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vaporizer carburetor

Vaporizer carburetor

This is all done from pictures sent to me of the vaporizer carburetor. When I was doing some research on it I found there was also a Ford version and one called a Simmons. If anybody has pictures of these and what the basic differences are please send them.
Now I do have one problem. 6283 on my drawing is the needle valve adjustment screw seat. On the cross section it shows a small niche in the base of the carb. none of the carb pictures I got showed that was ever a place for this part. My question is does in go down at the base of the hole from the top of the carb or is there some little niche where it goes like on the cross section?

By Larry Bohlen, Severn MD on Thursday, January 16, 2014 – 06:27 am :

You need to include the weighted “air damper” in the upper chamber.

By Martin Vowell, Sylmar, CA on Thursday, January 16, 2014 – 06:37 am :

Larry, do you know what it looks like? Also does the venturi come out or is it press fit in?

By Bob Shirley on Thursday, January 16, 2014 – 06:38 am :

Martin, there is a very big problem in that there is no venture in the throttle body. When I was a kid I used caustic soda to clean the castings and it ate the venture completely. I never knew there was supposed to be one in there until just a few years ago. Tried for years to get the dxxx thing to work but could never get the car to start. You got to have that missing venture.

By Bob Shirley on Thursday, January 16, 2014 – 06:54 am :

It’s been a while but if I’m thinking right the venture is held in by the little screw on top of the throttle body. I borrowed a throttle body and got the venture out and copied it, I think I used heat to unstick it.

By Larry Bohlen, Severn MD on Thursday, January 16, 2014 – 08:37 am :

It’s part labeled “O” in the cross section.

By James A. Mahaffey on Thursday, January 16, 2014 – 09:54 am :

Your diagram is gorgeous!

To cover the vaporizer variations, you also need to include the Kingston B-1 Gasifier and the Kingston B Vaporizer. I can provide you with tear-down photos if you wish to diagram these Ford carburetors.

The Simmons vaporizer is an interesting variation. Although it closely resembles the Ford/Holley vaporizer, it is different in several ways. Here are a couple of photos of the Simmons:

I can provide more pictures on request. Here is the Kingston B-1:

I can provide you with more photos, patent drawings, and Fahnestocks’s drawings of these carburetors on request. There is also a parts diagram for the Kingston in the last Ford Model T Service Bulletin in 1927.

On the Ford vaporizer, the drain-valve assembly was modified early in production with a metal disk installed in the top to defeat the coaxial through-hole. This modification completely changed the fuel/air mixture mode. Early Holley vaporizers do not have this modification,and restoration can be confusing without it. The Ford installation diagram in the previous message shows the disk in place.

By ED Henline on Thursday, January 16, 2014 – 10:10 am :

the 6283 is the seat for the needle valve it goes in the float chamber at the end of needle valve. Ed Henline

By Joe Van on Thursday, January 16, 2014 – 11:38 am :

Great work martin, I think it looks complicated seeing the exploded view. some of the more internal parts like venturi would be more difficult to photograph. I’ll have to look on the carb and make sure it is there on mine.

By Martin Vowell, Sylmar, CA on Thursday, January 16, 2014 – 05:55 pm :

Larry, I know that’s what the profile of that part looks like, but I don’t know what the depth view looks like. The first thing I did was trace that drawing and colorize it (because the crosshatch gets kind of had to read in smaller parts)

But as you can see on this drawing there is a place for 6283. but on the carbs I saw there was no such place for it.

Ed, does it go down the same hole 6278 screws into? That guides the mixture needle, must be at the bottom, right?

By Martin Vowell, Sylmar, CA on Friday, January 17, 2014 – 03:41 am :

I’ve decided that the assembly is just to complex to be shown on one sheet. maybe on a “B” size )11″ x 17″) but for an “A” size (8.5″ x 11″) it’s just too messy looking and seemed hard to follow.

