Mechanical linkage to bellcrank

[Blue Viking]

So, I finally got to begin my build with the kit being completed at FFR in the beginning of July, with the local inspectors finally dropping by for the start-up inspection. I am using a 352 stroker with the speedmaster throttle body injection. This has a bellcrank in the middle which is set up for a throttle cable. I would like to use Fortes mechanical throttle linkage. Has anyone found a good solution how to modify/ replace the bellcrank so it works it the Forte linkage?

[RBachman]

Just give Mike a call. He'll help you out, great guy!

[CraigS]

A picture would be helpful. A quick google shows one version that mimics a four barrel carb. The bellcrank would be on the passenger side and the top of the bell crank needs to be pulled to the rear. If that is what you have it will be pretty easy. This my home made linkage before Forte offered his. Layout is the same.
linkage two by craig stuard, on Flickr
Inside the foot box a long shaft from the top of the gas pedal goes to the bellcrank on top of the cross shaft that goes out to the firewall. Mount the cross shaft as close as possible to the 2x2 frame piece. Close enough so you need to grind a flat on the edge of the over sized washer. It needs to be low so the end of the bell crank inside the foot box clears the top panel. The other bell crank on the cross shaft should be positioned so it is in line behind the bell crank on the throttle body. Note that I positioned both of the shaft mount rod ends in the engine compartment. This is because I did this on a complete car. You could put one inside the foot box if you like but the shaft is way more than stiff enough to have the mounts in the engine compartment. Barely visible is a 1/8x2 inch piece of flat aluminum I used to reinforce the firewall. Now that I have seen these systems on several FFRs I don't think that is needed.

[Blue Viking]

I’d don’t have the throttlebody here right now, it’s at my engine guys place. I’ll get a pic when I go there. It’s the Speedmaster eight-stack throttle body with a horisontal disc connected to two rods going to each side. The disc has provisions for the throttle cable, trying to find a way to connect the linkage to it instead. Haven't seen a solution on Fortes site, the linkage is from him though.

[Hotyacht]

I looked at doing the same thing.....I have the Inglese 8 stack EFI which has a similar bell crank in the centre set up for cable actuation. I couldn't find a suitable mechanical bell crank and so contacted Inglese who recommended using cable on their bell crank as it is shaped to provide a progressive throttle response making the car easier to drive at lower throttle openings..............so I have a cable off the bellcrank attached to the first arm of the Forte linkage...then all mechanical from there. Slightly random photos and apologies for the dust as I had been sanding the body. I hope that it helps with one option anyway. In case you are wondering why it looks arsewise??? it is righthand drive
IMG_4124.jpg
IMG_4125.jpg

[Blue Viking]

You know, i never thought of combining the two, I might just do that. With only a short straight cable run and the rest being Fortes mechanical, I think it will be nice and tight.

[CraigS]

I’d don’t have the throttlebody here right now, it’s at my engine guys place. I’ll get a pic when I go there. It’s the Speedmaster eight-stack throttle body with a horisontal disc connected to two rods going to each side. The disc has provisions for the throttle cable, trying to find a way to connect the linkage to it instead. Haven't seen a solution on Fortes site, the linkage is from him though.

Oh wow, I saw that on their website. That is going to be sensational. Look at this.
speedmaster linkage by craig stuard, on Flickr
Looks to me like that disc needs to rotate counter clockwise to open the throttle. Of course I can't see if there is room underneath but let's hope there is. You would possibly need a longer shaft to get closer to the center of the engine but otherwise fairly simple. Need to drill the disc and install a stud or just a small bolt, some spacers, and a nut. I think going below is better if there is room because up top there are the existing linkage rods. So to put another stud up top it would need to be pretty tall to clear them. Once you figure this out, the rest is nearly identical to a typical 4 barrel carb linkage.

[Blue Viking]

That one is similar to mine, but not exactly like it. I will have to disassemble the bellcrank and take a look at it. Your suggestion is exactly what I have in mind if I cannot find anything ready made for the purpose. Seems I have to find my own solution to this. And yes, will probably have to find a longer rod to make it to the center of the engine.

[rich grsc]

Craig is on the right track, that's how I did mine, ball stud under the center disc. Be sure you measure a lot!!!
This site is screwed up when it come to posting picture. No matter what I try they are always sideways. Click picture to enlarge.

IMG_2311.jpg

[Blue Viking]

That looks very similar to mine. If that setup works fine for you I think we have a winner.

[NC Cobra]

Craig
Thanks for the tips on installation. I’m putting the Fortes kit into a completed car, any other advice you can share?
Thanks,
Jeff

[CraigS]

NC, the only other thoughts would be these. 1- Looking at both the carb and the gas pedal, the bell crank arm is above the pivot point. I like both bell cranks on the cross shaft to be the same as it seems to give a good smooth action. 2- I played around w/ bell crank lengths. I have a little more pedal travel than most which makes controlling the power much easier. 3- As I was mocking up the linkage I found that the bell cranks on the cross shaft worked very well being oriented on the shaft parallel to each other. I was glad of that because it made it much easier to get the positioning correct when grinding small flats on the shaft for the set screws to be tightened against. BTW for anyone else reading this and thinking, is this worth while, the answer is a huge YES. I had cables to my carb for 3-4 years, tried several types, (the braided SS from Lokar sucked) and worked a lot on getting it all smooth. Installed the linkage and went for a drive and only got a block away before coming back. I had the exact same throttle return springs that were on it w/ the cable, but the linkage was so smooth, that the effort was so low, it was almost impossible to drive smoothly. Every little bump would move my foot and the pedal. Amazing.