Micro 12VDC Generator with a Cox .049 Sure Start Diesel Engine

StevenStanleyBayes wrote:

robot797 wrote:mmm that sounds like a deal

that is (not converted) cheaper then my ether
(1.6L costs 55.84 euro)

I am suprised to hear there is more expensive Ether than here. As per previous posts from The UK, Ethere there is incredibly inexpensive.

Just for information,  Walmart sells an Ether based starter fluid, guaranteed to have 60% Ether for around $5CAD.This works for gasoline engines and diesel engines ( standard ).  You may wish to check the big stores near you, the stores which sell everything and have an automotive section. They may have the spray cans which should contain a great deal of Ether. Do not worry as far as percentages go. When you spray the contents in a glass, treat the fluid as 100% Ether and see whether works. You can always add more otherwise.

Ether is derived from Petrolium just the same as gasoline and diesel,  just more refined. Thus, Ether must not cost more than double the price of gasoline. However, the manufacturers and shops sell this for a lot more with the exception of The UK, where business is more fair and the demanf is higher and Ether is considered a normal,  general purpose chemical as should be.
.

I have submitted the link of your generator to www.coxengines.ca

They may be interested in knowing of your excellent design.

StevenStanleyBayes wrote:

Surfer_kris wrote:

StevenStanleyBayes wrote:

Surfer_kris wrote:

StevenStanleyBayes wrote:
As far as global experience is concerned, experience is not necessary anywhere. Necessary is knowledge in some cases. And knowledge has got nothing to do with experience. Not experience but knowledge reduces the possibility of a mistake.

Hehe, you should tell that to NASA, I believe that they are actually training their astronauts...

.... in Ohm's Law. I would not be surprised. : ) LOL

So ignorance is indeed bliss...  

Ignorance is lack of knowledge and knowledge has nothing to do with experience.

I have submitted your forum name to www.CoxEngines.ca and provided them with the information you have been using a Cox engine for your sand buggy.

They may be interested in knowing this.

Admin wrote:Here's the link to StevenStanleyBayes' Document http://www.steven-stanley-bayes.com/Cox%20.049%20SureStart%20Diesel.doc

I downloaded it and skimmed it, I'll need to fully read it later.


I had an idea similar to yours. Basically to build an .049 powered flashlight that could be also used to output 5vdc to power and charge USB devices such as a cellphone. I would use a car engine with a pull start for ease of starting and because of the clutch that disallows it from running backwards. A good 10+ years ago a stand that was selling gasoline generators out at the Minnesota State Fair had a Cox Babe Bee fitted with a big flywheel connected to a gearbox that was spinning a small ac alternator that could power a few flashlight bulbs and I think they even had a handheld TV hooked up to it. I regret never getting a picture of it.


Take a look at this site, http://dieselrc.com/projects/coxgen/

I don't recall what the average horsepower of a standard Cox .049 engine is but you can't load these down too much before they kill. That would explain the gearbox on the one I seen at the State Fair, needed to increase the torque.

I have submitted the link of your excellent CoxGen project www.CoxEngines.ca
They may be interested in knowing this.

I have not been asked by anyone to ask you to submit your NON STANDARD Cox engine projects to www.CoxEngines.ca  by email as per their web site. I have just taken this initiative.

I think this initiative will provide an excellent information to the company of your applications of Cox engines just for their reference. They may already know and may read this forum but, just in cases, please do so. We will not overload them with emails because there are not so many of us to work on non standard projects.

I think the company knows everything there is to know on standard applications for flying aeroplanes. Thus, by NON STANDARD applications, I mean anything which is not just putting the engine on an aeroplane as per the instructions. There may be some non standard ideas of Cox engine applications for aeroplanes, then, please also do so.

The idea is to inform the company of these applications. This may help the company in dealing with customers who may wish to explore these excellent engines for their projects. Also, the company may respond accordingly to some of your applications with their knowledge and experience and, thus, help you.

