PDA

View Full Version : Throttle cable



MadElf
09-09-2001, 02:16 PM
Ok guys... I'm hoping you can help me out here.
I know that somewhere in the archives is a reference to someone setting up a cable to replace the linkage all the way from the gas pedal to the carberator. (There may even have been some reference to a pedal swap)
I know it's in there... but I can't find it.

I am in semi-dire need of this exact sort of conversion myself. Does anyone remember what the scoop was on this? What cable was used? Will the existing pedal work, or do I need to change something?
Any help would be greatly appreciated.
Thanks!

painterchris
09-09-2001, 03:03 PM
I put a cable in my 64 and it works great. I used a "Trans-Dapt" cable, which was 72" long. I had to make several brackets to hold the cable. One of my brackets mounts via a miscellaneous mounting bolt that already existed on my intake manifold. I had to drill a hole through the radiator mount to route the cable around the radiator. Then, it comes up under the floor and does a u-turn before tying into the pedal. This way, I can use the stock pedal. I accomplished the u-turn by fabricating another bracket which attaches to one of the stop switch mounting bolts. I managed to use only the hardware that came with the cable, but depending on your application, you may need to fabricate something. I thought I might have trouble with the cable binding in the tight u-turn section, but it has worked trouble free for over a year.

LAter,
Andy.

MadElf
09-09-2001, 06:45 PM
Sounds perfect.
And I'm glad to hear the existing pedal can be used.
Thanks for the info.

vannman67
09-10-2001, 02:40 AM
I used a cable from Lokar. I ordered ten feet of the stainless braided cable and ran it along the frame rail to the rear of the doghouse. On the engine end I used a standard throttle cable bracket bolted to the manifold. At the pedal end I used an L shaped bracket attached to the floor of the van above the pedal (toward the front) and fixed the cable to that. Now mine is a bit tight when I step on the gas pedal and I believe that is because the loop is a bit tight. I'm going to try moving the bracket closer to the pedal arm and see if that helps. Anyway, I'll take some pictures and post them on my photo site.

Vannman

solid side 65
09-10-2001, 05:49 PM
After having the plastic liner melt with an aftermarket cable throttle assembly I went with a Morse cable. They have a heat resistant cover and bulkhead housings on both ends. I got mine at a boat supply house but Jegs and other race parts places carry them. I used a 4' cable with a clevis fitting on the pedal end and routed it straight back, like the stock rod, then around the radiator and over the front of the engine, it pushes the carb linkage from the front. I made a bracket on the side of the brake pedal bracket and another off the thermostat housing. This pic from the gallery shows the engine end of it:
http://www.vcvc.org/c65c7.html
The shortest distance between the pedal and the carb was the route I took, figuring less resistance and heat. Morse offers a variety of cable ends and mounting arrangements. Race cars and boats have used these cables for years for chutes, fuel shut offs, throttles etc. I liked it so much when I went to the tilt column I used another for the shift linkage, that one is long about 12 feet. I've had the throttle cable in service for about twenty years and the shift cable for at least fifteen and never a problem.

TurboVan
09-10-2001, 10:50 PM
I have to agree. Morse cables are the way to go. --- TV

vannman67
09-11-2001, 04:35 AM
Hey Solid Side, I'd really like to get together and check out your van. You've got some nice mods I'd like to see in person. I live in Vancouver, Washington. I actually think we've talked before, but its been a couple years. Drop me an email at bcorbitt68@home.com and lets get together. Take it easy, and nice work on the 65.

Vannman

Vanner68
09-11-2001, 05:05 PM
When I stabbed the 350 in my 68, I discovered the major linkage difference. I made a small angle bracket above the stock bellcrank at the rear of the doghouse. I then used a bolt drilled out to mount the cable from the 76 Chevy Pickup that the 350 came from. The end of the cable goes thru the bolt and is secured with a set screw. This has worked since 88 and still works well even tho the van has been immobile for 5 yrs. "Bucks Down Solutions for Bucks Down People"

MadElf
09-12-2001, 06:19 PM
Vanner68,
It sounds like you did something very similar to what I did, though the cable I used was not the one from the pick-up (a 76 in fact). But where did you connect the "pedal-most" end of your cable? I ran mine to the existing linkage "swivel-point(?)" down behind the engine. I'm thinking that you must have gone somewhere near there, since the pick-up cable is not very long.
The problem I am having though, is that the total travel of the linkage "arm" is signifagently less than that of the throttle linkage on the carb. As a result I have only 1/2 to maybe 3/4 capacity when I floor the gas pedal.
Did you run into this quirk? If so, how did you handle it?

Vanner68
09-12-2001, 08:22 PM
I hooked it to the swivel (bellcrank) at the rear of the doghouse. The reason you can't get full throttle is because your linkage is worn out. The gas pedal has a squared hole that the shaft goes thru that usually rounds out. try grabbing the pedal and pulling it back up and feel for "give". The only way to fix this is to remove the pedal, weld the edges of the hole, and file it to fit.
The rest of the linkage can get play at all swivel points. Check for grooves worn in the ends of the linkage rods.
Get the play out, and hang on!

