MODEL ENGINE DESIGNER AND MANUFACTURING PROFILES

Taplin Twin
No. 1 in a series compiled by David R. Janson,
SAM #273, AMA #78416 and MECA #210-04.

 

In the early 1970's, DINTON ENGINEERING LTD, Marlborough Road, Margate, Kent, England, was the manufacturer of the last model TAPLIN TWIN, Mk III .49 R/C vertical in-line compression-ignition (diesel) model airplane and boat engines. This beautiful red anodized cylinder head engine was the third model in a line designed by the late famous Lt. Col. H. J. "Taps" Taplin. Col. Taplin was a pioneer aviator, engineer, and engine enthusiast for over 63 years with the twin originating in the 1952-53 era when he built an experimental in-line twin using two E.D. .12 cylinder and piston assemblies. Col. Taplin successfully demonstrated the twin in an R/C boat during the 1954 season, culminating in the first Mark I twin of 7cc displacement .42 (cuin) with bright green anodized heads. In 1962 a Mk 11 twin of 8cc, .49 displacement was short lived but had found favor as it was more powerful and favored by the boaters. The MK III (pictured) was brought into the market in 1967, also of .49 displacement with red anodized cylinder heads and featured the ability to switch from air-cooled to water-cooled jacketed heads by simply screwing them on and off over the internal cylinder sleeves.

It was popular on the continent, very easy to operate, ran very smoothly for such a large diesel and was throttled extremely well with no tendency for one cylinder to cut out at idling speeds. Available only direct from the factory, it cost about $34 stateside in 1970. Dinton Engineering was then under the direction of one of the Taplin sons. Steady but not large sales both in Europe and the United States kept the factory busy as they concentrated on the MK III design.

With its modest porting and sideport induction, the Taplin Twin MK III was not a high speed engine and peaked out at about 9,000 rpms. Thus in the aircraft version the engines were "happiest" with 13/6 or 14/5 propellors. For those interested in the details of manufacture, the crankshaft is supported by ball and needle bearings, the cylinders are true chrome lined and the crankshaft is manufactured in three pieces and then joined permanently during assembly. The single carburetor services the two separate compression chambers and because the ignition timing is adjustable individually by means of the compression control levers, it is possible to compensate for any slight discrepensies in the requirements of each cylinder.

A most helpful and humorous instruction leaflet is included with each engine which contains "tweaking" hints (British lingo for tuning) and a proper scolding for those who "tweak" before they read the instructions and try the factory setting thus needing to retune the engine. In addition the recommended diesel formula for the engine is noted. So, in summation, the Taplin Twin Mk III, of 0.4875 cid (7.989cc) is an in-line, alternate firing, 3 port, two-stroke-cycle, compression ignition model engine with ball and needle supported crankshaft and throttle type carburetor, weighting approximately 17.07 oz, in the aircraft version, with specific power output determined to be .42 brake horse power. It is a truly handsome model engine.

Production numbers are not known, however the writers serial number of 4309 was purchased near the end of the 1970 model year and is thought to be near the termination of the twin production at Dinton Engineering.

Model engine collectors actively seek out the Taplin Twins for their multicylinder and twin collections and further know that the MK II is a rare "bird", indeed! The different heads configuration wherein there are not separate fins but are connected was of very short production in 1962 and it is doubtful if any of those produced survive in more than a handful of collections. As noted above the MK III had completely redesigned heads although the rest of the engine was the same.

In recent years, the Aurora Model Mfg. Co. Pvt. Ltd. of Calcutta, India, purchased the Taplin/Dunton Engineering dies, remaining stock and "good will" and has put out a number of the Taplin Twin MK III engines of varying quality.

 

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

 


 

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