In the summer of 1937, Charles Brebeck, Sr. was looking for a product to manufacture in his Herkimer, NY machine shop and responded to his son's request to make a model motor like the Brown a friend had. As Brebeck wanted to develop his own design, the true beginning of the "OK" 60 prototype took place. He saw the burgeoning business opportunity and he was in the right place at the right time. Between 1939 and 1942 his sixties, 49s and his twin came onto the market.
In August 1939 Model Airplane News published the first ad for the "OK" twin. This earliest twin had no patent numbers, was black painted diecast aluminum and none sold. The ad touted "Herkimer's answer to radio-control power problems, super power for super ships, smooth reliable 1/2 horsepower, all for $35". The clouds of WWII loomed on the horizon and Herkimer Tool and Model Works joined the government's needs as well as submitting plans for a drone engine. In the meantime the "OK" twin went through a number of design improvements...one ingenious aspect of the twin case was that there was no right or left cylinder...a single die cavity was utilized getting two crankcase halves for a single engine.
In 1946 the "new" twin, 1.208 cid, at $49.00 came back onto the market as a "near custom engine", ordered through "OK" dealers and was the most powerful, best looking, easiest starting twin sold in the entire spark ignition era. A true answer to the radio control and huge airplane builder's power needs. And ohhhh the sound of those twin cylinders perking away. In the last years of the twins manufacturing in the early 50s they sported gold anodized heads. Beautiful. Rare now.
The 1946 and on twins had two piece cast aluminum cases, with OK and patent numbers on the bypass. The back cover was also die cast aluminum with bronze bearings and the serial number stamped on the top front flange. The front cover had a ball bearing and two small screws placed to act as timer stops. Cylinders were beautifully turned from steel bar stock, with lower fins notched for screws holding the cylinder, black exhaust stacks and lower case together securely. The three piece steel shaft was of welded construction with connecting rods as a unit. Pistons with bronze pins were turned and bored from bar stock steel. The diecast timer was slightly larger than the Super 60 to support the screws which limited timer travel.
The under engine venturi was die cast aluminum with a long shaft needle valve and provision for an R/C "butterfly". A beautiful diecast aluminum center bracket fuel tank with two red bakelite (Super 60) tanks mounted end to end came with the engine as did a custom Aero two pole coil. Many of the major engine manufacturers have designed twins and Charles Brebeck patterned his after his "Super 60" and the twin when turned sideways looks like two of his sixties. And like the late Duke Fox whose hefty, powerful, loud twin 1.20 was patterned after his Eagle 60 11, had to design a new crankshaft to get the job done. Interestingly enough, the "OK Super 60" while being a rather steady seller over the years, was not a really popular engine, as its power could just not match the other sixties of the era, and thus one seldom saw one powering a free flight model. They were more popular in the U-control circles of those times, it seems. The beautiful "OK" twin, however dominated the small market for radio control and large airplanes.
For engine collectors, of course the rare and seldom seen prewar twin is eagerly sought after. The post World War 11 twin while not a rarity is hard to find nowadays in new and near new condition. Some 2,000 were manufactured and bring half a thousand dollars for this twin is considered a staple of the twin model engine collections of today.