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67 cj5,225 Dauntless, D30,chrome molies, detroit, D44, full floating detroit, custom steering, disc all the way around,2 inch lift on 31s, armored up
70 cj6 4 inch lift
OK guys, I have 2 dautless 225s, I need some advice from guys who have run an OLD engine a long time.
Is it worth it to have the heads sent out for new seats to handle todays fuels?
I will be running one on propane and another on regular unleaded, SO I was wondering if the old seats, designed for leaded fuel really need replacement?
we all are learning here and I have great faith in our community so let us each give our hoinest opinion based on running our old engines.
OK guys, I have 2 dautless 225s, I need some advice from guys who have run an OLD engine a long time.
Is it worth it to have the heads sent out for new seats to handle todays fuels?
I will be running one on propane and another on regular unleaded, SO I was wondering if the old seats, designed for leaded fuel really need replacement?
we all are learning here and I have great faith in our community so let us each give our hoinest opinion based on running our old engines.
You could always just run an additive if your worried about valve seat wear. Or - if it really troubles you - have hardened seats installed. If you don't plan on abusing the engines - many get by without additive or new seats.
In my humble opinion, yes. If the engine is going to be apart, or you need to pop the heads for any reason, hardened seats are well worth doing. No way I would pull a head and not do it while it was off.
OK guys, I have 2 dautless 225s, I need some advice from guys who have run an OLD engine a long time.
Is it worth it to have the heads sent out for new seats to handle todays fuels?
I will be running one on propane and another on regular unleaded, SO I was wondering if the old seats, designed for leaded fuel really need replacement?
we all are learning here and I have great faith in our community so let us each give our hoinest opinion based on running our old engines.
I would have hardened seats installed if I was planning to run propane.
WHY VALVE SEATS FAIL Nonintegral valve seats can fail for a number of reasons. Most of the seats that end up being replaced are replaced because they are either cracked or too worn to be reground or remachined. Seats can crack from thermal stress (engine overheating usually), thermal shock (a sudden and rapid change in operating temperature), or mechanical stress (detonation, excessive valve lash that results in severe pounding, etc.). A small amount of valve recession results from normal high mileage wear, but it can also occur when unleaded gasoline or a "dry" fuel such as propane or natural gas is used in an engine that is not equipped with hard seats. Recession takes place when the seats get hot and microscopic welds form between the valve face and seat. Every time the valve opens, tiny chunks of metal are torn away and blown out the exhaust. Over time, the seat is gradually eaten away and the valve slowly sinks deeper and deeper into the head. Eventually the lash in the valvetrain closes up and prevents the valve from seating. This causes the valve to overheat and burn. Compression is lost and the engine is diagnosed as having a "bad valve." The seat also has to be replaced, but it many instances it may not be recognized as the underlying cause of the valve failure. As a rule, a seat should be replaced if the specified installed valve height cannot be achieved without excessive grinding of the valve stem tip (less than .030 in.), or if the specified installed spring height cannot be achieved using a .060 in. spring shim. This applies to integral valve seats as well as nonintegral seats. The only other alternative to replacing the seat is to install an aftermarket valve that has an oversized head (.030 in.). This type of valve rides higher on the seat to compensate for excessive seat wear or machining, and can eliminate the need to replace the seat. A seat may also have to be replaced if it is loose or if the cylinder head is cracked and requires welding in the combustion chamber area (the seats should be removed prior to welding). One way to check a seat for looseness is to hold your finger on one side of the seat while tapping the other side with a hammer. If you feel movement, the seat is loose and should come out (so it does not fall out later!). The seats in an aluminum head may also loosen or fall out when the head is being cleaned in a bake oven or preheated in an oven for straightening. The same thing can happen to the guides. Whether or not this occurs depends on the amount of interference fit between the seats and head. The less the interference, the more likely the seats are to loosen and fall out when the head is baked. If you do not want the seats to fall out, turn the head upside down or stake the seats prior to baking.
Are any changes needed to allow for the corrosive nature of ethanol?? SS intake valves maybe??
In an attempt to not hijack this thread I would say that a valve seat replacement was a good idea if you are planning on putting any real hours on these motors.
LPG Conversions: Renewed Interest In The Use Of LPG (Liquefied Petroleum Gas) And LNG (Liquefied Natural Gas)
Alan Carver
The recent move to clean up inner city exhaust emissions has resulted in renewed interest in the use of LPG (Liquefied Petroleum Gas) and LNG (Liquefied Natural gas) as motor fuels. These fuels are almost pure propane with a little butane present.
Tax incentives are being offered to encourage fleet operators to convert to gaseous fuels and more vehicles are being offered by the OEMs that have already been converted. Many non-factory converted engines are being used in industrial type applications, and in propane delivery trucks that run on the fuel in the tank on the back. These non-factory converted engines often need valve and seat replacement in less than a year of operation because they do not have the correct valves and seats in them for propane.
What does this mean for cylinder head rebuilders today? There are great opportunities out there for the shop that does the work right the first time. Lets look at this fuel and what its use means to the rebuilder.
Gaseous fuels burn with an almost complete absence of ashy deposits. These deposits in gasoline engines protect the valve and seat faces from wear. These deposits are also the ones that turn the engine oil black.
A propane engine usually has clear oil when an oil change interval is reached. The absence of these typical deposits gives rise to the name "dry fuel" and is commonly used to describe LPG. The lack of these deposits, however, allows direct contact between the valve and seat mating surfaces in the combustion chamber.
This direct contact causes micro-welding to occur with metal from one surface transferring to the other. During the next open/close cycle the deposits heat up and oxidize. These oxides are both corrosive and abrasive and explain why some non-OE converted engines suffer severe and rapid valve and seat wear.
