Is Alcohol fuel in your Future?
I got interested in alcohol fuel in 1979 when OPEC went bananas. At the time myself and Wayne, a friend who was a stockcar builder and driver were hot line answer-men for Worldparts corp. We wanted to do something to help so our first thought was to declare war on all the OPEC nations. After about 15 seconds of deliberations and inventorying our arsenal of a couple of hand guns and one shotgun and checking our bank accounts which together we could probably scratch up enough loot to buy a rowboat with a one horse outboard, we scratched that idea.
What we believed we could do is design an engine that would be more fuel efficient. To do this we first looked at what was basically wrong with the piston engine used today from it's basic concept to each component. We worked on paper for about a year until we finally arrived at what we felt would out perform any known engine to that date. The final design had a few drawbacks though. Our engine would only run at full throttle and as best as we could figure would be running on about 40% alcohol. Not a mixture, it would need to be injected separate from the 60% gasoline. Being around racing we knew a little about alcohol as a fuel and as an ego enhancer. However, what we knew was not sufficient for what we were doing with it. So, I agreed to study the subject and purchased several books on the subject. We traveled a lot for Worldparts conducting technical seminars for mechanics in almost every state in the US. I found that I could concentrate on the books while on airliners. This achieved two things, one, I learned a little about alcohol and two, it kept my mind off of "I wonder what would happen to me if a wing fell off this thing at 35,000 feet and at 600+ knots." As usual, we, in the US, have everything bass akwords. Instead of drinking our alcohol and burning OPEC's oil, we should be burning our alcohol and tell OPEC to drink their oil.
It so happened that we were not the only ones thinking about alcohol as a fuel. Al Gore conducted a seminar on alcohol at MTSU, so I attended. They had an array of speakers on different aspects of alcohol. They were concentrating on efficient methods of producing alcohol on farms and covered several different methods to do this. Al said if we had any suggestions, to fill out one of their forms and submit it. Two of the methods to produce alcohol had serious faults but I noticed that each had the cure for the other which I had learned on all those airliners along with other facts, like: airline food is not as bad as all the jokes make out and that airline stewardesses work their butts off and take a lot of crap off of a lot of jerks.
I pretty much forgot about the suggestion I had sent in when at work about 3 months later, someone from the Nashville newspaper called me and asked if they could interview me. My first thoughts were; "This job is interesting but I don't think it warranted a newspaper article." and "Why didn't they call my boss? Bosses eat that kind of stuff up."
I then asked the obvious question. "Why do you want to interview me?" The response was; "It's about your grant." "My what?" "Your grant" "What grant?, I don't have any grant!" Now, my thoughts were; "Hmmm! I didn't know newspaper people were allowed to sip suds in the middle of a work day." or "This idiot was suppose to call our CEO about some grant Worldparts got for doing something " They then said; "You are Mr. Fitzcharles? You have a grant from the US Dept. of Energy."
The DOE had sent out a press release before notifying me that they liked my idea about the alcohol still and had gave me a grant to construct a prototype of it. My first thoughts were: "Cool" then my second thought was: "Good grief, what have I got into now?". I was told that the committee that picked the grants got into a heated discussion over my submission. It seems it was over whether to allocate money for the batching tank since my design only was unique for the distillation process. The winning argument was that you can't distill if you didn't batch first.
My plan was to build the still and modify a car engine to run on straight alcohol that I made with my distillation process. The car I used was a Triumph TR-7. It took me a year and a half to complete the project and the still worked even better than I had hoped. Although the first run produced something that looked and smelled like dirty dishwater and had about the same alcohol content too. I remember thinking; "Hmmmm! I just spent $8 K of the governments money to make dirty dishwater." I called an engineer at Jack Danials distillery and explained my problem. Luckily he was able to determine what I had done wrong and told me how to correct it. The next attempt netted me 143 proof alcohol. One more run a month later netted me a reasonable amount of 160 proof alcohol. At this point I had the TR-7 ready and wanted to try it. However, my target was 170 proof for the car so I added enough store bought alcohol to bring the proof up to 170. The following are the details of the work on the car.
The TR-7 was a 76 coupe that I had purchased disabled with a cylinder head problem. (didn't they all?) Being factory trained on the "7" I knew how to correct the problem and since it was an extra car, I could afford to use it for the modification project.
