Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots of
detail about the seals (for anyone who's followed rotary-valve engines over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

--
Ed Huntress

Ed Huntress wrote:
Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

Wow! That *is* cool!
I wonder if the rotating cylinder is prepared with
a cross-hatch or an axial hone pattern?

--Winston

On Aug 12, 3:25*pm, Winston wrote:
Ed Huntress wrote:
Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

Wow! That *is* cool!
I wonder if the rotating cylinder is prepared with
a cross-hatch or an axial hone pattern?

--Winston


And this is to be "almost" as cheap as a 2-stroke engine???

In whose dreams? Somebody got paid off.

Wolfgang

"Ed Huntress" wrote ...
: It's built by a British company, RCV Engines Ltd., and it's amazingly
: simple. They've made available a 7-year-old SAE paper about it, with lots of
: detail about the seals (for anyone who's followed rotary-valve engines over
: the years, that's where most of the action is):
:
: http://www.rcvengines.com/pdf_files/saepaper.pdf

Interesting and clever spin on an old problem.

Correct me if I missed something but it appears that with the cylinder rotating
and the piston not rotating there will be a lot more friction between the piston
and cylinder. Furthermore, the piston rings will be spinning with the cylinder
and against the piston. These ring/piston friction points will be difficult to lube
and could be a serious reliability issue.
Art

Ed Huntress wrote:
Maybe everyone knows about this engine but me, but if not, this is a
very cool little piece of machinery worth looking into. It's the
rotary-valve 4-stroke used in the Honeywell hovering drone that's
being prepared for field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with
lots of detail about the seals (for anyone who's followed
rotary-valve engines over the years, that's where most of the action
is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is
more than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

Reminds me a little of the Wankel design.


--
John R. Carroll

On Aug 12, 4:14*pm, "Artemus" wrote:
"Ed Huntress" *wrote ...
: It's built by a British company, RCV Engines Ltd., and it's amazingly
: simple. They've made available a 7-year-old SAE paper about it, with lots of
: detail about the seals (for anyone who's followed rotary-valve engines over
: the years, that's where most of the action is):
:
:http://www.rcvengines.com/pdf_files/saepaper.pdf

Interesting and clever spin on an old problem.

Correct me if I missed something but it appears that with the cylinder rotating
and the piston not rotating there will be a lot more friction between the piston
and cylinder. *Furthermore, the piston rings will be spinning with the cylinder
and against the piston. *These ring/piston friction points will be difficult to lube
and could be a serious reliability issue.
Art

An older spin on the problem:
http://en.wikipedia.org/wiki/Bristol_Centaurus

jsw

Jim Wilkins wrote:
An older spin on the problem:
http://en.wikipedia.org/wiki/Bristol_Centaurus

That was WWII, RSV's are even older than that:
http://en.wikipedia.org/wiki/Sleeve_valve

"They saw use in some pre-World War II luxury cars, sports cars, the
Willys-Knight car and light truck, ..."

Never heard of it,
Bob

On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:


It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots of
detail about the seals (for anyone who's followed rotary-valve engines over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf


Hmm, just looks like a variant of the Aspin engine to me. Nice to see pre-war
technology come back to life...


Mark Rand
RTFM

"Mark Rand" wrote in message
...
On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"

wrote:


It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots
of
detail about the seals (for anyone who's followed rotary-valve engines
over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf


Hmm, just looks like a variant of the Aspin engine to me. Nice to see
pre-war
technology come back to life...


Mark Rand
RTFM

There have been a lot of rotary-valve engines over the past century, but
they never get very far in the competition with poppet-valve engines. This
one looks particularly interesting. If they really have the seal and wear
problems solved, I'd like to know more about it.

The one used in the little drone is interesting, too, because it's a 60cc
spark-ignition engine that runs on JP-8 and produces 4.6 hp. I doubt if
there's another commercially available engine that will do that.

--
Ed Huntress

"Bob Engelhardt" wrote in message
...
Jim Wilkins wrote:
An older spin on the problem:
http://en.wikipedia.org/wiki/Bristol_Centaurus

That was WWII, RSV's are even older than that:
http://en.wikipedia.org/wiki/Sleeve_valve

"They saw use in some pre-World War II luxury cars, sports cars, the
Willys-Knight car and light truck, ..."

