Engine or mag problem - Need suggestions

[Shadrach]

22 hours ago, N201MKTurbo said:

People like to toute the benefits of electronic ignition by saying we can get more power and better mileage.  That is bull, our engines operate in a very narrow RPM range and fixed timing is fine. 

I would love to get rid of the points and the gears that spin the magnet in our magnetos. What could fail? A bearing?

Our engines do operate in a narrow RPM range.  However, that is the only parameter of operation that is narrow. In a single flight N/A aircraft engines often operate in about the widest of spectrum of conditions of an recip in service. Your assertion is correct if speed is the only measure of performance. Variable ignition timing would have little effect on cruise speed at a typical cruising altitude of 6000-8000'.  However, climb and BSFC would be noticeably optimized with variable ignition timing. Using 15-25% of  FF to slow the combustion event, is not what I would call an efficient way to operate, yet that's what we do in take-off and climb. Similarly, when climbing through 12,500', utilizing only the mixture to optimize power is well...suboptimal. The set up is leaving performance on the table. There is an ideal power mixture and there is an ideal crank angle at which that power pulse is best utilized by the prop, both will not be attained with mixture alone (though under certain conditions we can get close).  One could also run harder, cooler and more efficiently down low to avoid winds at altitude.

[N201MKTurbo]

Just now, Shadrach said:

Our engines do operate in a narrow RPM range.  However, that is the only parameter of operation that is narrow. In a single flight N/A aircraft engines often operate in about the widest of spectrum of conditions of an recip in service. You're assertion is correct if speed is the only measure of performance. Variable ignition timing would have little effect on cruise speed at a typical cruising altitude of 6000-8000'.  However, climb and BSFC would be noticeably optimized with variable ignition timing. Using 15-25% of  FF to slow the combustion event, is not what I would call an efficient way to operate, yet thats what we do in take-off and climb. Similarly, when climbing through 12,500', utilizing only the mixture to optimize power is well...suboptimal. The set up is leaving performance on the table. There is an ideal power mixture and there is an ideal crank angle at which that power pulse is best utilized by the prop, both will not be attained with mixture alone (though under certain conditions we can get close).  One could also run harder, cooler and more efficiently down low to avoid winds at altitude.

All that would be nice, but getting rid of all the mechanical failure points inherent in the current mag design would be the biggest advantage in my opinion.

The automotive world have used inductive pickups and solid state coil drivers for decades and they are extremely reliable (except for the early eighties fords, but I digress)

[Andy95W]

48 minutes ago, N201MKTurbo said:

All that would be nice, but getting rid of all the mechanical failure points inherent in the current mag design would be the biggest advantage in my opinion.

The automotive world have used inductive pickups and solid state coil drivers for decades and they are extremely reliable (except for the early eighties fords, but I digress)

Plus an extremely high energy spark for starting without having to have impulse couplings or shower of sparks.

[NotarPilot]

Well I just called them and there's no STC anyways. The EAB guys win again.

Edited October 24, 2016 by NotarPilot