Work on the exhausts of MY-14 ongoing

Sunnuntai 29.1.2017 - Member of Tuesday Club


The original engine planned to be used on the VL Myrsky was the British Bristol Taurus. Because of WW II this did not happen. Instead, the American Pratt & Whitney R-1830 two-row radial engine was selected, almost the same version as on the Douglas DC-3.

Myrskyn MY-14 - entisöintiprojektia varten on käytössämme DC-3 koneessa ollut Twin Wasp -moottori. Koska moottori on ollut DC-3 koneessa, se ei ilman muutoksia sovi Myrskyyn asennetavaksi. Yksi merkittävä muutoksen kohde koskee moottorin pakoputkia.

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The Twin Wasp with the exhaust collector of DC-3 in left picture and the Twin Wasp of VL Myrsky II with oval pipes in right picture.

On the DC-3´s Twin Wasp the exhausts from each cylinder is connected to a single exhaust gas collector from which there is a single exit pipe. On the Myrsky a different solution was implemented – The exhaust from each cylinder was gathered to be expelled through five oval exhaust pipes on top of each other on both sides of the engine under the NACA cowling ending at the back-part of the cowling.

At the end of each 10 round exhaust pipes 200 mm long, tapered nozzles were welded. At the weld the nozzles had a diameter of 60 mm but they were tapered towards their end, ending as a 28mm X 60 mm rectangles. A smaller final cross-section was used to increase the speed of the exhaust gases and thus creating some added thrust.

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The exhaust system that is to be built during the restauration will be a copy of the original one. At the moment the single pipes from each cylinder, forming a veritable “snake-pit” are being formed into shape by a partner contractor at Samet Oy. The nozzles are being made by the Tuesday-Club.

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They are being made from 28 rectangular parts cut out from sheet-metal. To form them into the requires shape the club made the necessary male and female mould parts used to shape the flat sheet-metal parts In a hydraulic press.

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After being pressed the edges to be welded were cleaned and chamfered for welding. The assembly, welding and fitting of the exhaust-system to the Twin-Wasp engine will be done by Patria Oyj.

Avainsanat: aviation history, restoring, old aircraft, VL Myrsky II, MY-14