Carfanatic

HI, I am looking your input. How much is to much crank case pressure? Should it be limited to 2lbs is 4lbs to much? I have a new forged engine with about 2000 miles running around 12lbs of boost. And the rear main seal keeps going out. The pvc set up is correct. The shop that did the engine and s/c install has done many fourced induction vettes and f-bodys over the years.
Do I need to run a vacumn pump?

T/A KID

iTrader: (12)

What is your setup, I just had a simliar problem and mine is fixed now.

conan

iTrader: (5)

A vacume would be the best solution if you can afford it. I pushed the timing cover seal out of my engine on the dyno and have since removed the pcv and am now running a vented catch to both rockers. When I have a extra $800 I will be getting a vac pump.
https://ls1tech.com/forums/forced-in...rs-inside.html
https://ls1tech.com/forums/forced-in...mp-system.html

Carfanatic

347 ls6 block in a c5 with a vortech t-trim. The valve cover is vented to a catch can. Did you just change the rear main or was something else fixed? Your 9sec goal is mine also. I just want my car back so I can enjoy it again.
If you need any more information let me know.

I would really not want to spend the extra on a vacume pump. Also the builder said that my set up did not need one when we original spoke.
When I first started this build I told him I wanted to just copy not inovate. He told me this was a proven setup.

conan

iTrader: (5)

I was never told about this problem by any one untill 5qt's of oil came out of my engine @5,000rpms I replaced the timing cover and seal just to be safe and removed the pcv system. I haven't had any problems with crank case pressure since. I would reomend capping the pcv nipple on the intake and venting you ls6 gally cover and rocker covers to a catch can.

1320

iTrader: (6)

I ve seen one breather not be good enough a few times now. Infact, it seems like any engine without total seal rings. But what I ve done for a quick fix is just vent both valve covers. You can run both covers together and run a large filter, or two filters, one on each side. Ive even run them just open ended tubes too. They just look better with filters on them. I have run into the filter being dirty enuogh to cause a problem also so clean them every once in awhile too.

xxrillixx

iTrader: (118)

1320 is right, we had just one side vented on mine and it kept blowing oil out the rear main even on low boost. It just couldnt evacuate the pressure fast enough.

So instead of running the y in the back and having the 2 valve covers meet into one, we disconnected the Y and made then both evap. It fixed the problem.


Another option i found to do on top of that would be installing a ls6 (corvette) valley cover as that would provide a 3rd place to relieve pressure. On the f-body ls1 block it requires a little gringing in the valley, but would be a cheap fix. There are write-ups on how to do it, just search.

Carfanatic

Thanks guys I will get with my tuner on Monday. I do remember him saying that it had enought breathers. I am going to have him do a leakdown test. And take it from there.

EPP

iTrader: (22)

I told one guy who kept blowing out rear main seals to run a vented breather. He put one on and his current leaking rear main seal quit leaking. It's worth a try. Bob

blacksi

iTrader: (3)

Running a filter on each of my covers with no problems and I also run turbo suction to a catch can to the valve cover.

I've watched my one large oil fill filter on the dyno and it turns black as the boost comes on and air is forced out of it. Then when they let off it goes back to white.

Carfanatic

Thanks from all again. I will report back with how my breathers are done.

bowtiguy

iTrader: (10)

here is what you need. A complete GZ motorsports Vac pump system. bolts right up to LS motors. plenty of extra fittings to run the catch tank anywhere you would like.

https://ls1tech.com/forums/lsx-parts...sx-motors.html

hymey

There are a few options, best to run open breathers(no rocker cover baffles) 3/4 inch each side to a catch can, encourage it to spew pressure and oil vapour an easier way out.

On one engine i ran 20 psi boost i had issues with blow by pushing oil back up the turbo drain so i ran a vdo pump on the oil drain and then drilled an extra hole and installed fitting on the sump(above oil level at the front of sump) that connected to a baffled catch can up top that could drain oil vapour and residue back to the sump. It was a 3/4" JIC fitting on the sump and a 3/4 inch hose to the catch can up top. This was by far the most effective method i tried as it relieved pressure at the source.