Don´t confuse a nominal rating of, say, 3000 rpm and 12 V or 24 V at maybe 200 W with a speed limit . This is not the speed limit of the motor. The good old 6 V dynamo did 7500 at 6000 rpm crank speed - and that with brushes, collector and windings. So when putting a brushless motor at the same place, where´s the problem ?
I operate a three phase hf spindle motor on the lathe for a few grinding jobs when CBN hard turning is not suitable. That 48mm watercooled spindle has a nominal 2800 rpm speed at 50 Hz, 75 V. The inverter for it does 1000 Hz, so I can have around 60 000 rpm for small bores to grind. So 10 000 rpm is no big thing for these brushless motors, I guess.
Running a dynamo off the timing gears would not be a big load really, you get just 100 W smooth load at best, nothing compared to valve gear pulses. But the half time very low speed there is not great to generate some wattage. Why not keep the dynamo at its old place? The dynamo is really only the victim of the triplex chain, not the root of the problem. Most forumites will know my thinking of what causes the primary troubles and it is not the little dynamo at 60 W . There is only some higher load on the dynamo drive and motor when blipping the throttle and the inertia of the rotor is some factor. I could put the Miller armature on scales and compare it with the brushless permanent magnet rotor weight, my guess , the magnet is less weight, so a bonus for the brushless.
Vic
Vic, the Hegeler device deliveres 150W plus, reliably. It is driven not by a half time pinion, but by a gear drive
with internal gearing, which you can see in his catalogue at:
www.vinsparesgermany.com. I did the testing of it by running it in a Comet (which does not need a dynamo alternative like the twin), but was the best test
bed, as a Comet is operated at much higher rev levels, like a twin. It was tested for several thousand kms,
both on a twin, as on the Comet and underwent some changes, before it was offered for sale. We did have
some break downs with the gear box due to wrong internal gearing, which was difficult to manufacture.
That has been solved, so far, and , up to now, no complaints of any sold generator since 3 years, now.
You may run your twin engine at electronic double ignition, full lights and tomtom sat-nav all day long,
without any problems. Ernst uses the free space of the dynamo of the twin for his starter solution.
This does not touch the triplex chain for starting.
