Page 45A Proposal

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Jim Symanski’s engine is pretty impressive.

2.5 hp from twin gamma displacers linked to a double acting piston. Pressurised to 10 bar
Interior finned displacer cylinders of 4” diameter.

Have a look at Jim Dandy No 6.

It’s actually the same design idea as Robert and James Stirling of 1843. The Dundee engine.

This is the design that I am embarking upon.

But you have been basing the last 43 pages around the beta engine Andrew?

Yes, it is the design that the UK group have had the most success with. But no-one has
reached 1hp let alone 2.5hp.

But, for me, major reasons are:-
There is no crankcase. The pressure is held within the displacer and piston chambers by
sliding rod seals. Pressurising a crank case in a private workshop to 10 bar is going to need an awful lot of bolts (and helium leaks from the wall plates) or you have to cut from solid.

The beta is an “integrated” design. The piston and displacer have to be the same diameter.
Tuning the piston stroke to match the expansion capability of the hot gas is not an option.
When the piston cylinder is separated from the displacer chambers it is possible to adjust the
piston stroke to match the heat and expansion capabilities of the displacer chambers.

My plan is to motorise the displacer rocker – like a Martini engine. Full speed control.

A working model has been built. Full size 3d plastic printing prototyping has been used.
There are no heater tubes, or cooler tubes.

So, give me a few years, (2020 onwards) and see what results!