Schneule porting
Geoff Martin
I am just planning a return to model airplanes.
Things have changed in the last 35 years (mostly for the better!)
I have read engine reviews which mentioned Schneule porting. It seems to
wonderfully improve the specific output of model engines (Diesels only?)
How does it work?
Are there any good texts om model areo engines?
Thanks
Geoff
--
Dr Geoff Martin, Associate of the Department of Computer Science and
Software Engineering
Monash University, 900 Dandenong Road, Caulfield East 3145, Australia
Ph: +61 3 9827 6308 gma...@ct.monash.edu.au
==============================================
Gerald43
>I have read engine reviews which mentioned Schneule porting. It seems to
>wonderfully improve the specific output of model engines (Diesels only?)
>How does it work?
Schneurle porting is the technique of adding a third intake boost port directly
across from the exhaust port. The extra breathing capacity helps give more
power to any engine, not just diesels. Harry Higley writes a nice book on
engines.
Gera...@aol.com
"Batman"
Ian Maclaughlin
Geoff Martin <gma...@ct.monash.edu.au> wrote:
>I am just planning a return to model airplanes.
>Things have changed in the last 35 years (mostly for the better!)
>I have read engine reviews which mentioned Schneule porting. It seems to
>wonderfully improve the specific output of model engines (Diesels only?)
>How does it work?
>Are there any good texts om model areo engines?
Geoff-
Welcome back - 35 years is a long layoff. Schnuerle porting has been
around for a number of years. I'm not positive, but I think it was
originally used in motorcycle engines, then picked up by the model
airplane racing engine pros in the US circa late 60's. Supertigre was
the first to offer it in production model airplane engines, in the
G15, IIRC. It is a fairly radical departure from the crossflow (or
'loop') scavenging scheme, which relies on a baffle atop the piston to
direct the fuel mixture influx upward in the cylinder, in turn
pushing the spent mixture downward and out the exhaust port. The
Schnuerle scheme does away with the baffle, and induces laminar flow
of the mixture influx up the cylinder wall by steeply angling the
intake ports upward. Viscous forces replace the baffle in directing
inflow to the top of the cylinder. Multiple intake passages,
including both primary intake and 'boost' ports are used, as
contrasted to the crossflow type, where a single intake port opposite
the exhaust is used. The objective of all these directed passages is
to optimize the scavenging of spent gasses and replace them with the
maximum charge of fresh fuel mixture. It works well enough that most
two-stroke engines now use it, whether diesels, semi-diesels (AKA glow
ignition) or spark ignition. It is easy to identify what sort of
scavenging an engine uses just by looking into the exhaust port. A
flat-topped piston, with no exception that comes to mind, indicates
Schnuerle porting. You can also generally spot the lumps on the
exterior of the crankcase that indicate multiple intake ducts lie
underneath.
Ian
San Diego
Bill...@cleaf.com
gera...@aol.com (Gerald43) wrote:
>>I have read engine reviews which mentioned Schneule porting. It seems to
>>wonderfully improve the specific output of model engines (Diesels only?)
>>How does it work?
>
directly
>across from the exhaust port. The extra breathing capacity helps give more
>power to any engine, not just diesels. Harry Higley writes a nice book on
>engines.
>Gera...@aol.com
>"Batman"
The third port opposite the exhaust port is not the determining factor in
Schneurle porting.
Schneurle porting is the arrangement of intake ports adjacent to the exhaust
port, directed towards the back wall of the cylinder. This arrangement
creates a flow of incoming mixture that scavenges the cylinder better (i.e.,
better than traditional single by-pass porting). Many Schneurle ported
engines have only the two main ports and no third (often called a "boost")
port, although most of our model airplane engines have all three.
Some pictures on the web might be of interest. A brand new F2D (CL FAI
Combat) engine from Cyclon (Russian engine) is pictured at
http://www.algonet.se/~ehnwall/c-15pccl.htm
In these pictures you will see a Schneurle ported engine which only uses the
two main port, no boost port. Also unique (i.e., not commonly seen) is that
the ports are actually machined into the cylinder liner instead of being cast
into the crankcase. Take a look at some really well-done pictures of a
beautiful engine.
Regards,
Bill Lee
(Remove the X to reply)
Iskandar Taib
>The third port opposite the exhaust port is not the determining factor in
>Schneurle porting.
>
>Schneurle porting is the arrangement of intake ports adjacent to the exhaust
>port, directed towards the back wall of the cylinder. This arrangement
>creates a flow of incoming mixture that scavenges the cylinder better (i.e.,
>better than traditional single by-pass porting). Many Schneurle ported
>engines have only the two main ports and no third (often called a "boost")
>port, although most of our model airplane engines have all three.
I've also read (somewhere) that the original Schnuerle patent used an
arrangement much like the Cox .049s used - two exhaust ports, with two
transfer ports in between.
>Some pictures on the web might be of interest. A brand new F2D (CL FAI
>Combat) engine from Cyclon (Russian engine) is pictured at
>
> http://www.algonet.se/~ehnwall/c-15pccl.htm
>
>In these pictures you will see a Schneurle ported engine which only uses the
>two main port, no boost port. Also unique (i.e., not commonly seen) is that
>the ports are actually machined into the cylinder liner instead of being cast
>into the crankcase. Take a look at some really well-done pictures of a
>beautiful engine.
