter I rather have a little bit of excess fuel because I'm not bouncing of the limiter while racing I wouldn't be worried about fuel washing down the cylinders. Where on the other hand I would be worried about the fuel cutting and my pistons melting so I rather just cut the spark and have no combustion. If there is no combustion then you cant run lean at the limiter...In my eyes this would make an ignition style rev limiter better.

Jeremy,
I'm calling you now.

reliability over monstrousity.

24 psi with detonation and that was all that happend . be glad.

We could talk about rev limiters in another thread but spark-based rev limiters have their own issues as Dave mentioned but also pre-ignition is a scary proposition.

Ideally you could cut fuel and spark during the same engine event. Supposedly many stand-alones can do this but I've seen my fair share of stand-alone mistakes on a per-revolution basis so I'm skeptical.

Well guys, I will be making a few calls tomorrow hopefully and getting the ball rolling on some new parts.