bulding a 12a for roadracing (and maybe a little mountain carving) and i'm wondering what to do for the pcv/overflow system.



the comp manual wants a cookie tin built into the filler neck



is there anything newer/better?

 

I dont know if it would be any use on a rotary, but a sorta common thing on piston engines is to plumb the pcv into the exhaust. The exhaust flow pulls a vacuum in the crankcase, which reduces windage losses. Ive seen dyno results of 2-3% on my type of bike from that. I plan on using an air oil seperator on my bike, but its probably even more important on a car.



Lynn has posted details on using a turkey baster to modify the breather on the oil tube to keep oil from coming up the tube and filling the catch can on hard right turns. Basically, you drill a hole in the center of the filler cap, and attach the baster so the small end is pointed down into the filler tube.

 

Oil windage in a rotary is a problem, but there has yet to be a method developed to handle it. Sealing the center iron drainback and plumbing it to one stage of a 4 stage drysump pump would work, but the gains might not be worth the effort. Anyway.........



Here is what is typical for breather set ups on racing rotaries. This is for conventional wet sumped engines. For dry sump engines the breather to catch tank hose runs from the oil tank to the catch tank.



The engine breather runs to the top of the oil tank, and flow is from the tank into the engine, because the scavenge sections keep well ahead of the engine breathing demands.



I am not familier with the turkey baster system??



Lynn E. Hanover

 

you came up with it!



seriously though, now that its been mentioned, its been covered before.

 

we did we did!



https://www.nopistons.com/forums/index.php?...370&hl=vent



https://www.nopistons.com/forums/index.php?...923&hl=vent



https://www.nopistons.com/forums/ind...howtopic=60986