Throttle Linkage

[farmerdick]

Hey Guys, Looking for some suggestions on how to set up for an updraft Holly model 94 utilizing original Model A rods and a homemade bellcrank. I am having a problem getting the correct throw from the original accelerator rod to the pivot arm to open the throttle plates properly.
Thank you in advance for any help.
I`ve enclosed a couple pictures to show what I`am up to.

Richard/Maine

[CarlG]

Unless I have the pictures upside down, they look like pictures of a DOWNDRAFT carb to me.

[BRENT in 10-uh-C]

The biggest thing I see wrong is the boss for the bellcrank is mounted in the wrong location. It needs to be upward about 2 to maybe 3 inches higher IMHO. This ratio can be figured by measuring the total amount of travel available on the throttle assy, and then measure the distance necessary to pull the throttle shaft to wide open. Compare the two and that will give you the ratio. Then move the axis of the bellcrank where the fulcrum is correct. This may require you Heli-arcing a new boss onto the side of the manifold where it can be drilled & threaded.

I hope this all makes sense...


.

[ctlikon0712]

Looks to me like you need to shorten up the homemade bell cranks upper connection so that its movement is the same linearly as that on the carb. Reattach the ball lower down or fab a shorter lever.... you kind of have to take a 6" ruler and play with where on the bell crank looks the same as on the carb. Good luck

[Tom Wesenberg]

I would make an angle bracket that comes straight back from the rear of the 2 bolts holding the intake to the exhaust, then straight down to the current bolt on the linkage on the intake. Right where the 90* corner of this bracket is would be a good place for the new bolt to mount the bellcrank. Then as Brent said just measure and figure the ratios needed for the two arms of the bellcrank.

In the picture, are the foot throttle and carb throttle both shown in the OFF (idle position)?

[1931 flamingo]

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I believe some of the vendors (speedway motors, jegs, sacramento vintage) offer the type of linkage you need. Is the brkt bolted to your manifold "home-made"?? From the pictures it looks like it.

Paul in CT

[hardtimes]

Originally Posted by [email protected]

Hey Guys, Looking for some suggestions on how to set up for an updraft Holly model 94 utilizing original Model A rods and a homemade bellcrank. I am having a problem getting the correct throw from the original accelerator rod to the pivot arm to open the throttle plates properly.
Thank you in advance for any help.
I`ve enclosed a couple pictures to show what I`am up to.

Richard/Maine

Richard,
Looking at your 'second' pic vantage point of the linkage....I believe that you are very close to having a workable situation. As I see it, your major problem as shown, is that you have NO leverage/mechanical advantage ....from your fulcrum/pivot point DOWNWARD. Looks only to be an inch below fulcrum and several above(mech advantage is upside down..if you will). Try extending the arm below and extending it three/four inches. You appear to have enough rod length to reach such an extension. Give it a try and you'll have more mechanical advantage(easier push operation). FYI , there's a lot of different ways of doing this operation and to look at other guys setups is interesting and different! I've given you a pic of mine to give you an idea of 'leverage' talked about. Don't forget an appropriate return spring also.

BTW- You've got a nice setup!

[farmerdick]

Originally Posted by hardtimes

Richard,
Looking at your 'second' pic vantage point of the linkage....I believe that you are very close to having a workable situation. As I see it, your major problem as shown, is that you have NO leverage/mechanical advantage ....from your fulcrum/pivot point DOWNWARD. Looks only to be an inch below fulcrum and several above(mech advantage is upside down..if you will). Try extending the arm below and extending it three/four inches. You appear to have enough rod length to reach such an extension. Give it a try and you'll have more mechanical advantage(easier push operation). FYI , there's a lot of different ways of doing this operation and to look at other guys setups is interesting and different! I've given you a pic of mine to give you an idea of 'leverage' talked about. Don't forget an appropriate return spring also.

BTW- You've got a nice setup!

Thank you for the info and complement. Where did you buy your pivot arm? I would like to have something more professional on mine.

Richard/Maine

[ken ct]

Originally Posted by [email protected]

Thank you for the info and complement. Where did you buy your pivot arm? I would like to have something more professional on mine.

Richard/Maine

I have one if you need one/ commercially made machined aluminum. ken ct 1-203-260-5945 or PM , EMAIL/

[farmerdick]

Originally Posted by ken ct

I have one if you need one/ commercially made machined aluminum. ken ct 1-203-260-5945 or PM , EMAIL/

Ken,

My mailing address is:

Richard Reed
22 Berry Road
Readfield, Maine 04355

207 685-4709