Skirt Scuffing Problem Solved!

We have been fighting a piston damage problem for several years...all below the oil rings and the transfer is from the skirt to cyl wall....and this year with a new blower the damage was only to the very front holes. I suspected we were washing the cylinders down on the burnout. We tried several oil additives over the past few seasons with little difference. Shortening the burnout was one alternative....but we are a match race team that mainly does exhibition style events - so there had to be a solution. Last weekend we tested at Eddyville and made 3 full 1/8 mile passes with 330' burnouts. Sean trimmed the pump with the fuel lever to raise the idle rpm from 1850 to 2200 on the burnout only....then opened the valve for the run. I know this is not a real scientific way to bleed some fuel as compared to a "high side/low side" setup....but the oil was not a pure white milkshake like before....but a nice golden brown color just as it went in after the run! We changed it every run anyway as was advised by Randy Meyer and Will Hanna at Topeka last weekend....and we will probably run the oil again after it cools as they suggested (thanks guys for the good advice on this). I took the engine apart yesterday and the pistons and cylinder walls were excellent! I would not suggest this trick unless you have a way to make darn sure the fuel lever stays put during the burnout....could be disaster if it vibrates shut....but we use a Waterman pump with the friction pin and a super tight cable....hope this might help another team with piston scuffing issues.....

 

Good to hear you got the problem fixed Scott.

I use this inexpensive little unit to keep the shutoff from vibrating shut, it works great and sure beats duct tape!

http://fuelinjectionent.com/webstore/product_info.php?products_id=154

Chris

 

problem fixed

Isn't it really a good feeling when the stars line up + and ugly problems get solved. It sure is for me. Good luck Don

 

vernier cable

http://www.goodboatgear.com/detail/6950/ Vernier Cables
http://eriksmilitarysurplus.com/thcoca10ftwi.html
Scott, We have always use this type of cable. We set it up to pull on and push off. The knob can be turned for fine adjustment if you are leaning the motor to warm up and is locked in place. A quick slap on the button shuts it off. The links are from google. Have alway purchased ours at local truck shop.

 

Why not jost put a pill holder and a return that you either open manually during the burnout or activate a solenoid for the burnout. Kind of like a pump loop that is only active during burnout.

You don't need to worry about getting the shutoff in the right position or having it close on you.

Of course the size of the pill will be trial and error....

Troy.

 

Troy - that was my plan after making sure that we had too much fuel on the burnout....and this was confirmed....your suggestion is kinda like the fuel cars that have a high and low pressure poppet and a valve ......but it is real easy with our cable & lever to put the idle RPM at 2200 for the burnout, so problem solved....no extra cables or plumbing....