Technical Very short throttle cable required

I'm got a situation where I need a short throttle cable - maybe 5" from firewall to throttle bracket. Complicating the situation is an offset of about 3" where it goes thru the firewall and the bracket. This results in a very tight bend.

I'm thinking I need to make a bracket/swivel with a shaft that takes care of the offset for me and so that both cables can just run straight...basically front to back in the vehicle. Has anyone run into this before? Looking for clever ideas before I attempt to build something.

 

1. Make a new bracket closer to the carb.

 

Put a loop in it. No, really.

 

yup, long cable with a loop....solve all your problems...but it'll look funny!

 

I tried a loop and it seemed like there was so much resistance that the pedal didn’t want to return even with the springs. Mind you, it was a pretty tight loop.

 

you need a big loop

 

Out past the radiator and back again. Just kidding.

 

Do you have room to extend a tube or bracket inside the firewall to allow for a longer cable, it may only need an extra inch or two.
Or make it a mechanical throttle linkage with a solid rod (like the old days).

 

The bend at the firewall is way too tight the way you have it now and the cable will bind up right there if it will even go though that bend. A loop and I'd say most of us are thinking around 6 inches or more. Then figure out how much room you need for travel for the cable and position the bracket up further to the front. You only need a half inch or so extra space besides what the linkage moves as far as cable travel goes. The way that is set up it looks like you have about six inches of space for 2-1/2 inches of travel at most. in diameter with a bracket to hold it in place would cut way down on the kinks.

 

Looks like a SBF and the loop is a good solution. But I still don't understand why the mounting bracket is so far back. I mean, you can mount the return springs forward if that's your reason.

 

I agree that the throttle bracket on the carburetor is too far rearward. Couldn't you move that ahead about 3 in and that would alleviate some of the tightness of the cable bends? How about can you move the hole in the firewall over so that it aligns with the carburetor arm?

 

My loop goes around the coil. No problems in 30+ years.

 

On very short runs with tight bends its the cable HOUSING not the cable that can't make the bends. I just bend up 3/16 brake line tubing to align with everything and then run a hood cable (very tough) through the tubing and add the needed ends. You can put a 360 degree bend in the tubing every few inches and the cable will slide with zero resistance. Also looks nice with it's exact fit.

 

If you look around, you should be able to find some old throttle bracket or transmission bracket that has a cross shaft. Then use a rod instead of a cable at each end of the offset. Might look at some kind of hydraulic set up............of course we all know how new cars control their throttles, but no one would do that on a Hot Rod.... would they?

 

Forget all the loops, and ugly bends. Just buy a bell crank and build a bracket to align the bell crank arms with the firewall hole, and the carburetor. Then you can use a short straight cable to the bell crank, and hard rod from bell crank to carb. It can even be used to give a different ratio, so the feel at the pedal can be whatever you prefer by changing mounting holes on the crank arms.
Speedway sells a universal for $23, and you can mount it horizontally to get things lined up properly.

https://www.speedwaymotors.com/Spee...E7NAuPHFekak6o5t0my7cBbUcm_MW87hoCwXMQAvD_BwE

 

Thanks for all of your advice, guys. I'm going to have to do some planning this weekend.

 

Gas pedal from a mid 80's Chevy Sprint with the top bent sideways and a home made mount because the original plastic broke.

 

I agree on the loop method.
I design a lot of Bowden cable applications for the industry I work in. We use 1/16" flexi wire cores with a nylon lined outer sheath and they still operate well with ~ 2" bend radius ...... they're ~1/4" OD.
That cable assembly doesn't look like a very good candidate for tight bend radii.

 

I am surprised nobody has suggested a bicycle brake cable. It works for me. They are very flexible and easy to shorten. Get a good one with a nylon liner in the housing. I made a spare to carry and have never needed it yet (20 yr hence).

Another alternative is a rigid tube bent to carry the cable.

 

All good fixes but I would head on over to my local Motorcycle shop and pick up a throttle cable for a mini bike. They are very flexible, super strong, and inexpensive. Have not broken one in over 45 years, Maybe give that a try. That will prevent loopty loops in the engine compartment.

 

You could also use a cable coming out of the firewall with the housing making a gradual 90-degree bend to the bracket and use a bellcrank as others have suggested.

 

My coupe has had a loop in the cable for years. Still working fine

 

X38 has the simplest idea. You don't need to move it forward a large amount to make a big difference. This is what I did.

 

Here's what I ended up with. (I tried to get to the rad with the loop, really ) A combination of a modified bracket and a loop.
thanks guys

 

Looks like your not done with your carb and intake work yet.

 

After everyone is done screwing with you, I know you probably don’t want to mess up your firewall but you need a shaft where one end goes threw the firewall and other with linkage goes to carb. It’s the fix