crank evac kit??

[aalugo2000]

hey guys,
a couple days ago i found out that i need a new rear main seal, (i have a small oil leak), when i asked my mechanic if there waas anything i could do to prevent this from happening in the future he recommended a crank evac kit, he thinks that im building too much pressure in the crank from using nitrous.
what do you guys know about these evsc setups? are there any drawbacks to it? should i get it?
and i also plan on upgrading to a 100-shot after i get a new fuel pump.. if that makes a difference.

[mcjoslyn]

You shouldn't be building up excessive crankcase pressure even with a nitrous kit unless you are getting a lot of ring blow-by. And even then, it shouldn't be anywhere near high enough to force oil past a main seal. If the pressure were that high, it would actually force the dipstick up out of its tube. Check with another mechanic.

[aalugo2000]

thanks for the input..
my mechanic was basically throwing that idea up in the air, cuz i wanted to know why i blew the rear main seal, he thought it might have been too much crank pressure, and that was the only thing (evac) he knew to prevent it, because i dont want it to happen again, he also said he'd look into getting a teflon seal, so it would hold up longer, has anyone else blown that seal? if so what did you replace it with? oem?

[xjarayax]

It's notorious for going out on our cars.

[aalugo2000]

ok thanks guys,
i guess ill just replace it , and hope i get another 80k miles outta it.

[12secondv6]

Hot Rod issue Feb 2000
Page 112
On a 556 ci street rat they installed Moroso vaccum pump and breather.

A vacuum pump is able to add power by reducing windage in the crankcase and by aiding the ring seal. While virtually any ring set would benifit from vacuum in the crankcase........

Dyno:
w/o it 790 hp at 6,700 rpm's
with vacuum installed and 19 inches of vacuum 813 hp at 6800 rpm's
with vacuum installed and adjusted to 12.5 inches 821 hp at 6,700 rpm's


With the same engine and a NOS big shot plate with 120 nitrous jets and 116 fuel jets and 114 octane it added 277 hp


With vacuum installed 310 hp gained on same shot.

This is all relating to a crank case evac system.

I pretty much copied a lot of it from the mag.

30+ hp.... on a BUILT to hell 556 ci motor.

Would we benifit... according to their information, yes. Would it be noticable... maybe not :(


Hope that helps

[mcjoslyn]

Thanks for the information. That's interesting. I know in the old days they actually ran baffle plates under the cranks on built V8s to keep the crankcase turbulence down. I doubt it would help us much on our V6s unless your engines lives around the red line all the time, although the extra ring seal effect might be good for a NOS engine.

[aalugo2000]

hey, thanks for the post 12sec, and can everyone in here check out my, i may have broken a rod post , that is my newest problem, im trying to figure out if it may have been caused when i got that rear main seal replaced.