Throttle/Choke Assembly with Intake Manifold

I’m guess what the Air Damper looks like, so if anybody really knows and can give me a picture of one I’ll make the change

Vaporizer Assembly with Exhaust Manifold

By James A. Golden on Saturday, January 18, 2014 – 10:46 am :

This photo is the best I can offer as to where that 6283 part is installed. It actually screws into that hole the arrow and pen point are trying to show and that hole ends in a roughly right angle turn to the center and just above the 6216/91 assembly at the bottom that holds the bowl in place.

By Chris Brancaccio – Calgary Alberta on Saturday, January 18, 2014 – 11:27 am :

Martin, great drawings, I think we should put your collection somewhere on the website, what do you think?

By Ron Patterson-Nicholasville, Kentucky on Saturday, January 18, 2014 – 11:54 am :

Martin
I have struggled with vaporizer carburetors (getting properly sealed with no leaks–it appears the Kingston B-1 Gasifier has none of these problems because of the physical design of the upper and lower sections?) and always thought the “automatic air valve” (air damper) was item “O” on “Instruction 98”? The illustrated parts breakdowns (source?) shows “air damper” with no part number (probably because there is no reproduction part available?) and shaft it rotates upon as part number 6263-S.
It sure would be great if someone obtained the Ford Vaporizer prints and listed each part by name and number as a breakdown.
Ron the Coilman

By Ken Todd on Saturday, January 18, 2014 – 12:29 pm :

According to the Ford parts book, 6283 is the: ADJUSTING NEEDLE SEAT
So wherever the needle end of 6279 ADJUSTING NEEDLE ASSEMBLY ends up, that’s where 6283 goes.
Simple.

By Ken Todd on Saturday, January 18, 2014 – 12:35 pm :

Ron, Ford ’26 parts list lists it as an “air valve, P/N 6262

By Terry Horlick in Penn Valley, CA on Saturday, January 18, 2014 – 02:12 pm :

Martin, I went to the shop and opened up one of my vaporizer bodies. I found an error in your part 6263-S.

6263-S consists of five parts not four as pictured. It is two identical screws and lock washers, and a pin. Your exploded drawing makes it look like one screw has a protruding turned pin extension. Instead there are two normal screws with a hole drilled in the threaded end on center. This hole accepts a steel pin on which the weighted air dampner flapper pivots.

There are two curious holes drilled in the back side of the flapper. I haven’t de-rusted this part to see if they pierce the part or were just used in the machining process.

By Terry Horlick in Penn Valley, CA on Sunday, January 19, 2014 – 11:01 am :

Martin, I figured out those two little holes. They do not go through or connect with anything. It is almost impossible to install that damper once it is removed, so I assume the original installation at the factory was not piece of cake. The two holes are for a tool to grasp the part and position it into the carburetor throat (before the choke plate is in place) so that the pin and screws can be inserted.

I’ve done this a couple of times without using those holes and an hour of trial and error is always in order!

By Martin Vowell, Sylmar, CA on Sunday, January 19, 2014 – 06:32 pm :

Terry, thanks for the pictures. I didn’t know what that bloody thing looked like so I drew it based on the cross section. As to the screw with the shaft. the parts catalogs have the assembly as the shaft is fixed in the one screw and the other side is just a screw. I didn’t know they came apart from what I saw in the catalog.

James, thank you for pointing out where that bloody little seat goes. on the pictures I got from Joe V. I didn’t see that hole. I’ll make that change. And that Kingston looks real interesting and a fun project. If you have any tear down pictures of it, please send them to me I’d love to draw that one. looks like fun.

By Terry Horlick in Penn Valley, CA on Sunday, January 19, 2014 – 08:50 pm :

Maratin,
Another “error” is that the 6277 is not pictured on the assembled view. Fahnestock made the same error in that scan Larry posted. It should be pictured on the “Instruction nr. 98” drawing from Fahnestock’s book and on your colored drawing. It sits inside the exhaust manifold on the primary air tube. It is a heat sink which is supposed to act the reverse of the fins on your radiator. I.e. it is to absorb exhaust heat and transfer it to the pipe. so it heats up faster in service. The thermodynamics dictate that this piece of helical wire wrap will not make the primary air tube hotter, just will make it get to operating temperature faster and to be less affected by very cold ambient air.

Out here in Cali I have thought about dispensing with it on my next rebuild as it is probably unnecessary in a warm climate. needed even less in Pacoima!

