Author Topic: a very small 4 stroke engine : 1.35cm3  (Read 10543 times)

Offline Zephyrin

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a very small 4 stroke engine : 1.35cm3
« on: May 23, 2020, 09:48:27 AM »
I present you my last engine almost finished and running; a mini 4T of 1.35cm3, (0.08cu in) (bore and stroke: 12mm).,
I wanted a 4 stroke engine, spark ignition, with a reasonable noise level, good power and not running too fast. The goal was to get an engine capable of moving a small mechanical diesel shunter for the 45mm,  gauge 1 track at 1/32 scale more precisely.
So I designed a model inspired by some early engines with a camshaft parallel to the cylinder driven by helical gears, with also a low compression ratio, about 4.3; the cylinder head having a large combustion chamber with face to face valves, quite in the style of the Wyvern and Centaur from ET Westbury, from which I also copied the rocker arm style. The cylinder head has 2 valves controlled by rocker, but I reserve the option to test an automatic intake valve if all goes well.
I also put a water tank for cooling, rather than a water jacket and its associated pump, radiator and fan owing to limited space.
There is also a large flywheel (relatively!) for the smoothness of operation for such a small engine, leaving me the possibility to put a second one on the future drive side.
There is for the moment a traditional ignition with breaker and HT coil; I  had to make some home made spark plugs, mini too, the 1/4 x32 being too bulky on this tiny cylinder head, especially with the carburettor too close to the spark plug, not easy to adjust air intake without receiving electric shocks!
After a rather long running-in, mostly because of my "shop-made" helical gears, it has no more stiffness and started easily, responds well to settings for air, fuel and ignition timing, and runs like a clockwork, but alas, far too fast for my taste, between 2500 and 5500 rpm, the noise being not the expected "put-put-put", but in an acceptable range.
I’ m actually doing an electronic ignition and rebuilding a more advanced carburettor than the simple mixer, and do some power tests to see if the rest of the program is feasible.
but I'm currently making an electronic ignition from a gas lighter as shown in the Jan Ridders website.
I’m also drafting a final version of my plans, but I’m not expert in this field !
I will post some pictures of the building of my engine, after the final result, I agree that this is not the usual way to proceed, but I have to select lot of pictures in my computer…

<a href="https://www.youtube.com/watch?v=gyDb5Gal7eM" target="_blank">http://www.youtube.com/watch?v=gyDb5Gal7eM</a>


Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #1 on: May 23, 2020, 10:27:13 AM »
Excellent  :praise2:  :praise2: Fitting a spark plug and valves into a 12mm bore is not easy. Did you use piston rings?
Best regards

Roger

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #2 on: May 23, 2020, 01:00:37 PM »
Congratulations Zephyrin on a great runner.  It is a really neat and compact design.

MJM460

The more I learn, the more I find that I still have to learn!

Offline fumopuc

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #3 on: May 23, 2020, 02:12:10 PM »
Hi Francois, very nice.
I should put something similar on my retirement list.

Kind Regards
Achim

Offline nj111

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #4 on: May 23, 2020, 04:15:15 PM »
That is fabulous! Thank you for sharing here.
Nick

Offline awake

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #5 on: May 23, 2020, 05:16:42 PM »
Wonderful sound - so even and consistent. Congratulations!
Andy

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #6 on: May 23, 2020, 07:30:44 PM »
Impressive that you got it running so well with such a small design  :praise2:

Offline Art K

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #7 on: May 23, 2020, 11:25:39 PM »
Zephyrin,
You have built quite a nice running engine. I hope it works for your shunting engine!
Art
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Offline Craig DeShong

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #8 on: May 23, 2020, 11:27:43 PM »
Not a lot of room for miss fit machining with a displacement so small.  Runs and sounds great!  Superb job :ThumbsUp:
Craig
The destination motivates us toward excellence, the journey entertains us, and along the way we meet so many interesting people.

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #9 on: May 24, 2020, 08:19:01 AM »

Thanks for all these appreciations and comments,
My engine is not as small as the famous "tiny" published some 10 years ago by putputman, with its 3/8" bore, and its superb hit & miss versions by Gail Graham and Georges Britnell, unsurpassed...

You are right Craig, but you can note that I left some length on the camshaft for a centrifugal regulation, I read and learn avidly on this forum...

