Potplate and engine for MY-14
Lauantai 15.7.2017 - Reino Myllymäki
VL Myrsky II has a 0,75 mm thick domed steel plate between the engine and the engine stand. It directs air stream and protects fuel tank, cartridges and cockpit against fire. There is no remaining pot plates of VL Myrsky II. Therefore it has to be made.
Antero Flander from Flanco Oy in Rautalampi started the work. He made the potplate according to the drawing E61328. Some finishings were lacking but all parts and markings concerning needed cuttings included to the delivery.
There is one blog about pot plate: 13.3.2016.
The pot plate was finished at the Finnish Air Force Museum workshop to correspond to the report for amendment number C302 and drawing E61328-I. According to the repair description dated October 30th 1944 the top of the pot plate of the MY-14 has converted to detachable.
The pot plate has been cut in two places and a hole was cut for the carburettor air intake. Needed holes for screws were drilled and the seams were strenghtened by strips. The flanged nuts were riveted. The edges of the hole for the carburettor air intake were strenghtened by strips and equipped with a leather border.
The engine stand was otherwise usable but the vibration observers were too poor and the bolts were disappeared. The barrels of the observers could be restored.
The vibration observer rubber of the VL Myrsky II is equal to one used in the Fokker D.XXI with Twin Wasp Junior engine. However, the hole for bolt is bigger. By using an original part as a model, a drawing has benn made and Korja-Kumi Oy in Tampere manufactured new rubbers according to the drawing.
The barrels were restored but needed bolts, nuts and washers were bought from a hardware store. A STW C3 engine has been installed to the stand. The STW C3 is a Swedish-built copy of the original Pratt & Whitney R-1830 SC3-G engine. The weight of the engine was 653 kg and a truck was needed in the installation work.
Firstly, the project tried to acquire a pure SC3-G engine for the MY-14. Although at least 127 engines were bought to Finland, none was survived! An alternative S1C3-G engine has been in Douglas DC-3 passenger plane and stored years at the Finnish Aviation Museum. During the fall 2016, a second alternative has been found: STW C3 of the Saab B 17A target tug aircraft.
STW C3 engine in the workshop of the Finnish Air Force Museum.
"I thought during last winter, that STW C3 is the most authentic engine for MY-14 in Finland", said conservator Harri Huopainen from the Finnish Air Force Museum. But the engine was not complete and needed a lot of work.
The engine of MY-14: a S1C3-G engine from the show of the Finnish Air Force Museum.
Due to that, the former DC-3 engine type S1C3-G from the show of the Finnish Air Force Museum has been chosen for the MY-14. The only difference between SC3-G and S1C3-G is the rated altitude of maximum boost. According to FAA´s flyer A-699, the SC3-G can be converted to S1C3-G by changing the fuel and by adjusting the ignition timing.
So, the fixed engine needs to be removed...
First photo: Antero Flander, others: Reino Myllymäki.