pvc plumbing question! - The 1947 - Present Chevrolet & GMC Truck Message Board Network

maxwedge528 · 02-09-2011, 06:35 PM

i recently installed power brakes on my 67 stepside with a 454 and TH400 transmission. i also have a dash mounted vacuum gauge and a MSD ignition system with centrifical advance. i also have a street demon carburetor. i use the large port at the rear of the carb for the power brake booster...the large port on the intake runner is plumbed to the TH400...one very small port on the carb is plumbed to the vacuum gauge....and i have one additional very small port capped. where do i get the vacuum for the pvc valve? the one available capped port is maybe 1/8 or 3/16 which does not seem large enough for the pvc valve.. i did use the search function and did not find the answer...maybe it was there...and i misunderstood! thanks in advance for the answer..

sjarrett71 · 02-09-2011, 06:39 PM

The PCV is usually attached to a large port on the carb or sometimes possibly the air filter housing.

69sixpackbee · 02-09-2011, 07:09 PM

Manifold runner or carb base.

**oldgold70c10** · 02-09-2011, 08:20 PM

I know Q-jet, Edelbrock, and some Holleys will have a large hose nipple barb on hte front for the PCV. I want to say its 1/4 or 5/16 size.

brad_man_72 · 02-09-2011, 08:22 PM

positive crankcase ventilation. Definitely best to have it routed someplace with alot of vacuume...... It can actually give you more power and a ccleaner engine.

maxwedge528 · 02-10-2011, 08:58 AM

not the answer as of yet! can i plumb the TH400 transmission vacuum source and the brake booster to the same port on the intake runner utilizing a large...3/8 inch vacuum Tee. Or can i run the TH400 vacuum line to the small port on the carburetor? still need input?

MARKDTN · 02-10-2011, 09:06 AM

Quote:

Originally Posted by maxwedge528

not the answer as of yet! can i plumb the TH400 transmission vacuum source and the brake booster to the same port on the intake runner utilizing a large...3/8 inch vacuum Tee. Or can i run the TH400 vacuum line to the small port on the carburetor? still need input?

Yes, if you have a large port on the intake you can put in a tee and run both brake booster and vacuum modulator.

brad_man_72 · 02-10-2011, 02:23 PM

use small port for the trans vac modulator.

maxwedge528 · 02-10-2011, 05:08 PM

thanks for the help! maxwedge528

02-09-2011, 06:35 PM	#1
maxwedge528 Registered User Join Date: Feb 2003 Location: easley, sc Posts: 45	pvc plumbing question! i recently installed power brakes on my 67 stepside with a 454 and TH400 transmission. i also have a dash mounted vacuum gauge and a MSD ignition system with centrifical advance. i also have a street demon carburetor. i use the large port at the rear of the carb for the power brake booster...the large port on the intake runner is plumbed to the TH400...one very small port on the carb is plumbed to the vacuum gauge....and i have one additional very small port capped. where do i get the vacuum for the pvc valve? the one available capped port is maybe 1/8 or 3/16 which does not seem large enough for the pvc valve.. i did use the search function and did not find the answer...maybe it was there...and i misunderstood! thanks in advance for the answer..

02-09-2011, 06:39 PM	#2
sjarrett71 Registered User Join Date: Dec 2006 Location: Rolla, MO Posts: 2,463	Re: pvc plumbing question! The PCV is usually attached to a large port on the carb or sometimes possibly the air filter housing. __________________ -Scott-

02-09-2011, 07:09 PM	#3
69sixpackbee Registered User Join Date: Jan 2001 Location: Sabinal, Texas Posts: 1,706	Re: pvc plumbing question! Manifold runner or carb base.

02-09-2011, 08:20 PM	#4
oldgold70c10 Who's got steelies? Join Date: Feb 2006 Location: Morrison, Oklahoma Posts: 1,026	Re: pvc plumbing question! I know Q-jet, Edelbrock, and some Holleys will have a large hose nipple barb on hte front for the PCV. I want to say its 1/4 or 5/16 size. __________________ 1969 C10 LWB W/ 250 I6 & 3spd 1970 C10 with '67 small window cab, 68 front end, blue; 305/TH350, 3.08 limited slip rear end, manual brakes, power steering; & 4-wheel drums-My daily driver. 1975 Chevelle Malibu Classic Coupe 350/th350 mint green 1970 C20 Suburban 350/700R4 4.10 gearing green & white 1978 Big 10 Silverado 350/th350, working ac, 2 tone blue-My summer daily driver 1983 GMC 1500 Sierra 305/SM465 2.73 rear end How to add a trip odometer to your 67-72 stock speedometer How to rebuild your Q-Jet My Truck Page My Youtube Channel

02-09-2011, 08:22 PM	#5
brad_man_72 the boat guy Join Date: Jul 2007 Location: springfield mo Posts: 2,339	Re: pvc plumbing question! positive crankcase ventilation. Definitely best to have it routed someplace with alot of vacuume...... It can actually give you more power and a ccleaner engine. __________________ 67, swb, fleet, tach, throttle, 5.3, 4l60e, 3.73's, fuel cell, 5 lug, p.d.b., 4-6 drop. great little truck 66, stevens drag/ski 18' silouette, 350, 2.02 doublehump heads. comp extreme marine 278 cam, vette 7 fin valve covers, old polished edelbrock intake, velvetdrive, casale v-drive, adj cavitation plate. 28, model a rpu project,

02-10-2011, 08:58 AM	#6
maxwedge528 Registered User Join Date: Feb 2003 Location: easley, sc Posts: 45	Re: pvc plumbing question! not the answer as of yet! can i plumb the TH400 transmission vacuum source and the brake booster to the same port on the intake runner utilizing a large...3/8 inch vacuum Tee. Or can i run the TH400 vacuum line to the small port on the carburetor? still need input?

02-10-2011, 02:23 PM	#8
brad_man_72 the boat guy Join Date: Jul 2007 Location: springfield mo Posts: 2,339	Re: pvc plumbing question! use small port for the trans vac modulator. __________________ 67, swb, fleet, tach, throttle, 5.3, 4l60e, 3.73's, fuel cell, 5 lug, p.d.b., 4-6 drop. great little truck 66, stevens drag/ski 18' silouette, 350, 2.02 doublehump heads. comp extreme marine 278 cam, vette 7 fin valve covers, old polished edelbrock intake, velvetdrive, casale v-drive, adj cavitation plate. 28, model a rpu project,

02-10-2011, 05:08 PM	#9
maxwedge528 Registered User Join Date: Feb 2003 Location: easley, sc Posts: 45	Re: pvc plumbing question! thanks for the help! maxwedge528



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