Technical School me on spoon pedal throttle linkage to dual strombergs

First, the specs: 34 pickup with original spoon pedal assembly mounted on firewall with dual 97s (direct linkage on drivers side) atop slingshot intake.
Searched for the steps on how link my spoon throttle pedal to dual 97s but can’t find what I need. I’ve got a pile of accelerator linkage rods to chose from but how do I:

chose or fab a correct length rod? How does this set the pedal orientation for the drivers foot and range of motion for acceleration?

Do I need a single rod from pedal assembly to the front or rear carb or use a rod between carbs and then link to center of this rod from pedal assembly (see last picture)?

 

Your plan for tying the carbs together and linking it from the center seems correct from what I normally see.

In my 46 I used the stock pedal which has a similar Z bar with a spring but to get it to connect to the throttle linkage on the drivers side I cut the upright off and welded it to the other side. So now it’s more of a T than a Z but acts exactly the same.

Then I just connected the dots with solid rod cut to length and threaded for the quick release ball joints like your showing in your last photo.

 

You need to narrow the firewall linkage or bend it so it lineup with the ball connection on the passenger side of the carbs. You can connect it to either the front or back carb, since they are connected together on the drivers side. Make the connecting linkage long enough that when the spoon is floored the carbs are wide open.

 

I'm in the process of replacing the heads so don't mind the mess, but this is what I did. Narrowed spoon pedal to fit the Model A firewall. Linkage rod to rear carb. Stromberg linkage on the other side tying them together.

 

Looks like you have the bell cranks on the carbs on the back side. This ties the two together....good!
Now all you need is a linkage from your foot throttle to either one of the carburetors on the other side. No reason to tie them together on both sides.
As mentioned, you can bend/cut/lengthen/massage the foot throttle arm to align better with the carburetor bell cranks.
You can also bend an offset or dog leg into the rod you use to connect the foot throttle to the carb.
I used the quick release ball sockets from a stock linkage, cut to length and gas welded it back up.
Hope this helps...

 

I found a rod that was pretty close to hook up to the spoon pedal. I also have a setup like yours on the other side of the carbs. You’ll see guys cut and weld to get the correct length

 

Looks like I have an extra hole in the firewall underneath the pedal assembly. Am I missing a part of the pedal assembly? Am I missing some sort of bushing under the red primered cup covering part of pedal assembly?

just above the pedal spoon I see a little knob that appears to be for a spring to attach?

last pic shows mock of linkage to measure for a single linkage rod.

 

Some commercial spoon throttle assemblies (not sure what year that started) had two circular supports. It's possible your's did or someone installed on at one time. You can still modify your's if you'd like.

 

I'd leave the linkage on the left side as you have it (make sure both carbs are sync'd) and make a new rod from the pedal arm to the front carb (less angle than rear carb).

The connection on the inside was for the the original hand throttle.

No bushing, the cover holds the housing down and the pedal shaft turns inside the housing.

 

That knob on the pedal inside is what separates a 32 pedal from the others. Adds a $100 to the price.

 

Any of these suggestions will work, but from a mechanical perspective attaching the linkage to the rod that connects the carbs is the better choice. You'll get less throttle shaft wear and easier synchronization.

 

The 46 style throttle has two of those heim joint looking bolts to hold it to the firewall instead of one single like you have shown. Maybe it had one of those at one point? I’m not familiar with 32 stuff enough to say your missing one or not

 

interested in this idea. I suppose this would mean modifying my pedal assembly so that linkage ball is sticking up on drivers side? How would I attach to the carb rod?

 

Looks like the setup in your last pic would work fine if you trimmed off the excess. You wouldn't need (and shouldn't have) the linkage on the other side.

 

Just make a correct length link from the pedal ball to the ball on the passenger side of the front carb and be done with it. Been done hundreds of times, you are over thinking it.

 

That's a good one above ^^.

I was going to suggest something like that. 2 ends and some bar stock, using a bigger piece of bar stock (with a set screw) to make a slider over the linkage for adjustment. That's the good thing about these cars, you can make whatever you can think of as long as it works properly.

 

Speedway sells all of those pieces.

 

As for your extra hole both my 33-34 firewalls don’t have that hole.

 

Same ish as @banjorear

 

As for the EXTRA hole, those are likely B MOTOR cars that had the LONG throttle shaft as the carburetor was WAY off to the right side of the engine.

I set my throttle up to pull off the front carb and aligned the throttle pedal ball end to be perfectly in line with the carbs and not pull at off angles.

 

Now that I have wiring done on my project and have started it up in the driveway so I can test brakes, clutch etc. I have discovered I need a throttle return spring ( in addition to the one that is part of the pedal assembly and the 2 springs on the stromberg linkage). Pedal wouldn’t return to full rest position.

Banjrear, if you added a return spring can you share how it’s attached?

 

Some great info and photos here. Keep the posts coming.

 

I found the original spring on the pedal was too strong for my long distance comfort, so I took it off. I just use the little springs that Stromberg makes for the base, and another lighter spring pulling forward on the linkage. I figured three light springs is safer than one heavy spring.

 

Here are a few pictures of some of the return spring setups I’ve come up with. Which one should I go with?

 

does the last pic seem the simplest?

 

A longer rod connected to the front carb would improve the geometry and make for smoother operation.

 

Yep

Might try that since I do have another 3ft of rod.

and on another note the rear carb started seeping gas on the last shake down run of the engine. Seepage around rear air horn gasket as well as both throttle lever shafts. Uncle max said he would take a look at them if I send them to him. What a pain.

 

RichB, here is my new throttle linkage to the front carb.


Well further discussions with Max suggests too much fuel pressure to the carbs since both are presenting leakage and one is displaying seepage. I didn’t have a regulator on my fuel system but did have a Charlie Schwendler rebuilt mechanical fuel pump (tested by him to work at 2.5 psi) as well as a fuel pressure gauge that was reading about 1 psi when idling. Instead of sending carbs back to him, I have reinstalled them and will add a Holley 12-804 regulator. So this leads toy next question on where to mount it? Not wanting to mount it on the firewall.

Can I mount it off the rear carb rear stud that fastens carb to manifold riser? In this location it’s almost a straight down connection to the fuel pump outlet.


Option 2, can I mount regulator directly off fuel pump outlet, in a vertical position, to allow regulator to be held in place by the fitting vs a bracket?

 

You'll find that mounting it in either of those locations will create future issues when you want to work on either the carbs, fuel-pump or both. I usually make a steel bracket that picks up TWO of the intake manifold bolts. You want a solid mounting - vibration is not a good thing for these "dead head" style of regulators.