Throttle Linkage

[lake_harley]

I've been rolling a few thought around in my head about throttle linkage. I want it to be constructed to be rod linkage so with a toe loop on the pedal the throttle can be returned to idle positively in case a return spring fails. The engine will have a single carburetor and I've been doodling various linkage arrangements, trying to work out the throttle pedal travel and position to travel of the linkage on the carb. Lots of balls in the air when working out the geometry. My head hurts already.

Just to have some clarity, does anyone have the body off of their FED to take a photo or two of your throttle linkage arrangement? Posting photos here can be a challenge (to me at least) so you could e-mail or text them to me at the e-mail address or number below.

Thanks....in advance!

Lynn Winter
winter62@att.net
(573) 286-3335 Cell

[crider]

I'm no help with pictures, but you can use a morse cable and it will also allow you to pull the throttle shut in event of a return spring failure. On my car the cable just loops around from the pedal and up in front of the engine. Pust the carb on backwards and cable pulls from the front of the motor. Works smooth as silk and was very simple to setup 

[lake_harley]

So you're saying "push" to open the throttle and "pull" to close? Pull to close would certainly be more positive and foolproof when it's needed. I may be able to modify the primary linkage for that operation. Hmmm.

Lynn

[Supercat]

I use a Morse cable for throttle also.
I have a return spring on my gas pedal and 2 more on my hat/injection .

[Finnish Fireball]

Morse cable here as well, loops from front to back. As said above this forces your carb backwards. I have twin carb side saddle setup on my blower, and the linkage/cable combo was pretty challenging to get working properly.

[tcoupekyle]

Yup Morse cable here too

[JEFF/21C]

my throttle is a horse shoe shaped on it's side that you can lift with your toe and the cable is attached to the upper part close to the driver when depressed pulls in a normal fashion  and a positive stop so you don't over extend the travel hurting the carb or bellcrank

[THE FRENCHTOWN FLYER]

I now use Morse cables on my cars. Because:
In 2000 I got out of shape and crashed head-on into the concrete guard wall. The block plate balooned forward about two inches and trapped the throttle rod and pinched it in the WOT position. Amazingly the car spun around still running at WOT and headed back toward the starting line where about 700 people were standing around. Thanks to an in-cockpit master shut-off switch I was able to kill the engine even though I was semi conscious and temporarily blinded by the impact (Now I know why the blindfold cockpit test is important.)

[wideopen231]

You mean tghere is somthing other than Morse cable? Bever had anything else in 38 years of racing everything from bracket 6.5 second car to TA/D. Esy install vesitle and no problem aking push/ or opposite..

[lake_harley]

Cable it is. Made a bracket to hold the cable at the carburetor today. Cable will "push" the throttle open and have positive "pull" return. Return will be springs, of course, but also have a loop over the foot on the throttle to be able to pull it closed in case of a broken spring or something hanging up.

Thanks for the input. Also appreciate the reasoning for a cable (thanks FTF) rather than hard linkage.

Lynn

[lake_harley]

Man, time really flies! I asked a question about throttle linkage back in May and I'm finally at the point of needing to source the throttle cable. My desire is to use the cable to "Push" to open throttle, and then, if the springs fail or the cable sticks I intend to use the loop on my pedal to positively "Pull" the throttle closed. Here's a link to what I'm considering, and yes, I do realize it's listed as a shifter cable, but it has the rigidity on the ends to work as a true "Push-Pull" cable. I like this particular one because it has "bulkhead", threaded ends to tune the adjustment of the cable, plus one threaded end to use a rod end and provide adjustment too.

https://www.jegs.com/i/B%26M/130/80735/10002/-1?gclid=CjwKCAjwzNOaBhAcEiwAD7Tb6MOHM_3Q2CxafUAdFpqGTMwk0l8xdfLVzMwysIlAX-WzadqmYvW2CxoCPL0QAvD_BwE

Also have a question on chute release. Chute cables with and without the handle are ,in my opinion, way out of line on price. I have a cable housing that has an I.D. that could serve as a "Pull" cable to pull a .070" "wire" out of the chute loop to deploy it. I will need to source the wire and was wanting to use stainless steel for the obvious reason to resist corrosion. The housing will have some bends in it to get from point A to point B, and I wonder if I need to be concerned about what alloy the stainless steel solid wire is so that it wouldn't work harden. The  one source of wire I'm considering says they make springs and sell a 302 alloy stainless wire, so I would think it would work out OK. I think the tightest bend would still be at least 6" radius.

FWIW....The track I plan to run has a 3000' shut down area for a 1/8 Mi. track and I really doubt the chute would ever get used except just to test that it actually works, so maybe questioning work hardening is not an issue at all. Then again, maybe my thinkin' is stinkin'.

As always....thanks for input.

Lynn

[Paul New]

Here are the type of cables I use “Morse”. These cables can make tight bends and still operate smoothly
https://goodvibesracing.com/Cable_Groove.htm