A hit & miss control would certainly make the sound more realistic for a small shunting loco, between idle and loaded...but as I have difficulties with the carb, I hesitate to add further trouble with a hit & miss control !

No Roger, no piston rings, a long and plain cast iron piston with 4 oil grooves.
I will post some pictures of the parts.

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #10 on: May 28, 2020, 09:28:15 PM »
I put some pictures of the building of my little engine on my Google album

https://photos.app.goo.gl/aDQ5aQCqALkuMuGs9

I tested the electronic ignition made with a gas lighter as shown by Jan Ridders on his website, and it worked a treat,
I will do a neat lttle ignition box to replace the ugly coil and cable...


Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #11 on: May 29, 2020, 07:52:49 PM »
At the end of this link there are some pictures of Johan van Zanten's Gauge 1 Deutz mining locomotive with a 2cc engine.

https://www.model-engineer.co.uk/albums/member_album.asp?a=6778

It was also written up in MiM,

https://www.vth.de/maschinen-im-modellbau/unsere-beitraege/minenlok-mit-verbrennungsmotor


Best regards

Roger

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #12 on: May 29, 2020, 09:17:36 PM »
Thanks for the links Roger, spot on.
magnificent model, impressive work, a tiny Hit and miss to drive this little Deutz shunting loco, very akin to the models of Gail Graham.
A hit and miss engine is probably more comfortable to use...
but as my engine is running now, I will have a go with my version of the shunter, making a H&miss version of my engine would be a spare wheel, just in case...

Here  is the link for the PDF of the plan my little 4St engine.

https://ti1ca.com/7dzxwa8z-Gedeon-4T-v2-Gedeon-4T_v2.pdf.html

FM

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #13 on: June 01, 2020, 11:48:01 AM »
Hi Zephyrin, a beautiful little engine which will look and sound fabulous in your locomotive.

I have been thinking about the issue of governing the hit and miss action, and can understand that the tiny size might mean that governor weights will have too little mass to operate the valve latching mechanism.

Hidden in your locomotive body, a little electronic governor might be able to operate a mini-servo for the valve operation to get the miss part of the action.  You might be able to get pulses for a “count” for rpm by shining an infrared LED through holes in a gear wheel, or special wheel, onto a photo transistor.

There would be no need for a complex PID algorithm, simply a switch between two servo Positions based on high and low rpm limits with some hysteresis.   

The electronics can be made quote small, and you already have a battery on board if the processor power can be separated from the ignition system, otherwise a separate 4.5 - 4.8 V battery pack.

It could be easier to implement and more reliable than a conventional mechanical governor in such a small size.

MJM460

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Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #14 on: June 04, 2020, 02:50:27 PM »
Hi,
Thanks for advice MJM,
electronics, well, actually, I just dropped my homemade electronic ignition, really unreliable in my hands, I'll work on that...later.
But there are example of working " tiny" H&M regulated engine, by G. Britnell & Gail Graham, 3/8" bore size, that small!

I've rebuilt a new carb for my "Gedeon" engine, I don't receive electric shock anymore during the tuning of air and gas...phew!
I could add a tiny hole for air bleed when idling, to limit smoke, or make a new carb, in steel and longer to prevent vapour lock
my engine run fine, I'm having fun with it : I will do tests for a gear train for transmission...

[youtube1]https://youtu.be/2-Kyi_7a4sA [/youtube1]

But I find the torque a little bit just to move a loco forward, she will stall constantly...but I'm only at the beginning of the tests.

Cheers

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #15 on: June 04, 2020, 09:19:30 PM »
I'm pretty sure Gail had a transmission with a gear reduction between his Tiny and the Loco's they are mounted in. This helps with the torque  :cheers:

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #16 on: June 09, 2020, 11:50:07 AM »
I've  tested my  little engine at work ;
 
somewhat better than at first, as he drives the bike dyno and produces light at the end, but if the rope (a large Oring) is just a little bit too tight, the engine stalls immediately upon switching the bulb on; it is due to few things !

<a href="https://www.youtube.com/watch?v=N_9a3OvkTx8" target="_blank">http://www.youtube.com/watch?v=N_9a3OvkTx8</a>

Offline awake

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #17 on: June 09, 2020, 06:04:20 PM »
Very nice! I appreciated your use of a pump as well as a dynamo - haven't seen that before, but it gives me ideas!
Andy

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #18 on: June 09, 2020, 06:28:48 PM »
Good stuff  :praise2:  :praise2: What output do you think you got?

