Belmont G9 (oz13678)

 

Belmont G9 (oz13678) 1939 - plan thumbnail

About this Plan

Belmont G9. Model spark-ignition aero engine.

For the full story on the Belmont G9 see: http://modelenginenews.org/cardfile/belmont_imp.html

Quote: "Background: This one is almost good enough to be a Watzit. The engine was first advertised in 1939 by 'International Models [Products]' of New York as the 'G9'. The ads quoted a bore of 7/8 and stroke of 15/16. Later, the manufacturer seems to have moved to Boston, changed their name to Belmont Miniature Motors and the engine became known simply as the Belmont. No ad we've been able to trace ever stated the capacity, only the bore and stroke, although Model Airplane News in their annual gas engine round-up for 1940 and 1941 quote the calculated capacity. The engine had disappeared from sale by 1942, precisely when, we don't know. Based on photos accompanying the various advertisements, it appears the G9 had a cast, streamlined tank, while the Belmont had a cylindrical tank secured under the venturi tube, per common practice.

Two cylinder types are apparent. One, features a solid cast-iron cylinder with a honeycomb of drilled passages forming the transfer passages. One of these which would otherwise open the whole system to the atmosphere, is closed off by the simple expedient of pressing in a .177 cal BB pellet! The second variety cuts the transfers into the rear face of the C-I cylinder, closing them off with an aluminum plate which carries the venturi. This arrangement required lugs to be cast into the sides of the cylinder to attach the plate - a simple enough mod to the original pattern, so it's reasonable to conclude this represents a later version. At the same time, the cross-drilled, cast-in exhaust was replaced by a bolt-on tube, surther simplifying manufacturing steps on the cylinder..."

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Belmont G9 (oz13678) 1939 - model pic

Datafile:
  • (oz13678)
    Belmont G9
    from International Models
    1939 
    9.247 cc
    Engine Spark
    clean :)
    complete :)
  • Submitted: 08/03/2022
    Filesize: 299KB
    Format: • PDFvector
    Credit*: EdHolly
    Downloads: 687

Belmont G9 (oz13678) 1939 - pic 003.jpg
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Belmont G9 (oz13678) 1939 - pic 004.jpg
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