By Martin Vowell, Sylmar, CA on Sunday, January 19, 2014 – 09:33 pm :

Ok here’s the revised version.

Throttle/Choke Assembly with Intake Manifold

Vaporizer Assembly with Exhaust Manifold

By Martin Vowell, Sylmar, CA on Sunday, January 19, 2014 – 09:36 pm :

Terry, ok, I see what you’re saying. I’ll fix that right now, thank you.

By Martin Vowell, Sylmar, CA on Sunday, January 19, 2014 – 09:39 pm :

Color Cross Section revised.

By Ron Patterson-Nicholasville, Kentucky on Sunday, January 19, 2014 – 09:44 pm :

Martin
Can you add the air/gas flow shown in instruction 98??
Ron the Coilman

By Terry Horlick in Penn Valley, CA on Monday, January 20, 2014 – 12:52 am :

Martin,
Very nice, . Bravo!

By Martin Vowell, Sylmar, CA on Monday, January 20, 2014 – 01:46 am :

Ok, I’m not sure this is going to help anybody, but this is the air flow as far as I understand
it.

If this is no help at all, let me know and I’ll scrap it.

By Ron Patterson-Nicholasville, Kentucky on Monday, January 20, 2014 – 08:24 am :

Martin
The reason I recommended adding the air/mixture flow to your excellent drawing is so one can fully understand how the Vaporizer carburetor actually works. Most of the problems with this type carburetor are caused by leakage in the Primary Air tube upper/lower seals and Outlet Tube Nut seal or the seal between the carburetor base and exhaust manifold with the Vaporizer Plate sandwiched in between. When it is not leaking and working correctly it is a great carburetor, but if it is leaking air or the Vaporizer Plate is rusted through I is a boatload of trouble.
Ron the Coilman

By Martin Vowell, Sylmar, CA on Tuesday, January 21, 2014 – 02:41 am :

Ron, sooooo, you’re saying this works for you? Or did you have something else in mind?

What I’m trying to show is that the air flow is a constant, forced through the carburetor by the greater flow from the choke opening above. It is drawn down the heat pipe with that coil wrapped around it that acts like a heat exchanger, leaching heat from the exhaust manifold and up along with the gas helping to vaporize it. The colder air coming from the choke opening, creates vacuum drawing the vapor up and out the tube, then mixes with the cooler air flow that is forcing it through the manifold into the head, which to my mind would reduce the mixture temperature slightly (shown by slightly cooler color). I’d bet this thing runs real rich until the exhaust manifold heats up right?

By Scott Conger on Tuesday, January 21, 2014 – 11:49 am :

Beautiful work! One error still is there, though. The drain valve body should have no through hole in it (like the normal Holley drain valve body has). Your illustration of 6216-91, the correct part call-out, is really of 6216-21. Many a Vaporizor has failed to perform due to this common error.

By Martin Vowell, Sylmar, CA on Tuesday, January 21, 2014 – 08:10 pm :

Scott. I went back and looked at that part, you’re right, it has no hole in it, so I made that change. The part number however is 6216-91 for the Vaporizer the part number for the Holley NH is 6216-21.

By James A. Golden on Tuesday, January 21, 2014 – 10:08 pm :

Has anyone ever discovered the purpose of that air flap or what happens different if it is removed?

I’m sure it mist be needed of henry would not have had it installed.

By James A. Mahaffey on Thursday, January 23, 2014 – 09:25 am :

The air flap automatically maintains a constant air-speed through the Venturi nozzle, and therefore a “constant depression”, or a constant level of vacuum in the vertical tube that feeds fuel vapor into the Venturi. When running slow, the volume of air per unit time is low, and the flap tends to close. The amount of air goes down, but the speed as it slips under the flap remains high. At high speed, the air rushing in opens the flap all the way, and the air-speed is about the same. The ratio of gas-to-air thus remains constant regardless of the volume of vapor required.

A similar strategy was used in the Stromberg CD-175 carburetors that were installed in most imported foreign cars in the US in the 1970s.

