Monday, April 11, 2011

M14P Ivchenko Magento Treatise

M14P  Ivchenko Magneto – Model M9-35M

The following was determined by teardown of two magnetos that had only 40 HRS TTS Factory New.

An auto advance magneto with a range from 23° BTDC to 37° BTDC totally advanced. Static setting is 23° +or - 1° degree. No data is available for “E” gap setting but only an approximate. 8°-12° breaker point opening after Rotor Lock would be acceptable for a 4 pole rotating magnet of Russian “Alnico” type of magnets which align breaker point opening to mark on housing to rotor out electrode. Primary winding of coil (p/n B20-1-0986∩) is .3Ω (ohms). The Secondary winding of coil is 8440Ω (ohms). The capacitor (there are none internal of the magneto) should be about 300Mfd for a primary winding of .3Ω (ohms) (mount outside). Resistance of high tension coil to the cap connector lead is .3Ω (ohms). There is a lubricator felt on the breaker point cam which should be done every 100 hours (not too much oil just till damp). Use continental # 10-86527 to have the least breaker rubbing block wear and maintain point setting except for platinum or tungsten erosion.

1) NOTE: Laminated steel is used for horse shoe poles as well as coil core. It is not known if a high silicon steel plate was used to make these so the magnetism would be total on or off (rapid fluxing).
 2)  NOTE: It is easy to check to see if you have a problem with the brass split counterweight advance mechanism by removing the distributor cap and turning the rotor in the direction of the arrow on the rotor, if it can be turned backwards any amount, this means you are trying to start the engine in a more advanced position than 23° and if you have the air start system fully charged it may start. But if you have the American Electric start, the inertia to overcome the compression to have your burning fuel mix carry over to the power stroke may be limited by a low battery or too much line loss in a small gage lead from the battery through the relay or too small a ground return through the flexible engine to frame bonding wire or the air frame components will not provide a good direct return limited by the fuselage skin primer or paint between the battery and the starter.
3) NOTE: Make absolute certain that the geared engine crank shaft is set to 23° before mating the magneto, which also should be set at 23° as the points break to collapse the field current built up in the capacitor and primary winding to get the transformer to induct the secondary winding and occur every time for consistent ignition subject to the centrifugal advance which should go up to 37° if everything works. Find a way to have a degree rose on the engine, use automotive timing light and strobe it as the engine is running and you will have a visual performance on where your spark is while the engine is running.
4) NOTE: If the engine is difficult to start, check the rotor by rotating opposite to the direction of the rotor arrow. You will find brand new magnetos have the axial ball bearings set .018 tight to give the rotating magnet enough resistance to hopefully load the driving member to the driven member so the 3 flat leaf type springs can push the advance back to 23° for starting. If not and the starting system doesn’t have enough grunt to get that #4 master rod all the way through the compression stroke. Starting the fire at 23° BTDC and burning all the way and not detonating (you remember the difference?) has to do with the quality of the fuel. More lead burns and doesn’t detonate, over the top of the compression stroke and down onto the power stroke.
5) NOTE: If you remove the brass non magnetic fly weights and reassemble the rotating magnet group, which is separated by non magnetic brass bushings and thrust washers, you will find that the driving and driven members will not find their way back to the 23° start position. The Russian designers knew this and tried vainly to correct the attraction and repulsion of the magnetic steel flyweight pivot pins by shimming the support axial ball bearings to .018 too tight for torsional resistance “sorry doesn’t work”. These bearings are the same used for 80 years on Bendix-Case-Magnetos and bearing manufactures setting tolerance is .000+.002 tight. The basic design has been plagiarized from Bendix. Bosch magnetos, right down to the “onion skin”, used to tighten and insulate the drive end bearing. The small bearing shims are the same as S-20 Bendix and the end-o procedure is exactly the same. To have good starting set up the left magneto to break her points at 16° BTDC which if the advance flyweights work will advance to 30° BTDC.
 This will be like the original design engine before revving up increased compression ratio, pressure carburetted and spark advance that has the 260HP original engine cranking out 400HP at 2900RPM which is about as fast as you can go with a 96” diameter propeller disc without going super sonic and creating a whole lot more problems.
6) NOTE: If a Bendix or Bosch vibrator is installed on the left magneto after the “E” event the primary winding of the left magneto coil will now go on make and break creating a “shower of sparks” for about 20° of piston travel on the power stroke making sure the fuel mix if it didn’t start to burn way back at 16° BTDC will have the fire set to it by the vibrator. Make sure the vibrator has a momentary switch as they are not designed for continuous use but starting only and they work only if your battery is up to snuff. If you cannot hear it vibrating it won’t help you if you were stupid and left the master on and ran the battery down.
7) NOTE: The 300MFD value of the capacitor is a starting point. As the engine is run, the capacitor is in balance with the primary winding and will leave the surface of the points a nice frosted look. If a crater or nib is formed on either side you are out of balance and will need to adjust the MFD value up or down as required. Old auto books tell you which way to go for each condition.
 I suspect that Ivchenko had to use Russian capacitors, so frequent failures of the known poor electronic parts needed easy, fast replacement. Mount them outside of the magneto.
8) NOTE: The bearing grease the magneto assemblers used was everywhere except in the bearings. Use continental grease # 10-27165. It stays put in the heat-“waxy type”. Remember every spark event must be strong and at the right time every time. 
9) NOTE: There is a poor quality paper sticker on the outside of the Ivchenko magneto near the “P” lead in Russian language requiring an external capacitor.
10) NOTE: Not to worry, American magnetos have had similar problems and continue to do so. The Bendix-TCM-Slick-Unison-Champion magnetos have airworthiness directives on many of their components including the impulse parts which are designed to “E” gap event after TDC so no back firing if you read the operators manual and it’s connected correctly.
 One old noted one with all of them is the unexpected magnetizing of their flyweights which later parts and models have a mouse trap type of spring to make sure the flyweight pawls are engaging to the stop pins. Well that worked for a few years and then TCM changed the alloy of their crankshaft which seemed to magnetize a lot of parts besides the pilot watches and the impulses were intermittent again. Remember to hang a steel paper clip on a clip near the crankshaft flange if it repels or clanks on, you may know what your impulse problem is. Ivchenko solved this problem by using nonmagnetic brass fly weights, he forgot about the magnetic pivot pins.