I got around 16W from my 3cc 4 stroke single but at rather higher revs:

https://www.modelenginemaker.com/index.php/topic,2093.210.html

How the dynamo matches the engine can have quite an effect on what you measure.

Best regards

Roger

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #19 on: June 11, 2020, 08:14:50 AM »
Hi,
the power output of this bike generator, just an electrical alternator of poor quality, is not easy to calculate; I could maybe convert it in DC…
I would say about 2-3 W at most, for my little engine, working hard with this test.
with my little centrifugal pump, about 0.36 l of water were raised of 0.1 m in 1 min, we have : 0.36x9.81x0.1/60 = 6 mW, but obviously the engine was not overloaded…
« Last Edit: June 12, 2020, 07:06:38 AM by Zephyrin »

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #20 on: June 11, 2020, 12:56:39 PM »
Hi Zephyrin, I am another interested to see your engine driving loads to do something useful.

The problem with trying to calculate the engine power output in each case is the efficiency.  I am thinking about perhaps 50% for the pump, but the bike alternator, I really don’t know.  But at 50% the engine output driving the pump is certainly double that first estimate, and as you say it’s not working hard so certainly has lots more to give.

Another great video of a delightful engine.  Now for the locomotive body, some gears and off to the track.

MJM460
The more I learn, the more I find that I still have to learn!

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #21 on: June 12, 2020, 07:28:56 AM »
thanks for the comments, greatly appreciated !
the locomotive, yes, I started to cut metal, progresses could be slow, as I should admit that I'm not fond of model making as long as it is not an engine...some nudge is welcome !

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #22 on: September 18, 2020, 09:35:04 AM »
Hi,
I have just finished a kind of gear box for my small 4 stoke engine, aimed to drive a gauge 1 little loco, with a diesel shunter aspect...

Instead of a centrifugal clutch, like the one found in RC cars, I installed a variable friction drive plate model, which allows to start the gear very gradually without stalling the engine as a driven roller moves from the center (neutral) to the periphery of a driver clutch plate (top gear). 
the result is more bulky than a traditional gearbox, but much simpler to build...
A set screw adjusts the pressure of the clutch plate on the roller. The O-ring is very stiff and the plate is well polished, which seemed counter-intuitive but works best; too soft rings were stretched under the pressure which can be very strong, and teared quickly.
This variable friction drive works satisfactorily, with neutral, forward and reverse gears.

But I have to add a positive lock of the speed control, which moves on its own towards top speed. 

The power available at the output shaft, which rotates at a speed of 1/10 of that of the engine and which will drive the wheels with a belt or a chain, is quite satisfactory, I am very pleasantly surprised even if it is in the range of 5 watt...

[youtube1]https://youtu.be/y9tjTjIrEdU[/youtube1]

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #23 on: September 18, 2020, 11:10:36 AM »
Hi Zephyrin,

That a very impressive demonstration, and a great basis for your locomotive.  And the engine sounds like it could give a lot more if required.

It might be easier to control that variable speed drive than the winch!

It also looks like good progress on the locomotive chassis as well.  It will be running before you know it.

MJM460

The more I learn, the more I find that I still have to learn!

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #24 on: September 18, 2020, 11:37:31 AM »
Great demo Zephyrin  :ThumbsUp:

I might be overthinking it, but if you compare to a small scooter - you got the transmission 'in the wrong order'. On the scooter the centrifugal clutch is directly on the crank, followed by the variable transmission, followed by a reduction gear box. This ensures that you got very little tourque where you might otherwise have the biggest slippage, in order to reduce it. Well only time will tell if it will be a problem or not ....

Best wishes

Per

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #25 on: September 18, 2020, 08:42:56 PM »
Hi,
thanks for the comments !

Per:
What worried me was to see the engine stalling as soon as the clutch is engaged, I thought that this risk would be reduced with an already reduced speed, and a slightly higher torque...hence my first reduction stage.
I hesitated a lot, because you are right about the order of the transmission layout, I agree...
Anyway, the final system works well, but I find it very cumbersome, I have some modifications to do to make it more compact and to make it fit under the bonnet of the loco...and I am not satisfied with its style "Meccano" like, but it is true that my engine too, with a rather "agricultural " look is not well suited for its "industrial" destination either.!
I’m planing another tiny  engine more suited to this destination, once my loco will have made its first laps...

