jonesolds442

RE: Rallye 350

Hi there-

I just had the carb rebuilt and it will not seal completely to manifold plate with the new baseplate gasket-still a noticeable vacuum leak (rough idle only). Aside from leveling the manifold plate/replacing the carb baseplate, for the interim, are there specific types of finer gaskets that can be used inbetween the carb/baseplate gasket and/or the baseplate gasket and the manifold to create a complete seal? Furthermore, would any of you recommend using a very fine bead of silicone as a temporary solution (ensuring that the bead was not at risk of flowing over and breaking off into the intake)?

oldcutlass

What carb and manifold are we talking ablout? Is it leaking between the carb body to base plate or manifold to base plate? Is your base plate warped?

69442C

Yes, specify what carb you are using and if you have a spacer between the carb and the intake manifold. Not sure what the "plate" is you are referring to.

BILL DEMMER

correct torque is 12-15 ft/lbs.


bill

allyolds68

Are you sure you have the correct base gasket? I used the Holley gasket that came in my rebuild kit and it wasn't correct. I had a HUGE vacuum leak that a new gasket fixed.

jonesolds442

I'm using the stock cast-iron intake with the stock quadrajet. The carb was recently rebuilt and they included a new base gasket. The "plate" I was referring to was the carb gasket-there is no spacer. I'm unable to tell if the leak is between the manifold and the gasket or between the gasket and the carb.

oddball

So I recently made a humorous knucklehead move.
Using starter fluid, I could tell there was a serious leak on both the right and left of the carb, between the base plate and the manifold. Poking around with some feeler gauges showed there was a gap around 0.005"! Took off the carb, and it looked like the base plate was bowed.
Turns out I over-tightened the base plate to fuel bowl screws and that actually distorted the plate. They don't need much. No white knuckle work here, just what I call "well snug" with a screwdriver.

Another fun thing happened - the high dollar rebuild kit from Ruggles had the wrong base to bowl gasket, and I didn't notice until much later. That was a leak.

oldcutlass

Glad you found it.