Pulsejet drawings

[dynajetjerry]

Hi, Gang,

Don Laird has made many excellent drawings of pulsejet engines and has told me he will send them to any who request them. He has done this in the past.

He has never asked for funds to defray his expenses but it would be fitting for those interested to enclose a few bucks. His portfolio includes most U. S. pulsejets (including the MEWs,)and the O. S. IIG.

With his approval, I offer his address and phone number:

Donald D. Laird
4706 Diane Drive
Ashtabula, OH 44004-4636
(440) 998-1371

Jerry

[Bruno Ogorelec]

Jerry, I would be strongly interested in anything on the Turbocraft P-82 engine. Do you know if Don has anything? I don't want to bother him if he doesn't.

In fact I am interested in any valveless Turbocraft model except for U-22.

Thanks!

[dynajetjerry]

Bruno,
Don has several Turbocraft drawings but I don't know which is which. Exactly what is the P-82? I don't think Don would be concerned about a phone call (he has no access to a computer,) but your costs for one might be excessive. I can contact him with your questions, if you wish.
Jerry

[Bruno Ogorelec]

Jerry, this is the one I am talking about. It has two chambers, one of which is the engine and the other is the fuel tank. (It used propane for fuel.)

The manufacturer claimed it to be self-starting -- "just connect the 1 1/2 Volt to the glow plug and turn it on" said the Turbocraft catalog entry. No bicycle pumps or shop air. It was said to work so well that remote-control in-flight restarting was possible with a servo actuator opening the fuel valve (!).

Once the engine caught, you disconnected the plug.

Also claimed was "full throttle control from 3 to 6 pounds of thrust" from the engine that (without the gas tank) looks smaller than the Dynajet.

For top performance, you apparently used acetylene, but I have no idea how they managed the fueling on that one. I sure hope to God they did not cram acetylene in that tank! I wouldn't want to be closer than a hundred yards from that thing if they did.

If I had a reasonably accurate drawing, I might try to have a replica built.

[dynajetjerry]

Bruno,

There were several "pulsejets" from Turbocraft that looked like your pictured P-82. I have one of them and Don (I think,) may have made a drawing. If so, he used information that I supplied, as with most others he drew.

The P-82 appears to be a pressure jet though it may pulseate during operation. Both propane and acetylene are self-pressurizing, a necessity in this application. My P-82 employs 6 fuel nozzles in the discharge end of the fuel tank, that are aligned with but forward of 6 ports in the front of the combustion chamber; there is a gap between the two to permit entry of the air. The flow of gaseous fuel into the ports induces a much larger flow of air, mixing as they enter the comb. chamber where they burn. My version lacks the flared exhaust outlet.

I've not tried to get mine to operate because the "throttling" needle valve is not sealed well enough to be safe.

A word of caution concerning Turbocraft products: I know of no one who has successfully operated any of their 6 or 8 jet products; further, as noted in Tim Dannels' engine books, NONE of those engines have thrusts that have been independently confirmed by anyone who has tested them.

Jerry

[Bruno Ogorelec]

A word of caution concerning Turbocraft products: I know of no one who has successfully operated any of their 6 or 8 jet products; further, as noted in Tim Dannels' engine books, NONE of those engines have thrusts that have been independently confirmed by anyone who has tested them.

Thanks, Jerry. A sad but familiar story. There is something about pulsejets that attracts gullible buyers and unscrupulous sellers. In that respect, the field is sometimes awfully close to the penis extension pill market.

Too bad. The thing looked beautiful on the photos. But, so did the U-22, possibly the most complex paperweight ever.

[dynajetjerry]

Bruno,
Unfortunately, you are correct in describing the predators who constantly try to get money for questionable products. However, John Swartzwelder must have know the man who came up with the Turbocraft line (I can't recall his name but Tim has it,) because he often commented on the man's brilliance (nothing about his morals.)
I should add to my statements on the P-82: Propane would be the fuel of choice because it is a liquid at room temp. and a pressure of 150 psi+. As a result, a given tank of propane would fuel an engine for far longer than acetylene in the same system. The latter is a gas at all reasonable pressures meaning a tank would hold vastly fewer ounces of that gas than one such as propane. In the real world, an acetylene tank usually contains foamed material that has been soaked in acetone. The latter dissolves the acetylene and permits the holding of more of it than otherwise. That system is also much less dangerous than pure gas because, among other reasons, the gas can boil off at no more than a limited rate and the pressure is not excessively high. Of course, acetylene also contains vastly more BTUs in each ounce than propane.
Jerry