An interesting observation when this happens is that the use of the wrong valve head material will often cause seat recession with minimum valve face wear. It would be a mistake to repeat the use of this material combination during rebuilding or conversion by reusing the valves. See photo at lower right.
Another cause of rapid seat wear is that valve heads flex under combustion pressures. In gas engines this helps the valve sealing process. In LPG applications, however, this flexing can accelerate a wear problem and lead to early failure.
To combat this wear, various techniques can be used. The first to consider is to widen the seat contact width to about 0.100". A full 76% of the heat transferred out of the valve goes out through the valve-face-to-seat contact area. Widening the seat allows more heat transfer and spreads the compressive load over a larger area. This helps prevent the welding process, also known as adhesive wear. Valve spring pressure should also be checked. Low spring pressure will adversely affect heat transfer.
The next concern is to ensure that there is good contact between the valve and seat faces. It is not recommended to machine an interference angle between these faces today; this is particularly important for LPG heads. It is also good practice to "blue" the contact area and hand lap if necessary. Valve rotators should be replaced or welded up to prevent excessive face wear.
While these are techniques to aid the rebuilder, the component suppliers can do their part to help the valves and seats survive, too. One action taken is to upgrade the materials of valves and seats used in such applications.
Let's look at the latest material trends used in OEM supplied LPG engines. Valves for these engines are specifically designed to withstand the extra wear experienced with the use of LPG fuels. The valve faces need to be protected as do the seat contact surfaces in the cylinder head.
In the case of valves, the addition of hard facing alloys or stellites is considered essential in preventing rapid wear and subsequent early valve failures. Rather than the valve head being made entirely of stellite, these valves have a cobalt-based inlay welded into the valve contact face.
Most factory converted engines use valvetrain components that are dimensionally identical to their gasoline counterparts, so it is easy to make application errors here. It is almost impossible to detect these valves except by careful attention to the part number on the valve.
There is no non-destructive test that I know of for stellite inlay detection, but the latest machining techniques can offer some insight. Most current stellite valve production uses a process called 'snag cutting'. This process produces a machined area at the top of the seat (the stem side) to clean up the inlay edge.
It often looks like the valve was intended to be fully machined under the head, but missed half of the process. Regular austenitic 'stainless exhaust alloys' are generally good to about 1300° to 1450° F depending on stress, while the stellites can survive up to 1600° F.
In some cases the valve head has to be made from a nickel-based super alloy such as the Inconel range of materials. These alloys approach the hot hardness readings of the stellites and are now used in all domestic big block applications that are factory converted.
These designs also feature an increased head thickness and underhead radii that reduce head flex, thus preventing face wear due to valve head bending. In some cases, 454 GMs and 429/460 Fords, for example, both stellite faces and Inconel heads are required to provide an acceptable service life with the Ford application being sodium cooled as well.
We are talking about a very high-cost valve here. Incidentally, the Inconels are prone to scuffing when used as a wear surface in a cast iron guide. Consequently, all Inconel headed valves are of welded, two-piece construction with the stem being a high-carbon intake style material.
Many people think that two-piece valves are 'cheaper' than one-piece valves but that is not the case. A welded valve must still have the head forged and then is inertia welded to the stem. More machining is required as is 100% ultrasonic testing of the weldment area.
Two-piece valves are far from being cheaper. In fact, these extra manufacturing processes add considerably to the cost. That just about covers the valves so let's move on to the seats.
Valve seats
The valve seats in the head also need some attention. If the head was not designed to run on LPG, the valve seats need to be inserted with a material specifically designed for gaseous fuel use. The aforementioned big blocks all have factory installed inserts in the exhaust when set up for propane by the OEM. These seats are generally made from non-magnetic, nickel-based alloys with some Limited use of high grade powdered metal technology in very late model applications.
These alloys have a higher hot hardness than other magnetic or iron-base alloys, and they withstand the corrosive and abrasive action present in LPG fueled engines. If you do not know what seats have already been put in a casting and you do not know if the head was factory prepared for use with propane, it is recommended to replace the seats with those designed for use with LPG fuel. It is cheap insurance in the long run.
We still get heads sent in with old cast iron seats that were installed in them in the days of leaded fuel. With propane you would be lucky to get the vehicle out of the garage with this type of seat installed.
When this type of seat fails it often disappears completely out the exhaust port. It actually looks like someone forgot to put the seats in. The factory seats often had a light press fit, about 0.003". Even though factory sized replacement is often available in the replacement market, if there is any doubt about the roundness of the counterbore it is recommended to go ahead and install an oversize O.D. replacement. Any head that has been severely overheated or has undergone a welded repair would automatically fall into this category due to the possibility of counterbore distortion.
It is worth a few more words concerning the 429/460 Ford engines. The only engine currently offered propane-converted by Ford is the 429. This engine uses a stellite intake valve with a 1.977" head diameter, and a sodium cooled, Inconel-headed, stellite faced chrome plated exhaust with a 1.654" head diameter. These are the fuel injected head valves from 1991 and later and have 11/32" valve stems.
It is highly recommended to use these valves in both the 429 and 460 heads for use with propane. Any conversion will involve installing 11/32" guides, the use of 11/32" retainers (Ford OEM p/n F1TZ-6514-B) and if it is a 460 with head casting, p/n E7TE-BD, and the use of the longer 2.090" spring. Any head with 2.083" diameter intake valves should have intake seats installed to bring the valve head diameter down to 1.977".
It is very often the service that comes after the sale that can really make the difference in engine survival. When an engine has been converted to LPG use and the cylinder head has been built specifically for that type fuel, it can still fail without attention to both the ignition system and the fuel mixture.
The distributor must be recurved to provide a total advance of 36 degrees at 1000 rpm (15" of vacuum) and total advance of 42 degrees at 3000 rpm. Initial timing can be advanced about 10%, but if this is done an equal amount must be removed from the total advance curve.