I, personally, have been conversing with the company and exchanging hundreds of emails and receiving important information in order to build this project on which I am currently working.

May I also take this opportunity to thank all at Cox International for their great help and support. Not only did they reply immediately to all emails and phone calls answering ALL questions and giving ideas and inputs BUT they mailed all of the parts and the engine IMMEDIATELY after I ordered them. They even synchronised their deliveries to the post office to be before the postman picks the mail from the post office in order to ensure as fast delivery as possible.

I am amazed not only how superb their engines and the products are but also what fantastic services they have.

In case we want to do something good, I think, informing other people of their excellent products, prices and services is going to be something which we can all do.

In this sense, I would like to inform you all I will submit this project to KickStarter whenever ready. May I also ask you all, for your own good as well as for the good of Cox', to submit all your projects to KickStarter as well. After all, all of us have spent money making these projects. Submitting them to KickStarter may recover some of the funds we have spent or all or even more.

Because I have been submitting other, non related, projects to KickStarter, knowing how KickStarter works, they would love ( in order of appearance ) the CoxGen project, the robot797 generator project and Surfer_kris' sand buggy ( Cars with RC engines have been available but Surfer_kris applied an aeroplane engine ( maybe with some modification ) to a sand buggy which should make the project meet KickStarter's requirements ). They would also love the project of using alternative fuels, as published here, but I am not sure KickStarter would understand this project and the significance thereof.

Anyway, I think these are good ideas for everyone.

Editing is to be done. This video is long and there are a lot of problems in the duration of the video and not so much of a generator run. Those of you who are impatient, please wait for the edited version. The video also shows a good run of the engine with or without a load at very low RPM which I have displayed for a while shutting the engine off for various reasons.

This has been a very difficult video due to lack of proper elastic bands for belts as well as wide pulleys and a good pulley arrangement which has been achieved in the duration of the video.

Regardless the pulley ratio was such as to make the dynamo spin faster ( with the speed of the engine ), the dynamo has stubbornly been giving 2W power output only. Looks like a lot of RPM are needed to make the dynamo give more power which means I need better pulleys and elastic bands. The next start would be with a 2 ( engine ) to 1 ( dynamo ) pulley ratio and, hopefully, the pulleys as well as the belt would be good enough to provide the dynamo with high RPM.

When large load is used ( 5 Ohms ), the engine when the load is switched on immediately as expected. I have continued the experiments after the video. When the engine RPM are reduced and then the 5 Ohm load is switched on and then the RPM are increased, things seem to be OK.

Here is more information :

Fourth Successful Start of the System : With a Load. No Tank, no Muffler.

Video Link : https://www.youtube.com/watch?v=ouW2OST5vn4
Video Link of the Edited Video : To be done.

Preliminary Information : This has been the fourth start on video. The whole generator was assembled without a tank and a Muffler. Three loads : 10Ω, 10W, 5% ; 7.5 Ω, 20W, 5% ; 5 Ω, 15W, 5% have been used. Started well after fuel loading as expected. Initial fuel loading has been carried out by reducing the compression a lot ( more than a turn ) and closing the Air Valve ( Throttle ). Engine run well and was controllable. Air Valve and intake ducts have been cleaned with Ether prior to start. Problems with the belts and the pulleys adjustments to be in a straight line. Many belts used and many of them got broken as expected. There was no much of a distance between the pulley and the propeller and the propeller was able to catch the belt on occasion. Very difficult test. As mentioned, initial fuel loading was carried out by closing the Air Valve ( Throttle ), reducing the compression and performing 2 to 4 “ empty “ spring starts. All spring starts, including the “ empty “ fuel loading spring starts are in the same settings ( except for the fully closed Air Valve ( Throttle ) specified thereafter. Here are the specifications :

