Looking for dimensional diagrams of 2 stroke engines

 Preferrably with high reliability.

I'm interested in building a 2 stroke engine.  I saw some sand-casting
wooden molds on eBay a few months ago, so I'm looking for the dimensions
of those, enough detail to build one.

Problems: Let's say that aluminum is easier than iron--how can I make a
crankshaft?

Other problem: what about reed valves, or valves on the engine?  I can
make parts, but I don't know about all the little things inside--I'm
willing to learn, of course.

If you have experience with or information about this kind of building
project, please let me know, thanks.

I'll come back here in a few days, to rec.motorcycles, in case anyone
else can benefit from the discussion.

 
If you need to ask this question, it does rather cast a cloud on the
prospects for the project as a whole.


Two strokes have no valves *inside* the engine. Reed or disc valves
exist between carb and engine, and power-valves of one sort or another
are attached to engines. Not "inside" as such: not really.

A two-stroke single is about the simplest engine there is. It's got to
be attached to some sort of drive mechanism, of course, and if you
think engines are tough to build, you might be fazed by building a
gearbox. S'pose you could use a scooter-type expanding belt drive:
they run on single-speed engines.

 
On the surface, yes - but making one work is another matter.  Getting high
crankcase compression ratios (not pressures) is but one example.  Tuning the
intake and exhaust another.  Then there is transfer port routing/shaping and
port timing.  And it all must work together. The piston rings even have to
be pinned.  The devil is in the details most folk never notice.

 

The fact that you asked that question suggests to me that your engine will never
run.  Why don't you find a running two stroke engine, tear it apart and put it
back together?

--
Jack

 Jack Hunt wrote:

  If he's really serious , he can check out the folks at
rec.crafts.metalworking  and some of the hobby casting groups on yahoo ( I
think it's still yahoo groups , changes , changes ...) . There are people
out there that are building running scale models of small block Chevy
motors - and V10 Jaguars . Dood better have a well-equipped machine shop and
lotsa time and talent ...
--
  Snag
  every answer
  leads to another
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