By James A. Golden on Thursday, January 23, 2014 – 11:15 am :

Jim, that sounds like a great plan that would have also improved the earlier carbs.

By James A. Mahaffey on Thursday, January 23, 2014 – 03:23 pm :

It was an excellent design, and possibly ahead of its time. The Simmons vaporizer used an identical swinging flap with a much more robust vaporizer plate, adjustable from the dash.

The Kingston B and B-1 vaporizers used an entirely different strategy. In the Kingston, the entire Venturi nozzle rotated in and out of the air-stream on a drum for throttling, and the fuel-air mixture was regulated by a coaxial valve assembly, with the vapor introduced at the side of the Venturi instead of the bottom. To choke, the air was valved off, and fuel was injected directly into the top of the intake structure. This solved a problem of having a long way for an initial fuel charge to travel in the vaporizer maze, but it was also possible to flood the engine with too much choke.

Vaporizer carburetor This is all done from pictures sent to me of the vaporizer carburetor. When I was doing some research on it I found there was also a Ford version and one called a Simmons. If

Vaporizer carburetor

This invention relates to carburetors and more particularly it relates to a type of carburetor especially adapted for use with higher than normal vapor pressure gasoline, in which the normally gaseous hydrocarbons are separated from the normally liquid hydrocarbons, and the two phases carbureted separately but in the same ratio as they occur in the original high vapor pressure fuel.

For automotive uses, the conventional carburetor is one in which liquid gasoline of from approximately 9 to 12 pounds Reid vapor pressure . is used as fuel. Some stationary internal combustion engines operate on natural or artificial gases, and in some regions trucks, busses and even motor-cars are propelled by internal combustion engines which are fueled by compressed gases. These latter engines are equipped with special types of carburetors for mixing the gas with air to form the combustible fuel mixture. In each of the above mentioned types of carburetors, the apparatus is used to carburet fuel from one phase, that is, from an all liquid phase, or from an all gaseous phase.

I have devised a carburetor which is designed to carburet a two phase fuel, that is, a fuel which is composed of liquid and vapor under pressure.

Fuels of this class may be such as high vapor pressure natural gasoline or even liquefied petroleum gases or mixtures thereof. 36 An object of this invention is to devise a carburetor for carbureting high vapor pressure fuels.

A further object is the control of fuel flow to the separating means in accordance with the mass of liquid phase therein. Another object is theprovision of gas responsive means for regulating relative feed of liquid and gaseous phases.

A still further object of this invention is to devise a carbureting device for use with a high 4( vapor pressure fuel, which upon reduction to slightly above atmospheric pressure, i. e., from 1 to 4- pounds per square inch gauge, is separated into a liquid phase and a vapor phase, and carbureting these two phases in the ratio in which 4C they are present in the original fuel.

Still other objects and advantages will be realized by those skilled in the art by a careful study of the following disclosure.

The figure illustrates one modification of my 5( invention showing my carburetor for use with high vapor pressure fuel.

Referring to the figure, numeral I represents a vaporizing chamber in which the normally gaseous components of the fuel are separated from 51 the normally liquid components. Liquid fuel is conducted from the fuel pressure tank, not shown, through line 2 through pressure regulator 3 and line 4 into vaporizing chamber I. Valve 5 operated by diaphragm 6 and tension spring 7 controls the flow of fuel from line 4 into the vaporizing chamber. The vaporizing chamber I is equipped with a heating coil 9 and thermoregulator 10. Heating fluid enters heating coil through tube II and leaves the coil through tube 12, the flow being controlled by control valve 13.

Vapor tube 14 connects vaporizing chamber I with vapor compartment 15, the bottom wall of which is equipped with a zero pressure regulator valve 16. This latter passes through passage II, the valve stem being attached to diaphragm 18.

Gas feed chamber 19 receives gas through the the passage 17. A spring 20 slightly compressed when valve 16 is closed and adjusted to open slightly below atmospheric pressure controls the operation of said diaphragm 18, air chamber 21. being open to the atmosphere through opening 22 or connected to air inlet 33 to balance air cleaner friction. Tube 23 connects vaporizing chamber I to the throttle regulating apparatus 24. The said throttle regulating apparatus is essentially a diaphragm regulator composed of a housing 25, diaphragm 26, tension spring 21 and push pin 28.