What will having the left magneto start 16° and advance to 30° BTDC do to max take off RPM?
 I guess a static tractor pull air test with the left-hand firing 30° BTDC and right-hand firing to 37° do to the peak RPM at take off be still 2900RPM maybe slightly less.
 I find it hard to believe that on these low compression engines there would be any RPM loss as the left-hand is only 7° behind the right-hand. It may even scavenge or give the burning fuel air mix and swirl, hopefully in the correct direction, to have a more even burn with more power that both did at 37° + or – 1°.
 It should take less electric starting motor amp draw as with the small B+C. Starting motor it took 250 amps with a 3 volt drop measured a the starting motor with both magnetos set at 37° BTDC.
NOW: L.H. set at 16° BTDC and R.H. at 23° - idle and start
    L.H. set at 23° BTDC and R.H. at 37° - full RPM in advanced operation.


Measured at the starter________ amps ________ volts during cranking with a full battery.
Full run up R.P.M.
 L.H. Magneto _______ RPM
 R.H. Magneto _______ RPM
 Both Magnetos ________RPM

An electronic tachometer on the propeller would be useful as an idle and full RPM check on the onboard tachometer once a gear box ratio conversion is calculated.
Further Notes on the Ivchenko Magneto:
1) Is made the same way as a Bosch or Bendix. The rotor and big gear, which is Russian micarta, are riveted together and maybe a problem later on coming loose like the Bosch radials do.
2) The Rotor and HT shield and Cap are make of cast hard rubber which can become conductors once arced or heated they become carbon or hydroscopic and soak in atmospheric moisture and will cause misfiring (can be dried out if not carburized from burning).
3) The wires are rubber insulated also and are copper not stainless so they can be replaced with the better American 7mm silicone stainless H.T. lead wires. Don’t pull too hard on these wires when pulling them through one common conduit for both magnetos. Use lots of electrician’s wire pulling lubricant to install as the stainless wire is strong and will cut through to ground. You try to find that when trouble shooting or to wire intermittently.
4) The breaker point lubricator canister has felt coiled around a center spring hole for adding oil and makes connection inside to a small felt strip that rides on the cam lobes. It looks like engine oil but I would use the proven TCM Lube #10-86527 which doesn’t dry out and will last a very long time.
5) The Rotor is adjustable on slots under the 3 screws plus the breaker plate is adjustable for “E” gap purposes. The brass dog drive is in two parts. Once the 2 bolts are uncottered and loosened. The one with the screwdriver slot will vernier the dog a full 360° then to trim, the base is slotted on the 3 mount bolts to finish adjusting.
6) The alnico type magnets are rechargeable but once in operation, they will charge themselves up to their maximum capacity.
7) Is the cam compensated? -Unknown-
8) These Magnetos have a boost coil high tension port on the distributor cap and a screw access port for the high tension wire to the remote mounted boost coil but do not have provisions for a separate retard set of points to complete this type of boost coil system.
Remember the vibrator system uses the stock existing coil’s primary winding while the running points are open after breaking to collapse the primary winding.
9) Some folks prefer the newer electronic types of solid state ignition; my experience is to try to repair a diode-transistor-capacitor in the bush with your jack knife.
10) Keep your hands in your pockets and tools in the toolbox while you think your problem through to clearly identify the real trouble with your brain, then and only then make the adjustment or correction to good health and proper operation. At first use your common sense then add diagnostic non invasive equipment such as spark plug and lead testers, volt–ohm meter, continuity light and all four of your body senses – 1) sight: look for deformities 2) smell: for burnt components 3) touch: for temperature and vibrations 4) use a mechanics stethoscope for bearing noise 5) probably you won’t need to taste anything at this time.
11) Don’t get me wrong, the Ivchenko magneto for the M-14P has excellent workmanship that is not found on today’s North American stuff. It’s old but well built and has some different innovative ways to do things. It just needed some trouble shooting to correct the deficiencies.