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Cox Engine of The Month
Multi cylinder Valentines
Page 1 of 1
Multi cylinder Valentines
By multi cylinder, I mean more than two!
This is a flat 6 cylinder. I have no data for it as it is a prototype but each cylinder is 0.98cc. Another very admirable miniature masterpiece.
It has been fired up and tested but not measured. I am not sure that it went into production so this may be 1 of 1.
This is a flat 6 cylinder. I have no data for it as it is a prototype but each cylinder is 0.98cc. Another very admirable miniature masterpiece.
It has been fired up and tested but not measured. I am not sure that it went into production so this may be 1 of 1.
ian1954- Diamond Member
- Posts : 2688
Join date : 2011-11-16
Age : 70
Location : England
Re: Multi cylinder Valentines
Magnificent Ian.. Thanks for posting! I'm trying to visualize the crankshaft(s)? Is it possible that it's a multi-piece component with separate indexed discs that key or mate together via their crank-pins on a 180 degree timing-geometry per cylinder pairs? Given a one-piece crankcase; I can't see any other way than this, to install the connecting-rods. I would also imagine the crank(s) riding in a full-length bronze sleeve-bushing in the case, with relief-slots milled for rod clearance and the intake manifold?
Are the #3 and 4 (central) cylinders prone to overheating? There's very little clearance between those cylinder heads. I wonder; if they were oriented 90 degrees to the opposing pairs.. whether it would alleviate that condition, if it existed? Of course; it would no longer be a flat opposed six.. and not as attractive.
I'm no engine designer.. but I'm fascinated by these tiny marvels!
Are the #3 and 4 (central) cylinders prone to overheating? There's very little clearance between those cylinder heads. I wonder; if they were oriented 90 degrees to the opposing pairs.. whether it would alleviate that condition, if it existed? Of course; it would no longer be a flat opposed six.. and not as attractive.
I'm no engine designer.. but I'm fascinated by these tiny marvels!
Re: Multi cylinder Valentines
Yes, it probably is. The conrods and crankshaft are assembled together and then inserted in the crankcase. Pistons were added later and cylinders were screwed on after. It's a similar idea as a Panhard engine
Lieven
Lieven
OVERLORD- Diamond Member
- Posts : 1807
Join date : 2013-03-19
Age : 58
Location : Normandy, France
5 Cylinder Radial - 5 x 0.98 cc
The 3 piece crank case is machined from bar stock. The engine has a central reed valve and is geared. The cylinders and spinner were anodized. Each cylinder has 2 intake and 2 exhaust ports.
Bore 5.0 mm
Stroke 5.0 mm
Rpm 9,300 rpm
Total combustion 5x0.098 ccm
Weight 65 gram
Intake Reed Valve
Bore 5.0 mm
Stroke 5.0 mm
Rpm 9,300 rpm
Total combustion 5x0.098 ccm
Weight 65 gram
Intake Reed Valve
ian1954- Diamond Member
- Posts : 2688
Join date : 2011-11-16
Age : 70
Location : England
Re: Multi cylinder Valentines
That's a neat one. Light too. Might actually work in a model!
Cribbs74- Moderator
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Posts : 11907
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
Power Max Flat four
This is the Power Max flat 4 cylinder diesel engine. The crank case was machined from bar stock and sand blasted. Each cylinder has 2 intake and 2 exhaust ports. It has divided connecting rods and a one piece crank shaft.
Bore 5.0 mm
Stroke 5.0 mm
Rpm 12,300 rpm
Total combustion 4x0.098 ccm
Weight 40 gram
Intake Rotary Valve
Bore 5.0 mm
Stroke 5.0 mm
Rpm 12,300 rpm
Total combustion 4x0.098 ccm
Weight 40 gram
Intake Rotary Valve
ian1954- Diamond Member
- Posts : 2688
Join date : 2011-11-16
Age : 70
Location : England
Rasant V-4
This is the Power Max V-4. A "V". The same basic construction as the Flat 4.
