Vacumn Pump Question
Thread Starter
Racer
Joined: Jul 2007
Posts: 348
Likes: 12
From: Ocala, Florida
Vacumn Pump Question
My 1979 Corvette with a 383 stroker motor with a high lit cam only produces 12 in of vacumn. I'm looking at a Hella street vacumn pump #009428081. Has anyone used this pump to power the headlites and brakes? JAY
Burning Brakes
Joined: Oct 2003
Posts: 836
Likes: 26
From: Harrisburg Pa
The electric vacuum pumps work really well, the Hella pump has higher vacuum than most but I wouldnt try an electric pump if you have a supercharger or turbo setup, they dont have enough volume.
But the electric pumps do work well with big overlap cams and heads.
But the electric pumps do work well with big overlap cams and heads.
Pro
Joined: Jul 2010
Posts: 691
Likes: 25
From: Boynton Beach Florida
I don't remember what brand pump I bought but I use it for the brake booster only and it's been great. I mounted a second Vacuum gauge to keep an eye on it and it produces 25 hg with engine vacuum between 5-7 hg with the cam I have. Lights open and close great for such little vacuum.
I picked mine up off of eBay but it looks just like the ones on summit and jegs but were $75 more. The relay went on it a few days after I installed it and the guy sent a new switch and relay assembly no questions asked. Very happy with everything.
I picked mine up off of eBay but it looks just like the ones on summit and jegs but were $75 more. The relay went on it a few days after I installed it and the guy sent a new switch and relay assembly no questions asked. Very happy with everything.
Melting Slicks
Joined: Oct 2002
Posts: 2,317
Likes: 111
From: St Louis MO
Actually, 12" of Hg of vacuum is fine... Put a vacuum gauge on it - you'll be surprised at how rapidly the vacuum increases at a fast idle. If you feel that 12" Hg is too little to operate your headlight system, look for vacuum leaks in that system and/or replace the headlight vacuum control valve. Or, just run at a fast idle when you're opening or closing the headlights.
Melting Slicks
Joined: Mar 2002
Posts: 2,164
Likes: 7
From: Beringen
I bought one and installed it but haven't driven the car yet, so I cannot comment on it's operation.
They Hella pump is originally used by Volvo, so it's not that bad.
However, you need several parts in surplus to make it work properly. One is a vacuum can, then you need a switch for have the pump switch on if the vacuum drops to much. You do not want the pump to run continiously.
They Hella pump is originally used by Volvo, so it's not that bad.
However, you need several parts in surplus to make it work properly. One is a vacuum can, then you need a switch for have the pump switch on if the vacuum drops to much. You do not want the pump to run continiously.
Tech Contributor
Joined: Aug 1999
Posts: 14,380
Likes: 6,390
From: At my Bar drinking and wrenching in Lafayette Colorado
12 inches should be adequate to run any power accessory, including brakes and headlights. Once you get down into the 8" and below range, you start having some issues.
Corvette Stories
The Best of Corvette for Corvette Enthusiasts
Top 10 Most Expensive Corvettes Ever Sold on Bring A Trailer
Brett Foote
10 Things Every Corvette Owner Needs (2026 Edition)
Michael S. Palmer
8 Most "Only Corvette Owners Understand" Quirks and Problems
Pouria Savadkouei
10 Reasons the C6 Z06 is Still A Performance Benchmark After 20 Years
Joe Kucinski
How Much Horsepower Every Corvette Engine "LOST" in 1972
Joe Kucinski
Top 10 DOs and DON'Ts for Protecting Your Convertible Top!
Michael S. Palmer
Top 10 Most Explosive Corvettes Ever Made: Power-to-Weight Ratio Ranked!
Joe Kucinski
150 hp to 1,250 hp: Every Corvette Generation Compared by the Specs That Matter
Joe Kucinski
8 Coolest Corvette Pace Cars (and Replicas) of All Time
Verdad Gallardo
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
12" Hg of manifold vacuum [at idle] is plenty to work the headlights. But, your system needs a sealed vacuum accumulator tank and a [working] one-way check valve in the vacuum line, coming from the manifold and prior to the vacuum tank.
Drifting
Joined: May 2005
Posts: 1,968
Likes: 44
From: East TN
I also have a stroker that produces almost no vacuum. I installed a SSBC Electric Vacuum Pump 28146 for the brake booster only. Headlights take a couple minutes for both to go up, but I started gathering the parts to convert them to electric. Still have to figure out what to due with my HVAC, not enough vacuum to operate it at all.
Drifting
Joined: May 2005
Posts: 1,968
Likes: 44
From: East TN
Mine does, new tank, and stock valves that worked with the original engine. Also all new vacuum parts for both headlights. Vacuum tested all systems and it was all good. I need to measure what the engine is producing.