Bore 3/4 in
Stroke: 3/4 in
Height: 3 1/2 in
Availability 1924-1926
Design: 2 cylinder marine engine for two propshafts
M.T.B. ENGINE No. 2
Weight 1-lbs. 14-oz. Height 3 1,2-ins.
Finished Engine Complete and ready for steam. £1 10 0
Castings and Materials
Iron Castings.— for Cylinders and Crank Chamber (2 castings), 2 Pistons, 1 each Valve Chest and Door, Flywheel, Cam-plate.
Gunmetal Castings.— for Connecting Rods, Slide Valve, Gland and Lever Bracket.
Sundries.—- 1 Crank Shaft, materials for Valve Rod, Lever, Lagging, Cam, Ball, Spring and all Screws, with Complete Drawing.
(Weight packed 4 lbs.) Post. 6d. extra … Price, 6/-
Design
This engine has been especially designed to run a twin screw boat. To that end the design is unique. A single casting makes up the cylinder block and sump. The valve chest and valce assebly appear to be the same as the No. 1b. The cladding over the cylinders indicate that they are probably contoured as in the No.1b. The bottom of the main casting is a box with the back open for a plate to close. In the front of the engine are mounted the two flywheels that are geared to synchronise the two pistons into opposing motion. Inside the two shafts are connected to the pistons by cranks fitted to the ends of the shafts. Inside one of them has a standard eccentric fitted that passes out a hole in the casing side to connect to the bottom ov the valve lever. The lever is pivoted on a small bracket fitted to the side of the main casting. As can be seen from the photos below the engine was designed to run with a custom boiler plant inside a commercial model boat, a Motor Torpedo Boat Destroyer. Could this be where the name for the range of engines comes from. A nice photo of the model being used in the 1920's is at the top of this web page. A photo of the real thing is found on the top of the next web page.
please let me know if you find a video of this engine running.