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #26 on: December 29, 2020, 06:02:17 PM »
Hi,
while repairing my tiny 4T engine, I wanted to test the spark plugs, as being of my own making, it's an additional source of failure.

More precisely I wanted to check if the spark was still present under pressure, because it is known that the voltage needed to trigger the spark increases with the pressure.

I made very simple setup: a small transparent plexiglas chamber with the sparkplug, a pressure gauge and a syringe to increase the internal pressure;

and to my surprise, on pushing the syringe, I clearly saw the spark become much brighter, the pressure rises up only to 3 bar, but obviously the light of the spark increases proportionally with the pressure, as it appears in the video.

https://photos.app.goo.gl/WoNhvgeUEBp3SAKp8

I was expecting the opposite, even though I am reassured about my sparkplugs, I wonder what's going on ?



« Last Edit: December 30, 2020, 10:50:27 AM by Zephyrin »

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #27 on: December 29, 2020, 06:10:33 PM »
Unfortunately the video wouldn't play for me, but what you say is reasonable. As you increase the pressure the breakdown voltage will increase so when the spark does jump the gap there will be more energy available, hence the brighter spark.
Best regards

Roger

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #28 on: December 30, 2020, 10:48:37 AM »

hi,
sorry for the video, I don't how to fix it.

Quote
As you increase the pressure the breakdown voltage will increase so when the spark does jump the gap there will be more energy available, hence the brighter spark.

this is something I don't get, the high voltage provided by the coil or the electronic device (which is also a coil at the end) doesn't is already maximal at atmospheric pressure, how this voltage gets higher ?

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #29 on: December 30, 2020, 01:26:26 PM »
In almost all ignition systems there is an energy store, a capacitor or the iron core of a coil, which is charged up and then discharged at the required time. This energy causes the output voltage of the coil to rise until something breaks down and a spark takes place. The bigger the spark gap or the higher the breakdown voltage of the gas between the electrodes the higher the voltage will rise. It maybe that something else will breakdown before the plug gap so you won't get a useful spark. Degraded insulation and dampness is a common cause of this.
Best regards

Roger

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #30 on: December 30, 2020, 04:25:58 PM »
Thanks for the answer Roger, it makes sens...





Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #31 on: March 03, 2021, 08:39:28 AM »
hi

The time has come to install the engine in the shunter frame now finished, but alas,  it doesn't want to run as I would like to :  just like he did during the test, ie as in the video above post #22 !
the engine now runs slowly, without power, has difficulty to turn alone, stalls immediately at the least mishap, impossible of course to ask him the slightest effort...
yet I feel good compression, the valves are tight, and I'm very happy with my electronic ignition, I don't understand what's going on with my engine!
where does this loss of power come from, too much wear of the tiny parts during the power tests?
do i need to rebuild an engine?

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #32 on: March 03, 2021, 11:28:50 AM »
If it can be avoided - do not take it apart ...!
As with any engine - every time you take it apart it usually deteriorates a bit (or more).

There was a Joke in my moped youth - Why don't you take i apart to see why it runs so well ??..!! - The reason was that everybody knew that it wouldn't run as well afterwards -> only the stupid did so.

I can relate to your frustration, but with good compression it ought to be mechanically sound - except perhaps for timing of valves or ignition ....  :thinking:

The last bit would be the carburetor (mixture) / Inlet passage or the Exhaust side blocked ...?

Best wishes and good luck

Per

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #33 on: March 03, 2021, 01:10:22 PM »
Some thoughts:

You say that the compression is similar to before. Is there more friction from anything?

Is the valve timing and valve lift similar to before?

Is this the same ignition system you used in the earlier tests? Has it been disconnected and reconnected?

Is the ignition timing the same as before?

Could there be an air leak in the inlet pipe?
Best regards

Roger

Offline gbritnell

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #34 on: March 03, 2021, 01:54:16 PM »
You can check all the things that Roger suggested It's easiest to eliminate the things that usually don't change, the ignition and carburetor and the valve seal. That generally leaves the timing and compression. I have found that a lot of my engines are affected by heat after running for awhile. The heat soaks into the manifold or carburetor and creates a vapor lock to some degree or another. My tiny engines all have home-made spark plugs and they either work or they don't so I wouldn't suspect that would be the case with your engine.
gbritnell
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Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #35 on: March 03, 2021, 06:59:15 PM »
thanks for the input...
I did this afternoon a test without the rocker on the intake valve, ie, like an auto or atmospheric valve (but with a somewhat stiffer spring), with a clear improvement in running, suggesting that the cam or the rocker or both doesn't function properly.
it seems to me that my engine is not able to take a big breath of air and gasoline, and to run with the air wide open as before.

