Tri Power Setup Question
Thread Starter
Intermediate
Joined: Mar 2006
Posts: 36
Likes: 0
From: Brookston IN
Racer
Joined: Aug 2003
Posts: 259
Likes: 2
From: Sacramento CA
Here are some pictures of a vacuum leak source if you use the wrong base gasket. First photo shows that PCV passage in the manifold. Second photo shows a wrong base gasket. I'm referring to the outside edges, not the bore edges. You can clearly see the open passage but with the center carb on you can't see it. You just have a vacuum leak as thick as the gasket is which is substantial.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
Here are some pictures of a vacuum leak source if you use the wrong base gasket. First photo shows that PCV passage in the manifold. Second photo shows a wrong base gasket. I'm referring to the outside edges, not the bore edges. You can clearly see the open passage but with the center carb on you can't see it. You just have a vacuum leak as thick as the gasket is which is substantial.
That was nice of you to go out and take your car apart to show the leak you were talking about.
Racer
Joined: Aug 2003
Posts: 259
Likes: 2
From: Sacramento CA
6th Gear
Joined: Apr 2009
Posts: 6
Likes: 0
tri-power center base gasket
I have read that all three base gaskets on the 427 holley tri-power carbs are the same .06 thickness. I don't see how the paper .06 thin gasket can hold up very long on the center carb. The vacuum chanel will surely suck it in and tear it. Surely the correct center carb base gasket is thicker and made from a composite material. I had a vacuum leak and sure enough the paper thin center carb base gasket was tore at the vacuum chanel. Does anyone know where to get the correct center carb base gasket?
Le Mans Master
Joined: Nov 2001
Posts: 8,780
Likes: 1,934
From: LONG ISLAND
2025 C3 ('68-'73) of the Year Finalist - Unmodified
2024 C3 of the Year Finalist - Unmodified
2023 C3 of the Year Finalist - Unmodified
i'm a bit lost trying to follow the problem here. Should the gasket cover the entire channel ? can someone supply a "CORRECT" gasket to compare it to ? can't see exactly whats wrong here ???
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
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
The gasket needs to cover the entire channel,otherwise air will be sucking in through that small opening. Once the carb is in place the opening will only be the thickness of the gasket but it is enough to cause a problem.
Burning Brakes
Joined: Mar 2006
Posts: 793
Likes: 1
From: Houston Texas
Hi
Multi-carb setups are notorious for being a pain to properly adjust.
Right, but this does not count for the original Vette tripower setup.
Only the ctr carb has a idle feature, the 2 2ndaries only come in on power. Idle setup is as easy as on a ordinary Holley 4150.
Carb rebuild, choke fully open and nor vacuum leaks and it just works fine.
Günther
Multi-carb setups are notorious for being a pain to properly adjust.
Right, but this does not count for the original Vette tripower setup.
Only the ctr carb has a idle feature, the 2 2ndaries only come in on power. Idle setup is as easy as on a ordinary Holley 4150.
Carb rebuild, choke fully open and nor vacuum leaks and it just works fine.
Günther
People that have problems with them have issues with the components. Warpage, old leaking gaskets, blown power valves, cobbed together Holleys, poor ignition systems, worn out motors. With everything in proper working order they are no more difficult than any other setup.
If not, they are just as bad as any Q-jet or Holley 1x4.
Dan