MadElf
09-12-2001, 08:26 PM
Well, I'll have to check the other points, but the pedal does not pull up any farther. I looked that over when I was wondering if I would have the same problem if I ran a cable all the way. Maybe it's one of the other locations. I'll check it out. Thanks.

MadElf
09-13-2001, 09:09 AM
Nope. Not it.
I re-checked the pedal, and all the moving parts of the linkage. There is no sigifagent looseness anywhere. Yet I still lack over an inch of travel at the throttle. Maybe I have a different carberator? My best guess at this point is to try and fabricate an extension of the bellcrank arm to give the end where my cable connects a greater travel. Unfortunately I won't be able to extend it much without hitting the header.
(I'm now half convinced that a cable all the way to the pedal will not help as the pedal seems to be operating at it's maximum span of travel now. I'll have to disconnect it from the linkage to see if it will pull up more, but it doesn't look it)

MadElf
09-13-2001, 09:36 AM
Got another question - for solid side 65...
(For future reference) On the tilt steering column you put it. I saw from your photo site that it was a 79 Chevy column. Was it a truck column or car? What model? Was it a bolt-in installation or was some special work involved? If it's an easy install, I might have to put it on my wish list.

MadElf
09-13-2001, 09:37 AM
Well, it just gets better...
I disconnected the linkage from the pedal & was able to pull the pedal up an extra maybe 3/8 of an inch that way. Nowhere near enough. Looks like I'll be extending the armature as far as I can and then I'll have to call it good enough. At least until I can come up with another idea.

[This message has been edited by MadElf (edited September 13, 2001).]

painterchris
09-13-2001, 01:32 PM
Madelf,

I'm not totally following how your linkage is set up, but here's some advice...

The stock linkage uses a long rod from the pedal to a swivel arm. That swivel arm is connected to the carb thru one or maybe 2 other rods with swivel arms. The way you can change the amount of travel you have on the linkage is to modify the swivel arms.

Basically, you have two rods tied to each swivel. The swivel pivots about a center rod, tracing out a circular arc. Logically, by changing the distance from the center rod, you will change the length of that arc. In other words, measure the distances from the rod connections to the center rod on the swivel arm. By moving the connecting rod holes, you will change the amount of travel on each rod. So, for instance, if you move the connecting hole from the long rod (the one tied to the pedal) closer to the pivot, and move the other connecting rod hole (the one that goes to the carb) further away from the pivot, you will increase your carb throttle travel while not changing the amount of pedal travel you have. This requires a lot of planning to do it right, but you seem like a smart guy, so I'm sure you can figure it out.

One caveat: moving these pivots will change the amount of force needed to push the pedal, but if your linkage moves freely, it really shouldn't be an issue.

Good Luck,
Andy.

Vanner68
09-13-2001, 08:32 PM
Here's the odd thing here, My linkage is all stock to the rear of the doghouse, and is in exceptionally good shape. I have plenty of travel. Is that one looooong rod from the pedal back flexing?

MadElf
09-13-2001, 09:07 PM
Painterchris: Yes, that's more or less along the idea I was thinking on, of extending the armature where the cable attaches (as it already is connected at the outermost point), but I hadn't thought about moving the other part inward toward the pivot point. I'll have to check that out, it might help.
Vanner68: Yes I guess it is possible that the long rod might be flexing. Maybe I should look at the idea of modifying the armature at the pedal for a greater arc of travel and then run cable all the way back, to eliminate even the possibility of play or flex in the linkage.

solid side 65
09-13-2001, 10:46 PM
MadElf: The tilt column is a 79 Chevy van. I chose this unit for it's keyless column, illuminated shift indicator, hazard flashers and that it was a GM product. No, it isn't a bolt in.

MadElf
09-21-2001, 04:14 PM
Houston... we have lift off.


Well I finally got around to re-building my throttle linkage. I didn't use the sheathed cable after all. In checking things out I noticed that if I set things up to pull the throttle linkage forward from the bottom, there was much shorter travel than pulling to the rear from the top. But it would be an awful sharp bend to go back to the linakge with a sheathed cable. So I went to the hardware store and got a couple of small pulleys (like the big rope hoist pullys they used to use to lift hay bales, but in miniature) and a length of braided wire. I hooked it all up and used a small c-clamp as a tension adjuster. It ain't pretty, but I've got full throttle control. Just to make sure things worked, I took it out on a side road and line-locked it. I had smoke pouring off the tires for a good ten seconds before I decided I'd wasted enough tread and backed off. Lets see people at the cruise-in laugh now when someone tells them my van is in the hot rod catagory.
HAHAHAHHAHAHAHHAHHAAA!

MadElf
09-26-2001, 02:27 PM
Well...
That didn't last.

The lightweight braided wire rope I used broke on me, and any heavier it binds up. I'm back to sheathed cable again.
I used the cable from the old pick-up as Vanner68 suggested. It actually works pretty well except that I'm back to the limited throttle travel again.
I don't understand why it is different with my setup. Maybe because I'm running a 2bbl carb? I think I may just leave it alone till I change over to a 4bbl (near the top of my list of improvements) and see if the problem goes away. If not, at least I won't be going to extreme measures to get the 2bbl working & then do it all over again for the 4bbl. I've messed with this throttle business about enough already.