Engine : Cox .049 SureStart Diesel

Muffler : Not Installed

Pulleys : Engine Pulley : 1.5cm, Dynamo Pulley : 1.5cm

Pulley Ratio : ~ 1

Dynamo : RS555, Brushed DC Generator ( Dynamo ) and a 12 VDC Electrical Motor

Fuel : 8mL Ether ( John Deere 80 Starter Fluid ), Kerosene : 7mL, Castor Oil : 5mL, Cetone Booster ( 2 Isopropyl Nitrate & Xelone ) 1mL. This is : 38% Ether ( John Deere 80 Starter Fluid ), Kerosene : 33%, Castor Oil : 24%, Cetone Booster ( 2 Isopropyl Nitrate & Xelone ) 5%

Amount of Fuel : 20mL

Preliminary Start without the Dynamo Attached : Yes, at the same settings. Reason : to heat up the engine for the start with the dynamo attached.

Propeller : 3.125 Inches Diameter, 2.5 Inches Pitch, 3 Blades

Belt : Elastic Band. Low tension. Higher tension also tried. Unable to find strong belt which is not flat but either square or rounded.

Dynamo Fan : Installed

Electrical Load : Two loads used. The fuel burned before being able to install the third one. Load 1 : 10Ω, 10W, 5%. Load 2 : 7.5Ω, 20W, ~5%. Load 3 ( not used but available ) : 5Ω, 30W, ~5%.

Fuse : 3A

Spring Starter : Yes

Other Means to Start the Engine : Not Used

Level of Spring Start Engagement during Successful Starts : Not fully engaged. Around 2 compression only.

Settings : Air Valve : 75% Open ; Fuel Needle Valve : 3.5 turns Open ; Compression : Close to Maximal but Not Maximal ( the compression screw was screwed gently until some resistance shown and backed until no resistance and a tiny more ). Increased after the start to be almost the maximal. When the engine was hot, the compression was adjusted to close to maximal ( until some compression screw resistance was found ) and the Air Valve ( Throttle ) was nearly fully open.

Engine Control : The engine exhibited a very good ability to be controlled by all controls : Air, Fuel and Compression. When load applied, the engine self increased the RPM. When load applied the dynamo resistance increases, the load to the engine increases trying to decrease the RPM and the engine sucks more fuel and air and increases the RPM. Engine self feedback.

Voltage and Current Achieved : Voltage without load : 24 to 30VDC. Voltage with load ( Load 1 and Load 2 ) : 3 to 4 VDC. Current : 0.5A or lower with all loads. Load 2 established : 4.025VDC and Load 3 : 3.2VDC, thus, 2W power. This is very strange. Looks like the dynamo cannot perform very well or requires huge RPM to do so. With 1 : 1 pulley ratio, the power achieved is lower than with 0.5 ( engine ) to 1 ( dynamo ) ratio although the dynamo RPM were higher with 1 to 1 pulley ratio.

Greasing the Pulleys Before Start : No.

Temperature of the Engine and the System : Room ( 20ºC to 25ºC )

Temperature of the Fuel : Room ( 20ºC to 25ºC ). Because Ether had been derived from a John Deere 80 Starter Fluid can with compressed Ether and propellants, the Ether was freezing when squeezed out. Thus, the fuel had to be warmed up. The fuel was put in a measuring glass where the fuel was mixed. Then the measuring glass was dipped into a jar with hot water and kept for a few seconds. Then the fuel was shaken to mix up even more at the new, high ( room ) temperature.

Noise : Yes but not as much as before because of the low RPM. Generally, the engine is powerful and noisy. Some reduction may be possible with the muffler. Not as much so the power is not reduced.

Messy : Yes but kept away by the yellow plastic protection installed around the dynamo. Exhaust fluids have not been canalised. Can be canalised through a pipe attached to the exhaust ( best modified with a bigger hole ) with a nipple attached to the exhaust to allow attachment of the exhaust pipe.

Conclusion : Only 2W achieved. The dynamo seem to be incredibly stubborn and works at around 3 to 5V and around 0.5A regardless of the RPM. Looks like huge RPM may be needed to make the dynamo perform to some extent. Poor dynamo performance was expected but not so poor.

The male cigarette lighter connector plug broke the female cigarette lighter connector socket. Hope I can super glue the broken part.

