DIY Two-Stroke Engine Construction Methods

On Mar 11, 3:20*am, Rufus wrote:
basilisk wrote:
"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
.3.70...
"basilisk" fired this volley in news:J4Nln.198564
:

you will have to provide a slave cylinder or roots type blower
to move the air.

Some variants use a cylinder skirt with reed valving.

LLoyd

You're right, *I didn't really consider that before posting.

I supposed it could be worked out but that looks hard to
do in a completely bottom assembled engine, just my 2 cents worth,
I'm not an engine specialist.

basilisk

Try modifying an existing engine...and don't go hard over on it being a
2-stroke. *I've often thought of trying to construct a full 9 or 7
cylinder aircraft radial using Harley engine parts - hell, those engines
have more in common with an air cooled radial than about anything I can
think of other than a Pratt & Whitney.

SNIP

--
* * * - Rufus

Worth noting:

there is a radial project out there with quite a few builders that
uses VW jugs and a custom crankcase and heads. Around 100hp if I
remember correctly.

There are also a couple of half VW engine projects with plans
available.

If you take a stroll around the national air and space museum you will
get a feel for the art that went into many of the early engines. The
old designers and machinists were a different breed, and their work
inspires awe in any mechanically inclined mind. It is worth noting
that many of the older radial and fan engine configurations used a pie-
wedge style crankcase, where the cylinder and the case were a single
piece, and the crankcase bolted together in pieces arranged in
circumference to the crankshaft.

With modern alloys and machining techniques, I've wondered if
returning to this style might be tolerable for a small engine today.
Lawn mowers are done similarly, and so I'd imagine an engine designed
in this fashion would scale up quickly from a production standpoint.

While building a new engine solely for art is a lofty goal, I can't
really see it for any other reason. What performance specs could you
be looking for that aren't currently available in a production engine,
or are not otherwise achievable by making minor modifications to a
production engine?

The engine of interest to me lately is the new subaru TDI boxer
motor. Wow that thing is fancy, and I'm hoping it makes its way to
the states some time soon. With modern boosting techniques I'd also
like to see the packard aero diesel configuration revisited, perhaps
integrating some of the features in the elsbett engines. .

If I was heading off in the scratch built direction, I would outsource
the casting process. There are many shops domestic and overseas that
can do short runs of castings based on a provided dxf file. It is
unlikely that a backyard foundry will ever get close to the level of
detail these shops can create. I would probably search far and wide
before starting to CAD the thing up.

Of course, thinking down the road, if ever I should build my own bird,
I'm thinking Rotec, or PZL Franklin. I'd like to go heavy kung fu into
engine design, but it is just way to much work, for way to little
optimization.

Thanks!