The first thing to work on was the compatibility of the fuel system to Ethanol Alcohol. No information highway to look that kind of info up so I talked to every drag racer using alcohol fuel that I could find. They mainly use Methanol but I still picked up a few points that were useful. I wrote to and called a bunch of companies that handled alcohol resistant auto fuel components and got absolutely no help. They either really didn't know anything or felt that they had some top secret info that they were wanting to keep for themselves. I finally resorted to pickling fuel system parts in jars of alcohol and dating them to watch for effects. This would not tell me of long term effects but it would give me a warning of rapid effects. I did know from reading that GM and VW changed the coating of the inside of their fuel tanks in Brazil for alcohol use. I had no way to do that so I removed the "7" tank and added a drain plug so I could drain the alcohol out and when not in use for a long time. The only thing I found that was effected was a two piece MG float. It didn't effect the plastic float but did melt the glue used to put the two pieces together. It also effected the float chamber itself of the Stromberg carbs. Some carbs on cars are made of mainly aluminum alloy and anodizing is said to help, but the Strombergs were probably mainly zinc and an attempt to anodize them failed. So I just removed the floatchambers every few weeks to clean them out of a jelly like substance unknown. I had planned to try different coatings on the inside at a later date.
Alcohol has less BTUs than gasoline so if you just put alcohol in a gasoline engine you will loose power and fuel economy right away. However, when you raise the compression ratio of an engine, you increase the volumetric efficiency of that engine. This continues as you raise it higher. Gasoline can only stand so much pressure when it detonates. This destroys the power and the engine itself. Alcohol on the otherhand can be pressurized much higher without detonating. Thus you can regain and surpass the possible power achieved with gasoline. Fuel economy comes up a little but will not catch gasoline. On this engine I had decked the block, surfaced the head and installed balanced 12.5 to 1 forged pistons and a heavier flywheel. The pistons struck the head so it was necessary to relieve the head in spots to make clearance. It would have been better to cut the tops of the pistons but they were balanced and I didn't want to take them back out to do that. I did not have a beret to measure the chamber volume to get a accurate compression ratio at that time. The compression was so high that the battery did not have enough umph to turn it over, so a second battery was put in parallel. this did the job. A deep charge or diesel battery probably would have corrected it also.
Alcohol has a very high latenheat of vaporization. Meaning that it requires a lot of heat to turn the liquid alcohol to a vapor so it can ignite. The high need of BTUs to turn the liquid to a vapor draws the heat from the area around and what ever is in contact with the liquid, this explains the cooling effect of vaporizing alcohol. This made cold starting impossible. There just was not sufficient heat in the manifold and air to vaporize the alcohol. I first installed a switching valve in the fuel line, another fuel pump and a small tank to hold a gallon of gasoline. This way I could start the engine on gas and switch over to alcohol after starting. Even with high-test gas with an octane booster in it, the detonation was severe. so I scrapped that as a starting method. I first ran some tests on starting. I ran the engine to operating temp. and shut down and waited 1 hr and it restarted on alcohol. then shut down and waited 2 hr and it restarted. I continued this until I was able to let it set for 4 hr on a 69 to 70 degree day and it would start on straight alcohol. I could just barely feel any heat in the head at that point. This told me it wouldn't take much so I made two insulators with tungsten wire laced across the bottom half and installed them between the carbs and the manifold. I connected them to a relay so I could control them from inside the car. The length and size of wire would get hot enough to smoke oil on the wire but not get red. This worked and I found that even on a cool morning it would start right away with the heat applied and as soon as it started I could turn the heater off.
Any time you modify an engine, it needs a different ignition timing. Alcohol burns slower than gasoline so you would expect to run a more advanced timing except that higher compression speeds up flame speed so a more retarded timing would be needed. I tried different settings to note performance without using a timing light and found where it performed the best was the exact timing used by the stock engine on gasoline. Performance was noticeably better than gasoline but fuel mileage was as expected down a little. At first glance you might think that this is a downfall for alcohol as a competitor for gasoline but not when you take another factor into account. I am running on 170 proof ethanol which is 15% water and I was not down 15% on fuel usage. The jet size does need to be larger due to less BTUs in alcohol which would indicate that I was further down than that but again a factor was not considered. The viscosity of 170 proof ethanol was higher than gasoline thus it required a larger jet to get the same volume of alcohol/water through.
Jetting for alcohol
I read two books that addressed the issue of jetting a gas engine to run on alcohol. One said that the jet must be 120% larger than one for gasoline, while the other said it was about 96% larger. This was a Volume %, not diameter %. The few people I talked to about this could not say because they built their engines to run on alcohol from scratch and had no idea what that engine would have taken if it could even run on gasoline. So, that left it to me to find out. Stromberg carbs are a constant velocity carb, using a metering needle to adjust the mixture through the RPM range. The taper of the needle determines the mixture at each RPM. This means the opening around the needle is the jet opening. The first step is to map the original gasoline jet opening. To do this I had to measure and figure the square inch area of the stock jet then mark and measure and figure the square inch area of the needle at each 1/16 of an inch of it's travel from the Idle position to it's full throttle position. then subtract that figure from the volume area of the jet itself. That gave me a map of square inch area of jet opening for gasoline on this engine.
