The Stovebolt Site Forums The Shop Area Engine Shop Just a question about carburetor mounting?

I see many of the vendors offer carburetor spacers for the Rochester "B" carburetor for mounting to the intake manifold. In the Chevrolet Truck Shop Manual it states that the carburetor mounts directly to the intake manifold with the carburetor mounting gasket. Question...which is the correct mounting of the carburetor on a 1949 Chevrolet 1/2 ton truck with the 216 cu.in. engine? Suggestions?

Tim

You need the spacer to prevent heat from getting to the carburetor.

As stated, the spacer is a heat isolator. If your trucks runs without any problems without the isolator, you probably don't need one. In high heat settings where the engine is subject to heat soak, then an isolator will help on restart. All engines need heat under the manifolds to help vaporize fuel and keep it from pooling on the intake floors, but having a hot carburetor is not ideal. The fuel heats up, expands, and can over power the float leaving a flooded engine, this is where the isolators come in handy, they keep the carburetor at lower temperature while the engine is cooling down. Spacers can help tune an intake and carburetor combination, but in the 216's case, they only serve as a heat isolator. Out on the road, you won't know the difference. Just be sure the gasket has the correct cut out for the vacuum signal on the bottom of the Rochester.

Joe

Carl and Joe,

I understand the spacer will insulate heat from the carburetor so it doesn't become heat soaked. Used spacers on many HiPo applications for that very same reason. Just wondering why the Truck Shop Truck Manual doesn't mention the spacer when mounting the carburetor?

Tim

Tim,

I looked in the Shop Manuals and I think I know why you are asking the question.

Most of my Shop Manuals are packed-away from moving, but in ones that are on-line I see no mention of the insulator/spacer (but I see it in a few pictures of the manifold assembly).

I think you might be looking in a section where the carburetor is removed and then, later, installed. The insulator/spacer (and, sometimes the gasket) is not specifically mentioned because they were not removed when the carburetor was removed.

What year Shop Manual and what section?

Tim,

Looking at the 1948-1953 Chevrolet truck shop manual section 6-59 through 6-64. I don't see anything mentioned or pictured with the carburetor spacer. When I removed the carburetor to rebuild it, there was no spacer. I have installed the spacer knowing that it will help to keep the carburetor cool, but questioning the spacer since it was not there before. Going to take a look at the assembly manual also.

Tim

Tim,

You will see the part (insulator) listed near top of this page.

No insulator here because the engine governor replaces it.

The insulator is shown in Fig. 70.

My original 1950 216 had it when I purchased it Tim. It was completely original when I got it. Good luck!

Is there a gasket on this set up? And, is it between the intake and insulator or between the carburetor and the insulator?
Thank you

That is a good question, Dennis

No gasket is mentioned in a Shop Manual.

Most people use a gasket between the carburetor and the insulator, and many people put a gasket between the insulator and the manifold.

Be sure the cut-out in the gasket between the carburetor and insulator aligns with the hole(s) in the base of the carburetor.