Pontiac GTO Forum banner

1 - 7 of 7 Posts

·
Registered
Joined
·
13 Posts
Discussion Starter #1
can any one help me i don't want to run a pcv valve but im worried about blowing oil out of my dipstick tube does any one have any solutions thank you
 

·
Super Moderator
Joined
·
5,782 Posts
can any one help me i don't want to run a pcv valve but im worried about blowing oil out of my dipstick tube does any one have any solutions thank you
As you've surmised, without PCV you still need some system to allow crankcase pressure to escape, otherwise it's going to cause problems like kicking oil out the dipstick tube, pushing out gaskets and seals, etc.

There are two solutions that come to mind: going back to the old style (pre-PCV) type system that just vents the pressure to the atmosphere, or running a race-style "pan evacuation" system that "pulls" the pressure into your header collectors and/or uses an engine-driven vacuum pump. The former is "bad" for pollution and doesn't work all that well unless the car is moving (and may prevent your car from passing inspection), the second can be expensive and often isn't recommended for street use because the pumps aren't designed to survive for long in that kind of environment.

Personally, I'd recommend running the PCV system. It's inexpensive, it works well, and there's very little "down side" to it. If you're worried about crankcase vapors diluting your intake charge and costing you power, realize that under WOT conditions when the manifold vacuum is at or very near zero, the PCV valve is going to tend to be -closed-, so no crankcase vapors will be present to dilute the charge. At WOT, it'll open only when crankcase pressure gets high enough to force it open - when you need it to be. Even then, unless you've got lots of cylinder blowby due to cylinder sealing issues, the air that comes out of your crankcase is still going to contain oxygen and therefore is still useable for the purposes of making power.

Bear
 

·
64-67 Expert
Joined
·
8,569 Posts
It's a disadvantage to NOT run a PCV valve. You're opening up the door for oil leaks and poor performance in general. Bear said it with the most tact and listed all the reasons. I'll leave it at that.
 

·
Registered
Joined
·
73 Posts
Got to agree with the last 2 replies. Some don't like the idea of oil vapor entering the intake side as there is always some oil in the mix. The addition of a "catch can" in the PVC line is an option. Really just an air/oil seperator that permits little if any oil past it. Every few thousand miles you drain the can depending on it's design. I recently installed one in my "new" car a G8GT, after 3000 miles it had collected a little over a tablespoon of oil that would have otherwise been inhaled.
 

·
Registered
Joined
·
13 Posts
Discussion Starter #6
thanks for the reply's idont have a vac source i need a pcv, pdb,trans mod,and advance on the distriburtor im running a victor manifold with a quick fuel carb
 

·
Super Moderator
Joined
·
5,782 Posts
thanks for the reply's idont have a vac source i need a pcv, pdb,trans mod,and advance on the distriburtor im running a victor manifold with a quick fuel carb
Shouldn't be difficult to drill and tap a hole into the intake near the plenum, and insert a hose barb fitting. That's where mine's connected.

Bear
 
1 - 7 of 7 Posts
Top