289 throttle stop

[LMH]

I got mine from John. It's good quality, like the original and I'm happy with it. We have to fab a lot of small stuff that either isn't made or what's out there isn't a very good copy. I can appreciate the work it takes to make it right. If something is for sale, is good quality and another part I don't have to make on my own, I'll spend the money to buy it.
An example; it has cost me over $2000 to make a set of S&H air cleaners. Originals just aren't out there anymore and the few that are, are either damaged or need total restoration. Sometimes you just have to pay if you want to play.
Larry

[CompClassics]

Being that this is in the "originality" portion of the forum I don't think "JB Weld" is a suitable method of reproducing the part. Don't get me wrong "JB Weld" is an awesome product for making repairs.

[mickmate]

So the correct original linkage with non adjustable connecting rods, not like the Mustang adjustables people have added, with the little sheetmetal bellcranks use a threaded stop but that thread isn't used to adjust the stop position???? The footboxes, engines and gas pedals are all put in exactly the right position relative to each other on a hand built car for that threaded stop and don't need to be adjusted on that thread.

[Dan Case]

Originally Posted by mickmate

So the correct original linkage with non adjustable connecting rods, not like the Mustang adjustables people have added, with the little sheetmetal bellcranks use a threaded stop but that thread isn't used to adjust the stop position???? The footboxes, engines and gas pedals are all put in exactly the right position relative to each other on a hand built car for that threaded stop and don't need to be adjusted on that thread.

I'll expand on what hand built means in regards to this subject. A collection of standard parts required fitting upon installation. Under throttle mechanisms for Cobras Nick covers it, the pedal stop didn't require a depth or length adjustment because other parts and processes required fitting. (The hardest part of throttle operation pieces to deal with on an assembled original car is the pedal stop as just about everything else close on either side of the forward foot box wall is in the way.)

The "adjustment(s)” were done by engine installers and remember Shelby American in California was just the largest volume shop not the only shop. There were several items to get right.
a) Foot box bracket location
b) Engine bracket location
c) Which hole to use in the throttle pedal drive lever
d) Where to set the throttle pedal drive lever itself as its lower end was an adjustable pinch clamp

The brackets for the foot box and intake manifold ends of the brazed bell crank assembly had to be installed by the engine installers. Both brackets required one car at a time fitment. The brackets were standard parts but:

1) Foot box side: the location for the bracket had to be fit and two holes drilled for fasteners.
2) Intake manifold side: the bracket for the spherical bearing for location and support had to be modified to suit. The normal method was to crudely slot and or enlarge one mounting hole so the bracket could be pivoted about the other. A little “swing” at one bolt hole meant longs of arc swing out at the end of the bracket.

Engine installers had to add the throttle pedal stop, which AC Cars did not provide with the chassis.

There are two last adjustments, which hole was used in the throttle pedal lever and slip fit adjustment of the pinch clamp made into the lower end of the lever on the pedal shaft.

When the installion is done hard foot pressure on the throttle pedal should not over pull the throttle lever of the carburetor. The small carburetor throttle shafts are no match for the strength of a human leg. When I adjust an original car I have somebody push the throttle pedal as hard as they can and I adjust the pinch clamp so that I almost but not quite get to exactly 90° W.O.T.; I stop just short. (I have repaired some carburetors used on original cars where attention was not paid to whether or not the carburetors were “over pulled” and their carburetor primary throttle shafts were twisted from pulling too far on them. )

The pedal stop is real important. I had the opportunity to work on a car that missed getting a throttle pedal stop day one in 1964 apparently as there was no signs inside or outside of the driver’s foot box that a hole had ever been drilled for a pedal stop. Throttle mechanism wise the car was a mess. The cast aluminum pedal arm AC Cars installed had been broken off at least once and crudely repaired, the lever on pedal shaft was bent and twisted, and the bell crank assembly was twisted. It appeared all those 1960s technology light weight parts suffered from a heavy foot or several with no stop to keep the pedal from literally being forced all the way to the forward wall of the driver’s foot box.

Dan

[LMH]

Sounds like someone was out to lunch at SA on that day Dan! (Assuming it was an SA finished car of course)
Larry

[CompClassics]

mickmate
NO

So in other words the adjustment was not made at the throttle pedal stop as I have stated, it was made elsewhere in the throttle linkage where there are provisions for adjustments. The throttle pedal stop has two washers that are fixed into position by brazing and the threaded portion of the assembly is put through a hole in the foot box and secured by another washer, a lock washer and a nut. How is this adjustable?

[Thor maine]

So it is still a bolt, a couple of washers, a MIG welder or a Oxy- Acetylene weld and some silver paint???

[Gaz64]

Originally Posted by CompClassics

mickmate
NO

So in other words the adjustment was not made at the throttle pedal stop as I have stated, it was made elsewhere in the throttle linkage where there are provisions for adjustments. The throttle pedal stop has two washers that are fixed into position by brazing and the threaded portion of the assembly is put through a hole in the foot box and secured by another washer, a lock washer and a nut. How is this adjustable?

I've wondered that as well for the whole thread.

Granted it is a pedal positive stop, just adjustment is elsewhere.

[rsk289]

It is adjustable by moving it in and out on the thread until it just touches the back of the throttle pedal on full throttle at the carb, or just before.
All this stop does is protect the throttle linkage and carb from being mashed by a heavy foot, as Dan has clearly described. I say that's 'all' it does, but it's pretty important.

[Dan Case]

The stock throttle pedal location fore and aft is not real comfortable for a lot of drivers in an original Cobra.

I don't notice it hot footing around playing but if we have an hour a long road at a steady pace my right leg is not comfortable in the bend it must be in to keep steady unless I prop it against the transmission tunnel (which gets pretty warm). Adding washers to the stop to move it closer to the seat would be the wrong way to go for me for sure and I am 5'8" tall.

The only modification I have noticed on an original car is cut the bolt shorter, which I guess allowed the owner to reposition the pedal forward for right leg comfort.

My discussion for stock length stop is for undamaged significantly unmodified original cars. If the geometry of the car you have is different, including an original car with reproduction foot box or just mislocated foot box, the parts specifics Shelby American came up with for new Cobras five decades ago might not be right for your application. I have worked on original cars that have been crashed badly at some point in their past. It is real easy to find various features in the front cowl / dash/fire wall area ¼” inch to ½” inch or more away from where they would have been before the crash(es) and repair(s).

Dan

[rsk289]

...and obviously my comments relate only to COB cars, RHD with different footwell boxes.

[CompClassics]

The available thread at the end of the bolt does nothing more than go threw a hole in the fiberglass, the hole in the fiberglass is not threaded in any way to allow the throttle stop to be adjusted. I suppose you could stack washer upon washer until you achieve some distance you are happy with going the other way requires fabricating a new stop, hopefully you have enough thread left to secure a nut with on the other side of the foot box? I can't imagine making multiple adjustments down inside the foot box, just getting in there to install the throttle stop (or anything else) is a pain in the rear.

[1985 CCX]

To reiterate another thread....

I started this tread to highlight my experience with "Racewhere", John Bessey, as a great resource, easy stop and with his attention to detail enlightening.
John and Bella are high on my list of folks to do business with.

Honest, sincere and experienced..... Kudos to them both

Dan is a top notch resource and a wealth of experience... Always a learning experience... I thank him as well.

Tom, just busting my balls.... We have history as I used to be a Mopar guy and he had his CCX..

[Thor maine]

I have said it before , I had a ride in an Arntz that had a 426 Hemi in it. It was fantastic, Mopar-Cobra , best of both worlds.

[CompClassics]

I still wish I had my "V" code 1970 GTX