S1dc_Drifter

iTrader: (2)

I am getting some blow-by at high rpm. I have a breather in place of the oil cap and a catch can with PCV deleted. I have oil coming out of the breather under heavy load. The motor is brand new with about 200km on it, it is used in a drift car so it sees high rpm majority of the time.

I spoke to my builder and he said I need to vent some more crank case pressure. I have a few options to choose from:

1) Moroso evac system and use my current catch can (I have open headers)

2) Ls6 Valley Cover with catch can and get rid of oil cap breather

I wanted to get some opinions, I have heard of people continuing to get blow-by even after the ls6 valley cover swap. Also I have heard mixed reviews about the evac system.

Basically I need to vent the most amount of crank case pressure to relieve small oil leaks and blow-by without spending 500-1000 on a vacuum pump.

Thanks guys!

01ssreda4

iTrader: (96)

Why do you have so much blowby?

S1dc_Drifter

iTrader: (2)

I am not quite sure. I will being doing a leak down test shortly. I have heard that these engines have blow by issues. The reason its spraying is because of the breather. The dip stick pops up a little bit also.

for people to run these evac and vacuum pumps I can't be the only one suffering from this.

I am just trying to get opinions on the best way to remedy the issue.

01ssreda4

iTrader: (96)

Brand new engine............sure the rings have seated?

Grr

iTrader: (2)

use the catch can and hook that PCV back up, its foolproof and you shouldn't get any oil in the intake

Trboboost91

Ill just add to this in hopes of more help without starting a new thread.
I have a roadrace miata that is ls1 powered and I guess I has the breather/pcv system hooked up completely wrong or I have a lot of blowby/crankcase pressure as it pushes oil right past my valve cover gasket on the pass side but not the drivers side (wierd?) when used at high rpm/load.
Looking for the best remedy for this. Possibly just a factory diagram of the correct hose routing.

01ssreda4

iTrader: (96)

Factory pcv is simple. Fresh filtered air from TB to the front of the passenger valve cover, this would be an inlet to the crankcase. Then both valve covers vent at the rear, the lines combine in a Y to a single line, to a PCV valve, then to the intake (vacuum) neck, this is the waste exit. The LS6 valley mod deletes to two valve cover exits (they get plugged off) and replaces them with a single front valley cover exit. The earlier model valley required a PCV valve, the later did not because is had a built in restriction.

Trboboost91

That's what it looks like on a ls1 on a vette I looked at at the track.
But mine has 2 90 degree vents on the pass valve cover (1 for fresh air, and I assume 1 for the pcv line, but the drivers valve cover has a rubber grommet at the back big enough that it has a pcv valve in it, unlike the pcv valve in the line like you speak of.
According to vin the motor came from a 02 z28.
Not gonna lie, I'm pretty green to the Ls motor. But I'm willing and wanting to learn.

01ssreda4

iTrader: (96)

The driver hole is much bigger. My car had an elbow and reducer there and the PVC was located at the front of the engine. However, on older engines it was very common to have the PVC valve installed like you described.

S1dc_Drifter

iTrader: (2)

Ok guys, So I have done some research and plan on doing the new ls6 valley cover with a dual catch can and leave the filler cap breather on. Hopefully this relieves the blow by.

One more question What happens do the driver side rear valve cover port. Does it just get plugged or is it routed to the passenger side?

Here is what I am going with

ssgunny

iTrader: (6)

I connected my rear drivers side valve cover port to the rear passenger side.

MIGHTYMOUSE

iTrader: (59)

those catch cans won't help with blow-by. Your best bet is to put a wristband around the breather and replace it whenever it gets saturated

RockinWs6

Do a leak down test............check piston clearances. What did the builder say they were? something is way wrong.