Oil for Alcohol
We run a Blown Alcohol Altered and use 20W50 Valvoline Racing Oil Part number 211 (versus the retail "Racing" oil). We run Federal Mogul competition bearings and have yet to have an engine problem due to oil issues. The motor is a 509 with a 14-71, 27lbs boost with significant cam. Rings are total seal gapless. We run hat & port injection (buzzard catcher). 2100Lbs car runs 7.10's @ 190 at 3330ft corrected altitude. Shift at 8000, launch at 4000. We purposely run rich and don't set it on kill (parts are expensive). We DO NOT get milky oil. The wash down of the oil due to alcohol is based on the whole combo in my opinion. Although there is a time when the horse power level calls for it to cushion bearing load, 50, 60 or even 70 weight oil is not needed for most people.
PS - We change the 11L (8 in the pan, 3 in the accusump) of oil every 12 passes.