The engine pulley is lousy. Will not be used again. Hope to find wine corks to make a wide pulley out of.

Must cut a wide elastic band in to to make a narrow one.

Next test would be with an engine pulley twice as big as the dynamo pulley to ensure 2 to 1 ratio which will make the dynamo spin twice as fast as the engine.

The pulleys must be ligned up perfectly.

Extremely important is to have a lot of room between the pulkey and the propeller. The new pulley goes over the propeller screw head. Hope I can put lots of spacers and washers between the pulley and the propeller. May try to heat up the propeller blades and bend them towards the engine to prevent the belt from being caught by the propeller.

I am immensly unhappy by the performance of the dynamo which cannot keep any voltage at any current higher than 100mA. Without any current, the dynamo is OK and can go to 24V, even 30V and then drops to 3 to 4V and 0.5A regardless of the RPM ( depends on RPM very slightly ). Looks like a zener dynamo. : ) I did expect so but not to such an extent. Well, this is a $1 DC electric motor which I try to use as a dynamo. What can I expect?

Two things : 1. The engine increases the performance when the engine sees a load. This is like an engine self feedback. 2. At lower compressions, the engine can overcome immediate ( surge ) loads more easily and stable.

I explain these two with a better suction at lower RPM and load. I explain 2. with even better suction at lower compressions.

When the engine works at given settings and load is applied, the load slows the engine while the settings remain the same. The slowed engine has a longer period of an open fuel hole at the dame settings and sucks more fuel and air. Also, the powerful explosion ( combustion ) leads to a more powerful blow of the exhaust fluids which may create a suction and Bernuli effect as the exhaust fluits exit. True more fuel and air will escape but much more will come.

The decreased compression of 2. allows for even more fuel and air to be sucked because no strong reaction to the fuel travelling to the upper cylinder is exerted at lower compressions.

ANY OTHER EXPLANATION IS WELCOME.

Here are all of the links :

Thesis : http://www.steven-stanley-bayes.com/Cox%20.049%20SureStart%20Diesel.doc

Edited Video of the Assembled Micro Generator, No Tank, No Muffler, Pulley Ratio : 1 to 1 : https://www.youtube.com/watch?v=nAMso-6gPfE

Video of the Assembled Micro Generator, No Tank, No Muffler, Pulley Ratio : 1 to 1 : https://www.youtube.com/watch?v=ouW2OST5vn4

Video of the Assembled Micro Generator, No Tank, No Muffler : https://www.youtube.com/watch?v=fPuUY2SubGY

Edited Video of the System Start and Work with the Dynamo : https://www.youtube.com/watch?v=P6sSJIbKgk4

Edited Video of the Engine Start and Work without the Dynamo : https://www.youtube.com/watch?v=KTbZ11njcn0

Video of the System Start and Work with the Dynamo : https://www.youtube.com/watch?v=vA0HQJMAUSo

Video of the Engine Start and Work without the Dynamo : https://www.youtube.com/watch?v=Y7FfparKL78

Pictures of the Back Panel : http://www.steven-stanley-bayes.com/Pictures%20of%20the%20Back%20Panel.doc

Pictures of the Engine, the Dynamo and the Stand : http://www.steven-stanley-bayes.com/Pictures%20of%20the%20Engine,%20the%20Dynamo%20and%20the%20Stand.doc

Pictures of the Engine and the Stand : http://www.steven-stanley-bayes.com/Pictures%20of%20the%20Engine%20and%20the%20Stand.doc

Pictures of the Assembled Generator, No Tank, No Muffler : http://www.steven-stanley-bayes.com/Pictures%20of%20the%20Assembled%20Generator,%20No%20Tank,%20No%20Muffler.doc

Electrical Schematics in .jpg Format : http://www.steven-stanley-bayes.com/12VDC%20Micro%20Generator%20with%20Micro%20Engine%20with%20Internal%20Combustion.jpg