The fuel injected engines with a computerized engine management system are particularly difficult to set up. The computer in these engines has too much retard under full load for propane fuel.
The fuel delivery system is also important. Most LPG systems require about a 2% exhaust oxygen content to ensure adequate cooling in the combustion chamber. Unlike gasoline engines, a rich propane mixture overheats the valves and seats causing seat recession and rapid valve wear. The recommended way to set up the engine with the correct fuel mixture is to use an exhaust gas analyzer. One source for this tool is NeoTronics, Flowery Branch, GA.
Check with your parts supplier for valves and seats designed for propane fuel applications. S.B. International, Nashville, TN, for example, stocks E-Loy stellite valves and J-Loy "Star Series" seats for the 34 most popular LPG engines in use, whether factory or aftermarket converted
67 cj5,225 Dauntless, D30,chrome molies, detroit, D44, full floating detroit, custom steering, disc all the way around,2 inch lift on 31s, armored up
70 cj6 4 inch lift
Are any changes needed to allow for the corrosive nature of ethanol?? SS intake valves maybe??
In an attempt to not hijack this thread I would say that a valve seat replacement was a good idea if you are planning on putting any real hours on these motors.
I don't have as much "Ethanol" experience as "Propane", but as far as I can tell there is no need for special valves under normal operating conditions.
With "Ethanol" it's a different set of problems.
[FONT=Times New Roman,Georgia,Times]Convert Your Car to Alcohol[/FONT]
[FONT=Times New Roman,Georgia,Times]by Keat B. Drane[/FONT]
[FONT=Times New Roman,Georgia,Times]Are you as tired of the "gasoline shortage" as I am? Long lines at the pump, shorter service station hours and higher prices are here to stay. Rationing has affected various areas of the nation. Unstable, international politics threaten our continued dependence on foreign crude oil. Politicians and oil executives predict the situation to worsen.
Faced with these grim facts, I began to search for an alternative energy source. I wasn't looking for a solution to the entire country's energy problems. I simple wanted to insure that my family and I would have the fuel to power our vehicles when and where necessary, without interference or restriction from Uncle Sam's energy "experts" or the whims of a greedy oil sheik in the Middle East.
Alcohol fuel is the little man's best hope for relief from gas "pains". The all-but-untapped, domestic resource has many advantages. The following is a list of the ones I feel are most significant:[/FONT]
[FONT=Times New Roman,Georgia,Times]Almost any gasoline-powered engine can be made to run well on alcohol.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Only minor and inexpensive modifications to the engine are required.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Anyone with reasonable, mechanical skill and common handtools can make the modifications once they've learned the procedure.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Alcohol can be produced from a variety of organic materials and is a natural substance.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Distilling can be done a small scale by individuals or on a very large scale by local companies.
[/FONT]
[FONT=Times New Roman,Georgia,Times]And profit generated by production of domestic alcohol fuels will stay in America and will pay American farmers.[/FONT]
[FONT=Times New Roman,Georgia,Times]With these thoughts in mind, I decided to undertake a test project. The first goal was to successfully convert a vehicle fuel rather than "gasohol". The vehicle was then to be driven daily to determine was practical for use under normal everyday conditions.[/FONT] [FONT=Times New Roman,Georgia,Times]The Test Vehicle[/FONT]
[FONT=Times New Roman,Georgia,Times]The test vehicle was a 1969 Dodge Dart. It had 80,000 miles on the motor at the time of conversion and was stock in every aspect. The Dart was equipped with a 318 cubic inch engine, automatic Transmission , power brakes and steering and air conditioning.
The Dart was donated for testing purposes by friends who shared my interest in finding a practical alternative to gasoline.
The conversion and test were a great success. I now feel secure in the knowledge that I'll never have to park my car for lack of fuel. I want to share my good fortune and results with you. The following pages outline the theory, mechanics, cost and materials which you should follow in converting your car.
Let me give you a word of caution. Please read this entire book before starting to modify your car. There are several variations discussed, and you will want to be sure which will reward you with success, You will have achieved personal independence from the gas pump and freedom from anxiety about shortages.
Good luck and happy motoring![/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 2
Types of Alcohol Fuel[/FONT]
[FONT=Times New Roman,Georgia,Times]You probably have questions in your mind about using alcohol as a motor fuel. We'll look briefly into the history and types of alcohol fuels.
In the early days of automotive industry several manufacturers produced motors designed to run on alcohol, instead of the relatively new and scarce product called gasoline. The Ford Model T was originally designed to burn alcohol, gasoline or a combination of both. However, Ford and other manufactures soon bowed to the intense pressure exerted by the emerging oil monopolies of the time and began designing motors with gasoline as the only intended fuel.
Several makers of farm tractors have continued production of alcohol engines. They are for export only, and you will probably never see a factory-engineered alcohol tractor in this country in this country at this time.
There are several different types of alcohol. Each type is derived by a slightly different method or from a different raw material. We are interested in two types - methanol and ethanol.
Methanol may be familiar to you as the fuel used in Indy-type racecars. At one time, it was distilled from wood and commonly known as wood alcohol. Petroleum is the source of most methanol today. It is very toxic and poisoning can result from ingestion. Methanol is one possible source for fuel for your car, although it yields less energy than ethanol.
Ethanol is the best choice to run your car. It is formed by the fermentation of sugars from a number of types of organic materials. Wheat, corn, rice, beets and cane are examples of materials with a high sugar content. They give a high yield when fermented and distilled. All types of liquors contain ethyl alcohol also known as grain alcohol.[/FONT] [FONT=Times New Roman,Georgia,Times]Home Distillation[/FONT]
[FONT=Times New Roman,Georgia,Times]The most economical way to obtain alcohol is to build a still and distill it yourself. You can legally distill alcohol fuel (but not alcohol to drink) by obtaining a permit from the Bureau of Alcohol, Tobacco & Firearms.
