tfringo

I have a pair of early 1968 holley center carbs 4055-1. Like I said, both are dated early 68. But, I noticed they don't have the fuel bowl vent/flapper on the top of fuel bowl (just behind the needle valve adjuster.

They essentially look like 67 style tri-power center carbs. The one has its original air cleaner stud for corvette.

So, was this a feature that was slowly phased out in the the 68 corvette model year?

Thanks!

JC68

Terry

67 and early 68 center carbs do not have the fuel bowl vent. It was add to the carb sometime during the course of the 68 model year in response to vapor lock problems.

John

tfringo

That makes sense.

But, a person could block a lot of the heat at the base of carburetor or at the intake manifold gaskets.

I recall gasket kit sets that provided a stainless insert to be placed in the passage between intake and cylinder head. Before I understood this issue I always scratched my head about using them. People also block those little ports in the intake manifold that come up under the carburetor.

I believe the heat riser deflects this heat up into the intake until it opens.

This whole process I assume is to just get the engine running efficiently and ecconomicly.

I wonder if you can go too far with blocking the heat off to the carburetor. I suppose the worst that can happen is that the choke pulls off a little slower.

Probably over thinking this. Hey, big thanks to your response. Have a great healthy and safe new year!

Terry