Throttle / Carburator

I have a carbureted 454 in a 1986 Chevy P/U with a 4 spd 4X4 as my project vehicle. I could use some help with ideas for throttle / carb design. If it has a dedicated place on the forum, could someone point me to it? I understand there are potential problems with a slide valve type arrangement with excess tar and sticking, but I am not familiar with what has worked well in the past. I don’t want to completely reinvent the wheel if there is a proven solution to the problem.

Hi Doug,

With a carburetor you have two options, going over or under. If you go over the top, down through the carb, you can keep the existing throttle, but you will eventually gunk up the internal passageways of the carburetor. It can be cleaned out, and this is how Wayne ran his red Ford.

If you go under, you will need a second throttle (junkyard throttle body is fine), and a purpose built box under the carb. Air leakage is more of an issue with this setup, but the carb stays out of the woodgas flow.

There should never be any tar under the hood. Other gunk and soot from the woodgas can cause sliding mechanisms to stick. Butterfly valves have lots of room and won’t get stuck with soot.

hey doug

heres a thread that may be of interest:

I converted a TBI engine instead of a carb but plumbing them in seems about the same. When I was first researching I thought below the carb would be far superior than above because of getting around the soot build up. However in practical terms I found it far easier to plumb in above than below the carb.

heres my experience plumbing in my gasifier with the TBI:

Doug I posted two videos of the setup I used under the carb on my chevy.


Gentlemen, thanks for the help.

Here’s another Doug. Happy New Year all. I have a unique experience that most people have long past used or never used in their life – a push pull cable on a fuel system. Since carburetor accessories gets sticky with time, many convert the choke over. My first choke 5 years ago was a local bought steel wound with steel wire. It worked for a couple years - some winter use only . Next it was replaced with another the same, guessing that there was some unseen rust somewhere making it stiff. Two months ago, I bought a vinyl coated steel wound steel wire cable from Jegs and routed it so direct and gentle. The stiffness is coming back. The carb is smooth by itself.
I seem to remember a Wayne under hood look that used copper tube as the outer wire guide as it traveled to the air cleaner. It seems to me that the most rusty kind of wire would not bind in a non steel covering. What do you others think?

I used copper tube with a peice of high tensel fence wire. worked real good.

Hey Doug,

I have used some copper but the main thing that keeps the cables sliding easy is that I will draw the cable out and take my grease gun and pump in as much grease as I can and put the cable back in.

Hey Doug, that was Mike Larossa’s pickup with that cable setup on his 4.3 L Chevy pickup that he had in Argos last May. I remember the copper tubing was electrical taped to his battery cable near the right front fender “Mikey style” and operated his throttle body woodgas valve.
Don M

Since I have a vinyl coated cable, there will be no mess dripping inside the car! Thanks guys

Mine got stiff so it was hard to operate but When I unhooked the the cable it worked freely. I found out that the throtle body has bearings that were freezing up, put some oil on them and it helped alot.

Throttle cables on boats are mostly stainless steel and heavy duty.

Power seats have small 1 1/4 inch 12 volt reversible motors that I am thinking of using for turning the distributor and possibly the air and gas butterflies. It would be a lot easier to route wires than stiff cables from the dash to under the hood and would also give more choices for switch placement (like on a stick shift stalk) .
Don M

Hey don
that would probably work, the only thing i could see is it wouldnt give you any feel for where the butterflies was set at, like the old hand choke on a car.

Hey DonM using those would be a trick idea for some with stiff 1/4 turn isolation and shut off SS ball valves in their systems. Much smaller, more compact and more pwerful than the window lift assembles I’ve been recommending.
Great Idea man.
Steve Unruh