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #36 on: March 08, 2021, 09:32:08 AM »
look at how my engine runs now, this jerky running is more or less strong but constantly present, I'm confused, I've checked that the sparks don't go out with the speed, and the jet inlet seems clean, I know it's not a real carburettor but it's the same as before !
spring valve too weaks, too stiff ?

https://photos.app.goo.gl/1kEwxgt5gMFVqXaL7

I am well beyond my skill level...

the complete album is here
https://photos.app.goo.gl/aDQ5aQCqALkuMuGs9

« Last Edit: March 08, 2021, 09:42:12 AM by Zephyrin »

Offline michaelr

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #37 on: March 08, 2021, 11:18:12 AM »
It sounds to me that the engine is Hunting, a check on the fuel supply may help.

Mike.

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #38 on: March 08, 2021, 11:33:35 AM »
My first thought was the same as Mikes .... and followed by - it might also be missing sparks .... I do not think that the cause is a mechanical, like a spring etc.

Can you see any air bubbles in the fuel to the carb ?

Best wishes

Per

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #39 on: March 08, 2021, 04:54:14 PM »
Unfortunately I can't see your video but another question; Have you changed the height or position of the fuel tank from your first runs?
Best regards

Roger

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #40 on: March 08, 2021, 06:05:11 PM »
Hi,
nice to have advices...thanks !
it seems to me that the intake phase is shortened owing to worn cam and rocker, hence the engine can't cope with an increase in speed, the engine is simply starved, as suggested.
the cure therefore is simply to make new cam and rocker...I hope.

I'm not against the making of a brand new engine, but it is frustrating to do not understand the causes of failure before !

Roger :
yes the fuel tank is higher, with a clear improvement...everythings that make easier the intake of fuel seems beneficial !

I don't know how comes you can't see the video on my google album
 you may test this site for the video

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #41 on: March 15, 2021, 09:11:07 AM »
Hi
Despite all the problems with the engine I tried a real test of the loco...just to see!
The engine is still far from giving all its power as it did before, due to an intake problem if I believe the noise in puffs...
it's the major problem, I'm working on it!
Nevertheless, she ran and I was very useful to see the many things to change :
- Transmissions with chains, there is too much slippage with the actual belts.
- The clutch switching wheel is a real pain, much too slow, and should be replaced by a lever.
- The clutch plate and the roller are quickly slipping at the slightest drop of oil, keeping this devices oil free will not be a simple affair.
I plan to make a real carburettor, with a decent idle.

<a href="https://www.youtube.com/watch?v=KCC9kLKGQrs" target="_blank">http://www.youtube.com/watch?v=KCC9kLKGQrs</a>

The positive point is that my miniaturized ignition on board works well, it is reliable, if I had the courage to change something in it, it would be to put a Hall effect switch.

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #42 on: March 15, 2021, 10:02:16 AM »
Hi Zephyrin, despite the problems still to be solved, that does look like a very encouraging run.

Having it run reliably like that is very encouraging for the fine tuning which remains.

Well done.

MJM460

The more I learn, the more I find that I still have to learn!

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #43 on: March 15, 2021, 05:01:20 PM »
thanks MJM,
yes I found it very encouraging, as the little shunter can cope with the tight curves of the plastic track, and the sloping surface...

many things to amend, but which are minor as soon as I recovered full power of the engine.

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #44 on: March 15, 2021, 05:50:50 PM »
Wonderful  :praise2: you must be proud of that  :wine1:

That sounds to be a too rich mixture problem ( I can see this video  :) ) Getting a good carburettor at that size will be an interesting problem.
Best regards

Roger

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #45 on: March 16, 2021, 08:41:19 AM »
Hi,
nothing new in the future carburettor Roger : a simple 2 needle model carburettor with an air valve that moves as it rotates and decreases the fuel intake while closing the air, a little bit smaller.
For miniaturization, I look carefully at your posts!

Offline Johnmcc69

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #46 on: March 16, 2021, 03:14:47 PM »
 :ThumbsUp:
 Looking good Zephyrin!

