Tri Power Setup Question
Thread Starter
Intermediate
Joined: Mar 2006
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From: Brookston IN
Racer
Joined: Aug 2003
Posts: 259
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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
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From: Sacramento CA
6th Gear
Joined: Apr 2009
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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
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From: LONG ISLAND
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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 ???
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Race Director
Joined: May 2006
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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
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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