The next step was to confirm which was correct, the 96% or the 120%. So, I dug through all my needles and found an SU needle that was too rich at idle position even if the 120% was correct and too lean at full throttle if it were the 96% that was correct. I made a ball for the end of the needle so the SU needle would fit in the stromberg carbs and installed them. Just running the engine without even driving it indicated that it was extremely rich at idle and lean at full throttle. Road testing the car confirmed this and I noted that at about 4500 RPM the engine was best. This was also true with no load so I measured the amount of carb piston lift at the 4500 RPM range. Then marked the needle and measured it and looked at my previous figures and found that around that point on the needle it figured out at about 96%. This confirmed the 96% figure should be used.
Now I must add 96% of volume to each of the gasoline figures and it gave me a rough map of the volume of jet opening for alcohol. Then I had to figure again to arrive at the diameter of the needle at each 1/16 in point down the needle length. One person said that all I had to do was increase the hole in the jet, but that only effects one spot in the range and makes all the others completely wrong. We are working with % of square inch open area not diameter. It sure would have been easier if it were diameter. The end result was a theory based needle that was so narrow that I could not make it. The next step was to increase the jet diameter and refigure. A .003 in. increase in jet diameter allowed me to make a set of needles. FYI it takes 8 hours to make one needle and I made 3. Why 3? I broke the second one at the 7th hour.
With my homemade needles installed, the car idled well, pulled very strong and clean and felt good at high RPM. This did not mean I was finished. The range of Rich to Lean that a gas engine will run well is a narrow band. However, that band of range that an alcohol engine will run well is much wider so how it feels and performs is not very exact as to correct mixture. There are several methods to get it closer to correct but this is at least in the ball park and I planned to trim it closer at a later date.
The Possibility of Valve Seat Recession
One of the very few useful attributes of lead in gas was that it helped stop valve seat recession. When lead was removed, valve seat ware was noted so most fuel producers put other additives in to slow this ware down and car manufactures started using much harder seats. From my reading I found a report where this was addressed for alcohol. Straight (200 proof) alcohol showed valve seat recession but 160 Proof did not. At first this puzzled the engineers doing the tests. Since water was the only difference and water is not a lubricant for metal to metal. They did arrive at a conclusion though. They believe that the incoming fuel/air charge would wet the valve seat and face which turned to steam which was trapped between the valve and the seat just as the valve hit the seat. which acted as a cushion to ease the valve into position. This satisfied me as far as the intake valve goes but I didn't think it would help on an exhaust valve. I decided to experiment with upper cylinder lubes added to the fuel. I tried to use several different types of upper cylinder lubes but found they would not mix with alcohol so I tried caster oil and that worked. Besides, from my years of racing motorcycles I always loved the smell of castor oil from an exhaust. Model airplane fliers are addicted to this smell too.
Combustion chamber temperatures are normally lower for alcohol than for gasoline so I did nothing to the cooling system. Temperature gauge indicated that everything was OK. But, the overflow bottle soon filled and overflowed. I checked the temp gauge with a known good one and even noted that the engine did not feel like it was to hot. A low pressure test of each combustion chamber showed no head gasket leakage. However, a cold engine started with the cooling system full netted a continuos overflow. Too quick for coolant expansion. I needed an exhaust analyzer to check for CO in the coolant but the only one I had access to was 30 miles away so I decided to run the cylinder pressure test again with a much higher pressure. There it was, # 4 cylinder was blowing into a water jacket. Removal of the head indicated no problem in the head surface, the block surface nor the gasket. At the rear of the # 4 cylinder head chamber is a 2 inch opening for coolant to transfer from block to head. this 2 in. opening has no support for the head chamber and with the high chamber pressures achieved from the high compression ratio and the alcohol would lift the edge of the combustion chamber up to allow pressure to escape into the water jacket. This problem can be corrected with a small reinforcement bridge installed in the middle of the 2 in. span.
It took me a year and a half to complete the project and even though the still was a success, oil prices came down and no one was interested in alcohol as a fuel. Within a couple of years after the OPEC price gouge, the US was 4 times as dependent on foreign oil as we were in 79. The sad thing is that if you turned all of the farm land in the US into producing grain to turn into alcohol you still could not come close the the fuel consumption we were at by the mid 80s and it is far worse today. And, even worse yet, there is no clear plan by corporate America or the politicians nor the people as to what to do WHEN NOT IF we run out of oil in the world.
Well, maybe it will do us all good to get back on bicycles and on horses.