DIY Two-Stroke Engine Construction Methods

cavelamb wrote:
frank wrote:

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.


When did this start???

Which? Stupidity on the internet or stupidity in our government?

Charles

On Mar 11, 8:17*am, Charles Vincent wrote:

When did this start???

Which? *Stupidity on the internet or stupidity in our government?


Government stupidity came first. Al G. just wanted to bring it to the
general public .................
===============
Leon

frank wrote:
On Mar 10, 9:02 pm, Rufus wrote:
durabol wrote:
The two main methods for homebuilt construction would be casting vs.
machining or some combination of both (probably the best option).
Forging probably isn't appropriate for home construction (either the

-- snip --

like a motorcycle engine - strip it down and just build the parts and
accessories required to make it turn a prop. And along the way one can
also machine it's component parts down to lighten it...run it on the
ground, if it breaks, you know you went too far.

--
- Rufus (pilot, engineer, jeweler, model builder...yadda, yadda...)

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

The FAA licensing process for homebuilts is much lighter weight than for
'regular' aircraft. People can and do convert automotive engines for
homebuilts, and fly them. There are many building processes that aren't
certified for general aviation, but which are acceptable to the FAA
inspectors for homebuilts.

Check the EAA website (eaa.org?) -- they'll have something.

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

wrote:
On Mar 11, 8:17 am, Charles Vincent wrote:

When did this start???
Which? Stupidity on the internet or stupidity in our government?


Government stupidity came first. Al G. just wanted to bring it to the
general public .................
===============
Leon

What? This?

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

This is completely false!

--

Richard Lamb
http://www.home.earthlink.net/~cavelamb/

cavelamb schreef:
What? This?

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

This is completely false!

The sheer fact that he implies the FAA has worldwide authority shows he
doesn't know what he is talking about. Least said soonest forgotten.

cavelamb wrote:
wrote:
On Mar 11, 8:17 am, Charles Vincent wrote:

When did this start???
Which? Stupidity on the internet or stupidity in our government?


Government stupidity came first. Al G. just wanted to bring it to the
general public .................
===============
Leon

What? This?

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

This is completely false!

Wrong.

My airplane, a Flight Design CTSW, has a
special light sport airworthiness certificate
and an uncertified Rotax 912ULS engine.

Rotax 912ULS engines are also the engine
of choice for many homebuilders.

On Thu, 11 Mar 2010 00:45:04 -0800 (PST), frank
wrote:

On Mar 10, 9:02Â*pm, Rufus wrote:
durabol wrote:
The two main methods for homebuilt construction would be casting vs.
machining or some combination of both (probably the best option).
Forging probably isn't appropriate for home construction (either the
piston or connecting rod).

One method I have thought of is to produce a wax model of the engine
with molds (to a fairly high tolerance to minimize machining) which is
then cast using lost wax casting techniques. I planned to have an
integral cylinder head/cylinder/half the crank case (this is for an
opposed style engine). The only bolts would be to bolt the two halves
together.

As someone whom has done lost wax casting, I wouldn't recommend doing
that for something I was going to bet my life on...not without investing
LARGE amounts of capital in equipment - a centrifugal or pressure
injection foundry...sand casting (which I've also done) is a far better
alternative for casting a raw engine casing. Â*Make a durable wooden
master model, preferably of a hardwood.

In any event, you're still going to have to sleeve the cylinders with
some alloy of machined, durable steel - which will have to be hardened
and polished in some way and interference fit into the block or stud.
And you need to match coefficients of thermal expansion when choosing
your materials in order to keep it all tight - same goes for choosing
and tolerancing your bolts and every other component in direct
contact...which means you also need to do some thermal analysis and
figure out how hot, as well as how, your engine is going to run...

A completely machined engine would need a large block of aluminium to
start with which I'm not sure how practical that would be. Perhaps
lost foam casting could be used as a general model of the engine was
made in foam and then cast and the resulting casting could be
machined.

Brock

Again - big investment in big machines to insure uniformity of the
casting...which will kill the project (and the pilot) if you screw it
up. Â*Hot spots, porosity, voids...not that simple. Â*Best way to
spot/find/quality check castings involve die penetrant or x-ray.

Also - don't overlook the fact that you are going to have to heat treat,
case harden, or otherwise machine or post-work any part you produce
depending on choice and application of materials...I don't know what
kind of tools and resources the OP has at hand, but if he's starting
from scratch he better be prepared to spend the amount of money he'd
spend on a mid-size car in tooling just to get started with such a
project...make it a large luxury car, now that I think about it...

The far easier (and safer) alternative is to modify an existing engine -
like a motorcycle engine - strip it down and just build the parts and
accessories required to make it turn a prop. Â*And along the way one can
also machine it's component parts down to lighten it...run it on the
ground, if it breaks, you know you went too far.

