Booster vacuum problem with big cam
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Joined: Oct 2003
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From: Malta
Car: 89 RS Camaro
Engine: 350 ci
Transmission: T5
Axle/Gears: 3:42
Booster vacuum problem with big cam
Hi
I am finishing my engine with a 510 lift and I am worried about the brakes because a friend of mine just finished his engine with 490 lift and he is having problems with loss of vacuum and harder brake pedal!
What is the best thing to do? any ideas? shoul I fit a vacuum pump or a vacuum tank?
thanks and iclude pics if any!
I am finishing my engine with a 510 lift and I am worried about the brakes because a friend of mine just finished his engine with 490 lift and he is having problems with loss of vacuum and harder brake pedal!
What is the best thing to do? any ideas? shoul I fit a vacuum pump or a vacuum tank?
thanks and iclude pics if any!
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Joined: Feb 2010
Posts: 395
Likes: 3
From: San Antonio TX.
Car: Currently have 3 cars and 1 truck.
Engine: 1970&92 Cams,both BBC's
Transmission: LS1 T-56 & PG w/vendor's
Axle/Gears: Built 10 bolt& 9inch w/spool
Re: Booster vacuum problem with big cam
Hey Manovox, My cam is a little bigger than that and I use a Vacuum Canister with great results. Its a CamDynamics brand and easy to plumb. Ill include some pic's but I dont know how well you can see it? Its located behind the drivers side headlite, laying on its side. If you look you can see the inlet hose coming out of the front of the forward intake air gap. The outlet hose runs over the drivers fender to the booster's check valve. Simple, cheap and effective. Last edited by 92 BBC Z; Sep 21, 2010 at 03:30 PM.
Thread Starter
Member
Joined: Oct 2003
Posts: 240
Likes: 0
From: Malta
Car: 89 RS Camaro
Engine: 350 ci
Transmission: T5
Axle/Gears: 3:42
Re: Booster vacuum problem with big cam
I will make an aluminium tank by myself but should I have to put a non return valve or just the tank
please expalain to me coz I am confused!!
thanks more pics will bemor ethan helpful
please expalain to me coz I am confused!!
thanks more pics will bemor ethan helpful
Member

Joined: Feb 2010
Posts: 395
Likes: 3
From: San Antonio TX.
Car: Currently have 3 cars and 1 truck.
Engine: 1970&92 Cams,both BBC's
Transmission: LS1 T-56 & PG w/vendor's
Axle/Gears: Built 10 bolt& 9inch w/spool
Re: Booster vacuum problem with big cam
Ok, your tank is going to need two ports, an inlet, and an outlet. The inlet is connected to a vacuum source on your intake, then routed to the inlet side of your tank, thats where you install the 'check valve' just like the one on your brake booster. Then route the other line(the outlet)to the brake booster's check valve, Done, assuming your tank is airtight. If you want more pic's, check Jeg's or Summit.
Thread Starter
Member
Joined: Oct 2003
Posts: 240
Likes: 0
From: Malta
Car: 89 RS Camaro
Engine: 350 ci
Transmission: T5
Axle/Gears: 3:42
Re: Booster vacuum problem with big cam
Sorry but English is not my language and to be sure if I understood
so I have to put the hose from the intake to the vacuum canister instead of the brake booster and another hose from the vacuum canister to the brake booster! and should I make another check valve?
how much hoses should the cansiter have?
so I have to put the hose from the intake to the vacuum canister instead of the brake booster and another hose from the vacuum canister to the brake booster! and should I make another check valve?
how much hoses should the cansiter have?
Member

Joined: Feb 2010
Posts: 395
Likes: 3
From: San Antonio TX.
Car: Currently have 3 cars and 1 truck.
Engine: 1970&92 Cams,both BBC's
Transmission: LS1 T-56 & PG w/vendor's
Axle/Gears: Built 10 bolt& 9inch w/spool
Re: Booster vacuum problem with big cam
Yes, you understood correctly. The tank should have two(2) hoses. One for the inlet(this is where the check valve goes), and one for the outlet(this is the one that goes to the check valve on the brake booster. Hope this helps.
Thread Starter
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Joined: Oct 2003
Posts: 240
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From: Malta
Car: 89 RS Camaro
Engine: 350 ci
Transmission: T5
Axle/Gears: 3:42
Re: Booster vacuum problem with big cam
Ok you was a great help for me!
tomorrow i will go to my friends shop and will make an aluminium tank to my measurments and will order a vacuum gauge for it
thanks
tomorrow i will go to my friends shop and will make an aluminium tank to my measurments and will order a vacuum gauge for it
thanks
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Member

