Technical Installing dual carb set up on 1937 Buick

I have a complete stock dual carb set from a '40/41 Special with the 248 engine. I'm altering the set up a little to fit and to operate better. Thanks to Carbking who provided a lot of help and information and rebuild kits.

First thing is I have a '41 engine in my '37, not the engine the dual set up came on. The major difference between the '37/38 and the later model cars is the engines in the new cars sit at a slight angel making the mounting surfaces at an angle to compensate and allow the stock dual carb air cleaner sit level. I had to make a couple of blocks to make the carbs sit straight and level in my '37.

First I did a CAD drawing of the mounting surface of the carb and then doubled it. I printed on adhesive paper and laid it on a piece of 3"x1/2" aluminum.



I used an 1/8" drill to make pilot holes and then used an 1 1/4" hole saw to cut the throat holes and a 3/8" drill to make the mounting holes. After drilling and cutting the holes I cut the pieces apart using my power miter box saw with a wood blade. I have cut pretty much aluminum this way and it works great although it tends to spit aluminum pieces all over. I again used the miter box saw to cut the angle pieces off. I bolted the pieces together and used an angle grinder to know off the corners and to true up the five sides. I used some sandpaper to clean up the throat holes and finished them off with a brake cylinder hone. I needed to have the bottom of the blocks go from 1/2" to 1/4" so I had a friend with a mill surface the angel.

 

Here's my dual carb set up for my 1937 Buick Special. I have a 1/4 inch phenolic spacer under each carb, and a 1 inch aluminum spacer under the rear carb. I've also been able to collect some carb linkages to see what combination will work best.

 

Nice job fabricating the angle blocks. However, something I am curious about. On my Buick dual carb setup there was a factory block/valve under the rear carb. That served sone purpose in the fuel distribution system, sort of like the secondaries on a 4 barrel carb as I understood it. Perhaps you had that part and chose not to use it, but without replacing it with a spacer (as shown in post #2 above) your carbs are not at the same height.

Ray

 

That's correct about the original damper valve, the rear carb on an original setup does act like a secondary on a four barrel carb. As the accelerator is is depressed, the damper valve opens up and the rear carb begins to go into action. On my setup, both carbs will open up at the same time. There's a good thread on this setup on the aaca.org site, in the prewar Buick forums. The setup there is for a Buick 320 setup, but much of the information applies to the Buick 248.

 

The butterfly valve on the bottom of the rear carburetor acts like the secondary when the linkage is configured as compound action. When linked as simultaneous both carbs will act the same at the same time. You will need two complete front carbs that match. Carbking, here and on the AACA site says this is the better set up than the compound set up. I don't need the aluminum block with the valve.

I also removed it so my stock air cleaner sits level. If you don't use the slanted blocks your carbs will forward at an angle and the stock air cleaner won't fit.

 

I'll be running two Carter WCD carbs on my setup, one is a 663s and the other is a 528s. The aluminum spacer is to even the carburetors out, height wise. I'm still learning and I'm also still looking for and collecting parts for my car. I think I'm really close to working on my car.

 

First, if you mount your set up the way you have it in your picture the carburetors will be slanted forward. The 41/42 engine sat on an angle while the 38/38 engine sits level.

Second, according to Carbking said that you need to use identical carbs front and back if you're going to run them simultaneously.

 

Ok, I'll be looking for another carb, probably the 663s. From there, I'll see how my manifold mounts up to my engine and I'll take it from there. Thanks for the advice, your setup looks like what I'm wanting to do.

 

Just an update. I got the carbs plumbed for fuel and vacuum to the fuel/vacuum pump and to the vacuum advance on the distributor.

 

Thanks for sharing this. Nice work.

 

Congratulations on getting your Buick running!