Making The Go Pedal Go

Hello Gray Ghost Fans!

Well, it's mid-winter and you know what that means.  Time for small projects to try and keep things moving forward while we wait for the warmer weather.  Now, these aren't time wasters, these are things that need to be done, but are always lower on the list.

One of those projects is to either adjust or make a new connecting rod that goes between the gas pedal and the engine block.  This rod is a part of the overall linkage system that controls speed through the carburetor.  The reason for having to do this is that the replacement engine block that I have only has one mounting point for the pivot (also a part of the overall linkage) and it is in a different place on the block than the engine that I am removing.  The mounting point for the pivot is about 3" closer to the firewall than the original engine.  That means that I could shorten the original rod or make a new one.  I chose to try and make a new one, so that I could preserve the original one.  Whenever possible, I try to keep original parts intact, even if I choose to use new parts.  The original rod and the proposed replacement look like this:

The original rod is in the top of the pic.  The ball at the top is what mounts to the back of the gas pedal.  You can see that the top portion of the rod is thicker than the bottom portion.  The bottom portion is 3/8" diameter.  The drawing below the rod is an outline of the rod's shape with hash marks added every 1/4".  I transferred the hash marks to the new rod, which is 3/8" the entire length.  The round part on top of the rod is a gas strut mounting ball that I bought for this purpose.  It came in metric sizes, but the ball measured the same as the original ball.  To make it fit, I got out the old tap and die set and added M6-1.0 threads to the rod.  Piece of cake, by now.

The thought is to put the rod into the bench vise, which is almost closed around the rod and make small bends at each hash mark.  The cumulative effect of many small bends is hoped to replicate the sweeping curve of the original rod.  To easily bend the 3/8" steel rod, I used a piece of iron pipe slipped over the steel rod..."give me a big enough lever and I can move the world"...works!  At any rate, the first pass through the process resulted in this:

Holy Cow!  This might actually work!  Time for a second pass.  It resulted in this:

OK, progress, but slow.  And that's alright!  I only want to do this once!  Time for a third pass.  That resulted in this:

Almost there.  One more time!  That resulted in this:

TaDa!  That is pretty darn close.  But wait, the end of the rod isn't quite at the same angle as the original after all that bending.  Will it even fit and be close to the linkage?  Time for a test fit....  It looked like this:

Here we can see the new rod coming through the firewall, after I attached it to the gas pedal.  The rod is resting on top of the fitting for the oil pressure gauge and remote oil filter.  The pivot mounting point is center frame and the rod goes right past it.  That means that it is plenty long enough and actually will work!  A side view of the rod, in position with the current pivot mounting point looks like this:

Remember, the new engine has the mounting point about 3" closer to the firewall.  That means that the new rod is way longer than it needs to be.  But, to void screwing it up now, I'm going to leave the rod as is, until the replacement engine is in the truck.  Then I'll measure exactly where the rod needs to be bent to fit the new engine.  Once bent, a quick trim of the rod to the correct length and drilling a small hole in the end for a cotter pin will be all that's needed.  At that time, I'll also add some thread locker to the rod and permanently mount the ball end to the rod.

Not too shabby, I'd say.  I guess the jury will be out until I actually use the new rod to work the accelerator.  The only concern that I have is the use of a 3/8" rod for the entire length and not doing what GM did and use two different thicknesses.  Truthfully, I don't see the rod bending, but if it does, I can always go back to the original rod and make it fit the new engine.

That's all for now.  Here's looking forward to some warmer weather!