MODEL ENGINE DESIGNER AND MANUFACTURING PROFILES
Nordec 60
No. 41 in a series compiled by David R. Janson,
SAM #273, AMA #78416 and MECA #210-04.

 

In the June, 1950 issue of MODEL AIRCRAFT, the "other" British aeromodeling magazine, the model engine tester introduced the NORDEC SPECIAL 60 and praised its overall performance as a high powered "U" Control, boat and model car engine. Never once was it mentioned that the manufacturer, North Downs Engineering Company, Godstone Road, Whyteleafe, Surrey, England had made direct copy of Dick McCoy's late 1940s and early 1950s engines. The picture speaks for itself. Hardly a "household" word in the USA, the NORDEC 60 was making a name for itself in England in first a spark ignition version then a glow conversion (remove the timer assembly, put a glow plug on it) and finally the improved glow version, the NORDEC SPECIAL 60 discussed here, with some needed changes for overall power.

The first version, spark ignition, in early 1948 was well made and powerful and on testing gave a greater output than the glow version, but the elimination of the battery, coil and condenser was desired and the glow plug was "in"!

This single-cylinder, air-cooled, two-stroke-cycle, glow ignition engine uses induction by disc type rotary-valve driven by a crankpin. The piston is baffled. Sand-cast aluminum alloy is used for crankcase and cylinder with a Meehanite cylinder-liner. The piston has two compression rings and the crank shaft of hardened and ground nicke-lsteel runs in two Hoffman ball races. Front crankcase and back crankcase covers are removable and both secured by four Allen-head screws. Six screws hold the cylinder head to the cylinder. The; carburetor is of machined dural and is locked into the rear cover with a grub screw to permit movement of the needle-assembly. Metal to metal joints throughout use no gasket. The Nordec like the McCoy is an attractive, masculine type of model engine with the "purposeful" look of power. Thus the outward improvements to the third model version were an inclined plug, black anodized cylinder head, polished fins, and drive spool. The improved Nordec's superior performance was gained by a number of detail modifications to the first series engine, resulting in greater volumetric efficiency evidenced by higher horsepower and peak revolutions.

The design of the combustion chamber (the interior shape of the cylinder head) was contoured to suit the highly domed deflector pattern of the head, as well as deepening the piston skirt clearance above the lower edge of the exhaust ports at top dead center. In addition transfer and exhaust port areas were increased in size and a new cylinder/crankcase casting having a transfer passage of much greater volume. The rotary valve was considerably opened out and the diameter of the carburetor throat was enlarged. The rest of the engine is identical to the first model Mk I spark ignition. With approximately 1.24 b.h.p. it is a powerful engine for the times. The question of the Nordec's "collectability" interest is a rather strange one. While the engine was produced in a few thousands numberwise, new and pristine examples of all three models, the first sparker, glow conversion and then the "Special" are difficult to obtain outside of the United Kingdom and seldom appear in collections.

It is one of those engines that collectors snap up when their attention is called to them, but are seldom advertised for. It is not known if the North Downs Engineering Company manufactured any other size but thought unlikely!

See also: Adrian Duncan's Nordec Review.

 

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

 


 

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