Electrical Schematics in .123 Format : http://www.steven-stanley-bayes.com/12VDC%20Micro%20Generator%20with%20Micro%20Engine%20with%20Internal%20Combustion.123

Glow Plug Voltage from a 12VDC Source : http://www.steven-stanley-bayes.com/Glow%20Plug%20Voltage%20from%20a%2012VDC%20Source.doc

Hi Stanley, I enjoyed your video. Is there a link that explains the function of the "knob" at the top of your fixture? I saw you adjust it several times during the test. Is the larger (or largest..) of the three resistors, too much of a load for the engine to sustain running? You've certainly done and documented a lot of work there.

roddie wrote:Hi Stanley, I enjoyed your video. Is there a link that explains the function of the "knob" at the top of your fixture? I saw you adjust it several times during the test. Is the larger (or largest..) of the three resistors, too much of a load for the engine to sustain running? You've certainly done and documented a lot of work there.

Thanks for your input. You have found the worst video to enjoy. : )

The large knob which is on the Aluminium rod which goes higher than the rest is a guitar tuning machine. When rotated, the lever turns the string to stretch or release. Instead of a string, I have attached a fishing line to the guitar tuning machine. On the other side of the fishing line is a tiny fishing hook which goes into the hole of the lever of the Air Valve ( Throttle ). A spring also goes there. When the tuning machine is rotated towards the engine, the fishing line's length decreases and the lever is moved to open the Air Valve ( Throttle ). When rotated the other way, the length of the fishing line increases and the spring pulls the lever towards the closed position.

The largest ( in size ) resistor is 5 Ohms, 30W, 5% ( three 15 Ohm resistors in parallel ). When the engine is run at low compression and low RPM ( low voltage ), they are OK. Otherwise, there is a surge which the engine may not cope well at certain speeds and settings.

StevenStanleyBayes wrote:

roddie wrote:Hi Stanley, I enjoyed your video. Is there a link that explains the function of the "knob" at the top of your fixture? I saw you adjust it several times during the test. Is the larger (or largest..) of the three resistors, too much of a load for the engine to sustain running? You've certainly done and documented a lot of work there.

Thanks for your input. You have found the worst video to enjoy. : )

The large knob which is on the Aluminium rod which goes higher than the rest is a guitar tuning machine. When rotated, the lever turns the string to stretch or release. Instead of a string, I have attached a fishing line to the guitar tuning machine. On the other side of the fishing line is a tiny fishing hook which goes into the hole of the lever of the Air Valve ( Throttle ). A spring also goes there. When the tuning machine is rotated towards the engine, the fishing line's length decreases and the lever is moved to open the Air Valve ( Throttle ). When rotated the other way, the length of the fishing line increases and the spring pulls the lever towards the closed position.

The largest ( in size ) resistor is 5 Ohms, 30W, 5% ( three 15 Ohm resistors in parallel ). When the engine is run at low compression and low RPM ( low voltage ), they are OK. Otherwise, there is a surge which the engine may not cope well at certain speeds and settings.

The, the RPM can be increased and the engine is capable to cope with the load as long as the load is not put instantaneously, say, by flipping the switch. When the engine runs at low compression, however, the engine can even take an instantaneously applied 5 Ohm load. I am not sure whether this is because of the lower RPM ( thus voltage and power ) at lower compression or because the engine is more stable at low compression or the two thereof. I think the two factors apply.

I think the dynamo puts a huge transient load to the engine when the load is applied instantaneously and then decreases the load to the engine. This may be expected because of the reactive way of work the dynamo and the low value of capacitance ( 47uF ) I have.

The problem is, after the transient process, the dynamo does not seem to be able to display any power more than 2W regardless of the RPM achieved with this 1 to 1 pulley configuration. This is why I will attempt 2 ( engine ) to 1 ( dynamo ) pulley configuration but I am not sure I would achieve a better result. The reason for this, I think, is the dynamo lacks power and must be span at huge RPM ( probably more than 20 000 ) to display some power. In case the voltage is the only problem of the dynamo, I can put all 6 resistors in parallel to achieve a 2.5 Ohm resistor. Then, in case the dynamo can reach 5V, I would have 10W. I must go to very low RPM and gradually increase the RPM until I reach a high power.