Never heard of it,
Bob

Willys-Knight. That was a sliding valve. A plate that slid back to open up
the port. My Kawasaki 350 2 cyl and the 500cc 3 cyl had an actual rotating
disk with a lot for the valve as opposed to reeds. This engine looks more
like a wankle with a fixed piston and the cylinder revolves instead of the
piston. The early Wankle was a very powerful engine in a small package.
Emissions sucked as ran hotter than a standard engine. So they sprayed oil
on the inside the rotary piston to cool it. Early ones had tip and end seal
problems, but those were corrected with good materials science. This engine
seems to have a fixed opening in the end of the cylinder and works during
the normal rotation, not and extra driven disk like the Kawasaki. Kawa's
disk was a fiber disk and when it comes apart at 70 mph, it totals the
engine. Been there, got the tee shirt.

"Winston" wrote in message
...
Ed Huntress wrote:
Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

Wow! That *is* cool!
I wonder if the rotating cylinder is prepared with
a cross-hatch or an axial hone pattern?

--Winston

Dunno. Rotary-valve engines usually have a sort of inverted cup in the
combustion chamber, which contains the ports. There have been some other
engines with the ports in a rotating cylinder, but I've never studied them
in any detail.

They can produce a lot of power, but they usually have sealing problems and
wear problems. That's why this one looks interesting. It sounds as if
they've solved them.

--
Ed Huntress

"wolfgang" wrote in message
...
On Aug 12, 3:25 pm, Winston wrote:
Ed Huntress wrote:
Maybe everyone knows about this engine but me, but if not, this is a
very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

Wow! That *is* cool!
I wonder if the rotating cylinder is prepared with
a cross-hatch or an axial hone pattern?

--Winston


And this is to be "almost" as cheap as a 2-stroke engine???

In whose dreams? Somebody got paid off.

Wolfgang

Their Type 58 model engine is $209:

http://www.hobbyhorse.com/rcv.shtml

The number of moving parts is less than in a poppet-valve 4-stroke. I don't
see anything in there that looks expensive, although the clearances look
pretty critical.

--
Ed Huntress

"Artemus" wrote in message
...

"Ed Huntress" wrote ...
: It's built by a British company, RCV Engines Ltd., and it's amazingly
: simple. They've made available a 7-year-old SAE paper about it, with
lots of
: detail about the seals (for anyone who's followed rotary-valve engines
over
: the years, that's where most of the action is):
:
: http://www.rcvengines.com/pdf_files/saepaper.pdf

Interesting and clever spin on an old problem.

Correct me if I missed something but it appears that with the cylinder
rotating
and the piston not rotating there will be a lot more friction between the
piston
and cylinder. Furthermore, the piston rings will be spinning with the
cylinder
and against the piston. These ring/piston friction points will be
difficult to lube
and could be a serious reliability issue.
Art

Apparently they've held up well in Honeywell's tests, and the fuel
efficiency is much higher than a two-stroke. So the friction doesn't seem to
be an issue in practice.

I've been reading about this engine in various places and the two reasons it
seems to have been chosen are that it has a power-to-weight ratio close to
that of a two-stroke, and it will run on JP-8.

--
Ed Huntress

On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:

Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots of
detail about the seals (for anyone who's followed rotary-valve engines over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

I saw that in the lab and they flew it once at lunchtime a few years
ago.

"Don Foreman" wrote in message
...
On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:

Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots
of
detail about the seals (for anyone who's followed rotary-valve engines
over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

I saw that in the lab and they flew it once at lunchtime a few years
ago.

I'd really like to see one run -- not that you could tell much by watching
it, but I'd like to see it anyway.

--
Ed Huntress

On Aug 12, 1:50 pm, "Ed Huntress" wrote:
It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

I think I disagree with your logic. Some of the reasons you use drones
are because they are relatively cheap, and because they don't contain
a human. That means you can get away with things that would be
considered unsafe/unreliable in a manned aircraft... Plus, if the
engines really are "cheap" they may not mind if they have to replace
them after every 20 hours of operation.

"Larry The Snake Guy" wrote in message
...
On Aug 12, 1:50 pm, "Ed Huntress" wrote:
It must be pretty darned reliable to be used in the drone, so this is
more
than just another weird engine curiosity.

I think I disagree with your logic. Some of the reasons you use drones
are because they are relatively cheap, and because they don't contain
a human. That means you can get away with things that would be
considered unsafe/unreliable in a manned aircraft... Plus, if the
engines really are "cheap" they may not mind if they have to replace
them after every 20 hours of operation.

I doubt if the drone is cheap enough to justify a "cheap" engine. And a
quirky engine isn't likely to make it past Honeywell, who is betting on its
performance and reliability for the sake of the nice government contract
they have for the whole device.

So, while not having to worry about human life eases the demand for engine
reliability, it's still up against all of that conventional competition,
which is well-proven and reliable.