Wow, thats a pretty engine. What are they going for?
--
-------------------------------------------------------------------------------
Iskandar Taib | The only thing worse than Peach ala
Internet: nt...@copper.ucs.indiana.edu | Frog is Frog ala Peach
Home page: http://bigwig.geology.indiana.edu/iskandar/isk2.html
Bill...@cleaf.com
nt...@copper.ucs.indiana.edu (Iskandar Taib) wrote:
<snip>
>
>>Some pictures on the web might be of interest. A brand new F2D (CL FAI
>>Combat) engine from Cyclon (Russian engine) is pictured at
>>
>> http://www.algonet.se/~ehnwall/c-15pccl.htm
>>
>>In these pictures you will see a Schneurle ported engine which only uses the
>>two main port, no boost port. Also unique (i.e., not commonly seen) is that
>>the ports are actually machined into the cylinder liner instead of being cast
>>into the crankcase. Take a look at some really well-done pictures of a
>>beautiful engine.
>
>Wow, thats a pretty engine. What are they going for?
I should have pointed at a different page/ The one mentioned above is a supplement to
the page with all the details. Try
http://www.algonet.se/~ehnwall/cycl15pc.htm
Following is the text from that page that might be of interest.
Regards,
Bill Lee
ENGINE SPECIFICATIONS AND INFORMATION :
No. 005-9 Engine. CYCLON 15 PC ( for expert use )
ŠIncludes: aluminium silencer, aluminium engine mounts and propeller.
ŠSwept volume - 2,48 cc.
ŠStroke - 14 mm.
ŠBore - 15 mm.
Š13 mm dia. crankshaft.
ŠChromeplated 6 mm dia. crankpin.
ŠBronze bushed piston without circlips.
ŠAngled rear exhaust w. aluminium silencer.
Š1,2 bhp - Works rpm. 33.000 - Weight 129 grams.
ŠWith special design inside "Turbo" head inserts.- No.1-3, delivered w. no.2.
ŠPRICE : US $ - 179.99.
_
The engine has a very long working life. The special Turbo-head is also fitted with 34
mm outside dia. to handle hot weather conditions.The conrod is specially designed to
prevent it from touching the backplate to eliminate friction. All spare parts are
available. 10 days delivery.(approx.)
The engine is designed and manufactured by double World Champion in F2A-Speed,
Alexander Kalmykov of the " CYCLON COMPANY."
_
ORDERS for, and Information about the CYCLON 15 PC engine:
"Cyclon Company" - Engines & Models
RUSSIA , 630112 Novosibirsk.
pr. Dzerjinskogo 2-67.
Alexander Kalmykov.
_
Preferably via E-MAIL : ro...@cyclon.nsk.su
or phone:
Š+7-3832-773771 (office)
Š+7-3832-205278 (factory)
Š+7-3832-677368 (home)
=======================
Iskandar Taib
In article <6dmapg$36n$1...@news7.ispnews.com>, <Bill...@cleaf.com> wrote:
>nt...@copper.ucs.indiana.edu (Iskandar Taib) wrote:
> <snip>
>>
>>>Some pictures on the web might be of interest. A brand new F2D (CL FAI
>>>Combat) engine from Cyclon (Russian engine) is pictured at
>>>
>>> http://www.algonet.se/~ehnwall/c-15pccl.htm
>>>
>>>In these pictures you will see a Schneurle ported engine which only uses the
>>>two main port, no boost port. Also unique (i.e., not commonly seen) is that
>>>the ports are actually machined into the cylinder liner instead of being cast
>>>into the crankcase. Take a look at some really well-done pictures of a
>>>beautiful engine.
>>
>>Wow, thats a pretty engine. What are they going for?
>
>
>I should have pointed at a different page/ The one mentioned above is a supplement to
>the page with all the details. Try
>
> http://www.algonet.se/~ehnwall/cycl15pc.htm
>
>Š1,2 bhp - Works rpm. 33.000 - Weight 129 grams.
129 grams is about 4.2 ounces I think..
>ŠWith special design inside "Turbo" head inserts.- No.1-3, delivered w. no.2.
>
>ŠPRICE : US $ - 179.99.
>
>Preferably via E-MAIL : ro...@cyclon.nsk.su
>
>or phone:
>
>Š+7-3832-773771 (office)
>
>Š+7-3832-205278 (factory)
>
>Š+7-3832-677368 (home)
Yeah, we talked about this on the Combat mailing list recently.
Apparently, Mike Willcox bought something like 20 of these. If you buy
10 or so the price goes down to $100 or so.
I wonder why the folks who fly 704 don't buy these.. save over 2
oz. in the engine department alone, and outpowers practically every
.15 out there except for the old Nelson units. Especially when one can
bore out the venturi. The one drawback is the $4 props. No throttle?
Use a shutoff.
Bob Adkins ought to buy one to just to see whats possible in terms of
ultra-lightweight powerhouses.
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