Bore 5.0 mm
Stroke 5.0 mm
Rpm 12,300 rpm
Total combustion 4x0.098 ccm
Weight 40 gram
Intake Rotary Valve
Bore 5.0 mm
Stroke 5.0 mm
Rpm 12,300 rpm
Total combustion 4x0.098 ccm
Weight 40 gram
Intake Rotary Valve
ian1954- Diamond Member
- Posts : 2688
Join date : 2011-11-16
Age : 70
Location : England
Re: Multi cylinder Valentines
Those engines are amazing! Simply Amazing!
Shawn
Shawn
sdjjadk- Platinum Member
- Posts : 640
Join date : 2012-04-07
Location : Southern Maryland
Re: Multi cylinder Valentines
Owning those would kill me because I would want to either RUN them or worse - take them apart, put them
back together and then RUN them!
Beautiful machines.
Phil
back together and then RUN them!
Beautiful machines.
Phil
pkrankow- Top Poster
- Posts : 3025
Join date : 2012-10-02
Location : Ohio
Re: Multi cylinder Valentines
It is not that the grape is sour, but I always wonder how these multi-carb glows, or even more so, the multi-cylinder diesels can be tuned for each cylinder to work at the peak performance? by the time you set the contra-pistons on each cylinder you run short of the fuel in the tank...
balogh- Top Poster
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Posts : 4958
Join date : 2011-11-06
Age : 66
Location : Budapest Hungary
Re: Multi cylinder Valentines
I wonder how its done if they had glow plugs it would be just a matter of each cylinder having a even fuel flow.
1/2A Nut- Top Poster
- Posts : 3536
Join date : 2013-10-20
Age : 61
Location : Brad in Texas
Re: Multi cylinder Valentines
A diesel is in general more tolerant to the air/fuel ratio, and even if it is off a little the engine doesn't quit like a glow engine can/does.
The first start of a new engine can be tricky but once you've found a suitable compression ratio there is very little tuning needed (if the same prop and fuel is used). Some require a slightly higher compression ratio to fire from cold, but if you can prime the side of the piston it will almost always fire on a single flip...
The first start of a new engine can be tricky but once you've found a suitable compression ratio there is very little tuning needed (if the same prop and fuel is used). Some require a slightly higher compression ratio to fire from cold, but if you can prime the side of the piston it will almost always fire on a single flip...
Surfer_kris- Diamond Member
- Posts : 1912
Join date : 2010-11-20
Location : Sweden
Re: Multi cylinder Valentines
pkrankow wrote:Owning those would kill me because I would want to either RUN them or worse - take them apart, put them
back together and then RUN them!
Beautiful machines.
Phil
MAN! I don't know how a guy could NOT run one of those !!! That V-4 is SOMETHING. I'd probably mess it up, but I'd HAVE to try to make it go!
What a beautiful piece of work !!!!!!!!!!!!!!
Drooling Kim
Kim- Top Poster
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Posts : 8625
Join date : 2011-09-06
Location : South East Missouri
Re: Multi cylinder Valentines
Two of the above have been run by me. The 5 cylinder radial and the four cylinder flat.
It is not difficult but it is nerve racking!
Diesels are easy to bring on song. The five cylinder radial is set up by slackening off all cylinders except the top one and finding the firing point by priming.
Priming with the piston closed and the smallest drop of fuel until it fires. Then repeat for each cylinder after slackening off the cylinder just fired.
Reset the top three cylinders to fire (from previously noted compression screw positions) but completely slacken off the bottom two. (Very important!).
Gradually open the needle and flick. Constantly check the bottom two cylinders for flooding. Blow out the bottom two cylinders with air constantly.
The engine will run on three cylinders gradually increase compression to the firing point on the bottom two.
Mistakes will be costly - when all cylinders are firing they can be adjusted but it is advisable to leave the bottom two slightly under par.