Homemade alcohol can be distilled for as low as 40¢ per gallon depending on the size of the still, the fuel used to power it and the cost of the grain. An increasing number of enterprising individuals, particularly farmers, are cutting their fuel bills by distilling their homegrown crops.
If distilling sounds attractive to you, there are several publications available on the topic. A good, basic primer on distillation is Forget The Gas Pumps -- Make Your Own Fuel written by Jim Wortham and Barbara Whitener. It provides diagrams of small stills, step-by-step directions on how to make alcohol and the information necessary to obtain a permit. A model application is also included.
[/FONT] [FONT=Times New Roman,Georgia,Times]Buying alcohol[/FONT]
[FONT=Times New Roman,Georgia,Times]Industrial ethanol can be obtained from a wholesale chemical supply company. The price per gallon varies widely according to the quantity purchased, I purchased a 55-gallon drum of 200-proof ethanol for $124 or about $2.25 per gallon. Bulk quantities are more economical, but you must have a tank or other provisions for storage. Also, you must buy a large quantity to achieve the best price.
Check out all possible suppliers in your area, as there seems to be a wide variation in price from company to company. Comparison shopping may save you money.
Any alcohol you may purchase commercially has been denatured. Denaturing is a process required by the government to render the alcohol unfit for consumption. Treat denatured alcohol as you would gasoline or any poisonous substance.[/FONT] [FONT=Times New Roman,Georgia,Times]
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 2-1 - Here's how I "fill 'er up" with alcohol. If my tank had not been portable, a hose would have reached my car.[/FONT]
Chapter 3
Preparing Your Car for Conversion[/FONT]
[FONT=Times New Roman,Georgia,Times]Let's assume you have decided to convert "Old Betsy" to alcohol power. Maybe that old clunker in the yard-the one that barely runs, is undependable and isn't worth trading in. A second car not necessary for daily use is a dandy choice for initial conversion. You won't be without transportation during the workweek and working on an older car may ease those fears about how alcohol may adversely affect the engine of your later model car.
Just keep this one fact in mind; if it won't run on gasoline you're defeated before you started. Alcohol will not magically cure a sick engine.
Take a realistic look at the condition of your engine. My test vehicle required replacement of a bad starter, old spark plugs and cracked spark plug wires. If you intend to keep to keep the car for any length of time, the expense of major repairs will be justified.
When your car is running reasonable well on gasoline, it is ready to be converted.[/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 4
Modification of the Fuel Line[/FONT]
[FONT=Times New Roman,Georgia,Times]A decision will have to be made at this point. Is the conversion going to be a permanent one; or do you want to use gasoline when readily available to reserve your car's new capability to burn alcohol for possible fuel shortages?
In a permanent conversion, the gasoline tank will become an alcohol tank. This involves running the tank completely dry and replacing the gasoline with alcohol. It is undesirable to mix alcohol with gasoline. They will not mix unless the alcohol contains almost no water.
I decided to install a dual-fuel system since the car would be run primarily on gasoline when returned to the owners.
The alcohol tank was constructed from a 5-gallon heavy-walled Nalgene plastic container. This container was obtained from a laboratory at no charge. Since it was small enough to be portable, I did not permanently mount it. The level of liquid could be seen at a glance since the plastic is translucent. A metal container would have served the purpose, but would not have been quite as handy.
A larger alcohol tank could be mounted on the trunk or roof of the car. The choice will depend on what you have to work with and you individual preference. By all means, pick a container that is sturdy, leakproof and clean.[/FONT]
[FONT=Times New Roman,Georgia,Times]
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 4-1 - This is my homemade 5-gallon fuel tank and pickup tube. Everything shown was scrounged up at no cost whatsoever.[/FONT]
Install a pickup tube of the same outside diameter as you existing fuel lines. The tube should reach to approximately 1/16" from the bottom of the tank and protrude from the top approximately 1". Also install a vent tube to allow air to replace the liquid as it is consumed. Without the vent vacuum will collapse the tank. Make suitable holed in the tank for the vent and fuel lines epoxy or braze them into place. I brazed my pickup tube to a pipe plug. The exact method will depend on what material you use.
Next, mount the tank in the selected location on your car. A large tank should be fastened or strapped securely to prevent shifting or overturning. My small tank was wedged in between the back seats and could not move at all. I don't recommend that you mount the tank in an enclosed space, however.
With the tank securely mounted, some provision must be made for connecting into the existing fuel line. For this purpose, I used a "T" valve. This device can be purchased at any recreational vehicle supply house. The price will range from about $5 for a simple, manual valve to $40 or more for an electric valve remotely controlled from the dash.
My "T" valve was donated by a neighbor who had removed it from his truck. He had replaced it with a more costly electric valve. This particular model had three inlets. Only two inlets were required, and I plugged the third one.
I mounted the valve on the inner fender well, as close to the fuel pump as was practical. It could also be mounted under the floorboard so the handle could be operated from within the car. This arrangement would eliminate the need to raise the hood in order to change from one fuel to the other.
[/FONT][FONT=Times New Roman,Georgia,Times]I used standard black fuel hose for all necessary rerouting of the fuel lines. Standard barb fittings were used to connect the hose to the "T" valve. Teflon tape was used on all threaded connections to prevent leaks.[/FONT]
[FONT=Times New Roman,Georgia,Times]
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 4-2 - I mounted my "T" valve on the inner fender. The line on top is the alcohol inlet. The right is the gasoline inlet.[/FONT]
Here's how to install your "T" valve and change the fuel lines.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Mount the "T" valve in the location you prefer.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Install barb fittings, if required.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Connect the alcohol to one inlet of the "T" valve using black fuel hose of the correct size.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Locate the inlet side of the fuel pump and remove the short piece of hose between the pump and the metal, fuel line from the gasoline tank.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Connect the metal fuel line to the remaining inlet on the "T" valve with black, fuel hose.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Connect the outlet of the "T" valve to the inlet side of the fuel pump with a third length of black fuel hose.
