PCV Valve

[mattpiotr]

whats the point of a PVC Valve? i have not ran one on my truck for about a year. i thought about putting it back on and tying it in the back of the break booster line. i think the main reasson i took it off was it sucked to much vacuum off my edelbrock 600 and i didnt really have alot of power at the start. i do have 2 breathers on my valve covers tho.

[donut]

Do a site search, this has been covered almost as much as an E-Bay HEI.

PCV will suck all of the nasties from your engine oil as it warms up, it can also clean up your engine compartment as the vapors your currently venting go there.

There should be a port near or at the front of the carb for the PCV, I personally wouldn't T into the booster (personal preference). It shouldn't pull to much vacuum from the carb, essentially it's a controlled leak, if it is, check the PCV valve (or change it, they're cheap). The Big 3 ran them for YEARS successfully.

I know there are folks that don't run one, my opinion, there's no reason not to

[Firebirdjones]

No real reason not to run one unless the car didn't have one, and it would have to date back to about 67-68 before the big 3 started phasing them in.

Just an emissions device of sorts so you aren't venting raw vapors into the air. Rather the PCV vents them back into the engine where it is burned.

And that's where the removal of the PCV comes into play. They can dilute the air fuel mixture to some extent costing power. But the bigger concern is some poorly made PCV systems can actually suck some oil through the intake system, or an engine with worn oil control rings. This coats the intake manifold, intake valves, pistons, etc....and generally makes things very nasty inside. A catch can is a very good idea at this point.

I have cars here that are either way and don't have an issue with it. Generally the cars that came with a PCV, I have it functional. Cars that never had them, just your typical open breathers

[mattpiotr]

so its not really hurting anything if i dont run one or not? its going on a 86 2500 besides it being a daily driver its also my plow/work truck

[Firebirdjones]

Originally Posted by mattpiotr

so its not really hurting anything if i dont run one or not? its going on a 86 2500 besides it being a daily driver its also my plow/work truck

No it doesn't hurt a thing, unless you have to go through emissions tests and they do a visual. They might squabble about not having it An engine with worn rings may leave oily messes on the valve covers too, if that doesn't bother you then,,,,it's up to you.

[rayfinseats]

I think they run better with them installed. They have to do with crank ventelation. On NASCAR and drag cars they win vacupan setups and air pumps and so on just to reduce crank pressure. I always ran one on my drag cars.

[THE "10" SILVERADO]

If it cost you power it can't be much, so if it makes your engine run better by sucking the pressure out and keeps the fumes out of your engine (and possibly your cab) why not run one?

[Firebirdjones]

Originally Posted by THE "10" SILVERADO

If it cost you power it can't be much, so if it makes your engine run better by sucking the pressure out and keeps the fumes out of your engine (and possibly your cab) why not run one?

It's not alot. On a daily rig or a mild engine, it's not a big deal. You generally don't see a PCV on max effort higher HP builds for this reason though. The goal there is to vent the crank case, in some cases with a vacuum pump, but you won't see those guys venting it back into the fuel mixture, that's a no no.

[425HP409]

Never tie your PCV valve into the Power Brake hose as it will cause a loss of vacuum to the booster.

[RexDodge]

I ran crank evap ports in my header collectors (drag car). Ran hose from my valve cover breathers to the ports. It helps with cavitation of your oil at higher rpm's. If the pressure is not equalized the oil whips up into the crank and then into your cylinders...not good. Really not needed on a street to mild engine...at least that's my opinion.