The Stovebolt Site Forums The Shop Area Engine Shop Help needed in finding Dual rochester carb linkage

Ok folks I have Offy dual carb intake I'm going to use on my 61 235, it currently has two single barrel rochesters on it. I have the carb linkage but I'm not sure I have the linkage from the truck throttle cable to the carbs if that makes sence. It certainly doen't to me.

The carbs are joined by a single shaft that operates vertically. I can't imagine what linkage I would need to install this on my engine.

I spoke with Patrick @ Patrick's and he said that the instalation kit as he called it he was currently out of stock.
If anyone could offer a picture or some direction as to where I could find linkage to make this work that would be great.

Thanks....

I think I've got a new one laying around. I'll check and let you know.

Dave,

I would love to see a picture if you do. I'm quite convinced that I'm missing something. I'm trying to solve the puzzle.

Thanks.....

My next search project will be air cleaner for the same set up. I like some of the stuff on Vintage Speeds website. Maybe something aluminum and finned....

soba_03,


Unless this is something 'new', the linkage from bellcrank to the piece supplied by Offy is just a bent piece of 1/4" rod.

Bending it so that it allows full throttle and closed throttle takes some work, as the space through the manifold runners isn't very large, plus the bellcrank tends to make the motion of the rod forward and backward as its point of connection at the top has been moved..whew, what a sentence!

The Offy linkage that connects the two Rochesters is poor at best. Be sure to fasten it to the arms on the carburetors very well. Getting both carbs to open evenly and to close properly can be a real big chore. Good luck.

Stuart

soba_03,

Are you referring to the dash-mounted throttle cable connection, when you state ". . but I'm not sure I have the linkage from the truck throttle cable to the carbs . . "?

How did you connect the choke cable? Do you have the choke/throttle cables bracket that mounts on the top of a single Rochester carb?

I used one of those brackets for the choke on the rear of the rear-most carb, and I used another one of those brackets on the front edge of the rear-most carb and ran the throttle cable down to the throttle rod (the rod described by Stuart, above).

If you are asking about the throttle cable, I will see if I can take a picture tomorrow (I sold the truck but might be able to get over to see it tomorrow).

Tim

atomarc,

I have the Carbs and the intake and the carb linkage. I don't have the belcrank. The carbs have the 1/4" rod that your speaking of. How do I connect that to the throttle cable and make it work? (I think I'm missing the bell crank.)

Tim,

I think your on to my problem. The gas pedal is basically a push/pull set up. I'm trying to determine how to make it work when looking at the two carbs and the linkage it appears to need something to move the (rod) that Stuart mentioned verticaly to open and close the throttle. Yes I still have all of the parts off the single rodchester that it currently on my truck. And from the sounds of what your discribing the set up you used to make it work looks and sounds alot like what was used on mine too.

If a picture is possible it would certainly help clear up alot of this mystery...

Thanks to all of you....


Ok after a re read of the posts, the bellcrank that Stuart is talking about is on the carb. I have that. I have the 1/4" rod that links both carbs together and it is securely fastened to both carbs. My question is how to I attach that to the throttle cable from the truck and I think that was answered in the last post.

soba_03,


You might be all clear on this by now, but here is a picture of what is referred to as a bellcrank.

Tim is describing the "cable" system from dash mounted throttle knob to rear carburetor.

I am talking about hard throttle linkage...no "cable" in this system.

The gas pedal on the floor is connected to the carburetors through rods and a bellcrank.

The choke and a cable operated throttle are connected by means of cables from knobs in the dash.

http://home.twcny.rr.com/schickling/1940Chevy/rebuild/dscn2210.jpg


Stuart

Stuart,

Now your talking, my carbs and intake are complete. I'm missing the bellcrank. I'm not the greatest at trying to explain what your picture shows. ""THAT IS IT""

Thats what I'm missing to get mine working. Currently I just have the stock single carb.

soba_03,

The bellcrank pictured isn't something special, it's a stock Chevrolet part that should be on your engine...it has to be in order for it to work.

You haven't mentioned what exhaust system you are going to use. I think the linkage from bellcrank to the Offy piece is a cake walk unless you are dealing with Fenton exhaust headers. With the Fenton's, you have to turn that piece of linkage from the bellcrank into something that resembles rigatoni to make it work.

Stuart

OK, based on what I'm seeing on the carb and intake setup the throttle rod that we discussed earlier would seem to have to operate Up and Down as opposed to fwd and aft.

I guess I'm confusing what I know about conventional carb operation and this old thing. Let me study this a bit more when I head to the shop. The Exhaust I'm running are Ceramic coated Tube headers from "Hot Rod Inc." they are not Fentons.

Don't mean to make a mountain out of a Mole hill. It's just it runs now and I would hate to disable it trying make this new dual set up work.

Soba - after re-reading all this couple of times I'm not convinced that you do understand waht is trying to be explained. It's so darn hard to see those pictures in another guys head isn't it? HA.

To make it a skoche easier please look at my Picturetrail account shown here and on the pick up photos you'll see one named Carbureutor Linkage. It shows the two carbs (not the ones you have) the rod between them and the center lever that the vertical rod attaches to. This is somewhat different than the Offy linkage (which I'm still looking for)and available from Stovebolt Engine Company. I do have the Fentons on this motor and don't know why it takes Rigatoni to make it work. I made my own vertical linkage from 1/4" stock and cut the threads on it.