[/FONT]
[FONT=Times New Roman,Georgia,Times]Make certain the lines you have added are secure, leakproof and do not interfere with any moving parts.[/FONT]
[FONT=Times New Roman,Georgia,Times]You now have a dual-fuel system, interchangeable at the flick of a valve.[/FONT]
[FONT=Times New Roman,Georgia,Times]
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 4-3 - The above diagram describes how I arranged the fuel line on the Dart.[/FONT] [/FONT][FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Bigger image[/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 5
The Carburetor[/FONT]
[FONT=Times New Roman,Georgia,Times]Types of Carburetors[/FONT]
[FONT=Times New Roman,Georgia,Times]The carburetor is to your car's engine what your heart is to your body. Its job is to feed fuel and air to the cylinders in the correct amounts.[/FONT]
[FONT=Times New Roman,Georgia,Times]Figure 5-1 is a simple diagram of a carburetor. It has one bore of barrel for air and fuel to pass into the intake manifold and one main metering jet to measure out fuel. This type works on engine with a single bank of cylinders, such as a straight six-cylinder engine.
A"two-barrel" carburetor has two bored and two main metering jets. Each barrel is responsible for the cylinders on one side of a V-type engine such as a V-8. A better distribution of fuel is obtained with this arrangement.
[/FONT][FONT=Times New Roman,Georgia,Times]Large displacement engines require more fuel, under some conditions, than a two-barrel carburetor can provide. If the "two-barrel" were large enough to meet peak demand, it would waste fuel under a light load. The "four-barrel" carburetor has two small primary and metering jets, plus two additional secondary barrels and jets. The larger secondaries remain closed until the engine needs the extra boost they provide.[/FONT]
[FONT=Times New Roman,Georgia,Times]Whichever type your car may have, the operation is similar.
Fuel is pumped through the line and enter the carburetor's float bowl. A needle valve admits fuel to the bowl and closes off the flow when the bowl is filled. The valve is opened and closed by a float which rises and falls with the fuel level in the bowl. The fuel level is very critical and must be kept within the close limits by the float and needle valve.
Air enters the carburetor through the air horn. It is drawn down past the venturi, where the passage narrows. This restriction causes an increase in air velocity and results in the creation of a vacuum below the venturi.
This vacuum sucks fuel from the bowl through the metering jets. The jets are carefully sized to give the correct ratio of fuel to a given volume of air. Metering rods may be used to partly close the main jets at idle.
The metered fuel passes into the venturi and is misted into the barrel. Here it is mixed with air and distributed to the cylinders by the way of the intake manifold.
A smaller idle passage is equipped with an adjustable jet. The smoothest idle can be obtained by screwing the stem of this jet in or out.
A third fuel passage leads from the accelerator pump, located next to the float bowl. This passage provides an extra shot of fuel only when the accelerator pedal is pressed down. The extra fuel balances the excess air which is sucked in as the throttle plate is suddenly opened during acceleration. The accelerator pump is inactive at idle or when the accelerator pedal is held at a steady position.
The choke valve is located in the air horn above the venturi. It's purpose is to restrict the amount of air entering the carburetor while the engine is cold. Fuel will not vaporize well in a cold engine and less air flow is desirable. An automatic chock will open and admit more air as the engine heats up. It is necessary to open a manual choke by hand.
A gasoline engine runs best with an air/fuel ration of about 14/1. The jets in the carburetor are sized to provide this ratio.
Alcohol burns most efficiently with a ration of around 9/1. The next chapter will outline the procedure for removing, modifying and replacing the carburetor to attain this ration.[/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 6
Altering the Carburetor[/FONT]
[FONT=Times New Roman,Georgia,Times]You may want to obtain a second carburetor to convert and keep your present one for gasoline use. I obtained a used one for $10 from a salvage yard. Rebuilt carburetors are available from your auto parts dealer. In either case, make sure the one you purchase is compatible with the engine you plan to use it on. You parts dealer will be helpful in determining the most efficient.
Next, get a carburetor overhaul kit. Be sure the kit is for your particular model carburetor. The model will be cast into the body or on a metal tag attached to it. The kit contains new gaskets, check valves, an accelerator pump plunger and the necessary parts to make an old carburetor perform like new. Best of all, it has detailed instructions and an exploded view of all the parts. Each part is numbered and named for reference. This will a real aid for reassembly.[/FONT] [FONT=Times New Roman,Georgia,Times]Remove and Disassemble the Carburetor[/FONT]
[FONT=Times New Roman,Georgia,Times]Take a good look at you engine before removing the carburetor. Notice how each linkage or hose is attached. Remember - everything must go back on correctly, so be alert. Unbolt the carburetor and put any small fasteners away where they won't get lost.
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 6-1 - This is the carburetor with the air horn and float chamber cover removed. The jets are lying just below the carburetor body.[/FONT]
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 6-2 - Here's the carburetor disassembled a step further. The jets, metering rods and float have been removed. Be sure you know where each part goes before you remove it from your carburetor.[/FONT]
[/FONT] [FONT=Times New Roman,Georgia,Times]Enlarging the Metering Jets[/FONT]
[FONT=Times New Roman,Georgia,Times]Try to find a clean, uncluttered table or counter to work on. Use the exploded view as a guide and disassemble the carburetor far enough to remove the main, metering jets. The jets are more accessible in some models than others.
