Pcv filter?? NERVOUS

[Bowtietillidie93]

Hello everyone. New member
Got a 78 big 10 bonanza 350/350 longbed.
Just replaced stock air cleaner and am curious about the tube that comes out of passenger side valve cover it ran to the atock cleaner and the cleaner had a filter just on inside of the cleaner that thae tube connected to. So i replaced the air cleaner with a pretty chrome one and am curious and a little nervous how important this tube and filter was i dont wanna do damage to the ol truck simply to make it look a tad prettier. Hope to hear something thanks guys

[Henry]

Hi Bowtie:
That stock tube and filter arrangement going to the pass side valve cover is the air supply to the PCV system. Air flows into the crank case from this tube and filter. The driver side valve cover has the return pipe which goes to the base of the carburetor. The return pipe supplies the vacuum to pull all the gasses in the crank case into the intake manifold. The PCV valve on this pipe opens when the engine is on and closes when the engine is off. So if you choose to disable the PCV system, you should at least have valve covers with vents with filters on them. If you keep the drivers side valve cover PCV valve and hose to carburetor, you should have a pass side valve cover with a filtered vent, or atmospheric intake to the system so it continues to work....or get a chrome valve cover with the hole and filter for the stock intake piping. If you block off the air supply and return paths on the valve covers I think the engine will still run fine and any pressure build up will vent through the oil filler cap and dipstick. You should be advised that it may be illegal in your state to disable the PCV system on your truck...if your state does annual inspections of the safety and emissions for your truck they may ding you on it...you just need to check it out. I personally like the PCV system because it: 1) keeps the environment cleaner with no sacrifice to engine performance and economy, and 2) keeps all the oily vapors from eventually coating the engine compartment with a film of half burnt oil.
Regards,
Henry

[75gmck25]

Do not disable or remove the PCV valve!  Your engine will definitely suffer. 
You need to have the PCV valve in the driver's side valve cover drawing air and moisture from the crankcase (into your carburetor base), and you need a filtered breather cap or hose in the passenger side valve cover to supply air to the crankcase.

However, its easy to resolve the problem with your new air cleaner. 
- Most of the Edelbrock air cleaners come with a metal fitting for the hose running to the driver's side valve cover, but you have to install the fitting.  The fitting mounts in the base of the air cleaner, inside the filter, so you are still providing filtered air.  I think you may be able to buy the fitting separately.
- You can buy various types of breather caps to install directly into the valve cover, instead of using the hose to the air cleaner.  They will still allow filtered air to be drawn into the valve cover.
https://www.oreillyauto.com/shop/accessories-16449/chrome---dress-up-16531/valve-covers-16832/crankcase-breathers-17853

Bruce

[Bowtietillidie93]

Thanks for the replies glad to be apart of something w people willing to give honest help. Much appreciated

[Henry]

Hi Bowtie:
In my response to your post, I misspoke about finding a chrome valve cover....I meant you  should be able to find a chrome AIR CLEANER with the factory port for the PCV filter. I have seen them in some of the popular aftermarket catalogs.

Any yes, as 75gmck75 states, the PCV system is better to have than not as it keeps a positive air flow through the crank case. One of the by-products of the combustion process is water and this does go into the crank case by piston ring blow-by so eventually you will get water condensation inside the engine which will cause corrosion. I have an old boat with a big block engine and just valve cover filters without PCV...I have noticed vapor condensation and corrosion inside the valve covers when I remove them every few years for maintenance. So, PCV would minimize this by drawing the water vapor into the intake manifold.
Regards,
Henry

[Bowtietillidie93]

I actually bought a cheap one from oriellys today to keep it all functioning. Its my daily drivers and its pretty well paycheck to paycheck to cover bills so id like to keep everything working properly if for no other reason a little piece of mind thanks guys

[Jerr-conn]

Bow tie----just happened to see your post. I'd like to add that a good running engine needs an
In/ out crankcase breathing system. Fres air in/ old out. Also, may not realize, but if you don't
Have this system and build too much crankcase pressure, your engine will start leaking oil
From the rear main seal, valve cover gaskets and even at front and rear of intake manifold,
Or some place else. Eliminating crankcase pressure also lets engine run free,er.