magnoman

Hi guys ,
Have ls6 with cam been running for years this spring decided to get a set of nice CNC ported heads with 11.4 CR had tune done gained 45 RWH .
These motors always have lot of Blow by but know with head swap noticing mush more BB than before puddle of oil behind TB .
Been running catch can for years decided to try plugging high pressure port behind TB where catch can would go and vent out to atmosphere to see if stopped oil behind TB . Did one HPDE event and still large puddle behind TB and catch can empty.
Come to find the oil is coming back through the fresh air feed line on low pressure side of TB to valve cover ! Not sure why or how to stop it .

Also I did install the updated valley cover with internal baffle few years ago and was under the impression that the updated VC had an PCV built in ? but just found out thats not the case . So have been running w/o PCV valve . The big Q is would not running PCV valve cause oil to feed back through the fresh air line to TB ?

Sorry for long winded post but really thinking of pulling new heads and going back to stockers .

vettenuts

Did you go with a different oil pump when you did the cam? Are you finding the puddles only after high RPM running or normal driving?

I have been running the updated valley cover for years and not had any issues with oil. Do you know the part number of the cover you used? There were two that were produced as I recall and I thought one required an external PCV valve and the other didn't. The later cover with the PCV restriction is 12577927.

magnoman

Yes when did cam installed ported oil pump . Mostly oil after a track day and high rpm WOT throttle .
Has always been issue with oil in intake but heads seem to have made problem excessive.
Sure the increased cylinder volume and pressure there is more crankcase pressure ?
I did pull valley cover and take off baffle , there is no PCV valve in there ..

vettenuts

It is not a PCV in the normal sense, rather there are small restrictor holes on the bottom. Did you take a photo of the valley cover you installed or have paperwork from the purchase? The part number is key on whether you need an external PCV.

If you removed the baffle, what did you leave on the bottom of the valley cover? That may be why you are picking up excessive oil.

magnoman

just removed baffle today to see what was under there . did not run car without it .
Yes it has t small restrictor holes on the bottom.
Will try to find PN ..
thx

vettenuts

Unfortunately the part number is on the underside of the cover.

magnoman

its still off can look .
Just think the new style with baffling and restrictor holes would cause more crankcase pressure and not release it ?

vettenuts

Only thing I can base an opinion on is my car and I have had no such issues. If you are getting oil in the intake after track day, some have had to use oil restricted pushrods as these motors are known for filling the valve covers at high RPM. Others have drilled a hole in the lifter tray, which unfortunately requires head removal. It may not be a mechanical issue with the motor, rather the sustained high RPM is putting oil into the valve cover faster than it can drain and it is simply getting pushed into the intake. Here is a good thread on your issue, note that "Eric D" worked for GM and he discusses the GM lifter and how GM made corrections later in production to address the issue.

Pushrods & Oil Flow to the Heads

magnoman

Thnaks ,
Actually just spoke to very helpful person @ Manton and he thinks by installing a oil restrictive push rods @40% will greatly help by limiting the amount of oil to top of head .
And this more so happens with after market rockers like the YT I have .
cheap fix @$175.00 .
Will see how it goes .

outsideline

You need to put 2 catch cans in. One on the pvc side & one on the fresh
Air side from the valve cover to intake. At full throttle oil is getting forced
Through there & into intake. If that doesn't work, drink heavilly.
I have the restrictive pushrods. Waste of money.
I finally dry sumped. End of problems.

magnoman

Thx ,
Was thinking about another catch can just need to find place to put it ... lol...

vettenuts

Just be careful as some of the guys in the other thread were starving the motor for oil since it was all out of the sump and up top in the motor. There were several ideas in that thread about how to resolve, with the ultimate being dry sump.

magnoman

How would it starve motor . Was under the impression that restrictive PR would keep more oil in bottom of motor ?

CactusCat

Dry sump = super nice but Dry sump = big $$$

vettenuts

If you already have an aftermarket setup and plan to buy from Manton, I would also move up to 11/32" pushrods.

outsideline

There is room to mount one on passenger side frame rail in front of radiator. I have a black and a blue one if interested.