PCV and Breather or Oil and Breather? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Smokin72on20s · 10-18-2004, 01:59 AM

which do i need to get for my valve covers? PCV valve and Breather caps or oil and breather caps?

Tx Firefighter · 10-18-2004, 06:47 AM

You need a PCV valve in one cover and some type of breather on the other cover.

Smokin72on20s · 10-19-2004, 01:37 AM

why PCV?

68LSS1 · 10-19-2004, 02:16 AM

Some people don't like running their stuff without a PCV system. It's to help the piston rings to keep a good seal due to pressure getting past the rings and pressurizing the crankcase. The pcv system keeps this pressurization from happening. A vented breather will do this also but it will not create a small negative pressure for this. A very high percentage of this blowby is unburned fuel so it can be reintroduced. Personally I am not a fan of either so I usually retain somewhat of the stock set up but modifed to look better. And sometime I go with the breathers. The bad thing about the open breathers is they allow moisture inside the engine. When I want to go the breather route I get a little valve from one of the race car or hot rod shops that allows positve pressure from the crankcase out but doesn't allow anything in. It's basically a check valve. You can get them with weld on or bolt on bungs and your breather mounts on top of this. But to specifically answer your question I would run definately vent both covers somehow and have a oil fill cap on one.

10-18-2004, 01:59 AM	#1
Smokin72on20s Ebay Junky Join Date: Oct 2003 Location: CO Posts: 893	PCV and Breather or Oil and Breather? which do i need to get for my valve covers? PCV valve and Breather caps or oil and breather caps? __________________ 1972 CHEVY C-10 SWB 2WD - Possible Typhoon 4.3 turbo drivetrain.. 1983 Chevy c10 swb 2wd - possible 350tbi supercharged...

10-18-2004, 06:47 AM	#2
Tx Firefighter Watch out for your cornhole ! Join Date: Jun 2003 Location: Azle, Texas Posts: 14,162	You need a PCV valve in one cover and some type of breather on the other cover. __________________ I'm on the Instagram- @Gearhead_Kevin

10-19-2004, 01:37 AM	#3
Smokin72on20s Ebay Junky Join Date: Oct 2003 Location: CO Posts: 893	why PCV? __________________ 1972 CHEVY C-10 SWB 2WD - Possible Typhoon 4.3 turbo drivetrain.. 1983 Chevy c10 swb 2wd - possible 350tbi supercharged...

10-19-2004, 02:16 AM	#4
68LSS1 Registered User Join Date: Dec 2002 Location: Tampa Posts: 1,191	Some people don't like running their stuff without a PCV system. It's to help the piston rings to keep a good seal due to pressure getting past the rings and pressurizing the crankcase. The pcv system keeps this pressurization from happening. A vented breather will do this also but it will not create a small negative pressure for this. A very high percentage of this blowby is unburned fuel so it can be reintroduced. Personally I am not a fan of either so I usually retain somewhat of the stock set up but modifed to look better. And sometime I go with the breathers. The bad thing about the open breathers is they allow moisture inside the engine. When I want to go the breather route I get a little valve from one of the race car or hot rod shops that allows positve pressure from the crankcase out but doesn't allow anything in. It's basically a check valve. You can get them with weld on or bolt on bungs and your breather mounts on top of this. But to specifically answer your question I would run definately vent both covers somehow and have a oil fill cap on one. __________________ '68 Short Step LS1/T56, Hydratech, Fatman Fabrications Stage III, Baer, Hot Rods to Hell, US Body, S&W, etc Last edited by 68LSS1; 10-19-2004 at 02:19 AM.



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