Do I need to run a PVC valve

I have a 292 chevy, inline, that started to leak a lot of oil, freash engine with cork gaskets. I am running Two Offenhauser Hi-Riser engine breathers that are bolted to an Offy finned aluminum valve cover, also the side covers have started to leak as well. so do I also need to run a PVC valve, or replace the gaskets with some RTV sealer and see what happens.
Thanks for your time
mike

 

Your oil leakage may or may not be related to the PCV.

You should run a PCV to improve the life of you oil and your engine. It removes moisture and corrosive fumes from the crankcase.

It could be that by not having one that pressure is building up and forcing the oil out. But with two breathers, I have my doubts.

 

Yes...I would.



This old picture from a 1948ish shop manual shows that they knew even back then that you need air flow through the engine for long life and not just a vent to the atmosphere. Do a search for PCV systems Google it too. There are lots of post on this subject and answering it every time with an explanation of how it works and what it does gets old after several years. Lots to read in the archives.

 

sounds like alot of blow by if 2 breathers wont relieve the crank case pressure. do a cyl leak down test to determine the problem. good luck

 

I used that old timey Indian Head Gasket Shellac on all of my gaskets on both sides....absolutely zero leaks !!!...the only down side is that you may never get the covers off again without a stick of dynomite !!!....I have no intention of taking my engine apart for a long time anyhow....I drive the hell out of it, and I am using a PCV system in the valve cover with a breather cap on the opposite valve cover .....318 Mopar.

 

a pcv will help relieve crankcase pressure by vac*** . good idea ..............

 

I installed one on my 235 inline and haven't looked back.

 

Mike, were there "knockouts" or something similar in the valve cover that are punched out in order to use the breathers, or did you have to drill holes in order to vent the cover through the breathers? Make sure there is a big enough "hole" between the valve cover and breathers, otherwise that could be a restriction.

 

Yes. Install a PCV system. You will have fewer oil leaks due to the lower pressure within the crankcase. If you currently do not even have a draft tube, and have the crankcase completely closed, you are causing it to leak.

~Alden

 

I like to hide the "modern" stuff. I have had good success using a Fram FV-407 pcv valve. Pipe thread one end, 3/8" hose barb on the other, and about the right amount of "****". Be sure to have some sort of baffling, otherwise it will pull oil.

Added one to my 235's road draft tube. Capped the down pipe, welded in a fitting on the side to screw it in, hose to the manifold, done. No more smell and tasting the blowby out of the breathers either.

 

PVC valve, probably not... PCV, I would

 

I tried to run a sbc without one and there were leaks. Installed a pcv and all the leaks stopped.

 

In order for a PCV to work properly it has to have a "non" positive vent.Thats why they have a tube that usually goes from the valve cover to the bottom of the air cleaner when vacuum falls from the manifold the crank events thru the tube, being pulled in by the vacuum in the air filter housing.So what i'm saying is that the PCV isn't really creating a vacuum on the engine!!
its actually setting up a "lean" condition for the engine, if you pull the PVC out & put your finger over it the engine slows down!! If you blocked off all the breathers then it would create a suction.
If you were to put a lot of breathers all over your engine it should also stop any leaks by not building up crankcase pressure & forcing oil out.But then again it will be back to the old "down draft" tube setup.
JimV

 

Is it leaking or blow by? Cork tends to shrink. I too like to use something to "glue" the side cover gaskets on. The design isn't the best for holding that cover on and it doesn't have to come off.