Tube 29 connects the liquid containing portion of vaporizing chamber I with the float chamber 30, the flow of liquid fuel being controlled by the float mechanism 31 and valve 53.

The throttle valve portion 32 of the carburetor Scomprises the air-fuel mixing apparatus. Air enters this apparatus through air inlet tube 33, the stream of air being divided into two portions, one passing through the liquid carbureting side 34 of the device and the remainder passing Sthrough the gas carbureting portion 35. These carbureting parts are equipped with Venturi sections 36 and 37. Liquid carbureting jet 38 connects the liquid containing portion of float cham’ber 30 with the point of essentially maximum suction in the liquid carbureting venturi 36, while tube 39 connects the gas feed chamber 19 with the gas carbureting jet or tube 40 in the gas carbureting section of the dual carburetor. Flow of gas through tube 39 is adjustably restricted or ) controlled by valve 40.

Throttle valve operation is adjustably controlled by a slotted lever 42 which in turn is connected to and controlled by diaphragm 26 through push pin 28 pivoted to lever 42 at one end 5 and pivoted to diaphragm 26 at the opposite end.

The push pin 28 has vertical movement in a slot 52. Any suitable means responsive to gas pressure in the vaporizing chamber may be used in place of the diaphragm and push pin arrangement shown to impart relative movement to lever 42. For example, a piston and cylinder arrangement may be utilized connected to lever 42 by suitable means. The said lever is supported by fulcrum pin 44 and manually operated by the manual throttle control 43. Butterfly throttle valve 49 is connected by arm 45 through pivot 41 to the lower side of lever 42 near one end thereof, Similarly, butterfly throttle valve 50 is connected near the opposite end of lever 42 by pivot 48 and arm 46. The liquid carbureting tube or side 34 and the gas carbureting tube or side 35 join into a common tube at the outlet end 51 of the carburetor.

Tube 55 connects the float chamber 30 to the carbureting side of the carburetor on the downstream side of the throttle valves 49 and 50 and carries the control valve 56. A branch tube connects tube 55 with the vapor space in the float bowl to prevent liquid from draining into the manifold when the engine stops. The float chamber is vented to the air inlet tube by a passage, not shown.

In the operation of my carburetor, hydrocarbon fuel comprising natural gasoline, high vapor pressure natural gasoline containing substantial quantities of normally gaseous hydrocarbons under pressure, flows from the fuel storage tank, not shown, through line 2, pressure regulator 3 and line 4 into the vaporizing chamber I. Pressure regulator 3 reduces the pressure of the incoming 35 gas. fuel from that of the storage tank to approximately from 1 to 4 pounds per square inch. Fuel at this lower pressure enters vaporizing chamber I through valve 5, which valve is operated by diaphragm 6 and tension spring 7. The liquid fuel upon entrance into vaporizing chamber I evolves as vapor some of the normally gaseous hydrocarbons, and the amount of vapor formed is dependent upon the specific hydrocarbons present in the fuel and upon the pressure and temperature maintained within said chamber. I have found that by maintaining a temperature of approximately 120″ F. at between 1 to 4 pounds pressure, excellent gas-liquid separation is obtained when using natural gasoline of from 26 to 40 pounds Reid vapor pressure. Provision for warming of the liquid fuel in the vaporizing chamber is made in the form of the hot water coil 9. Hot water from the motor cooling system, not shown, passes through line II, into the above-mentioned coil 9, through tube 12 and reenters the cooling system. The rate of flow of the heating water through the coil is thermostatically controlled by the action of the temperature bulb or thermoregulator 10 and control valve 13 in said hot water line.

The separated vapor from the vaporizing chamber I passes downwardly through tube 14 into vapor compartment 15, the pressure being essentially the same in these two compartments.

