On 8 Jan, 17:37, Stealth Pilot
wrote:
veedubber and others
the venerable old VW engine conversion is quite usable.

if you were to take all the lessons learnt from all the engine
building done so far and apply them to a new engine design, what would
the new engine design look like?

I think the flat 4 makes a very serviceable aircraft engine.
underslung pushrods like the O-200 and VW would remain.
I'd use hydraulic lifters.
the castings for the crankcase would be simpler, more like the O-200
than the complexities of the VW casing.
the crankshaft would be a little more robust at the front end
I'd fin the pushrod tubes and use the oil returning to the crankcase
as a radiator.
the engine would be mounted on dynafocal lord mounts.
I'd use electron for the crankcasings.
spin on oil filter. (z79)
magnet in the sumpplug.

For a new design I really really really like this -
http://www.deltahawkengines.com/
http://www.deltahawkengines.com/status00.shtml
http://www.deltahawkengines.com/Broc...osh_2003.shtml
http://www.deltahawkengines.com/specif00.shtml

It's a water cooled two stroke diesel.

Fuel availability (Kerosene etc)
Fuel efficiency at cruise power
No valves/valvetrain
No electrics needed for operation
Can safely run for a while without coolant too.

Obviously the sizes that they are making (160hp +)
are too big for your requirement but I doubt that there
is a fundamental reason that a smaller one could
not be made.

My one worry (for which I have no information) would
be that it might be noisy - dont know.