Venting a drysump motor

[FF21]

Should you run the 2 breathers in the left valve cover, or use a peterson pop off valve in the left cover or just run a line say -8 from the left valve cover to the drysump tank and vent it that way?Thanks Rick

[hogracer3d]

Our sprint car motor has a -12 from the left valve cover to the tank, and a front crossover between the two valve covers with two breathers

[Kwaz-13]

it depends on the number of stages your pump uses. There's a lot of good info on the peterson fluid systems site, if you haven't already checked it out

[FF21]

Its a 4 stage with all three lines are coming from the pan.Using a Dart Little M block.I have seen some motors with just a pop off valve.the two breathers on the left side and some with nothing.Just trying to figure out the best way

[fast_crew]

If you get to much vacuum with the engine sealed, you would want to run a pop off or an adjustable bleed to adjust the amount of vacuum in the engine. There are a few things to consider. If the engine uses thin, low tension rings there is a good bit of power to be had by running vacuum. If the engine has thick, or standard rings there isn't really much power to be had, only benefit is no oil leaks generaly. But remeber where oil can leak out, dirt can be sucked in!!

[sj valley dave]

We run a 5 stage with vacuum. We run a .043, .043 1.5 mil ring package and have a pop off valve mounted to the intake spider, nothing on either valve cover other than the oiler lines...