Throttle valve modification

An application of additional shnyure port in OS 25LA cylinder brought several changes in combustion state, inviting powerful rotation 12,100 rpm with Graupner 9-5 prop under K&B 500 fuel taking along vigorous vibration, but is within tolerance. Apparent improvement of combustion efficiency was observed. In order to eliminate 3 dimensional vibration adequately, several trial experiments should be performed utilizing mechanical vibration tachometer gazing at trembling directions though the method might be so primitive now a days, re-balancing of the counter weight is performed like this even in the manufacturer's research and developing division.
Some lean mixture at idle speed of 25LA on the testing bench reminds me of the very important advice 30 years ago done by the former representative of Yamada Industrial Company at Inuyama City in Aichi Pref, the lower throat of the drum type throttle valve should be slightly opened because of lean mixture compared with the condition of natural aspiration carburetor, YS regulator controls only at middle speed and the slow speed mixture should be established promptly. In another words, very accurate and perfect balance of the drum throats upper and lower throat comparison could eliminate complicated mixture control and adjusting at idle speed in the carburetor construction. Careful checking on this important point, the fact was revealed that all of the genuine YS motors has throttle valves so designed as he had said to me.
Though I do not know he is now alive or not, hope I he is still now in our world, because we have a lot of fond memories. Now, the company has been finished the change of generations, his sun is inheriting the company.
Anyway, the bench test of modified carburetor in 25LA would be performed fairly after such modification on the throttle valves, I'm sure that the experiment would obtain favorable result.
By the way, the main needle valve for natural aspiration design makes it difficult to control and adjust precisely, dull angled needle shape makes it too sensitive and too keen to adjust it in NA fuel supply condition, only one click changes the mixture ratio effusively, but it is not impossible, within my tolerance at all.
Once obsessed by the attractive interests and curiosity of the internal combustion motors, it is very difficult for me to withdrawal from it.

An accident!

Too low temperature outside invited several problems for Rooky10's flight early in the morning yesterday. As a matter of fact, it was obliged inevitable emergency landing not on the run way but on the vegetable garden near by, the damage at that time was not so much as imagined. Plowed soft soil must have reduced the damage, in addition, the weight of Rooky10 is below 1kg. 2 degree below zero celsius affected on atomization of fuel alcohol and the activity of batteries for both Tx and Rx resulting motor stop and loosing control from 100m distance. I knew after that a digital camera cannot work around 2 degree because of the physical property of Nickel-hydrogen battery. A plane crash has never been experience for these 30 years, I fee like myself a beginning layman in this field if I fly a trainer airplane?

As a revenge of this accident, I made up my mind to make a Shnurle scavenge port that lack in 25LA cylinder. Brass material of the cylinder made it relatively easy to engrave additional port on the adequate portion and much more efforts were required to engrave it's gas way in the crank case inside. Opening timing of newly prepared Shnurle port was the same as existing side ports. Test running would be performed soon.

Improved VW1302 Super Beetle

From the beginｎing I have been setting my heart on the performance of the old VW air-cooled 1600cc Boxer motor does not run at higher rotation because of OHV design that might invite some hesitation to gain higher rotation, but an improvement on ignition constructive design just applying semiconductor in the in the primary coil circuitry proved my selfish consideration was completely out of focus. The transient property to higher rotation is comfortable enough to satisfy myself! In another words, the character of my VW1302 Super Beetle has completely changed from dull and lazy boy into a young crisp Parisian, how come?
On the other hand, an energetic motor transformed by newly invited semiconductors in the ignition system revealed some lack of potential in the axle constructive design that has too movable and soft rubber bushes. Anyway, the principle that the total balance is indispensable at all, any reinforcement on one part in the vehicle design causes some destruction of the originally designed total balance, realized I again this fact last night.

OS 46LA port timing

The bulged shape on OS 46LA's crank case for Schnurle scavenging main port shows the possibility to make additional port by myself. Schnurle ports were were examined precisely setting a comparison criteria on YS 45 SR motor's design, because I believe in YS superb performance as a reliable competition power. Observations show that the timing of Schnurle side ports are exactly the same but exhaust port opening timings were considerably different each other, this is because of prerequisite conditions of use, the former a normal muffler on the other hand the latter a tuned pipe. Anyway, in order to make up OS 46LA to a competition motor like YS 45SR, some desperate efforts would be required, engraving gas passing way Schnurle main port in that crank case and doing main Schnurle port on the closed cylinder. As I hope to see what will happen after a modifications on 46LA motor, this work would be performed relatively soon.

