crankcase breathing.....

[jick]

i'm just trying to get as much info as possible on what people are doing to vent their engines, i'm mainly talking about 200hp plus  race/street motors that are turning up to 8500rpm...

anyone here running lines direct from the bottom of the heads back to the sump?

is that a good idea or a case of overengineering?

whats your set-up and why?

thankyou men!

[besserwisser]

Running a line from the bottom of the head back to the sump has nothing to do with crankcase breathing. It´s more a way to get oil back to the sump so the oillamp doesn´t go on at 402m when your reving close to 8000rpm. You use force to get the oil out of the sump but gravity to make it come back. If you look at the case and the small amount of space between the pickupptube and the case you can see that it will take oil a while to trickle back into the sump. At the same time a melling heavy duty pump is emptying the sump like there is no tomorrow.If you have a lot of problems with crankcase preasure there could be a lot of different reasons. Worn rings, new aluminum case not blueprinted, to small of a diameter of the hose for crankcasebreathing,worn cylinders out of round.The type of crankcase breathing kits they sell I would mainly use for hi po street cars. All out race cars need a lot more breathing than a 12 to 15mm hose can handle. Just my 3 cents