The diaphragm 6 serves as the bottom of the vaporizing chamber I and the top of the vapor compartment 15, and since the gas pressures in these two chambers are essentially equal, the operating force on said diaphragm is the mass of the accumulated liquid fuel as modified by the active tension in the tension spring 7. Thus when the weight of the residual liquid reaches a certain predetermined value, the said diaphragm closes valve 5 which in turn closes off the flow of liquid fuel into the carburetor. The spring 7 is so adjusted that the valve 5 remains closed during the presence of a preponderance of liquid fuel in the vaporizing chamber and until at least a small portion of the residual liquid fuel has passed through tube 29 to float chamber 30, thereby lessening the weight of liquid upon the diaphragm and causing valve 5 to open admitting more fuel to the vaporizing chamber. In ordinary operation due to the normal sensitivity of the diaphragm and adjusting spring, the level of liquid remains essentially constant or varies only within very narrow limits while valve 5 remains partially open depending on the rate of fuel consumption. When the gas pressure in gas feed chamber 19 becomes less than atmospheric as occasioned by the suction of gas from chamber 19 through tube 39 and gas carbureting jet 41 into venturi 37, the diaphragm 18 rises thereby opening the gas metering valve 16 allowing gas to pass through valve opening 17 into gas feed chamber 19 in accordance with the demand. In gas feed tubing 39 is inserted a valve 40 for the restriction or control of gas flow. When valve 16 is open, the gas pressure in chamber 19 and in tube 39 tends to build up due to the presence of the restricting valve 40 and when the pressure becomes greater than atmospheric the diaphragm 18 acts to close valve 16, thereby shutting off the gas flow. In actual operation when the amount*of gas issuing from gas carbureting jet 41 is constant, a pressure equilibrium results which holds the metering valve IS open an amount necessary to furnish the proper flow of The vapor-free residual liquid fuel from the bottom of the vaporizing chamber I passes through gasoline feed line 29 to the float chamber 30 under the 1 to 4 pounds pressure heretofore mentioned. When this liquid reaches a certain predetermined level in the float chamber, the float 31 rises and the attached valve 53 closes off the flow of liquid from fuel line 29. A liquid carbureting jet 38 extends from the bottom of the said float chamber 30 through the wall of the venturi 36 on the liquid side of the dual carburetor.

The diaphragm throttle regulating device 24 being connected to the top of vaporizing chamber I proportions the amount of residual liquid and separated gas entering the throttle valve portion 32 of the dual carburetor so that these two fractions of fuel may be used in the same ratio in which they are present in the original fuel. This regulating device operates by pressure variations communicated from the vaporizing chamber I through tube 23. When the pressure in chamber I increases, diaphragm 26 within housing 25, moves from left to right according to the drawing, and this movement increases the tension on tension spring 27, and is transmitted through push pin 28 to move lever 42 from left to right.

Slotted lever 42 may move in the above given direction until pivot 47 is directly under fulcrum pin 44, then upon downward movement of the manual throttle control 43, pivot 48 and arm 41 move downward, thereby opening butterfly throttie valve 50. When this gas-side throttle valve is open, air from inlet 33 passes through the gas side 35 and the corresponding venturi 37 and the vacuum set up at the gas jet 41 communicates backward through tube 39, valve 40 and through tube 39 extended and tends to evacuate the gas feed chamber IS in the lower part of the vaporliquid separator I. This pressure drop causes diaphragm 18 to open the gase metering valve 16 which permits the separated gas to flow from the vapor containing portion of the vaporizing chamber I Into the vapor compartment 15, through valve 16 and into vapor feed chamber 19, thence through tube 39, valve 40, jet 41 and into the air stream. This operation continues until the gas pressure in vaporizing chamber I drops to a predetermined value during which time metering valve 16 remains open permitting continued gas flow, and at the time of said pressure drop, regulator 24 functions to move diaphragm 26 from right to left, which movement is communicated by push pin 28 to slotted lever 42 causing the latter to move from right to left until pivot 48 is directly under fulcrum pin 44 or at some intermediate point. All during this operation, the manual throttle control 43 remains open, that is control 43 is held depressed.

