Adjustable PCV Valve - Page 2

Frank Castros · 01-31-2019, 08:14 PM

Interesting subject, I hope more with contribute to this thread.

Ed Wright · 01-31-2019, 10:56 PM

Quote:

Originally Posted by Hacksaw

OK, we are talking a drag race engine here so why would you want to let crankcase pressure fumes enter the intake side and taint the fresh fuel charge?

It's air.

Billy Nees · 02-01-2019, 08:23 AM

Quote:

Originally Posted by Ed Wright

It's air.

^^^^^^^^^^^^^^^^^^^^^^BINGO^^^^^^^^^^^^^^^^^^^^^^^ ^^^^^^^^^^^

Especially in a severely restricted engine.

Bobby DiDomenico · 02-01-2019, 11:39 AM

Quote:

Originally Posted by Dragsinger

The tech sheets show the valve works with an idle vacuum above 7" Most of our stockers or super stockers do not have 7" vacuum idle.

Who says it has to work? (Or work as the emissions system was designed?;-)
Remember those NASCAR and other intakes with the drilled out mounting studs? This is a lot bigger hole.

Ed Wright · 02-01-2019, 12:41 PM

[QUOTE=Bobby DiDomenico;581432]Who says it has to work? (Or work as the emissions system was designed?;-)

Yeah, and nobody ever clipped a spring, with a restricted engine that, naturally, pulls manifold vacuum @ WOT, right?

Coleydog · 02-01-2019, 02:49 PM

Just like another throttle blade, kinda bad mixture at idle but wide open a good increase, just richen up the jets. Big breather on other valve cover, not much oil spray. Would be interesting to see what cfm goes thru it. I can see why tech would shoot it down.

Ed Wright · 02-01-2019, 05:17 PM

I have heard of guys using epoxy & a drill to convert the PCV hose nipple from manifold vacuum, to "ported" vacuum, which only pulls air with the throttle blades open. Just heard stories about that. Don't really know.

Timetraveler · 02-01-2019, 08:25 PM

I had one that rattled when I shook it. I thought it was broke "So I fixed it".

Tom Meyer · 02-01-2019, 08:39 PM

There are guys running check valves from power brake units instead of the pcv valves. Its a poor mans vacuum pump. was always told if you could keep some vacuum in the crankcase say 3 in it would free up some power. Remember for all the air that is moving on top of the piston there is air moving below it also. Back in the day they said it helped ring flutter. But with todays ring combos who knows. Tom

Coleydog · 02-02-2019, 10:39 AM

Back in the 70s I used a hemi fuel pump hooked to a PCV on my max wedge 64 Plym (later valve covers) I did it mostly for blow by, had to use a catch can so it was doing something.

01-31-2019, 08:14 PM	#11
Frank Castros VIP Member Join Date: Nov 2001 Location: The Lowcountry. Posts: 2,954 Likes: 2,536 Liked 2,610 Times in 948 Posts	Re: Adjustable PCV Valve Interesting subject, I hope more with contribute to this thread.

02-01-2019, 12:41 PM	#15
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Adjustable PCV Valve [QUOTE=Bobby DiDomenico;581432]Who says it has to work? (Or work as the emissions system was designed?;-) Yeah, and nobody ever clipped a spring, with a restricted engine that, naturally, pulls manifold vacuum @ WOT, right? __________________ Ed Wright 4156 SS/JA

02-01-2019, 02:49 PM	#16
Coleydog Senior Member Join Date: Jul 2014 Posts: 569 Likes: 36 Liked 53 Times in 38 Posts	Re: Adjustable PCV Valve Just like another throttle blade, kinda bad mixture at idle but wide open a good increase, just richen up the jets. Big breather on other valve cover, not much oil spray. Would be interesting to see what cfm goes thru it. I can see why tech would shoot it down.

02-01-2019, 05:17 PM	#17
Ed Wright Veteran Member Join Date: Mar 2005 Location: Sand Springs, OK Posts: 8,132 Likes: 896 Liked 390 Times in 170 Posts	Re: Adjustable PCV Valve I have heard of guys using epoxy & a drill to convert the PCV hose nipple from manifold vacuum, to "ported" vacuum, which only pulls air with the throttle blades open. Just heard stories about that. Don't really know. __________________ Ed Wright 4156 SS/JA

02-01-2019, 08:25 PM	#18
Timetraveler Member Join Date: Aug 2002 Location: Florida Posts: 103 Likes: 79 Liked 12 Times in 6 Posts	Re: Adjustable PCV Valve I had one that rattled when I shook it. I thought it was broke "So I fixed it".

02-01-2019, 08:39 PM	#19
Tom Meyer Senior Member Join Date: Aug 2003 Location: Pierce NE Posts: 933 Likes: 74 Liked 351 Times in 120 Posts	Re: Adjustable PCV Valve There are guys running check valves from power brake units instead of the pcv valves. Its a poor mans vacuum pump. was always told if you could keep some vacuum in the crankcase say 3 in it would free up some power. Remember for all the air that is moving on top of the piston there is air moving below it also. Back in the day they said it helped ring flutter. But with todays ring combos who knows. Tom __________________ Tom Meyer 5240 SS Stock ???

02-02-2019, 10:39 AM	#20
Coleydog Senior Member Join Date: Jul 2014 Posts: 569 Likes: 36 Liked 53 Times in 38 Posts	Re: Adjustable PCV Valve Back in the 70s I used a hemi fuel pump hooked to a PCV on my max wedge 64 Plym (later valve covers) I did it mostly for blow by, had to use a catch can so it was doing something.