sbc/pcv question

[Guest zfan]

Ok this is probably a stupid question but here it goes anyway.

 

Does it matter what side of the valve cover you hook up your pcv valve to? Reason I'm asking is It is much easier to run my line to the passenger side valve cover and I have always run mine to the driver's side before.

 

Ok go ahead and laugh but I didn't want to do a NO NO!

 

Mike

[Guest greimann]

It makes no difference. Unless, if you have a right hand drive car and the passenger side is really the drivers side, and visa versa. Then the PCV will be really be on the opposite side of what we would normally think, which doesn't really matter anyway.

[ToplessZ]

In regards to your question and with an addition of my own. I dont think it matters which side you hook it to my question is with all smog issues aside can you just hook up a breather in the valve cover and get rid of the pcv valve all together. Say on a 75 smogged 350??? any input would be great

[Guest greimann]

There are a few of reasons why tossing the PCV is a bad idea:

 

1. The PCV is usually plumbed into the base of the carb or TBI, or what ever you have, and that induction device is tuned to function with that amount of air bleed. If you cap off the connection, especially on a carburetor, you will have all kinds of idle tuning problems.

 

2. The PCV finctions to burn the crankcase vapors that would normally be expelled into the air. This small amount of vapor does not even kill one fraction of a HP, so there really is no penalty to have a more environmentally sensitive engine.

 

3. The vapor that would escape through a breather contains oil mist and it would eventually be a real mess in your engine compartment.

[DavyZ]

Even if one cares little for the environment, a messy engine compartment is just a no no!

 

Seriously, Greimann brings up excellent points and all the info makes excellent sense.

 

Davy

[Mike C]

Positive crankcase ventilation can also improve ring sealing at high rpm by removing negative pressure below the pistons. (same effect drag racers get with crankcase evac plumbed into the exhaust) All in all I'd keep it. On the vehicles I had where I removed it I have subsequently replaced it.

[Guest Anonymous]

As Mike said its a good thing. It cost you no horsepower, if anything maybe nets you a tad. Consider what happens when pistons come down (granted some are going up too but...) and the windage from the crank assembly is slinging things around causing quite alot of air for the crank and pistons to have to push around while doing they're primary job. By vacuuming some of that out of there, it makes it easier for them to do they're job. Its the ONE smog part that is really ok to have. Check out the econo-rails and other race cars sometimes, often they'll use the header collectors to pull the blowby from the motor (hose going from the valve cover to the head collector). Or they'll even run a dedicated vacuum pump which is worth as much as 25hp!

 

On a side note, if you notice a vacuum leak and it doesn't idle well when you hook the PCV up, it can be defective, many are right out of the box believe it or not.

 

Regards,

 

Lone