Joined: Feb 2010
Posts: 395
Likes: 3
From: San Antonio TX.
Car: Currently have 3 cars and 1 truck.
Engine: 1970&92 Cams,both BBC's
Transmission: LS1 T-56 & PG w/vendor's
Axle/Gears: Built 10 bolt& 9inch w/spool
Re: Booster vacuum problem with big cam
Just remember, a vacuum canister only stores vacuum, so after you first install your new tank the gauge will read low or no vacuum at idle. You will have to build vacuum by raising the rpm's before the gauge will register/read vacuum. A good vacuum system should hold vacuum for days, if not then you got a leak.
Joined: Aug 2006
Posts: 12,804
Likes: 103
From: Central NJ
Car: 86 Trans Am
Engine: 408 stroker sbc
Transmission: TKO600
Axle/Gears: Moser full floater m9, 3:70 trutrac
Re: Booster vacuum problem with big cam
i have a larger cam than that and have no problems with brake vacuum. You will be fine. If your friend is having problems, there is something else wrong
Junior Member
Joined: Aug 2010
Posts: 62
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From: yonkers
Car: 87 formula
Engine: 350
Transmission: 700
Axle/Gears: 12 bolt strange 3.73
Re: Booster vacuum problem with big cam
i have a 525 lift and i had a problem with vacuum. i put the can on it and it worked great.
Member

Joined: Feb 2010
Posts: 395
Likes: 3
From: San Antonio TX.
Car: Currently have 3 cars and 1 truck.
Engine: 1970&92 Cams,both BBC's
Transmission: LS1 T-56 & PG w/vendor's
Axle/Gears: Built 10 bolt& 9inch w/spool
Re: Booster vacuum problem with big cam
Sure.
Thread Starter
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Joined: Oct 2003
Posts: 240
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From: Malta
Car: 89 RS Camaro
Engine: 350 ci
Transmission: T5
Axle/Gears: 3:42
Re: Booster vacuum problem with big cam
thanks for all te help
will fabricate one out of aluminium for sure as the motor will be ready for sure!!
will fabricate one out of aluminium for sure as the motor will be ready for sure!!
Joined: Aug 2006
Posts: 12,804
Likes: 103
From: Central NJ
Car: 86 Trans Am
Engine: 408 stroker sbc
Transmission: TKO600
Axle/Gears: Moser full floater m9, 3:70 trutrac
Re: Booster vacuum problem with big cam
im in the neighborhood of 550/570 lift intake/exhaust and have no brake issues. the rest of the cam specs are relevant to the issue too. I still dont think he will have issues
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Joined: Apr 2009
Posts: 554
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From: montreal-canada
Car: 1985 camaro Z/28
Engine: 305 V/8 4bbl carb
Transmission: T5 WC
Axle/Gears: 3-23 posi with 4 wheel discs
Re: Booster vacuum problem with big cam
hi , can you tell me where i can find this tank you have, does jegs have this?...where did you buy it?...thanks.
Member

Joined: Feb 2010
Posts: 395
Likes: 3
From: San Antonio TX.
Car: Currently have 3 cars and 1 truck.
Engine: 1970&92 Cams,both BBC's
Transmission: LS1 T-56 & PG w/vendor's
Axle/Gears: Built 10 bolt& 9inch w/spool
Re: Booster vacuum problem with big cam
Sure, the part number# is 99590-1 . Cam Dynamics is now CraneCams,and its black in color not yellow, but the part number is the same. Yes both Summit and Jeg's carry this piece for $85. Hope this helps
Joined: Sep 2003
Posts: 25,895
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From: Pittsburgh PA
Car: 89 Iroc-z
Engine: 555 BBC Turbo
Transmission: TH400
Axle/Gears: MWC 9” 3.00
Re: Booster vacuum problem with big cam
Its not lift that matters really..its overlap of duration at idle that kills vacuum. Adding a bunch of timing and keeping idle higher can give you some good vacuum but there will be a point where you just dont have enough. For reference I had a 230/245 duration cam with .603/.613 on a 109 lsa and didnt have any problems with brake pedal feel. STock discs sucked anyway even when stock, so didnt notice much of a difference. Ran it leaner at idle with 28 deg timing overall and it worked out. Dont know the exact numbers it put out but I got a feeling it was around 12-13 inch Hg. My current 233/233 .564/.564 on a 112 in the 401 motor idles nicely at 15-16 inch Hg with about same 28 deg timing
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