--
Â* Â* Â* - Rufus (pilot, engineer, jeweler, model builder...yadda, yadda...)

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

Not true.
Experimental/homebuilt can use ANY engine - absolutely no
certification required.

"Tim Wescott" wrote in message
...
frank wrote:
On Mar 10, 9:02 pm, Rufus wrote:
durabol wrote:
The two main methods for homebuilt construction would be casting vs.
machining or some combination of both (probably the best option).
Forging probably isn't appropriate for home construction (either the

-- snip --

like a motorcycle engine - strip it down and just build the parts and
accessories required to make it turn a prop. And along the way one can
also machine it's component parts down to lighten it...run it on the
ground, if it breaks, you know you went too far.

--
- Rufus (pilot, engineer, jeweler, model builder...yadda,
yadda...)

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

The FAA licensing process for homebuilts is much lighter weight than for
'regular' aircraft. People can and do convert automotive engines for
homebuilts, and fly them. There are many building processes that aren't
certified for general aviation, but which are acceptable to the FAA
inspectors for homebuilts.

Check the EAA website (eaa.org?) -- they'll have something.


www.faa.gov the eaa is a pilot organisation, not a controling authotiry :-)

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com

--
Remember Altitude is more important than Attitude

"Garry O" wrote in message
u...
"Tim Wescott" wrote in message
...
frank wrote:
On Mar 10, 9:02 pm, Rufus wrote:
durabol wrote:
The two main methods for homebuilt construction would be casting vs.
machining or some combination of both (probably the best option).
Forging probably isn't appropriate for home construction (either the

-- snip --

like a motorcycle engine - strip it down and just build the parts and
accessories required to make it turn a prop. And along the way one can
also machine it's component parts down to lighten it...run it on the
ground, if it breaks, you know you went too far.

--
- Rufus (pilot, engineer, jeweler, model builder...yadda,
yadda...)

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

The FAA licensing process for homebuilts is much lighter weight than for
'regular' aircraft. People can and do convert automotive engines for
homebuilts, and fly them. There are many building processes that aren't
certified for general aviation, but which are acceptable to the FAA
inspectors for homebuilts.

Check the EAA website (eaa.org?) -- they'll have something.


www.faa.gov the eaa is a pilot organisation, not a controling authotiry
:-)

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com


and I must remember to read what is written after the first coffee of the
day 'DOH
your correct, the EAA will have a lot of information on homebuilt and
experimental A/C, they will also want you to get regular inspections during
the construction, even on experimental I think, and at various benchmarks
during the build.
personally I wouldn't fly with any home made engine, and by home made I'm
talking about things like casting your own cylinders etc, why re-invent the
wheel when there is a plethora of R&D'd engines that can more easily and
cheaply be converted.

--
Remember Altitude is more important than Attitude

Garry O wrote:
"Garry O" wrote in message
u...
"Tim Wescott" wrote in message
...
frank wrote:
On Mar 10, 9:02 pm, Rufus wrote:
durabol wrote:
The two main methods for homebuilt construction would be casting vs.
machining or some combination of both (probably the best option).
Forging probably isn't appropriate for home construction (either the

-- snip --

like a motorcycle engine - strip it down and just build the parts and
accessories required to make it turn a prop. And along the way one
can
also machine it's component parts down to lighten it...run it on the
ground, if it breaks, you know you went too far.

--
- Rufus (pilot, engineer, jeweler, model builder...yadda,
yadda...)

Anything that flies a person has to be certified by the FAA anyway.
Especially homebuilts due to some fatal crashes early on.

The FAA licensing process for homebuilts is much lighter weight than
for 'regular' aircraft. People can and do convert automotive engines
for homebuilts, and fly them. There are many building processes that
aren't certified for general aviation, but which are acceptable to
the FAA inspectors for homebuilts.

Check the EAA website (eaa.org?) -- they'll have something.


www.faa.gov the eaa is a pilot organisation, not a controling
authotiry :-)

--
Tim Wescott
Control system and signal processing consulting
www.wescottdesign.com


and I must remember to read what is written after the first coffee of
the day 'DOH
your correct, the EAA will have a lot of information on homebuilt and
experimental A/C, they will also want you to get regular inspections
during the construction, even on experimental I think, and at various
benchmarks during the build.
personally I wouldn't fly with any home made engine, and by home made
I'm talking about things like casting your own cylinders etc, why
re-invent the wheel when there is a plethora of R&D'd engines that can
more easily and cheaply be converted.

I'd also point out that much of the homebuilt FAA
regulatory footwork is done by designated examiners
and inspectors that are EAA members.