Carefully determine the hole size of the metering jets. This can be done by actually measuring the jet or looking in a shop manual. If you have no way of determining the hole size, take the jets to an automotive machine shop. They have the tools to measure and enlarge the jets.
Determine the proper jet size by the following example. This is the calculation I used from the Dodge.
[FONT=Times New Roman,Georgia,Times]Original Jet Diameter[/FONT]
[FONT=Times New Roman,Georgia,Times]0.62[/FONT]
[FONT=Times New Roman,Georgia,Times]Increase Jet Diameter By 40% For Alcohol[/FONT]
[FONT=Times New Roman,Georgia,Times]x 1.4
248[/FONT]
[FONT=Times New Roman,Georgia,Times]Correct Jet Diameter For Alcohol[/FONT]
[FONT=Times New Roman,Georgia,Times]÷ 062
.0868[/FONT]
NOTE: The 40% figure used here will assure a rich enough mixture to prevent burning the valves due to an over-lean mixture.
After testing the car, you may find the jets are too large and the mixture is very rich. If this is the case, install new jets enlarged 35% or even smaller as your car requires. Just decrease the size in increments of 5% over stock size to be safe.
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 6-3 - A standard machinist's drill chart.[/FONT]
Next I looked up .0860 in a standard drill size chart. This chart can be found in most auto repair manuals or machinists handbooks. The closest drill size is a #44 which is .0860.
Once you have determined the proper drill size, use it to carefully enlarge each jet. A drill press is best for this job, but a hand drill can be used if caution is exercised. Do not attempt to drill the jets without removing them from the carburetor. The shavings will fall into tiny passages and create problems.
You may be able to avoid drilling. Auto parts dealers stock jets in various sizes for many types of carburetors.
They are inexpensive and if you can find one in the proper size, it will save time and labor.
I opted for the drilling method.
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 6-4 - This is a typical set up to drill the jets on a small drill press. The "V" block hold the jet parallel with the drill bit.[/FONT]
[/FONT] [FONT=Times New Roman,Georgia,Times]The Float -- Two Possible Alterations[/FONT]
[FONT=Times New Roman,Georgia,Times]Alcohol is heavier and more dense than gasoline. The float will ride higher in a given amount of alcohol than in the same amount of gasoline. Since fuel flow is cut off when the float rises to a specific point, the alcohol level will be lower than if the float bowl were filled with gasoline. Some method must be used to raise the fuel level to normal. Otherwise, the engine will cut out during turns due to lack of sufficient fuel.[/FONT] [FONT=Times New Roman,Georgia,Times]Bending The Float Linkage[/FONT]
[FONT=Times New Roman,Georgia,Times]One way is to simply bend the linkage between the float and the inlet valve.
The exact amount to bend the linkage is subject to trial and error. Several settings may be required to find the correct float height.[/FONT] [FONT=Times New Roman,Georgia,Times]Adding Weight To The Float[/FONT]
[FONT=Times New Roman,Georgia,Times]A difficult but more accurate method is to add weight to the float. Carefully weigh the whole float assembly on a balance (a powder scale will do an excellent job). Weigh a piece of solder or epoxy glue equal to 10% of the total weight of the float assembly. Fasten this to the top of the float, distributing the weight as evenly as possible.
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 6-5 - A powder scale is just the thing for weighing the float. My float weighed 253 grains.[/FONT]
I tried both methods. The bending method was tedious and involved disassemble of the carburetor several times before the correct setting was found. Also, some float bowls don't have enough clearance above the float to allow it to be bent enough to do any good.
The weight method worked just fine. It is preferable because you can set the float just as the instructions in the overhaul kit call for.
Reassemble the carburetor. Follow the kit guidelines for reassembly and adjustment.
Got any leftover parts? Hopefully, your answer will be no! Now replace the carburetor on the engine and connect everything back up.[/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 7
Altering the Ignition System[/FONT]
[FONT=Times New Roman,Georgia,Times]Once the fuel system mixes the proper ration of air to fuel and delivers the mixture to the individual cylinders, its function is completer.
The actual firing and production of usable power is controlled by the ignition system. Its task is to ignites the fuel/air mixture at a precise instant in relation to the movement of the piston. If the mixture fires too early, pre-ignition pinging will occur and may damage the engine. If the mixture ignites too late, power will be lost and fuel wasted.
A gasoline engine is timed to fire just as the piston reaches the top of it's stroke or just an instant before. Gasoline ignites and burns so rapidly that the result is more like an explosion than a burning.
Alcohol burns at a much more even rate. It is harder to ignite and requires more time to completely vaporize and burn. To allow for this extra time, it is necessary to "advance" (cause to fire earlier) the timing of the engine. This is done by loosening the distributor and turning it in the opposite direction from the direction the rotor in it turns.
If you aren't sure which way the rotor in your engine turns, take the distributor cap off and have an assistant crank the engine. Whichever way the rotor turns, you must turn the distributor body the opposite way to advance the timing.
A timing light will make this job a snap, if you have access to one. The engine can be timed by ear, if you develop the knack for it.
Here's how to do it:[/FONT]
[FONT=Times New Roman,Georgia,Times]Loosen the bolt at the base of the distributor until the whole unit can be turned.[/FONT]
[FONT=Times New Roman,Georgia,Times]Initially advance the timing by turning the distributor about 1/16 of a turn. Snug the hold-down bolt so the distributor won't turn itself (but you can still move it with a little effort).[/FONT]
[FONT=Times New Roman,Georgia,Times]Start the engine and run any gasoline remaining out of the fuel line. Now advance it still more until you get a faster idle, but still a smooth idle.[/FONT]
[FONT=Times New Roman,Georgia,Times]Check the timing by driving. If you hear "pinging" in the engine during acceleration, the timing must be "retarded". The correct setting will be just below the point where the pinging disappears.[/FONT]
[FONT=Times New Roman,Georgia,Times]I initially time the Dart by ear and made several changes in timing before I was completely satisfied. After several days of driving, I checked the timing with a light. The original setting had been 0º TDC (top dead center). After converting it to alcohol, the optimum setting had become 24º BTDC (before top dead center).