All in all, it looks like a situation in which the engine is being taken
seriously by serious people.

--
Ed Huntress

On Thu, 13 Aug 2009 00:09:23 -0400, "Ed Huntress"
wrote:


"Don Foreman" wrote in message
.. .
On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:

Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots
of
detail about the seals (for anyone who's followed rotary-valve engines
over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

I saw that in the lab and they flew it once at lunchtime a few years
ago.

I'd really like to see one run -- not that you could tell much by watching
it, but I'd like to see it anyway.
Just like I would like to see the Napier Sabre engine running, just to
say I'd seen one running, likewise the big four bank radial, or the 24
cylinder "W" Allison.
Gerry :-)}
London, Canada

The most impressive small engine I've ever seen run was a small turbojet in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn for the
end of time.

"cavelamb" wrote in message
m...
The most impressive small engine I've ever seen run was a small turbojet
in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn for
the
end of time.

Do they still use any pulse jets in models? I was around 6 years old, which
would have been 1954, when I saw a control-line speed event with pulse jets.

I can still remember the pain in my ears and the vibration like it was
yesterday. My God, those things are loud.

--
Ed Huntress

Ed Huntress wrote:
"cavelamb" wrote in message
m...
The most impressive small engine I've ever seen run was a small turbojet
in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn for
the
end of time.

Do they still use any pulse jets in models? I was around 6 years old, which
would have been 1954, when I saw a control-line speed event with pulse jets.

I can still remember the pain in my ears and the vibration like it was
yesterday. My God, those things are loud.

--
Ed Huntress



I remember one of those from when I was a child (middle of last century).
They were *loud*.
I haven't seen one since.

There are a few Jetex sites up even today.
That's a slow burning solid fuel rocket engine.
I've thought about playing with those.
There are cheap enough - if you can get them.

But the jet was just plain eerie...

On Thu, 13 Aug 2009 23:12:26 -0500, cavelamb wrote:

Ed Huntress wrote:
"cavelamb" wrote in message
m...
The most impressive small engine I've ever seen run was a small
turbojet in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn
for the
end of time.

Do they still use any pulse jets in models? I was around 6 years old,
which would have been 1954, when I saw a control-line speed event with
pulse jets.

I can still remember the pain in my ears and the vibration like it was
yesterday. My God, those things are loud.

--
Ed Huntress



I remember one of those from when I was a child (middle of last
century). They were *loud*.
I haven't seen one since.

There are a few Jetex sites up even today. That's a slow burning solid
fuel rocket engine. I've thought about playing with those. There are
cheap enough - if you can get them.

But the jet was just plain eerie...

Jet-X engines were revived a few years back, and there's a new one out --
"Rapier" -- that is of different construction (it's not a cannister with
naked fuel pellets, but more like an integrated rocket engine with the
fuel in a cardboard tube, AFAIK).

A little bit of web searching goes a long way...

--
www.wescottdesign.com

Tim Wescott wrote:
On Thu, 13 Aug 2009 23:12:26 -0500, cavelamb wrote:

Ed Huntress wrote:
"cavelamb" wrote in message
m...
The most impressive small engine I've ever seen run was a small
turbojet in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn
for the
end of time.
Do they still use any pulse jets in models? I was around 6 years old,
which would have been 1954, when I saw a control-line speed event with
pulse jets.

I can still remember the pain in my ears and the vibration like it was
yesterday. My God, those things are loud.

--
Ed Huntress



I remember one of those from when I was a child (middle of last
century). They were *loud*.
I haven't seen one since.

There are a few Jetex sites up even today. That's a slow burning solid
fuel rocket engine. I've thought about playing with those. There are
cheap enough - if you can get them.

But the jet was just plain eerie...

Jet-X engines were revived a few years back, and there's a new one out --
"Rapier" -- that is of different construction (it's not a cannister with
naked fuel pellets, but more like an integrated rocket engine with the
fuel in a cardboard tube, AFAIK).

A little bit of web searching goes a long way...


That's the one. Couldn't remember the new name.
Jetex has a brain cell of it's own - since about 6 years old.

I have a dozen or more plans for Rapier / Jetex power.
Maybe some day...

I still have fun with basic rubber band power.
They make no noise at all - other than the laughter of the kids
(of all ages)

Richard

"cavelamb" wrote in message
m...
Ed Huntress wrote:
"cavelamb" wrote in message
m...
The most impressive small engine I've ever seen run was a small turbojet
in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn
for the
end of time.

Do they still use any pulse jets in models? I was around 6 years old,
which would have been 1954, when I saw a control-line speed event with
pulse jets.

