EVAC... Big block???? Help

[rayray]

I have a 528 CI Hemi. Im trying to figure out best way to vent crankcase pressure. It now has a rear main seal leak. It has very few miles on it like 400. It was leaking from first trip through the gears. its a street car has 867 HP at 7000.
Moroso says EVAC into collectors wont work on full exausht. So now what do I do I can get a pump kit, which didnt sound to streetable to me after talking to Moroso tech line,or i can get two air oil seperater tanks.
Just wondering if anyone else had similar situation.I would like some input before spending more money....Thanks

 

[funwithfuel]

I suppose the question is are you are you building Crankcase pressure ? I would not think that a fresh build would have too much blow by . honestly I would lean more towards a seal failure do you know anybody with a slack tube . it is basically a loop of clear vinyl tube with about 10 inches of coolant in it 1 side goes to your crankcase breather the other side is vented to atmosphere if the fluid moves more than 2 inches at full throttle with full load you have too much blow by

 

[jameskernz]

Talk to ("GZ motorsports") they make a vac. pump for the street.. Had one on my 550 Hp. mustang. It worked good and was reasonably priced. My motor would push the dipstick about an inch and motor was recently rebuilt. But it also had low tension rings which was the cause of the problem, engine builder told me later. If I remember correctly the pump kit was about $375.00
Jim

 

[OldmanRick]

I'm not sure how a street pump vs a race pump is as far as the amount of vacuum produced. Sounds like a reasonable alternative?

I remembered a article by David Reher (pro stock builder) regarding oil control on wet sump engines......here is a quote and the link to the whole article.

"I am not a fan of crankcase vacuum pumps on wet-sump engines. Lowering the pressure inside the crankcase with a vacuum pump can increase power because the crankshaft has less drag - just as an airplane can fly faster in the thin air at high altitude than it can in the denser air at low altitude. But from the standpoint of the oil pump, a little positive crankcase pressure is actually desirable because it forces oil into the pickup. Positive crankcase pressure primes the pump and helps to ensure a steady flow of oil into the pickup. When the crankcase pressure is artificially lowered with a vacuum pump, there is less pressure differential to push the oil through the pickup tube".

http://www.rehermorrison.com/blog/?p=69

 

[Darter6]

My 472 hemi has a PCV valve,full exhaust, street, I am running 1 carb.