Questions about installing woodgas on a carbureted truck with a manual transmission

Thank you La Chaim!

The stepless change-over mechanism from woodgas to gasoline and back has no delay in it, provided the gasoline carburettor is supplied with gasoline pressure. The set ratio is realized instantly.

There is nothing to patent; the change-over mechanism works on steam engine principals.

No need to stack carburettors upon each another;
using horizontal carburettors, one can enter from right and the other from left and joining tangentially into a flat round horizontal “swirl bucket” feeding the intake manifold.

Chris has just built a horizontal double-throat gas-air mixer…

Max

Hello again all,

Yes, carbon on the intake manifold does sound like it would be a problem… A good reason to use an OBDI system…

I am hoping that I will be using a truck with an old enough vintage to have plenty of clearance under the hood.

Why would I need an extra fuel pump? Wouldn’t I just use to factory one and add a switch to its power supply wire so I can shut it off when necessary?

Ahhh, ancient technology returns again…

I will have to look into that swirl bucket idea, it sounds quite interesting…

Thanks again all!

~L’Chaim

It seems to me, that if you had the undercarb plenum with a woodgas air inlet, You could link the gasoline throttle to the air throttle so opening the gasoline throttle would close the other proportionately. Now then, to drive hybrid, you would just open the gasoline throttle with hand lever, and you would get a consistent percentage of gasoline in your woodgas wherever you move the main woodgas throttle based on what percentage of air was coming through the carburetor.

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Hi, Handy_Andy!

I think you need to draw a sketch of your proposal
to be able to formulate the functions intended.

As the text stands, you are abandoning the footpedal
demand function for gasoline-driving.

As the text stands, you are interfering in the woodgas-air
proportionate 50/50 mixing.

Studying Chris’ video model, one can see that the
footpedal movement for demand is the fundamental one function.

Added to that, the mechanism for proportionate choise.

The mechanism for proportionate choise is shifting
the ratio between: Ready mixed fuels.

Air/gasolinefog and/or woodgas/air.

Max

Good morning Mr. Shmitt,

The vehicles I have gasified with carbs were also old enough they had mechanical fuel pumps . I have used an electric inline gasoline shut off valve to kill the gasoline flow to the carb. One of the problems with this set up is when I forgot to turn the gasoline on before shutting down and to restart was almost like running the tank out of gasoline.

Depending on how hot a day it was and how hot the motor compartment was the gasoline can vaporize and push the gasoline from the inlet side of the mechanical pump all the way back into the fuel tank ( vapor lock ) .

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Perhaps I am as confused as my verbal description suggests, but here is the picture in my head.

Well, think about the results… as you close the air valve, you richen the woodgas. As the throttle opens you’re adding gasoline at a balanced air-fuel ratio. The overall mixture will still be rich, so the motor will bog down. This will get worse the more you open the gasoline throttle (and close the air valve).

The other problem you’ll have is trying to run gasoline. The woodgas and air flaps will have to be shut air-tight in order for the carburetor to function at an idle. Any leaks will cause lean gasoline running.

The correct way to do it is with the air and woodgas mixed before the throttle. This way at any position of either throttle, the engine receives a correct mixture. Since the second throttle is before the plenum, it is much easier to close air-tight for gasoline running as well.

There is an advantage in leaving out the bottom (main) throttle; it will leave the full manifold vacuum over the woodgas and secondary air flaps.
This makes them the “dominant resistance” in their respective flow routes (plumbing).
They have to be ganged together to give 50/50 mixture, as they have the same dimensions and geometry.

This reduces the control “organs” down to only 2;
one for gasolinemix, and the other for the woodgasmix.

If the plenum is a flat cylinder, the woodgas and air can enter it horizontally and tangentially to make a swirl mixing “just in time” before diving into the mainfold.
The gasoline carburettor can also be a horizontal one. This makes a free “poff-lid” available, as nothing is attatched from above…

These 2 independent routes (ready mixed for delivery) can now be handled by the “choise and demand” model that Chris has made a video of.

Max

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Hi again all,

The plenum under carb setup makes sense, it seems to me that that would be the best way to go. (for me) …also really interested in the auto mixer Chris made…

Another question I have; is are there any ideal types of ignition systems for woodgas/gasoline use? I am planning on replacing most all the ignition system stuff on my '73 350 chevy engine soon, so I thought that while i am buying stuff, if there was somthing better than stock than it should be looked into. (got my engine broke loose yesterday!) I am somewhat green to ignition systems, so any other tips are appreciated too.

Thanks!

