pcv valve
Thread Starter
Racer
Joined: Mar 2006
Posts: 349
Likes: 0
pcv valve
Do i need one? i replaced my 350 with a 383 stroker and i ran 2 filters instead of a pcv, only problem is there crappy filters and you see oil come out of them but anyways.
what deos a pcv do and do i need one
what deos a pcv do and do i need one
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
PCV system sucks oil/fuel fumes up and runs them into the base of the carb so that the engine will burn them [instead of coating the inside of your engine compartment]. Your engine bay will love you...the EPA will love you. Just put one in the hole on the rocker arm cover and run a hose from it to the front/center inlet tube at the base of your Q-Jet. You should still do SEARCH on the topic to learn other "neat stuff".
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The "carb" input from the PCV valve must be a suction (vacuum) line. Usually this is a port into the base of a carb (manifold vacuum). If the port you are connecting to provides a vacuum from the fuel inlet system, it should work OK. This line can't be plumbed in after the blower [then it would be pressurized].
Drifting
Joined: Jul 2002
Posts: 1,254
Likes: 1
From: Edinburgh
The purpose of the PCV valve is to remove crancase pressure caused by the bellows action of the pistons going up and down. The PCV valve is a one way valve to prevent air being sucked in by that same bellows action. The reason your oil filters are leaking is that you are allowing carnkcase pressure to build up and the its going for the weakest link, your filters.
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
without one,there is a good chance you will start blowing seals and/or gaskets.There is a reason its called POSITIVE crankcase ventilation. One doesnt want positive ,or even negative pressure, inside that oilpan/rocker arm cover/timming cover.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Instructor
Joined: Feb 2006
Posts: 118
Likes: 25
From: Killearn Scotland
New engine - high crank pressures
I found that during the first 500-600 miles (brerak-in period) of my 383ci motor, I had excessive crankcase pressure.
Despite using a PCV system, I had oil coming from the filter/filler on the "intake" side of the system.
I also blew the sealant out of the ends of the intake manifold (although this was partly my fault for using a non-setting sealant).
Now, with about 2500miles on the motor, the positive pressure has gone and everything is oil free.
I guess that until new rings bed into new cylinders, there will be enough blow-by to affect the crank pressures.
My 383 is also running quite a high 10.5:1 SCR with a 290 cam, which may have added to the problem.
That said, I would still recommend that you use some form of draw-through crank venting, either from the filter base or direct onto a suitable carb port.
Despite using a PCV system, I had oil coming from the filter/filler on the "intake" side of the system.
I also blew the sealant out of the ends of the intake manifold (although this was partly my fault for using a non-setting sealant).
Now, with about 2500miles on the motor, the positive pressure has gone and everything is oil free.
I guess that until new rings bed into new cylinders, there will be enough blow-by to affect the crank pressures.
My 383 is also running quite a high 10.5:1 SCR with a 290 cam, which may have added to the problem.
That said, I would still recommend that you use some form of draw-through crank venting, either from the filter base or direct onto a suitable carb port.