Maintenances

Fully mechanical Vocar 34PICT3 carburetor in VW1302 Super Beetle was readjusted following to the principle of it's designer, both bypass screw 2and 1/2 turn counter clockwise and air volume control screw also 2 and 1/2 turn to the same direction. Stable throttle actions were obtained after the work this morning. I have realized again the importance of setting the reference angular positions prior to the starting, any guesswork that needs precise adjustment could not bring good results, we should respect and admire the intent of the designer of this carburetor. Improvement of the combustion due to applying Semi-Transistor ignition system taught me how I did it imperfectly for these 3 years as a matter of fact. Probably, unfavorable fuel consumption would be improved also.
I have 2 another carburetors for Beetle as spear part, 2 distributors and 2 ignition coils. I lack spear one of mechanical fuel pump? I must prepare it sooner or later, because the fracture of diaphragm rubber means critical stuck.

The inner door handle destroyed by my mistake was repaired thoroughly by adhering the portion utilizing the material, Autopolymerizing Acrylic Resin as a additional reinforcement structure. Though, I hated the using quality with old sense of really old half broken automobile because of hanging out handle, all the bad habit disappeared after that except the inconvenience of right rear door lock actuator pin fracture. All the machinery should be continued with love on it and with some admiration to the machinery designers, because all of them exerted desperate efforts to design serving our field with good operations intentionally.

20 years long used Digital Multi Tester was disassembled and maintained on the sliding contacts inside. LR44 cell batteries also replaced into new ones, original performances could be re-obtained again after that. Development of tools and devices are also an important task for craftman in the world. 

Cute Jill VW1302

Thanks to the application of DIY Semi-Transistor ignition system, VW 1600cc air-cooled AD motor was back to innate life. Though I have been obliged to regard some hesitating character of the OHV motor as an inevitable physical property of original designing, the clogged transition adjacent to high rotation was caused by the primary contact & break point terminal following-up on Earth. I know that there are many negative opinions by some professional engineers in Web site, but as for my experiment, favorable results were obtained, the primary signal into the coil that is clean enough to establish an astringent spike strained the inconvenient and unnecessary noises by the semiconductor circuitry brought an very important benefit, very easily discerned the mixture condition, rich or lean not only at idle speed also transition phase and highest speed rotation. Very comfortable feeling while accelerating phase is obtained I have been giving up to ask on this OHV motor. The tendency to motor stall immediately after the automatic choke system stops was disappeared. Now, my 1302 Super Beetle has become my cute Jill without any bad habits at all.

Semi-Transistor ignition system DIY

Considerable contact points surface wear in VW 1302 Super Beetle obliged me to think over about some modification on ignition system, though I make it a rule to keep it's pure original condition. Seeking in my junk box, found out I NPN Transistor C1137 , a piece of diode and 120 ohm cement resistor, so no consideration interrupts me to try as an experiment. Not a few minutes were necessary to realize me an amazing improvement motor response compared with original lazy condition, after some barrack wiring of the junk parts and the system application into 11AD engine room, as a temporal setting on the cooling fan case surface. About the necessity of a heat sink for power Tr, heating amount was not not so apparent as imagined, so adhering a small piece of aluminum plate must play a good part of the purpose.
Writing the truth, 2 pieces of C5352 were prepared already for Semi-Transistor Ignition system DIY, initial barrack wired system would be used for the time being as an experimental trial.
The improvement in this trial setting must be brought by the semiconductor character of spike noise regulation, so fine signals are oscillated in the primary coil resulting strong sparking on every distributed plug.
Both idling and high speed rotation performances are excellent that has not been experienced before.(Written yesterday)

DIY semi-transistor ignition system for air-cooled VW 1302 Super Beetle was remade finally as shown in the photo, 2 pieces of C5352 PNP Tr. were applied and regular heatsink also. Care must be taken of the use of this Trip. because the Emitter terminal is connected with holding plate inside, so some isolating method should be considered. Upside down setting could carried out the purpose. All the AD motor performance was improved eye-openingly and carburetor mixture and idle valve setting were required including ignition timing. Negative opinions are observed here and there in Web site, but actual application of the additional circuitry shows incredible differences at all. Probably, this changing of phenomena must have brought by the semiconductor's effect of fine cutting on spike noises after it's on and off actions.(Heute)