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I have a V8 trike that has a small block Chevy engine.
It is a 267 and has a small 4 barrel carb.
The trike has a foot throttle.
The gas pedal has very little "travel" from nothing to
foot on the floor.
How can I modify the carb linkage to give me more travel
in the gas pedal?
Thanks to all.
Happy holidays to all the members on here!
:confused:
sure .. on either end I would bet .. on the carb end find or create another place for the cable to hook onto the throttle lever so it is longer in arc ..the longer the throw the longer the travel ..
You only need two throttle positions anyway.....idle and wide open!
say Triker, just a quick tip, the mods you ask about. You would be much better served if you snap a photo and post it along with the question.Quote:
Originally Posted by Triker
Lots of good seasoned wrenches hanging out here, trying to imagin how to fit a mod or faburicate a solutation for a specific instance is not easy. Most of us build repair cars, trikes or biked have their own set of space and limitation that must be dealt with.
say Triker, just a quick tip, the mods you ask about. You would be much better served if you snap a photo and post it along with the question.Quote:
Originally Posted by Triker
Lots of good seasoned wrenches hanging out here, trying to imagin how to fit a mod or faburicate a solutation for a specific instance is not easy. Most of us build repair cars, and can visualize the problem quickly. On the other hand trikes or bikes have their own set of space and limitations that must be dealt with.
I will take a picture and post it here so all you seasoned wrenches can give me ideas.
I have never tried anything like modifications to a carduretor before.
Thans to everyone for posting.
Hope all of you had a Merry Christmas and hopes for a great New year!
Triker
Attached (I hope) is a picture of the carb on my V8 trike.
What can I do to give me more "travel" for my gas pedal?
It HAS to be done at the carb end.
Any ideas?
Also,Any way to tell what CFM this carb is?
Hope everyone had a great Christmas.
First thing that comes to mind, is to bolt an extension arm to the bellcrank. It will increase the arc, might help some.
[B]Firebird77clone--
Excuse my lack of knowledge---What is a "Bellcrank"?[/B]
Is the carb opening fully now with what you have?? or is it limited by the housing over the cable contacting the carb bell crank??
:rolleyes: this is what i believe you need to try .. the top drawing is what you have .. short bell crank .. short throw .. short foot pedal travel .. the bottom drawing is what you need .. longer bell crank .. longer foot pedal throw .. longer travel .. add/bolt something to the short bell crank to make it longer ..
http://www.turbobuick.com/forums/att...39-jpg.181493/
This might give you the idea of what you need to do
Since that carb is a Rochester Quadrajet, it's almost surely 750 CFM. There were some 800 CFM, but those are in the minority. An extra 50 CFM wouldn't matter much any way.
Hoss429----WHAT A GREAT CAR!!!!
I has a 1969 Mach I for several years.
I understand about a longer bell crank equals a longer travel---BUT---
The bell crank is attached to some shaft inside the carb.
That shaft only rotates so many degrees--"Regardless of how long the bell crank is" right?
Or am I missing something?
Thanks for the reply
Jerry Dayton,
I guess I am looking at a longer than normal bell crank, right?---BUT---
The bell crank is attached to a shaft inside the carburetor.
I am assuming that the brass "thing" is the end of the shaft that is
hammered over.
That shaft only rotates a certain number of degrees, right?
So why would a longer bell crank give me more pedal travel?
What am I missing?
Thank you.
What you're missing is how levers work.
Pulling a longer lever the same distance as a shorter lever results in less angular rotation.
In this example, the point where the lines come together at the bottom is the throttle shaft. The pull is 1" for both levers. The 4" lever would rotate about half as far as the 2" lever. That means you would have to pull the throttle cable further, resulting in more pedal movement.
Experiment with different lengths of levers, and you can tune your pedal travel.
Attachment 62935
And to further clarify Jack's excellent post, from idle to wide-open-throttle (WOT) is right at exactly 90 degrees of rotation, from butterfly flat level to straight up. Your picture doesn't show it, but if the sheath of the throttle cable is not constrained at both ends that adds to your problem.Quote:
Originally Posted by Henry Rifle
The ideal configuration of your throttle lever on the carb would be angled 45 degrees towards the front of the engine. WOT would then be about 45 degrees to the rear. That gives an even pull throughout the throttle range.
Attachment 62936
Triker---we need a photo showing more of your linkage and cable mounting-----------and please include the foot pedal area
With the pedal floored is the cable pulled into the sheath, no braided wire showing?
Could the sheath just need to be trimmed back to allow the cable more travel ?
How much are the butterflies opening, how much more travel is needed to obtain WOT ?
most likely the problem is on the pedal end and we are trying to crutch him thru a carb end fix .. the carb worked fine in stock configuration .
I agree, and was thinking the same thing when I saw the thread pop up in "Today's Posts". Gotta be on the pedal end, plus maybe some basic cable/mount issues.Quote:
Originally Posted by HOSS429
I feel a little silly now. All those trees getting in the way of my view of the forest.
Jack, I think that everything you posted was of value, in order for Triker to understand the length of throw issues. That said, I've never seen a problem with the OEM bell crank relative to pedal travel, but he's the one who posted the question.....Quote:
Originally Posted by Henry Rifle
