Mags to EI

[rv6ejguy]

Originally Posted by DanH

Gents, I'm not suggesting you should not switch. If I were rigging a 540 for myself right now, I would select a system that triggered right behind the prop, because the 6-cyl engines naturally exhibit more torsional vibration issues at the accessory end even with pendulum absorbers. That's why they have rubber couplers.

A 4-cyl with pendulums? I'm running dual EI with mag hole triggers right now. I think the timing light is showing me some torsional chatter at around 1500, but run time and inspection says it's not a problem. A 4-cyl without pendulums? A wild card. I have no idea. Front-triggered is probably better.

And allow me to be clear on something. If you think I'm somehow opposed to EI, or electronic fuel injection, you're dead wrong. I am greatly opposed to BS about what they can do, or apples-to-oranges comparisons, or ignorance of how to install or operate them. And I'm definitely opposed to illustrations of "system failure" that are in fact human failure, for mags or for EI.

A fair commentary Dan. I always appreciate your thoughts and even weighting of pros, cons, cause and effect.

In my view, there are simply less things to go wrong with crank triggered setups assuming they're well designed and properly implemented and just like with mags or rear triggered systems, sometimes they are not.

[Carl Froehlich]

Originally Posted by DanH

Gents, I'm not suggesting you should not switch. If I were rigging a 540 for myself right now, I would select a system that triggered right behind the prop, because the 6-cyl engines naturally exhibit more torsional vibration issues at the accessory end even with pendulum absorbers. That's why they have rubber couplers. SNIP.

Dan and I have exactly opposite opinions on six cylinder trigger approach. The "control box, coils, crank triggers, backup batteries and associated connecting wires" screams at me that I'm adding complexity and system vunerablies. But - each builder does what he wants - as shall I.

On Dan's specific comment about torsional vibration for an accessor case mount, he does have some foundation for his concern but this is very depending on what you are plugging into the mag hole. So let's compare a standard mag that seems to be working for most people and the 200T series pMag (yeah - I know it will not be out for a few more weeks but that is what I'll be installing on the RV-10).

Internally magnetos swing a sizable magnet past a coil to generate electricity. The drive pad for almost all six cylinder installations turn at 1:5 to 1, which significantly adds to the load the mechanical coupling endures.

The 200T pMag loads on the mechanical coupling are a small fraction of those produced by a magneto. The pMag rotating mass is far less in overall weight and is concentrated much closer to the center of rotation. The result is the 200T pMag loads are tiny compared to a standard mag.

Carl

[rv6ejguy]

Originally Posted by Carl Froehlich

Dan and I have exactly opposite opinions on six cylinder trigger approach. The "control box, coils, crank triggers, backup batteries and associated connecting wires" screams at me that I'm adding complexity and system vunerablies. But - each builder does what he wants - as shall I.

Carl

By all means use what you are comfortable with but be aware about what's inside. With the P Mag you still have a circuit board, CPU, trigger mechanism, wire connections which are not particularly well strain relieved or water proofed, all subject to direct engine vibration and relatively high heat compared to off engine mounted electronics. Have a look inside a P Mag sometime.

I get to talk to lots of folks about their P Mag experiences. That's all I'll say here but maybe you can guess why they are calling us...

[Rbpilot]

I ditched my slicks on my 0-290 when they came time to overhaul. Went with flyEFII dual ignition. Widened my battery box by about an inch to house dual batteries. Rebuilt my electrical system with a ground bus, which is the way I should have done it in the first place. About 50 hours on system and all runs great! My next build will have fuel injection as well. Probably the new system 32 that flyEFII just came out with.