No. 66 in a series compiled by David R. Janson,
SAM #273, AMA #78416 and MECA #210-04.


WEBSTER: "THOR..Norse God of Thunder." In the annals of naming model airplane engines America's Hobby Center in New York City, pulled one of the goofs of all time. Their "Mighty Thor" 29 cid model engine was anything but mighty and had no resemblence to thunder. And as many a wiseacre said, I got mighty thor in trying to get it started. It was (along with the GHQ) one of the most famous slag (cheap) engines of modelenginedom. Heavily advertised, low priced, and really puny looking, thousands were sold and after a short time tossed into the junk bin. Yes, they did run occasionally, but they didn't last very long. Classified as AMA Class B, they sold for $9.95, complete with coil and condenser and at $6.95 as a fully machined, five minutes to assemble kit. The cylinder and head were cast aluminum as were the piston and lower crcnkcase with a machined steel crankshaft. Shallow head and cylinder fins (cast) did not allow needed cooling.

The engine cylinder did not have a liner and the piston ran in the aluminum cylinder. A cast in exhaust and intake on the back of the cylinder, along with beam mounts and detents for screwing upper and lower case parts together completed the unit. The needle valve extended down through the back intake into a stamped aluminum gas tank. The timer unit consisted of the sweeping action of one of the contacts which revolves with the crankshaft, and of all things, a starter dise, around which a string is wound and pulled to turn the prop over several times with one yank. A Champion V-2 spark plug is centered on the cylinder head to complete the engine. Even though the tank is aluminum it cannot be run on "hot" fuels without seriously damaging the tank and other alloy parts. The engine was meant to lend itself nicely to Sunday sport flying, only, and for that purpose the Thors, flying smaller Class B airplanes did pretty well, again, of course considering one was able to get the engine started.

As all of the so called "slag" engines (Syncro, Rogers, Geni, Buzz etc.) were, the Thor was manufactured by the Judson Co. There were actually three or four different Thors, three with "improvements" after the original. The original timer was a thin stamping of very flimsy bronze. The small tab (used as the static point) was punched out on three sides and it rubbed against the back of the drive washer as the device for closing the ignition circuit. The "Super Thor" 29, a later version was identical to the "Mighty Thor", with improved timer. The third Thor version had little or no radius fillet where the intake joined the cylinder, while the earlier ones had a large fillet. (Why?) A few engines in much later production had a bright polished aluminum cylinder, and a chromed piston.

One Mark Fechner of Salt Lake City, in the late 1970's utilizing the full case of the Thors added an "Ohlsson" type enclosed timer, and hang tank to make a number of "improved" Thors which he sold locally and through MECA.

Interestingly enough, just as the GHQ had a collecting "after life" so has the original Thor 29 become a favorite of modern collectors. And they are difficult to obtain, especially in new condition...and even though thousands were manufactured from 1946 on. Today a true collector is willing to pay upwards of $75 for a pristine example. It seems what goes around comes around. Sadly, we do not know who the original designer was of this cheap little "gem"!


This page reprinted from "Model Engine Designer and Manufacturing Profiles" by permission of the author, Mr David R. Janson.



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