However, I think the dynamo may not be able to give high power even at low voltage. I will know more after I test the system with 2 to 1 pulley ratio.

Keep into account the electrical load does not represent the engine load. In other words, the dynamo may display 2W and load the engine with 20W. This is because of the efficiency of the dynamo which depends on the load and RPM. I have always been sure this dynamo has a very low efficiency but I have not expected to be so low. Higher pulley ratios are welcome, yet, I am not able to use anything than 2 to 1 ratio because I do not have pulleys. Also, when the dynamo spins at high RPM, a good belt is of essence and I do not have such. I use elastic bands.

Hopefully, I would have a better output with the bigger engine pulley with which I was able to run the engine with these high power settings : Air Valve ( Throttle ) fully open, Fuel Needle Valve 4 turns open, compression low ( to start ) to highest ( during run ). The engine does not allow for a great deal of control with the other controls but responds well to a control with compression. The power which the engine displays at these settings is tremendous. I hope everything is better with the dynamo.

I am looking for a machine screw with a thread of 5 40 ( Imperial, North American ) and a length of 1.5 inches or more. Anything longer than 1 inch with this thread would be OK.

Any suggestions? Any online place? Does anyone have any which would like to sell? Any information would be helpful.

StevenStanleyBayes wrote:I am looking for a machine screw with a thread of 5 40 ( Imperial, North American ) and a length of 1.5 inches or more. Anything longer than 1 inch with this thread would be OK.

Any suggestions? Any online place? Does anyone have any which would like to sell? Any information would be helpful.

http://www.microfasteners.com/sca0524-5-40-x-1-1-2-socket-head-cap-screw-alloy-steel.html

RknRusty wrote:

StevenStanleyBayes wrote:I am looking for a machine screw with a thread of 5 40 ( Imperial, North American ) and a length of 1.5 inches or more. Anything longer than 1 inch with this thread would be OK.

Any suggestions? Any online place? Does anyone have any which would like to sell? Any information would be helpful.

http://www.microfasteners.com/sca0524-5-40-x-1-1-2-socket-head-cap-screw-alloy-steel.html

Thanks. I will see whether they can ship to Canada with a standard USPS stamp.

I have some for you
Send me a pm

robot797 wrote:I have some for you
Send me a pm

Thank you for your help.

Found a loose connection.

Checked whether the capacitor was wrongly connected. Was OK. Will be removed for some tests.

The cigarette socket was assembled lousily with the bottom just snapped to the rest. Now is superglued.

Heated the propeller with a cigarette lighter and bent them towards the engine and away from the belt.

Cut a couple of wide elastic bands and made 3 narrower bands. Will attempt to use 2 or even 3 one on the top of the other. Unsure whether this would work.

You all were very helpful with the information in regards to the propeller screw. Does anyone know anything of a lower lenght yet thick square or round elastic band?

Try an o-ring instead, they perform better as belts than regular rubber bands do...

Surfer_kris wrote:Try an o-ring instead, they perform better as belts than regular rubber bands do...

I have already done so. I have ordered five 8cm, 2mm O rings. The diameter which the system uses is around 10cm.I have been using 6cm elastic rubber bands. O rings do not stretch as much as elastic rubber bands. Therefore, I have decided to order 8cm O rings which would hopefully stretch to more than 10cm without too much tension.

In case I want to pre stretch them I would heat them u and gently stretch. A heat gun would do but the best way to evenly stretch them is to dip them in heating water at a certain temperature which is to be defined by dipping them in normal water, heating the water and checking once in a while by gently stretching.

I hope 8cm is OK or I will know what to look for next when I am to purchase even better O rings.

The 8cm, 2mm O rings hane been ordered, purchased, processed and shipped by the seller on eBay. Hope to receive them soon.

