Bell Crank for Down Draft

[Fillinjc]

Hi,

Fabricating a throttle linkage for my new Stromberg 81. Wondering if I could get opinions on how this looks? I have been trying to keep the upper and lower linkage to pivot distances equal or if anything the lower leg longer thinking that would give me a longer throw at the pedal. Better control. I still need to add a return spring. Probably from the vacant front threaded spot on the manifold to a point on the bell crank just below the upper linkage connection. Will trim the top off, round the corners when I am happy.

Thanks,
Jerry

 

[old victoria]

check out weber kit linkage, you don't need those long arms, I would move the pivot point up ( rods moving horizontal) I build the weber kit. spent a lot of time on the linkage.

 

[MikeK]

As old victoria states, the pivot point is too low. The angularity and length of the lower arm is troubling. Try replacing the bolts that hold the two manifolds together with longer studs. The first nut on the studs will hold the mani's together, then a plate you fab to hold a new pivot point, then two lock nuts to hold the new pivot support plate in place.

Second point- Your idea of a throttle return spring is rather unsafe. You may wish to mount a spring like that to take up the majority of the inertia load of the added linkage, but what happens when that ball cap link pops off the carb throttle shaft! WOT!! You also need a Stromberg ‘Snapback’ throttle return spring, which wraps around the end of the carb throttle shaft.

 

[RawhideKid]

Hey, what kind of exhaust manifold is that? That is cheating, the clamp part is not only straight, it has a nipple to slide the exhaust pipe over it so no chance of leak!

I wants one.

 

[Fillinjc]

Hey, what kind of exhaust manifold is that? That is cheating, the clamp part is not only straight, it has a nipple to slide the exhaust pipe over it so no chance of leak!

I wants one.

Snyder's ceramic exhaust manifold (A-9430-C) with an exhaust sleeve (A-5234).

Yeah, I cheat when I can.

 

[Dick So. Cal.]

I don't see a fuel pump. Are you running one?

Dick

 

[zzlegend]

Jerry, your looks very similar to mine. I bought this from a guy who was running it with this linkage and I just installed it to try it. Not sure if I am fond of the linkage arm yet and I might change it when I get a chance. Return spring picture also. I tried to gravity feed and would idle nice but not under power. 6 volt pump installed. Good luck with yours. Mark.

 

[Fillinjc]

Second point- Your idea of a throttle return spring is rather unsafe. You may wish to mount a spring like that to take up the majority of the inertia load of the added linkage, but what happens when that ball cap link pops off the carb throttle shaft! WOT!! You also need a Stromberg ‘Snapback’ throttle return spring, which wraps around the end of the carb throttle shaft.

Uncle Max built my carb so I checked with him regarding the SnapBack spring. He thinks that it would be too much along with his already installed heavy accelerator pump fulcrum spring.

Thanks,
Jerry

 

[Fillinjc]

Jerry, your looks very similar to mine. I bought this from a guy who was running it with this linkage and I just installed it to try it. Not sure if I am fond of the linkage arm yet and I might change it when I get a chance. Return spring picture also. I tried to gravity feed and would idle nice but not under power. 6 volt pump installed. Good luck with yours. Mark.

Thanks. Still thinking about this linkage. Comments from the majority here is that my setup requires a pump so I am kind of expecting that. I would like to take it around the block using gravity first just to see.

 

[john in illinois]

Here is mine.
You need a straight pull on the carb. An angle will make last part of travel hard.
John

 

[Phred]

http://www.thehotrodcompany.com/blog/2010/12/default.aspx

for throttle return spring see above link.

 

[Fillinjc]

Thanks for the feedback.

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