Your car may not require exactly 24º of advancement. This is a ballpark figure. The exact amount will depend on your particular engine.[/FONT] [FONT=Times New Roman,Georgia,Times]Spark Plugs Can Make a Difference[/FONT]
[FONT=Times New Roman,Georgia,Times]Let's discuss spark plugs briefly. As you may already know, each type of spark plug is made in three or four heat ranges. The only difference between two plugs of the same type but different heat ranges is the rate at which they dissipate heat. The plug with the higher number will hold heat longer and is referred to as a hotter plug.
[FONT=Arial,Helvetica,Geneva,Swiss,SunSans-Regular]Figure 7-1 - Spark plug heat range system. The lower number denotes a colder plug.[/FONT]
Alcohol fuels, as I mentioned before, don't ignite as easily or burn as quickly as gasoline. To increase the temperature in the firing chamber, it may be desirable to use a plug that is one or even two ranges hotter than your engine has been using.
The Dart originally had Champion N-14-y spark plugs. After conversion, the engine was prone to miss due to poor vaporization of the fuel. More heat was needed to turn the alcohol into a combustible gas.
After installing a hotter set of N-16-y plugs (I had to go up two heat ranges), I could tell a definite difference. The increased heat was getting more fuel to completely vaporize and cutting the time it took for the engine to warm up.
Be careful not to go to extremes and install a plug that is too hot. The telltale sign will be a white or blistered-appearing electrode. Check your plugs often for the first few miles until you are certain they are correct.[/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 8
Firing Up the Engine[/FONT]
[FONT=Times New Roman,Georgia,Times]At this point point, you should be ready to start up. The carburetor is modified and back in position. Timing should be advance to the first tentative setting. Any necessary fuel line changes have been completed.
Prime the carburetor with a few drops of gasoline, fill the alcohol tank and crank the engine. You may have to "feather" the gas pedal to keep it running once the alcohol begins to reach the engine. (The idle mixture is still set for gasoline at this point.)
Let the engine warm up before you set the idle. Then slowly back the idle adjusting screws out 1/4th turn at a time until a smooth idle is obtained. If there are two idle screws, move both the same amount each time.
Get in the car and test drive it. Notice any symptoms which seem irregular. The chart I have provided lists some symptoms I have encountered the possible causes and alterations.
[FONT=Times New Roman,Georgia,Times]Symptom[/FONT] [FONT=Times New Roman,Georgia,Times]Possible Cause[/FONT] [FONT=Times New Roman,Georgia,Times]Alteration[/FONT] [FONT=Times New Roman,Georgia,Times]Engine cuts out under acceleration[/FONT] [FONT=Times New Roman,Georgia,Times]1. Low float level
2. Accelerator pump not at a full stroke[/FONT] [FONT=Times New Roman,Georgia,Times]1. Raise float or add more weight
2. Adjust accelerator pump for a longer stroke[/FONT] [FONT=Times New Roman,Georgia,Times]Engine dies when turning a corner[/FONT] [FONT=Times New Roman,Georgia,Times]Low float level[/FONT] [FONT=Times New Roman,Georgia,Times]Raise float or add more weight[/FONT] [FONT=Times New Roman,Georgia,Times]Pinging under hard acceleration[/FONT] [FONT=Times New Roman,Georgia,Times]Timing set too advanced[/FONT] [FONT=Times New Roman,Georgia,Times]Retard timing until symptoms stop[/FONT] [FONT=Times New Roman,Georgia,Times]Engine dies at idle[/FONT] [FONT=Times New Roman,Georgia,Times]1. Carburetor improperly adjusted
2. Spark plugs incorrect heat range: if wet - too cold, if white - too hot[/FONT] [FONT=Times New Roman,Georgia,Times]1. Adjust as advised in alcohol kit and this text
2. Change plugs to proper heat range[/FONT] [FONT=Times New Roman,Georgia,Times]Engine will not start when cold[/FONT] [FONT=Times New Roman,Georgia,Times]Poor fuel vaporization qualities[/FONT] [FONT=Times New Roman,Georgia,Times]1. Read the next chapter for solution
2. Proof of alcohol may be too low. Use 160-proof or better.[/FONT] [/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 9
Cold Weather Starting Problems[/FONT]
[FONT=Times New Roman,Georgia,Times]How To Cure Them[/FONT]
[FONT=Times New Roman,Georgia,Times]Alcohol does not readily vaporize below about 70º F. Unless you live in a tropical climate, some provision will have to be made for starting the engine in cold weather.[/FONT] [FONT=Times New Roman,Georgia,Times]Starting the Engine on Gasoline[/FONT]
[FONT=Times New Roman,Georgia,Times]If you installed the "T" valve type fuel system, you can start the car on gasoline. I used this system on the Dart and had no significant starting problems. Each time I parked the car for an extended period, I would switch the "T" valve to gasoline just a minute or so before shutting the engine off. The gasoline burned very rich, but would burn. In the morning, I would start the car and switch back to alcohol in a minute or so. A gallon of gas would last a week or so with this type or starting method. (Mind you I said a gallon of gas - not a tank.)
In practical use, the smaller tank could be one gallon or less in size and alcohol could go directly into the regular tank. Alcohol will clean any old gunk out of the regular tank. You may have to change the fuel filter several times until the tank had been cleaned by the alcohol.[/FONT] [FONT=Times New Roman,Georgia,Times]Using Gasoline as a Primer[/FONT]
[FONT=Times New Roman,Georgia,Times]Gasoline is also used in another method. This method involves installing a surplus windshield washer pump and reservoir. The pump has a hose leading to a tube or spray nozzle brazed into the air cleaner lid. The reservoir is then filled with gasoline.
