Fuel into crankcase Incident

Hi ITA--

Hoping for some advice on what to look for after an incident that occurred during late staging/while on trans-brake (grid limited rpm). Engine is KB hemi, conventional roots blown alcohol setup.



Burnout/staging was normal, creeped into 2nd bulb, got on trans-brake, released button--car immediately took a hard fast right turn. Car tried to roll over, zoomies on driver side kept it from going over. Just missed tree and my opponent (I was in left lane). Was able to keep it off the wall(s), pure luck.

Turns out i launched through my own oil slick which was a result of dry sump tank overflowing with alcohol (overflowed tank, then vented out the breather tank).

When i returned to pit, inspected check valves, return lines, even pulled fuel pump to look at seal around drive shaft. Nothing obviously wrong.

Any ideas? I haven't launched car since that last run.

[Pro mod car, dry sump tank up front by fuel cell]

 

which pass of the day was this? 1st, 2nd, 3rd? I’d also like to know when was the last time it was drained and also what the circumstances were before the run? Is it possible you have a hurt hole recently you thought was ok? Were you on the twostep longer than usual? Do you use a leanout on the two step?

 

Thanks as always ITA. Great amount of veteran advice here for sure.

I have fought a very rich condition from day 1 with my setup, have not been able to pin it down. (Fuel sys has been flowed twice, with mostly similar setup resulting). Slowly been creeping toward correct burn--but huge changes on main jet (like 20 numbers) have made only small changes in how rich it runs. Definitely points toward something significant that I have put together incorrectly--like backward checks, incorrect plumbing, etc.

Whatever had been causing it to run rich seems to not be the reason for "the bad event", as while I have run rich, filling the oil tank had not been even a remote issue. I am a small crew--2 of us, and the driver/owner (me) is the only guy that gets to put oil in. Not that i couldnt screw that up--but i dont think extra oil was the situation. Plus the oil was so milky, it seems to be all fuel and not extra oil.

i will definitely check how many main jets are in the barrel valve. I could see that happening (but might be too embarrassed to admit it if I find that is the case).

I am wondering if debris could have wedged into the port check during start/burnout and then was pumping fuel past rings during back-up and staging. I have about 1-1/2 gallons of reserve capacity in the dry sump/catch tank--maybe that was enough time to pump it all full?

Like so many things done during the heat of racing, i took everything apart and now the motor has even been freshened since. Didn't find a single thing yet that would have caused it. Putting it all back together this week, will fire over the weekend and see where i am at.

 

I know its going off Topic Will...... But do you really think Oswald did it ;-)

 

Can you move things around so that you don’t puke oil on the tires? I would have wrecked every car I ever put a blower motor in if my puke tank dumped in front of my tires.