Carburetor mixture control

We had cold sleet this morning in OSAKA today and Vocar 34 PICT3 carburetor in air-cooled VW Beetle 1302 was obliged to adopt the fuel-air mixture onto cold season, make it richer with turning mixture control screw(lower and smaller one) clockwisely 1/16 turn and idle speed control big screw counterclockwisely 1/8 turn. Spark advance is set at BTDC 10 degree as many owner's of Beetle do. I have never changed till now from hot Summer setting to cold Winter one. Scientific Physical Property that in the very cold condition, motors require richer fuel supply is exactly the same as model motors. In order to adjust the mixture by human capability according to the change of atmospheric condition, we should have an indispensable capability to know the actual mixture ratio immediately encountering the scenery of inconvenient motor in bad conditioning. Judge!, rich or lean now. This is a key to establish the most suitable mixture control from idling to maximum rotation. In the Radio controlled Model Airplane field, I have very often seen that Laymen destroyed their important self-fabricated airplane at the first flight because of lack of motor conditioning especially in the carburetor mixture setting. Even some factory young engineer shows unnatural correspondence at the flight site? Long nourished experiences might be required to make an appropriate reactions on to a carburetor setting and adjustment?

As an another story, I'm intending to modify OS 46LA motor into a pressurized fuel injection equipment applying the same YS pressure regulator component as done on 25LA and 32F. As I am doing to use in some eccentric way pulling out the surpassed capability of the original designing with big throat and pressurized fuel supply. Probably, additional digging of the 4th Shunyure port by myself might be required like an upper model FX46. The difference between them are the existence of crank shaft supporting bearings, but the use of the rotation around 11,000rpm would not make any physical difference? The lighter weight and the release from troublesome bearing maintenance would be convenient for me. Tuned silencer pipe is one of a choice for this 46 motor, this NOS motor would show remarkable performance in Sutkoi 40 maneuver airplane.

Smallest but excellent performance

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Crowded tube arrangement shows this Rooky 10 and OS 25LA has some unusual fuel supply system. Thank to YS fuel injection utilizing crank case primary compression pressure, very stable pressurized fuel supply is performed whatever attitude an airplane might take, such as rising up and down, spin or avalanche with no anxiety of power down nor motor stopping phenomena. Rising up without any stall stress makes me possible to draw F3A-P15 pattern with this smallest Rooky10 trainer airplane? I wanna show the incredible scenery in front of the top flyers in the field, I would do that with confidence. Also this over-powered Rooky10 would distribute a good opportunity to control this at the most adequate slow speed all through drawing the pattern. Only highest speed and lowest motor rotations were actually used over 30 years ago, but now the slow speed silent stunt is popular and prevailing, so the motor controlling technology is required in P15. Hopeful motivation to be an applicant of the future contests comes up in my mind, I do not accept any situation like being guided by other persons especially by the production company engineer's one, I enjoy myself on my way just with surprising the factory engineers. As an another story, OS 32F has fully disassembled and maintained with applying pressure nipple at the usual portion for preparing next step to burden in Rooky20, procedures would be exactly the same as Rooky10. As for my regretting matter, very important part of YS pressure regulator block is missing, so must I fabricate it by myself.

Leitz copy stand

Leitz copy stand lasts me as long as 40 years since silver salt period of time. This Leitz genuine product was supplied for Leicaflex users in the world at that time, but still now the accuracy of the main pole verticality and the stage flatness still remains through almost the half-century. I'm surprised to know the quality control of products produced by Ernst Leitz GmBH at that time. Not a few German Leitz products are still kept by myself, all of them still satisfy my difficult desire that hard to please. It goes without writing that the quality of their superb lenses at all, now Leica M lenses, a few Visoflex lenses and those of R ones, 2 M-Summicron 50, M-Summilux 50, M-Elmarit 90, Tele-Elmar 135, Elmar 135, Hektor 135, V-Macro Elmar 65, Summar 120, V-Telyt 180, V-Telyt 280, R-Macro Elmarit 60, R-Elmarit 135, R-Apo Summicron 180, R-Apo Telyt 280 and so on, they are all my favorite treasures.