I can still remember the pain in my ears and the vibration like it was
yesterday. My God, those things are loud.

--
Ed Huntress

I remember one of those from when I was a child (middle of last century).
They were *loud*.
I haven't seen one since.

There are a few Jetex sites up even today.
That's a slow burning solid fuel rocket engine.
I've thought about playing with those.
There are cheap enough - if you can get them.

Yeah, I had several Jetexes. The actually were rockets, with come kind of
oxidizer in the fuel pellets. They were heavy little suckers but they were
reliable. I made a balsa glider powered with one and it burned up
spectacularly at about 100 feet of altitutde.

I also used one on a little three-runner sled I made when I was about 11,
which I ran on the pond next to my house. It was fast. My buddy lashed an
Estes model rocket onto it and drove it through the side of his garage. d8-)

But the jet was just plain eerie...

I've been hearing about these miniature turbojets and they sound like
amazing pieces of work.

--
Ed Huntress

Ed Huntress wrote:
"cavelamb" wrote in message
m...
Ed Huntress wrote:
"cavelamb" wrote in message
m...
The most impressive small engine I've ever seen run was a small turbojet
in a
RC model.

It turned something over 100,000 rpm and the harmonics were amazing!

sounded like something between a wailing banshee and the warning horn
for the
end of time.
Do they still use any pulse jets in models? I was around 6 years old,
which would have been 1954, when I saw a control-line speed event with
pulse jets.

I can still remember the pain in my ears and the vibration like it was
yesterday. My God, those things are loud.

--
Ed Huntress
I remember one of those from when I was a child (middle of last century).
They were *loud*.
I haven't seen one since.

There are a few Jetex sites up even today.
That's a slow burning solid fuel rocket engine.
I've thought about playing with those.
There are cheap enough - if you can get them.

Yeah, I had several Jetexes. The actually were rockets, with come kind of
oxidizer in the fuel pellets. They were heavy little suckers but they were
reliable. I made a balsa glider powered with one and it burned up
spectacularly at about 100 feet of altitutde.

I also used one on a little three-runner sled I made when I was about 11,
which I ran on the pond next to my house. It was fast. My buddy lashed an
Estes model rocket onto it and drove it through the side of his garage. d8-)

But the jet was just plain eerie...

I've been hearing about these miniature turbojets and they sound like
amazing pieces of work.

--
Ed Huntress



If you ever get a chance to see one run, take ear plugs AND muffs.

Gerald Miller wrote:
On Thu, 13 Aug 2009 00:09:23 -0400, "Ed Huntress"
wrote:

"Don Foreman" wrote in message
...
On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:

Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots
of
detail about the seals (for anyone who's followed rotary-valve engines
over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm
I saw that in the lab and they flew it once at lunchtime a few years
ago.
I'd really like to see one run -- not that you could tell much by watching
it, but I'd like to see it anyway.
Just like I would like to see the Napier Sabre engine running, just to
say I'd seen one running, likewise the big four bank radial, or the 24
cylinder "W" Allison.

Or the 16-cylinder 1.5-liter W BRM

"Steve Lusardi" wrote in message
...
Ed,
I am a gearhead and I never heard of this either, but I spent some time in
studying this in detail and it is amazing and yet simple, although the
seal IS seriously high tech. The seal screams for a ceramic solution and
they are keeping that solution in reserve. I think this holds incredible
potential in performance, fuel efficiency and cost. I think you will see
these next in outboard motors. Multi-cylinder variations are some ways
down the road, but I see those problems being addressed in the future
economically as well.
Steve

Yeah, if they have a rotary-valve solution that seals tight, that's not too
expensive, and that really lasts, it could be a very big deal.

--
Ed Huntress



"Ed Huntress" wrote in message
...
Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots
of detail about the seals (for anyone who's followed rotary-valve engines
over the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is
more than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

--
Ed Huntress

Ed,
I am a gearhead and I never heard of this either, but I spent some time in studying this in detail and it is amazing and yet
simple, although the seal IS seriously high tech. The seal screams for a ceramic solution and they are keeping that solution in
reserve. I think this holds incredible potential in performance, fuel efficiency and cost. I think you will see these next in
outboard motors. Multi-cylinder variations are some ways down the road, but I see those problems being addressed in the future
economically as well.
Steve

"Ed Huntress" wrote in message ...
Maybe everyone knows about this engine but me, but if not, this is a very cool little piece of machinery worth looking into.
It's the rotary-valve 4-stroke used in the Honeywell hovering drone that's being prepared for field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly simple. They've made available a 7-year-old SAE paper
about it, with lots of detail about the seals (for anyone who's followed rotary-valve engines over the years, that's where most
of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm

--
Ed Huntress

cavelamb wrote:

If you ever get a chance to see one run, take ear plugs AND muffs.