 What did the final gear ratio work out to be?

 John

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #47 on: March 17, 2021, 10:28:33 AM »

Thanks John !
 This diesel shunter drags at about 50 km/h on the track, so 265 rpm for its 1 m wheels; value which has to be kept on the Gauge 1 scale model (1/32), that is 300 rpm (which gives an actual speed of 2 km/h on the model with 34 mm dia wheels).
Therefore, a 15 times reduction of the engine speed (4800/300) should be in the right range.
This is what I got with a fixed reduction of 6, followed by a variable reduction on the friction drive of about 3 to 0.9 ( about 1.5 at the middle), and a final reduction of 1.66 on the loco's axles.
I would clearly prefer faster locos...but unrealistic for the trains buffs at the club

Offline Johnmcc69

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #48 on: March 20, 2021, 06:09:12 PM »
 :ThumbsUp:
 Thanks Zephyrin!

 John

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #49 on: September 12, 2021, 11:20:55 PM »
Hi,
We had the authorization to meet us at our model railroad club, (thanks to a anticovid vaccination certificate !) and of course we ran our steam locomotives...

i took the opportunity to start the engine of my little "diesel" shunter and run it some laps on the track...
I was waiting for doing these runs for several months !

<a href="https://www.youtube.com/watch?v=QoGXdqTmF0U" target="_blank">http://www.youtube.com/watch?v=QoGXdqTmF0U</a>

<a href="https://www.youtube.com/watch?v=VwDeO6ktf7A" target="_blank">http://www.youtube.com/watch?v=VwDeO6ktf7A</a>

I was very happy to show her to colleagues, and happy too with her performance too...
even if I had to add an extra wagon to carry the bulky HT coil and battery, my electronic ignition planned to be housed under the bonnet being still not at its best !

« Last Edit: September 27, 2021, 10:40:13 AM by Zephyrin »

Offline RReid

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #50 on: September 13, 2021, 12:19:02 AM »
That looks and runs great, Zephyrin. Very glad you finally got the chance! :ThumbsUp:
Regards,
Ron

Offline crueby

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #51 on: September 13, 2021, 12:33:10 AM »
Fantastic!!   :praise2:

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #52 on: September 13, 2021, 05:12:43 AM »
Wow!  I'll say!  That little guy just buzzes around the track like nobody's business!  You SHOULD feel quite good about this!

Kim

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #53 on: September 13, 2021, 07:40:25 AM »
Excellent  :praise2:  :praise2:  :wine1:
Best regards

Roger

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #54 on: September 13, 2021, 09:26:31 AM »
thanks for the appreciations..
i really enjoyed this "public test run" at the club.

https://photos.app.goo.gl/hc6CcCxBbx1GbPTu6

I have to think to the next model,  a new project or finishing an unfinished ones at least ?

Offline john mills

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #55 on: September 13, 2021, 09:53:45 AM »
great engine looks good towing the wagons
John

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #56 on: September 13, 2021, 11:15:57 AM »
Looks like you could not ask for more - did you have to do a lot more fine tuning to achive this performance ?

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #57 on: September 13, 2021, 01:49:52 PM »
Hi Zephyrin, congratulations, that is running beautifully.  Thanks for the video.

MJM460

The more I learn, the more I find that I still have to learn!

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #58 on: September 13, 2021, 06:49:08 PM »
Hi,
Yes it is exactly that, this model is finished for me ! 
Maybe I should ask to a fellow at the club to make a neater video at a next meeting.
the engine is not that complicated, very conventional design, its just the small size to fit under the cockpit (?) that make some parts difficult to machine.
most of the things went well when I leaved my electronic ignition !

Offline Johnmcc69

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #59 on: September 14, 2021, 01:30:04 AM »
 :NotWorthy:
Magnificent!
 Very well done & glad to see it on the track!

 John
 

Offline steamer

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #60 on: September 14, 2021, 01:55:22 AM »
Oh what a sweet little engine!   I always like to see our engines doing something.    Great job Zephyrin!!! :praise2:

Dave
"Mister M'Andrew, don't you think steam spoils romance at sea?"
Damned ijjit!

