Thread: center tri carb won't idle...

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I got the tubes unplugged using carb cleaner and a piece of copper wire small enough to up the tubes. Sprayed carb cleaner all around and found no leaks around the carb, but major leaking where the intake meets the heads. We did not use a sealant on the sides, only the gasket by itself. We did put sealant on the front and rear with the rubber pieces that come in the gasket kits. Perhaps these are not pulling down enough. Will take them out, and put sealer all around the intake and see what happens. thanks much - kip

KB

I don't know what intake gaskets you used, so what I'm about to say may be off base.

When I set my tripower up several years ago, it was recommended that I use thick soft gaskets on the intake to head surface. I was told not to use the hard gaskets like the ones that come in most gasket sets. As a matter of fact, Edelbrock had a warning on their website about not using these hard gaskets on any of their aluminum manifolds, but I can't locate it now.

Offy actually sells special thick gaskets(part # 5305 Special) for their tripower manifolds.

I used Victor graphite impregnated gaskets(sorry, no part #, been a long time) that my local machine shop had on the shelf. They were pretty thick and very soft.

I was told to torque the manifold down in several small steps, too( more steps than you would normally). The way it was explained to me is this: The tripower(and 2x4) manifold is very stiff in the main body, but still has regular thickness flanges. This makes it easy to distort the sealing surfaces and get vacuum leaks if you're not careful, especially with hard gaskets.

This info came from Hot Rod Carburetion and they said that most of the vacuum leak problems could be traced to improper gaskets and torgue. I took their advice and mine have been trouble free for about 7 years.

Hope you get it figured out.

Mike

Oh well, I used the hard gaskets that came with the kit, and did not torgue the intake manifold bolts down. I tightened them to what seems to be "tight". Is there any where to locate a larger but soft intake gasket? Is possible to make them out of gasket material??? My guess is no. I don't know that I understand what you were saying about the reason the harder gaskets are not the best to use. My guess is that there are still vacuum leaks, thus still hard to get to idle right. There are several places that sell tri carb materials, wonder if any would know of such gaskets? And what their recommendation would be? I'll check. Thanks - kip

KB

Here is the warning form the Edelbrock website I referred to:

CAUTION: Always use new gaskets as recommended. Check
with gasket manufacturer for compatibility with aluminum
intake manifolds. We recommend Fel-Pro Printoseal gaskets.
The use of Permatorque gaskets can lead to improper sealing
due to the hardness of the gasket. Don't use Permatorque
gaskets.

Here's a link to the document:

http://www.edelbrock.com/automotive_...e_Manifold.pdf

Don't blame you for being skeptical of the explination. Just passing on info from someone who had delt with far more of these manifolds than me.

Mike