When slotted lever 42 moves from right to left, pivot 41 and arm 45 move upward while pivot 48 and arm 46 likewise move upward, thereby opening butterfly throttle valve 49 and permitting more inlet air to pass through the liquid side 34 of the dual carburetor and closing valve 50. As inlet air passes through this section of the carburetor, and thrugh venturi 36, vacuum or suction is communicated through jet 38 which action draws residual vapor-free liquid fuel through said jet 38 into contact with the flowing air for mixing and passage through the outlet end of the dual carburetor 51 and into the intake manifold, not shown. Upon continued consumption of residual liquid fuel the liquid level in float chamber 30 drops until float 31 causes valve 53 to open, thereby permitting vapor-free residual liquid to flow from the vaporizing chamber I into the float chamber 30. This liquid continues to flow in this direction as long as float valve 53 remains open. If during this flow the liquid in vaporizing chamber I becomes lowered to a predetermined level or what amounts to the same thing, the weight of the residual liquid is lessened to a predetermined amount, diaphragm 6 opens the fuel valve 5, thus permitting raw fuel to flow from the pressure storage tank, not shown, through the pressure regulator 3 into the vaporizing chamber I, thereby increasing the weight of liquid on the said diaphragm and valve closes. Upon the addition of this raw fuel to the vaporizing chamber, vaporization occurs thereby increasing the gas pressure within said chamber. This pressure Increase acts through tube 23 on the throttle regulating apparatus 24 to move the push link from left to right to open the gas side butterfly valve 50 for consumption of the vapors evolved in said vaporizing chamber.

The gas side of the carburetor functions as long as the gas pressure in the vaporizing chamber remains within a certain pressure range, say from 1 to 4 pounds per square inch, then when this pressure drops to less than 1 pound the tension spring 21 contracts pulling the diaphragm 26 and connected parts from right to left and feeding more liquid fuel to the carburetor. Thus when the mass of the residual liquid on diaphragm 6 is lessened to a predetermined value, valve 5 opens wider permitting more raw fuel to enter the vaporizing chamber at which time the pressure in said chamber increases to open up the gas side of the carburetor as heretofore explained.

When the motor is operating at a constant load and at constant speed, the operation of the carburetor reaches a state of equilibrium in which raw liquid fuel enters the vaporizing chamber I in a small but essentially continuous flow through valve 5, the slight gas pressure increase in said chamber I holds diaphragm 26 in such a position that the push link 42 is held at an intermediate position allowing both throttle valves 49 and 50 to be partially opened, thereby permitting consumption of residual gas-free liquid and separated gas in the same proportion in which they occur in the original high vapor pressure fuel.

The tension spring 20 is so adjusted that the diaphragm 18 plays its part in maintaining the operating equilibrium under the above mentioned conditions.

, During periods of acceleration when the manually controlled throttle is opened, the separated gas may be consumed more rapidly in proportion than the residual liquid fuel and the valve 5 is so arranged, as explained heretofore, that the flow of original fuel through line 4 into the vaporizing chamber is controlled solely by the mass of residual gasoline on the diaphragm 6 and not by the pressure of the liberated vapor or gas in the upper portion of the said vaporizing chamber.

The pressure of the liberated gas or vapor in the vaporizing chamber controls the relative position of link 42 so that under certain conditions only separated gas will be carbureted, while under other conditions only residual gas-free liquid fuel will be carbureted, and under still other conditions both the separated gas and the residual liquid are carbureted simultaneously, the overall separate and individual carburetion of said gas and said liquid being in the ratio in which these components are present in the original liquid fuel.

For idling of the motor, there may be sufficient air leakage through the butterfly valves to draw sufficient fuel or definite provision may be made.

In this latter case, tube 55 connects the carbureting portion of the carburetor at a point on the downstream side of the throttle valves 49 and 50 to the float chamber 30 for liquid fuel idling and to the top of the vaporizing chamber I for gaseous fuel idling. In either case an adjustment valve 56 is provided in tube 55.

