carbide engines

Hi: I am interested in finding out more about carbide gas generators and engines that run off of the resulting acetylene. It seems that acetylene will spontaneously combust above 15 psi, which seems to suggest that no ignition system is necessary. A Gustave Whitehead built lightweight engines to power his early flying machines (planes) about 1901. I am researching the plane with the intent to build an r/c model for the 100th anniversary later this year. I do not intend to pursue modeling his engines (a 10 hp, 22lb - 3 7/16 X 8 in stroke ground engine and a 20 hp, 35 lb - 2 1/4 and 3 7/16 X 7 in stroke, compound, flight engine) I just want to understand how they worked and if they could really produce the claimed power at such a light weight and low (1000-2500 rpm) speed. It could be that the engines themselves were light enough, but that the carbide gas generator (required) was heavy and should be included in the total weight. My model will be electric powered for simplicity and convenience. Would you know of any old engine collectors that are familiar with carbide gas fueled versions?

Thanks for any help, Mark Denney 4368 King Valley Dr. Smyrna, GA 30082

I took a class years ago that told me why they restrict acetelene gas pressure in welding hoses to no more than 15 pounds per square inch. I always abide by that, but have forgotten the exact reason why. The acetelene stored in the tank also has acetone with it, and that the tank pressure is several hundred (500?) pounds so maybe there must be some other explanation other than self ignition.

The carbide acetelene gas generators are a messy thing to have to service. The gunk remaining in the bottom of the tank has to be cleaned out periodicaly.

Getting back to the aircraft engines, I never heard about these acetelene engines before. Do you have any library references that I could research as that sounds like an interesting little detail of aviation history?

Acetylene is not a good fuel for gas engines because the fuel and air mixture will spontaniously ignite at low compression pressures. I ran an engine on acetylene with 4:1 compression and there was an obvious pre-ignition knock. Also the exhaust was very smokey with carbon.

The original source is Stella Randolph's book "Lost Flights of Gustave Whitehead", but I have been unable to find one I could afford. Her later book "Before the Wrights Flew" is good and readily available at some of the online book brokers, I think mine was less than $30 including shipping. There are magazine articles (Scientific American, June 8, 1901 plus others) excerpts from which many are available at http://www.deepsky.com/~firstflight/ and http://www.weisskopf.de/index.html. It IS a facinating story, almost unbelievable that it could be so widely unknown, and involves a "conspiracy" between the Smithsonian musuem and the Wrights family in which the museum would lose the Wright flyer if they admitted that anyone else "could" have flown before the Wrights. The museum evidently was afraid enough of this threat that possible investigations of Gustave Whitehead were shelved. As a result, a great deal of valuable historical data about Whitehead were lost during WWII because his family was destitute after his death and unable to store his notes, models and engines most of which were sent to the dump. At the very least, a good read.

Thanks, Mark Denney 4368 King Valley Dr. Smyrna, GA 30082 770 436-4396


http://www.deepsky.com/~firstflight/

The Wright Brothers were pretty good at protecting their patents and their version of aviation history. They were involved in many lawsuits over their patents, particularly with Glen Curtis over his ailerons versus the Wright's wing warping, both accomplishing the same effect by slightly different methods. Maybe aviation designers will get back to a modified wing warping method someday as a better way for controling ultra high speed aircraft about the roll axis without having movable parts out flapping in the airstream.

I suspect that the carbide fueled engine would be basically the same as any other gas fueled engine such as ones using propane. I wonder what the octane rating of acetelene gas might be?

When they designed the first uranium atomic bomb, they used a modified howitzer to fire half the critical mass into the other half to make the bomb explode. The problem was the weight of the gun barrel. The whole thing was going to be too heavy for the aircraft to carry. Someone then suggested that the gun didn't have to function more than once, so they machined off most of the metal around the breech and barrel to make it much lighter. All the excess metal was originally required to make the weapon durable and capable of being fired many times in the field without blowing the gun up, or wearing it out.

I wonder if some of these early aircraft engines were constructed very lightly with a limited expected life time. The early goal was to make the aircraft fly a few times for a little while, rather than to expect them to be placed into regular airline service at first. The engine speeds you mentioned were not all that common in those early days and so with higher rpm's and lighter weight, maybe flight was going to be possible, but at a reliability price.

Thank you for the information.

That sort of sounds like the fuel air mixture was exploding rather than burning. The question becomes, if you could tolerate the knocking, would such an engine be self igniting like a diesel, or would you have to get it hot first running with the spark ignition before it would run by itself?

I think I'm gonna have to disagree with this idea. Acetelene is one of the fuels military multifuel engines are capable of burning. That engine is definitely more akin to a Diesel than it is to a gas engine, but it will run on Gas, diesel, acetelene, and propane if I recall correctly.