~L’Chaim

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Hi L’Chaim,you have an old truck as i too use as learning tool for wood gas. My plentom is about 3" tall and after i built a shorter air cleaner,it still hits the hood.After i bought the plans i see why they like port fuel injected v8 dakotas,I think they are the 93 too 95’s that are best with the timeing adjustable, there is a few guys working on the obs2 timeing problems in the premium sections.on the other hand don manns drives a geo tracker on wood from the wayne keith plans he modified the package too fit all in back of his tracker,he gets much better wood miles per pound,though he dont have much reserve power too pull a trailer.i haven’t finished my truck on wood gas so i have not any results too offer, my truck is 4.3 carb truck.All I do know is that it SUCKS gasoline at 10 MPG. my next truck is 1985 s10 and since it is a 22 r toyota motor when done, it wont have the power take off of the dakota v8s, it may require a little hybriding in some gas too take off fast in traffic,it will work for light loads,transportation.

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Kevin; As I posted yesterday, I am running a 4920 lb. truck with a 4.3. Your correct, I won’t keep up the the Dakotas, but I do travel with out gasoline. Isn’t that the point? As you, I would like to find a good S10 V6. What do you mean it is a 22r Toyota motor? TomC

If you have hight “problems” skip the under- and above-plenum thinking!
Make horizontal tangential feed into a cylindrical plenum!
Acheive swirl mixing with any fuel mix!
Take them all in tangentially horizontally!

There are horizontal carburettors for gasoline, single and doble throat.

Use a single or double throat for gasoline and a double throat for air-woodgas mixing.

For woodgas mixing Chris used a Ford F-150 twin horizontal throat carburettor… 50/50 mix on a golden plate!

Hopefully, you have already read that the 50/50 mix is the best to ignite…

Go horizontal and you have all the room and swirl mixing!

If your ignition system is “failproof” keep it!
If it gives 1" or better sparks, that’s enough!

Advancing ignition with a mechanical distributor is easy, but if it is made by a computer, a thorough investigation of the type and its character has to be taken…

Continuing,
Max

Hi tom ,yes i have a low miles toyota motor home motor and tranny too install in the s10, That i think is about the same weight too horse power ratio as your 5000 pound work truck, the s10 is 3000 pounds and the motor is 2.4 I am still working on finishing my big 4.3 2500 truck project,after i get stoked up with heating wood for winter.
And Max gasman are there any actual pics of an horizonal tangnial plentom,this sounds interesting,i just dont visualize the plentum,and i havent seen any horizonal carbs the size for small block chevy or 4.3 ,ware would one get a salvage yard carb.? Thanks

Hi, Kevin!

Just look at Chris’ video series of the build he made this summer! They are many…
His plenum is mainly rectangular, so there is not a horizontal swirl, but he has a horizontal “screwing” between the twin throttle body outlets and the plenum, in the connecting tube.

His gasoline is “squirted”-in into the connecting tube, which happens to be his horizontal “carburettor”… computer-driven.

This improvision, because of easyness to arrange the existing (gasoline)throttle and the twin woodgasmixer flaps in tandem, operated by foot as before.

Later, the footpedal wire will be connected to the “choise & demand”, from where the choise of fuel will be performed… then on individual, separate routes to the plenum.

Max

I think i seen some horizonal carbs on a triumth or forien car someware.Now an added twist could be an exoust rought through a small cat converter,then drip some waist veg oil too add some btu while driveing for the horizonal carb,and temp control.Is chris’s latest horizonal carb build in the premium sec.or the beginners section at the front of DOW. :hammer: :paperclip: :key:

I think L’Chaim is interested in this:

Max

The dual throat Ford throttle body MaxG is referring to that ChrisKY used is a very common late 1980’s thru 1990’s Ford V-8 engines parts: 302, 351, 460.
Should be no more than a $20. USD as a take off part. These were mounted with the air flow holes vertical/shaft vertical into the engine plenum horizontally. One throttle bore air feed one cylinder bank; the other bore air feeds the other cylinder bank. So WILL not work on the original Ford V-8 to feed just air in one side and wood gas on the other!! (experience . . . I was so-o-o stupid)
As a throttle body without a float bowl or gasoline handling these are Not positional sensitive. Can easily be turn 90 degrees sideways or even upright.
Throttle plates are on the same shaft so gang locked together. Shaft can be severed and set up for independent bore control.
S.U.

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Them old ford v8 motors really got some nice dual bore throtlebodys, too use on wood gas conversions,Thanks

Ok, time to update this thread, Ive gotten the engine running, with an all new ignition system and a re-kitted carb. She runs pretty good I think. So now Ive come up with another question. How will an aftermarket cam effect woodgas? Dad tells me that this engine has a cam in it, but he doesn’t remember what type it is. to give you all an idea, the engine also has a 650 CFM 4165/6210 Holley double pumper carburetor, hooker headers and glasspacks, (I think they are gone now), and and some sort of cam. Other than that I don’t know of any other changes it has had.

Really felt good to hear it run! I don’t know engines, but the idle does sound a bit “camy” to me if that helps anyone.

Thanks to all of you!

~L’Chaim

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Save the time and expense and try it with the cam in it. I ain’t no expert but maybe a RV cam might match wood gas but I really do not know…

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