The thermoregulator 10 and valve 13 which control the flow of warm water from the en5O gine’s cooling system are set to maintain the temperature of the liquid fuel in the vaporizing chamber such that the proper amount of high vapor pressure hydrocarbons will be vaporized therefrom. Such an amount of said high vapor pressure hydrocarbons should be removed from the liquid so that there will not be a tendency of the residual liquid to form vapor in tubes and chambers in which there should only be liquid fuel, or in other words the vapor pressure of the Sliquid fuel should be so reduced that there will be no tendency to form vapor lock. While the temperature of the liquid fuel in this vaporizing chamber may be varied within not too wide limits, some variation is permissible. I have found that under normal operating conditions a vaporizing chamber temperature of 120* F. gives excellent operation when using a natural gasoline of 26 to 40 pounds Reid vapor pressure. When using fuel of higher vapor pressure, the vaporizing chamber temperature may be lower than 120° F. and for lower vapor pressures the tem: erature should be somewhat higher. By controlling the pressure and temperature in the vaporizer, I can obtain the volatility characteristic desired in the residual liquid fuel.

The gas metering valve II is so constructed that there will be essentially no gas leakage therethrough when the valve is in a seated or closed position. To assist in preventing gas leakage, the valve may be faced with such hydrocarbon insoluble material as synthetic rubber, fiber or other’swellproof material, the face being identified by numeral 54 in the drawing.

While one embodiment of my dual carburetor has been described in detail, it is obvious to those skilled in the art that many changes and alterations of the component parts may be made. and yet remain within the intended scope of my invention.

I claim’ 1. In a carburetion system for internal combustion engines adapted for handling higher than normal vapor pressure fuel, including a vaporization chamber normally containing a body of liquid and a volume of gaseous fuel, a dual branched carburetor, each branch including a Venturi tube and fuel nozzle, a passage for liquid fuel leading from the vaporization chamber connected with one nozzle and a passage for gaseous fuel leading from the vaporization chamber connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable lever adjustable with respect to said fulcrum, arms pivoted to said lever on opposite sides of the fulcrum and operably connected with said valves and pressure responsive means for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel induced in the branches by air flow through the Venturi tubes.

2. In a carburetion system for internal combustion engines adapted for handling higher than normal vapor pressure fuel, including a vaporization chamber normally containing a body of liquid and a volume of gaseous fuel, a dual branched carburetor, each branch including a Venturi tube and fuel nozzle, a passage for liquid fuel leading from the vaporization chamber connected with one nozzle and a passage for gaseous fuel leading from the vaporization chamber connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable member adjustable with respect to said fulcrum, means pivoted to said member on opposite sides of the fulcrum operably connected with said valves and means for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel.induced in the branches by air flow through the Venturi tubes.

3. In a carburetion system for internal combustion engines adapted for handling higher than normal vapor pressure fuel, including a vaporization chamber normally containing a body of liquid and a volume of gaseous fuel, a dual branched carburetor, each branch including a Venturi tube and fuel nozzle, a passage for liquid 1. fuel leading from the vaporization chamber connected with one nozzle and a passage for gaseous fuel leading from the vaporization chamber connected with. the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable lever adjustable with respect to said fulcrum, arms pivoted to said lever on opposite sides of the fulcrum and operably connected with said valves and means responsive to pressure of the gaseous phase in the vaporization chamber for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel induced in the branches by air flow through the Venturi tubes.

4. In a throttling arrangement for an internal combustion engine carburetion system adapted for handling higher than normal vapor pressure fuel including means separating said fuel into liquid and gaseous phases, a dual branched carburetor, each branch including a Venturi tube and a fuel nozzle, a passage for liquid fuel leading from the separating means connected with one nozzle and apassage for gaseous fuel leading from the separatiig means connected with the other nozzle, to induce liquid and gaseous fuel flow in accordance with air flow through said Venturi tubes, the improvement comprising a valve in each branch of the dual carburetor to control the air flow and thereby the relative fuel flow thereto, a fulcrum, a manually operable lever adjustable with respect to said fulcrum, arms pivoted to said lever on opposite sides of the fulcrum and operably connected with said valves and means for shifting the pivots toward and from the fulcrum to vary the position of the valves and thereby the relative proportions of liquid and gaseous fuel induced in the branches by air flow through the Venturi tubes.

This invention relates to carburetors and more particularly it relates to a type of carburetor especially adapted for use with higher than normal vapor pressure gasoline, in which the normally gaseous