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Otto Alternates and Diesel
Diversions
By Ron
Cairns
The Split Cycle engine by Rick Mayne from Austria is a different
approach to standard engines which use the expansion of air to do
meaningful work.
Conventional engines all fall into the grouping that relies on
the theory that the higher the combustion temperature, the more
power; the higher the compression ratio, the greater the power; the
longer the stroke, the greater the torque. The Split Cycle engine
seems to dispel some of these theories.
This engine doesn’t use either a crankshaft or connecting rods.
In the Split Cycle engine the pistons push on a Geneva wheel which
acts on a planetary type of gear cluster. This gearing allows the
Geneva gear to turn 30 degrees while the output shaft turns 15
degrees. The shape of the Geneva wheel allows the piston to stay at
top dead (Outer Dead?) center much longer than a conventional
piston does.
The Split Cycle engine is designed to run in the 10 to 500 rpm
range for the output shaft and the designers claim to be getting
210 ft. lbs. of torque from a 150 cc SCT engine at 150 rpms. In
comparison a conventional 2 stroke 150 cc engine only produces
about 11 ft. lbs. at that speed!
There are four pistons pushing on each set of Geneva wheels.
That brings us to another amazing fact; the prototype engine has 48
pistons that produce a power stroke every 30 degrees or 12 power
strokes for each revolution of the output shaft.
Mayne has also come up with a Pulsing Fuel Injector that both
reduces the fuel droplet size and reduces puddling. Both of these
issues have been real causes of concern for fuel injection
designers.
His website goes into a fair amount of detail about the engine
so I encourage you to visit http://www.splitcycle.com.au.
Any comments or questions that you may have about the stories
that are in Otto Alternates… or any new engines that you would like
to let me know about; e-mail me at clear.solutions @shaw.ca | 