A few squirts of gasoline will fire up the cold engine. Once the engine has generated a little heat, it will run well on alcohol.[/FONT] [FONT=Times New Roman,Georgia,Times]Preheating the Alcohol[/FONT]
[FONT=Times New Roman,Georgia,Times]Several solutions involving preheating of the fuel have been found. Most involve applying an external source of heat to the carburetor or the fuel line. Any method of raising the fuel temperature above 70º F will be most helpful.
Your ingenuity can get a workout in this area. Don't be afraid to experiment with any ideas you may have which will hold in engine heat and ease starting.[/FONT] [FONT=Times New Roman,Georgia,Times]Manual Choke[/FONT]
[FONT=Times New Roman,Georgia,Times]Another aid which I found helpful is the good old-fashioned hand choke. These are available at auto parts stores and will replace your automatic choke. The hand choke will allow "pampering" of a "finicky" cold engine. It will also allow you to open the choke wide to take advantage of the window-washer method of priming.
[/FONT] [FONT=Times New Roman,Georgia,Times]Chapter 10
Vital Statistics[/FONT]
[FONT=Times New Roman,Georgia,Times]Materials and Cost of Dart Conversion[/FONT] [FONT=Times New Roman,Georgia,Times]Used Carburetor[/FONT]
[FONT=Times New Roman,Georgia,Times]$10.00[/FONT]
[FONT=Times New Roman,Georgia,Times]Manual Choke Kit[/FONT]
[FONT=Times New Roman,Georgia,Times]2.49[/FONT]
[FONT=Times New Roman,Georgia,Times]Eight (8) Feet of Fuel Hose[/FONT]
[FONT=Times New Roman,Georgia,Times]4.80[/FONT]
[FONT=Times New Roman,Georgia,Times]"T" Valve (free)[/FONT]
[FONT=Times New Roman,Georgia,Times]xx[/FONT]
[FONT=Times New Roman,Georgia,Times]Five (5) Gallon Tank (free)[/FONT]
[FONT=Times New Roman,Georgia,Times]xx[/FONT]
[FONT=Times New Roman,Georgia,Times]Three (3) Barb Fittings for Fuel Hose[/FONT]
[FONT=Times New Roman,Georgia,Times]1.26[/FONT]
[FONT=Times New Roman,Georgia,Times]Eight (8) N-16-y Champion Spark Plugs[/FONT]
[FONT=Times New Roman,Georgia,Times]8.80[/FONT]
[FONT=Times New Roman,Georgia,Times]One (1) Roll Teflon Tape (for fittings)[/FONT]
[FONT=Times New Roman,Georgia,Times].69[/FONT]
[FONT=Times New Roman,Georgia,Times]Overhaul Kit for Carburetor[/FONT]
[FONT=Times New Roman,Georgia,Times]7.00[/FONT]
[FONT=Times New Roman,Georgia,Times]Total Parts Cost[/FONT]
[FONT=Times New Roman,Georgia,Times]$35.04[/FONT]
[FONT=Times New Roman,Georgia,Times]Ky. 5% Sales Tax[/FONT]
[FONT=Times New Roman,Georgia,Times]1.75[/FONT]
[FONT=Times New Roman,Georgia,Times]Labor Supplied by Writer[/FONT]
[FONT=Times New Roman,Georgia,Times]xxxx[/FONT]
[FONT=Times New Roman,Georgia,Times]Grand Total[/FONT]
[FONT=Times New Roman,Georgia,Times]$36.79[/FONT]
[FONT=Times New Roman,Georgia,Times]
[FONT=Times New Roman,Georgia,Times]Automobile tested[/FONT]
[FONT=Times New Roman,Georgia,Times] 1969 Dodge Dart[/FONT]
[FONT=Times New Roman,Georgia,Times]Mileage at time of conversion[/FONT]
[FONT=Times New Roman,Georgia,Times] 79950 Miles[/FONT]
[FONT=Times New Roman,Georgia,Times]Engine type[/FONT]
[FONT=Times New Roman,Georgia,Times] 318 C.I.D. V-8[/FONT]
[FONT=Times New Roman,Georgia,Times]Carburetor type[/FONT]
[FONT=Times New Roman,Georgia,Times] Carter Model BBD 2BBL[/FONT]
[FONT=Times New Roman,Georgia,Times]Fuels tested[/FONT]
[FONT=Times New Roman,Georgia,Times] Ethyl alcohol AMC 150 /200 proof[/FONT]
[FONT=Times New Roman,Georgia,Times]Best proof (Determined by test)[/FONT]
[FONT=Times New Roman,Georgia,Times] 180 proof[/FONT]
[FONT=Times New Roman,Georgia,Times]Miles per gallon - 180 proof[/FONT]
[FONT=Times New Roman,Georgia,Times]11 miles[/FONT]
[FONT=Times New Roman,Georgia,Times]Miles per gallon - Gasoline[/FONT]
[FONT=Times New Roman,Georgia,Times] 13.5 miles[/FONT]
[FONT=Times New Roman,Georgia,Times]Price per gallon - 200 proof[/FONT]
[FONT=Times New Roman,Georgia,Times] $2.25[/FONT]
[FONT=Times New Roman,Georgia,Times]Price per gallon - 180 proof (diluted)[/FONT]
[FONT=Times New Roman,Georgia,Times] $2.07[/FONT]
[FONT=Times New Roman,Georgia,Times]Percentage of fuel cost for imported oil[/FONT]
[FONT=Times New Roman,Georgia,Times]0%[/FONT]
[FONT=Times New Roman,Georgia,Times]Writer's Satisfaction[/FONT]