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #61 on: October 08, 2021, 08:33:21 AM »
Thanks for the appreciations, a good nudge for the next project!

last Sunday at my club i ran my little loco among the live steam trains, the first real meeting for over a year, it was really nice!
a pal made a nice video of this great day, and you can see my loco at the beginning of the film, just to show how much fun we had!

i'm really so pleased of its operation that I'm afraid I've left the live steam engine for good for my next loco project!

<a href="https://www.youtube.com/watch?v=EBCrCk04Baw" target="_blank">http://www.youtube.com/watch?v=EBCrCk04Baw</a>

Offline gbritnell

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #62 on: October 08, 2021, 12:30:37 PM »
Congratulations!  You did a truly outstanding job on both the engine and locomotive!
Talent unshared is talent wasted.

Offline propforward

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #63 on: October 08, 2021, 01:19:28 PM »
That's a fantastic engine - it's delightful to see it running around the track.
Stuart

Forging ahead regardless.

Offline Johnmcc69

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #64 on: October 08, 2021, 04:37:31 PM »
 :ThumbsUp:
 Some VERY nice models there!
 I'm looking forward to what you come up with next,

 John

Online scc

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #65 on: October 08, 2021, 09:17:02 PM »
Lovely engine and loco, a great runner!  Many Congrats :cheers:       Terry

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #66 on: October 09, 2021, 11:26:21 AM »
thanks for the appreciations, so welcome from engine builders !
As everyone knows, when everything works as expected, it seems so simple and easy to do, and yet, phew!!

I wonder actually if such a small engine (or a triffle larger) would be able to drive an electrical generator, powerful enough for electrical traction, more akin to a large main line diesel electric loco...
a few interesting tests to perform in the weeks to come...

Offline MJM460

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #67 on: October 09, 2021, 12:14:05 PM »
Hi Zephyrin, A genuine diesel electric transmission would be impressive, even if with a spark ignition.  I hope you will post your testing to develop the system.  It will offer many useful control options that are no so easy with direct engine drive.

It will be interesting to see what you select for the generator as well as the motor.

MJM460



The more I learn, the more I find that I still have to learn!

Offline Admiral_dk

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #68 on: October 09, 2021, 07:24:54 PM »
I seem to remember seeing a model loco with a .40 OS four stroke connected to a generator, that supplied the electric permanent motors on the axles - all RC controlled.
He had originally planned a multi cylinder diesel (with all the problems Roger can tell you about), but realized that the OS didn't sound far off the planned at the right RPM, with a special muffler. Another reason was that he was not left with much available space inside the finished Loco.

I don't think that I have that magazine anymore ....

Offline Zephyrin

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #69 on: October 10, 2021, 08:24:17 AM »
At the moment it is just brain rummaging on the feasibility...
I have to look at other attempts successful or not !

Quote
Another reason was that he was not left with much available space inside the finished Loco.
I'm ready to understand this point !
tiny engines become huge as soon as we put them into the loco frame !


Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #70 on: October 10, 2021, 09:59:29 AM »
My 3cc engine will give 15-18w at fairly high speed. It may do better with a better matched generator but I think that is more than enough to move a locomotive.

Many years ago Robert Symes-Shutzmann built a Hymec based G1 diesel hydraulic powered by a Taplin twin and also a diesel electric based on a British Type 4.

I met him at an exhibition and saw the 'Symec' but unfortunately he had just hydraulic locked it and broken the crankshaft (he used an electric drill for starting) so I didn't see it running  :(
Best regards

Roger

Offline Roger B

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #71 on: October 10, 2021, 11:01:41 AM »
This is his Class 47 starting and running (around 3mins in).

<a href="https://www.youtube.com/watch?v=0_IHBZkuDWk" target="_blank">http://www.youtube.com/watch?v=0_IHBZkuDWk</a>



Best regards

Roger

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Re: a very small 4 stroke engine : 1.35cm3
« Reply #72 on: October 12, 2021, 02:53:37 PM »
Thanks for the input Roger,
And on the last min of the video, I’m impressed by the way this model engineer domesticated the taplin twin, really amazing. 
I looked further on the internet and gathered about half a dozen of similar tests, very successful achievements of diesel-electric traction on 45mm track, either in scale G (1 / 22.5) or G1 (1/32), all based on large sized "glow" engines with their noise and smoke problems that make these locos difficult to run in a club beyond a brief demo...
and in fact this "nitro-electric" traction does not correspond to what I imagined, too much sound and fury!
I'm not going to rush and will somewhat amend the project !

 

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