Fuel supply

Not a few modifications were operated on Rookie 10 small trainer airplane yesterday. First of all, carburation has completely changed from normal aspiration to YS fuel pressure injection system, this is operated under a special device with diaphragm regulated and primary crank case pressure supplying into the fuel tank. Although, this one had been kept as one my juely for as long as 40 years. The carburetor should have fuel measuring system at idling speed, this is one of an indispensable requirement for YS fuel injection system. Trial running on a test bench showed reliable performance to be used on actual flight. The biggest advantage of well controlled fuel pressure system is that, operative condition does not change in any attitude of the airplane keeping decided amount of fuel injection, up & down, spin and avaranches with no anxiety of motor stop if the adjustment was adequate enough, but not difficult.
The injection system consist with a regulator, a pressure outlet nipple, an one way valve and micro mesh fuel strainer, very simple construction.
The regulator was positioned at just the nose gear portion outside because of shallow mounting space.
Over powered OS 25LA on Rooky10 is operated under a half throttle condition on ordinary flight and the full power is used only when it comes up while maneuver, so mechanical dumping stopper was invented on the transmitter stick portion, very simple as it is, so works well, the convenience of this modification would be realized if tried actually.

Peaky and difficult motor OS 25LA

It's snowing out side this early morning for the first time this year in spite of the beginning of the Spring on the diary yesterday. Cold weather would inhibit our customer to come to us today.
Started old hobby, Model airplane that is radio-controlled provides me many research projects, now I'm in the proposition of 2 cycle gas motor combustion. Reduction of compression ratio improves the condition with increasing chamber volume by applying 0,200mm thickness gaskets one by one, 2 sheets are not enough to come to plateau point, waiting next trial experiment. As my opinion, this OS 25LA gas motor has too high compression ratio to be used by some ordinary beginners or laymen, remembering my past experiences to come across with the scenery, no 25LA motor was not performed in it's best performance. In another words, a peaky and high compression gas motor has tendency to be difficult to be treated with relieve, because small change of circumstance invite nowhere fast. But, once the condition was fixed in the best one, this must show great and eye opening ultimately high performance. Even some manufacture production company engineer would stunned by the sight. Pulling out the surpassed performance is my dreamy intention!

Consideration

Even a small model gas motor for beginners OS25LA gives me some precious opportunities to examine much deeper on the condition of combustion. In spite of additional 0,20mm thickness gasket application, still vanish production does not stop between piston and cylinder walls surfaces, especially on the portion between the side ports, note here, this economic motor has not main shnuerle ports but 2 side ports only, so this port designing must be a sensational affair, not a few researched must have been done by OS factory engineers?
But, found out I some description in Wikipedia about the uneven heat temp. distribution in the Shnuerle ported cylinder. Additional port forming there is in my imagination? Many description and articles are shown in the Web site, so, I have world wide opened biggest library here in front of my LCD with internet condition!

One of my old friend kindly gave me JR Explorer model for free of charge, this is an old new stock of his fabrications. So, the time would be relatively near future to come back this model airplane F3A field.
Too much care and kindness by circumstantial friend might make me spoilt child neglecting self efforts.

11AD Beetle repaired thorughly!

Removing spark plug #4, I found out that no sparking was triggered at all in spite of some fuel smell remained inside. My VW 11AD Super Beetle has not been serviced on the contact-breaker point gap as long as over 10,000km running. Before finding out the criminal of the affair this time, replacing procedures were done, a capacitor on the spark distributor, a spark coil and distributor assy. Even a trifle physical phenomena, too narrow contact point by melting down can cause fatal phenomena like this. Any way, replacing several keeping replacement parts had some good opportunity to be checked their healthy performances. Remember that Super Beetle I am keeping is basically different from recent automobile, fully mechanically controlled at all, so, periodical maintenance are indispensable at all. Now my babe has recovered original good condition. I don't know why my nose holes are so blacky after car maintenance?