Meanwhile, I will continue with elastic rubber bands.

I have not decided but I may make a guide or two to be put on the two sodes of the engine pulley to prevent the belt from escaping. Just nothing but two giant washers with a tiny screw hole to insert the propeller screw through.

I hazitate because the 3cm engine washer is deep and good even without guides. Guides may allow for a lower tension belts for the same reason.

The loose bottom of the cigarette lighter socket was super glued to the cylinder of the cigarette light socket. Looks fine. Must be very careful when inserting the plug and must not press strongly.

Generator reassembled. Capacitors not installed for the next test.

The heat bent propeller broke when empty spring starts were tested. All three blades broke. Replaced the propelled with the four blade yellow propeller, the same as the one on the dynamo. Slightly more difficult to turn to wind the spring. Also, very strange, looks like the lack of inertia is makes the spring turn with a difficulty. May be a mistake. Cannot imagine such a tiny 3.125 inch propeller would make a difference in inertia. Hope everything is OK. Otherwise, I have 2 more 3.125 inch Cox propellers but I would like to use the yellow fan which has 4 blades and the blades are wider for more air displacement. The fan is of lower diameter ( around 6cm ) and does not reach the level of the cylinder head of the engine but the geometry of the fan, the twists and turns, are such so the fan blows slightly upwards towards the cylinder head which means the cylinder head would get enough aeration.

The 3mm red engine pulley was installed on the propeller screw. Then two spacers and a washer. Then the propeller. There is plenty of room between the propeller and the belt.

Sniper adjusted the propeller pulley to be in a straight line with the dynamo pulley. Used thin elastic rubber band to give a line. Looks OK although to adjust the pulleys in a perfectly straight line is a challenge.

As mentioned, wide elastic rubber bands were cut in half and I have three narrower ones to use as belts. I shall attempt to put two or all three of these one on the top of the other to make one stronger and narrower belt.

I hope to be able to achieve enough RPM for the dynamo to give 12V output at 10 Ohms. In case of a linearity, I should expect to achieve 8V but I would run the engine at Air Valve ( Throttle ) fully opened, the Fuel Needle Valve 4 turns open and low to close to the highest compressions using the compression screw to decrease and increase the RPM. Higher RPM, higher V but also higher P thus lower RPM but the engine must be able to compensate for the RPM drop because of the higher power consumption.

I am, afraid, however, a higher diameter engine pulley may be needed to achieve a practically high power at lower engine RPM. OK, fair enough, I would struggle more and make a 6cm ( effective ) engine pulley to give a 4 to 1 engine to dynamo ratio. However, will I be able to START the engine at this high pulley ratio? I have only tried and succeeded with 2 to 1 ratio.

The dynamo, when used as a motor, is said to be able to spin 12000RPM when 12VDC are applied at zero mechanical or dynamics load consuming 1.3A. Although not exactly true, believed is the motor to work with similar parameters when used as a dynamo : In case I am able to spin the dynamo 12000RP, I should be able to get 12VDC and 1.3A which is around 15W.

I can only wish to be wished luck for now.

Just checked the rotation with the new propelker. works OK. Got mislead before. Obviously, the tinier the propeller the more difficult to manupolate.

So far, everything looks OK. Will see after the test.

Yes. I am to be blamed. I screwed up the fuel.

Regardless. Managed to start the engine with different settings but without the dynamo. The engine worked perfectly with the new fuel and allowed for a wide range of control by all three controls.

However, the system could not start with the dynamo because of the 2 to 1 pulley ratio, 2 for the engine pulley and 1 for the dynamo.

The dynamo puts a big load to the engine which the engine cannot overcome at start. Still managed to start the system but for a few seconds only. Was unable to sustain and I was unable to react quickly to switch the electrical load.

Considering I have to run the dynamo with 4 to 1 pulley ratio, even higher, 6 to 1 welcome, I am disillusioned and I am not sure I would be able to ever start the engine with the dynamo. Will see but looks impossible now.