One of the fellows at work saw the UAV in question this morning. It's a
screamer. The characterization was gargantuan leaf blower.

Kevin Gallimore

On Fri, 14 Aug 2009 09:05:36 -0500, RBnDFW
wrote:

Gerald Miller wrote:
On Thu, 13 Aug 2009 00:09:23 -0400, "Ed Huntress"
wrote:

"Don Foreman" wrote in message
...
On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:

Maybe everyone knows about this engine but me, but if not, this is a very
cool little piece of machinery worth looking into. It's the rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with lots
of
detail about the seals (for anyone who's followed rotary-valve engines
over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm
I saw that in the lab and they flew it once at lunchtime a few years
ago.
I'd really like to see one run -- not that you could tell much by watching
it, but I'd like to see it anyway.
Just like I would like to see the Napier Sabre engine running, just to
say I'd seen one running, likewise the big four bank radial, or the 24
cylinder "W" Allison.

Or the 16-cylinder 1.5-liter W BRM
At a tractor show in Caledonia, ON. some years ago, a guy had a radial
diesel tank engine - impressive.
At the same show, someone had an X-8 flat head, water cooled aircraft
engine supposedly an experimental Ford product. It was mostly a rusty
lump of cast iron, nowhere near having any moving parts; I have never
found any further information on this particular engine.
Gerry :-)}
London, Canada

"Gerald Miller" wrote in message
...
On Fri, 14 Aug 2009 09:05:36 -0500, RBnDFW
wrote:

Gerald Miller wrote:
On Thu, 13 Aug 2009 00:09:23 -0400, "Ed Huntress"
wrote:

"Don Foreman" wrote in message
...
On Wed, 12 Aug 2009 13:50:43 -0400, "Ed Huntress"
wrote:

Maybe everyone knows about this engine but me, but if not, this is a
very
cool little piece of machinery worth looking into. It's the
rotary-valve
4-stroke used in the Honeywell hovering drone that's being prepared
for
field use by the US Army:

http://www.nytimes.com/2009/08/12/bu...l?ref=business

It's built by a British company, RCV Engines Ltd., and it's amazingly
simple. They've made available a 7-year-old SAE paper about it, with
lots
of
detail about the seals (for anyone who's followed rotary-valve
engines
over
the years, that's where most of the action is):

http://www.rcvengines.com/pdf_files/saepaper.pdf

It must be pretty darned reliable to be used in the drone, so this is
more
than just another weird engine curiosity.

Here's RCV's home page. They make model engines, too:

http://www.rcvengines.com/index.htm
I saw that in the lab and they flew it once at lunchtime a few years
ago.
I'd really like to see one run -- not that you could tell much by
watching
it, but I'd like to see it anyway.
Just like I would like to see the Napier Sabre engine running, just to
say I'd seen one running, likewise the big four bank radial, or the 24
cylinder "W" Allison.

Or the 16-cylinder 1.5-liter W BRM
At a tractor show in Caledonia, ON. some years ago, a guy had a radial
diesel tank engine - impressive.

Was that the Caterpillar corncob engine from WWII? My father-in-law worked
on that. It was a great engine, but it had so much torque that it kept
twisting off the transmission input shafts, so it wasn't used.

At the same show, someone had an X-8 flat head, water cooled aircraft
engine supposedly an experimental Ford product. It was mostly a rusty
lump of cast iron, nowhere near having any moving parts; I have never
found any further information on this particular engine.
Gerry :-)}
London, Canada

--
Ed Huntress

On Fri, 14 Aug 2009 21:06:52 -0400, "Ed Huntress"
wrote:

At a tractor show in Caledonia, ON. some years ago, a guy had a radial
diesel tank engine - impressive.

Was that the Caterpillar corncob engine from WWII? My father-in-law worked
on that. It was a great engine, but it had so much torque that it kept
twisting off the transmission input shafts, so it wasn't used.

At the same show, someone had an X-8 flat head, water cooled aircraft
engine supposedly an experimental Ford product. It was mostly a rusty
lump of cast iron, nowhere near having any moving parts; I have never
found any further information on this particular engine.
Gerry :-)}
London, Canada
Sorry but I don't recall many details other than it was somewhere
around 6 feet in diameter. This was around 1980.
Gerry :-)}
London, Canada