Do not try to start with a rich mixture without slacking off the compression. Once set, restarting is a quick matter and little needs changing.
It might seem strange to not fully tune all cylinders but those bottom two will be prone to running rich - this is a single carb engine.
Why haven't I got this on film? .........Because this is the most nerve racking experience I have had starting an engine. These are "delicate" and very rare and demand concentration.
The flat four is easy same process but start with the front cylinder and work backwards.
You would have to be very brave to bring all cylinders up to full tune. Over compress either by the compression screw or over richening the mixture and it will be damaged.
I did film this one - well nearly! After I had got it to running state - I set the camera up, fired the engine first flick and let it run for two minutes. Afterwards, I cleaned and lubed the engine (as I always do) and loaded the camera on to my pc. I had taken loads of images and videos - it took ages to load up. When I checked everything a week later - that video wasn't there!!! I had forgotten to start recording!
It is not difficult but it is nerve racking!
Diesels are easy to bring on song. The five cylinder radial is set up by slackening off all cylinders except the top one and finding the firing point by priming.
Priming with the piston closed and the smallest drop of fuel until it fires. Then repeat for each cylinder after slackening off the cylinder just fired.
Reset the top three cylinders to fire (from previously noted compression screw positions) but completely slacken off the bottom two. (Very important!).
Gradually open the needle and flick. Constantly check the bottom two cylinders for flooding. Blow out the bottom two cylinders with air constantly.
The engine will run on three cylinders gradually increase compression to the firing point on the bottom two.
Mistakes will be costly - when all cylinders are firing they can be adjusted but it is advisable to leave the bottom two slightly under par.
Do not try to start with a rich mixture without slacking off the compression. Once set, restarting is a quick matter and little needs changing.
It might seem strange to not fully tune all cylinders but those bottom two will be prone to running rich - this is a single carb engine.
Why haven't I got this on film? .........Because this is the most nerve racking experience I have had starting an engine. These are "delicate" and very rare and demand concentration.
The flat four is easy same process but start with the front cylinder and work backwards.
You would have to be very brave to bring all cylinders up to full tune. Over compress either by the compression screw or over richening the mixture and it will be damaged.
I did film this one - well nearly! After I had got it to running state - I set the camera up, fired the engine first flick and let it run for two minutes. Afterwards, I cleaned and lubed the engine (as I always do) and loaded the camera on to my pc. I had taken loads of images and videos - it took ages to load up. When I checked everything a week later - that video wasn't there!!! I had forgotten to start recording!
ian1954- Diamond Member
- Posts : 2688
Join date : 2011-11-16
Age : 70
Location : England
Re: Multi cylinder Valentines
http://www.ebay.com/itm/Vintage-antique-custom-hand-machined-Cox-quad-4-cylinder-airplane-engine-motor-/271608158654?pt=Radio_Control_Parts_Accessories&hash=item3f3d1b99be#ht_38wt_1083
FYI 4 cylinder custom made cox engine for sale.
FYI 4 cylinder custom made cox engine for sale.
1/2A Nut- Top Poster
- Posts : 3536
Join date : 2013-10-20
Age : 61
Location : Brad in Texas
Re: Multi cylinder Valentines
Very interesting, Ian. I'm glad your thread finally got some attention.
Rusty
Rusty
_________________
Don't Panic!
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
...and never Ever think about how good you are at something...
while you're doing it!
My Hot Rock & Blues Playlist
RknRusty- Rest In Peace
- Posts : 10869
Join date : 2011-08-10
Age : 68
Location : South Carolina, USA
Re: Multi cylinder Valentines
Goodness Ian! What a ritual, I wondered about the firing sequence and now I know.
If you ever catch it on film please post.
Ron
If you ever catch it on film please post.
Ron
Cribbs74- Moderator
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Posts : 11907
Join date : 2011-10-24
Age : 50
Location : Tuttle, OK
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