The best way to Generate more Vacuum? - The 1947 - Present Chevrolet & GMC Truck Message Board Network

jmking9 · 10-21-2009, 09:07 PM

I just got my CPP Booster and MC installed this afternoon, and finally completing my disc conversion.(had pics but cant get them to load) I knew I would probably be short on vacuum, but I'm really short. My motor only generates about 8-9 inches of vacuum.My question is, what has everyone with big cams used to generate vacuum? Is a vacuum canister enough, or do I need an electric pump. Any Input?

mixermike · 10-21-2009, 10:05 PM

a vacuum canister works for me.

toddtheodd · 10-21-2009, 10:30 PM

I said screw it... going slow (when vacuum is low), I'm not moving fast enough to really hurt, and I just push harder on the pedal.
At speed, you have enough vacuum to stop.

But yeah... a canister, or a pump.
You could also go to the hydromatic power brakes and not worry about vacuum.

Jim_PA · 10-21-2009, 10:36 PM

What are the engine specs? Timing? vacuum advance? Seems pretty low unless you've got a pretty huge cam

67ChevyRedneck · 10-21-2009, 10:55 PM

It's been a long time since I checked mine, but I thought my 350 was running at around 18-20 @ idle. I checked it 'cause I thought I had a leak, but I didn't. 8-9 seems really low to me. I will admit to NOT knowing a lot about engines though...

68gmsee · 10-21-2009, 11:04 PM

Condition of the engine has an affect on vacuum also. If it's old and long in the tooth, it may need some valve or ring work.

69TowRig · 10-21-2009, 11:07 PM

My brother runs a dual-diaphragm booster and uses a vacuum accumulator on his 502BB Chevelle.

*highperf4x4* · 10-21-2009, 11:38 PM

Quote:

Originally Posted by jmking9

I just got my CPP Booster and MC installed this afternoon, and finally completing my disc conversion.(had pics but cant get them to load) I knew I would probably be short on vacuum, but I'm really short. My motor only generates about 8-9 inches of vacuum.My question is, what has everyone with big cams used to generate vacuum? Is a vacuum canister enough, or do I need an electric pump. Any Input?

What are your engine specs and what style of intake?

lost wages · 10-22-2009, 02:58 AM

hydroboost all the way, it will stand y our truck on its nose. Its what i did after spending a bunch of money trying to fix it cheap. http://www.hydratechbraking.com/Hydr...D926717302BC91

10-21-2009, 09:07 PM	#1
jmking9 Registered User Join Date: Sep 2006 Location: Riverton KS Posts: 832	The best way to Generate more Vacuum? I just got my CPP Booster and MC installed this afternoon, and finally completing my disc conversion.(had pics but cant get them to load) I knew I would probably be short on vacuum, but I'm really short. My motor only generates about 8-9 inches of vacuum.My question is, what has everyone with big cams used to generate vacuum? Is a vacuum canister enough, or do I need an electric pump. Any Input? __________________ 1970 SWB Build

10-21-2009, 10:05 PM	#2
mixermike Registered User Join Date: Jan 2008 Location: Post Falls, Idaho Posts: 606	Re: The best way to Generate more Vacuum? a vacuum canister works for me.

10-21-2009, 10:30 PM	#3
toddtheodd The oddest Todd around Join Date: May 2004 Location: Miami, Florida Posts: 1,418	Re: The best way to Generate more Vacuum? I said screw it... going slow (when vacuum is low), I'm not moving fast enough to really hurt, and I just push harder on the pedal. At speed, you have enough vacuum to stop. But yeah... a canister, or a pump. You could also go to the hydromatic power brakes and not worry about vacuum. __________________ "The greatest pleasure is to vanquish your enemies and chase them before you, to rob them of their wealth and see those dear to them bathed in tears, to ride their horses and clasp to your bosom their wives and daughters." Ghengis Khan IIOY???

10-21-2009, 10:36 PM	#4
Jim_PA Registered User Join Date: May 2005 Location: PA Posts: 2,696	Re: The best way to Generate more Vacuum? What are the engine specs? Timing? vacuum advance? Seems pretty low unless you've got a pretty huge cam

10-21-2009, 10:55 PM	#5
67ChevyRedneck Hittin E-Z Street on Mud Tires Join Date: Nov 2004 Location: Greenville, SC Posts: 23,090	Re: The best way to Generate more Vacuum? It's been a long time since I checked mine, but I thought my 350 was running at around 18-20 @ idle. I checked it 'cause I thought I had a leak, but I didn't. 8-9 seems really low to me. I will admit to NOT knowing a lot about engines though... __________________ Jesse James 1967 C10 SWB Stepside: 350/700R4/3.73 1965 Ford Mustang: 289/T5-5spd/3.25 Trac-Loc 1968 Pontiac Firebird: Project Fire Chicken! 2015 Silverado Double Cab 5.3L Z71 2001 Jeep Wrangler Sport 4.0L 5spd 2020 Chevrolet Equinox Premium 2.0L Turbo 2011 Mustang V6 ~ Wife's ride American Born, Country by the Grace of God 1967 CST Shop Truck Rebuild! My 1967 C-10 Build Thread My Vintage Air A/C Install Project "On a Dime" Trying my hand at Home Renovation! 1965 Mustang Modifications! Last edited by 67ChevyRedneck; 10-21-2009 at 10:56 PM.

10-21-2009, 11:04 PM	#6
68gmsee Active Member Join Date: Jul 2007 Location: Centrally located between Houston, Austin and Waco. BCS area. Posts: 7,947	Re: The best way to Generate more Vacuum? Condition of the engine has an affect on vacuum also. If it's old and long in the tooth, it may need some valve or ring work.

10-21-2009, 11:07 PM	#7
69TowRig Senior Member Join Date: Jan 2005 Location: Raleigh, NC Posts: 894	Re: The best way to Generate more Vacuum? My brother runs a dual-diaphragm booster and uses a vacuum accumulator on his 502BB Chevelle. __________________ -Chris Building a stripper, one part at a time: 1969 K5, 307, 3spd, 3 seats, hard top. Added Pwr Discs, Pwr Steering, Aux Battery, T-case Skid, Lighted Sidemarkers, HEI, Lock-Right Diff, ECE Class IV Hitch, 32" MT/Rs. Parts to Install: Hand Throttle, Console, Tow Hooks, Dual Horns, AM-FM, Dealer Swing-Away Tire Carrier, Gas Tank Skid. Also building a 1950 Willys CJ-3A and off-roading a 2001 Nissan Frontier on 1-Ton Portals...

10-22-2009, 02:58 AM	#9
lost wages Registered User Join Date: Apr 2001 Location: jefferson city, mo Posts: 1,364	Re: The best way to Generate more Vacuum? hydroboost all the way, it will stand y our truck on its nose. Its what i did after spending a bunch of money trying to fix it cheap. http://www.hydratechbraking.com/Hydr...D926717302BC91



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