Dan wrote:
Not sure what the engine monitor’s got to do with the mag or EI
my guess is that it’s about RPM signal pickup and might or might not be an issue, in my aircraft engine monitor is connected directly to electronic ignition
Our engine monitor (MVP50) gets RPM info by counting spikes on the P-leads which are connected by what they call an „insulator“. I guess it’s a quite small capacitor under a heat shrink. The SureFly I installed produces a synthetic spike on the P-lead but it’s not as strong as with a magneto and therefore not detected via the „insulator“. I had to google an experiment a bit and found that a .1uF capacitor does the trick. I don’t see why this shouldn’t work with a double ShureFly installation.
To answer the question: we’ve a single E.I. and one magneto. That’s what’s possible currently with a certificated aircraft.
@terbang
Have you been able to better test the Surefly on your aircraft ?
Have you been able to better test the Surefly on your aircraft ?
Unfortunately not yet. I’ll take here home from the paint shop this afternoon, if everything goes well.
@Dan
For NA engines, I wonder if variable (advanced) timing at altitude can significantly improve performance. What is your experience on this ?
@terbang
I think your engine is turbocharged so it may not work the same.
Why did you decide to go this way ?
Also, I read a 10A breaker should be installed as direct and as close as possible to the battery. Where did you install it ?
PetitCessnaVoyageur wrote:
significantly improve performance
First, define significantly 
A couple of months ago, we ditched both mags and replaced them with Pmags EI on the RV-8. As a matter of fact, I went flying today (the usual €500 pizza at Locarno 
) with it, for the first time since we installed the EI.
The increase of performance at altitude is probably small in term of speed or ROC. Precise measurements would have had to be done before, and now, to quantify any of this.
OTOH, two things have significantly improved: the starting (hot and cold), and above all the ability to lean well LOP.
Overall I’d say that having EI, or better yet EFI + EI, quite significantly ( ) improves efficiency.
If EI improves the ability to run LOP, that’s very interesting because it suggests that spark generation was substandard on the old mag at low densities of vapour in the cylinder.
I think your engine is turbocharged so it may not work the same.
Why did you decide to go this way ?
Also, I read a 10A breaker should be installed as direct and as close as possible to the battery. Where did you install it ?
Yes, that’s right. We can’t activate the timing advance under the STC. The reason we went this way is that the SureFly is (or is supposed to be) mx free. Our original magnetos are identical, so we sent the one replaced by the SureFly for IRAN. Once the other one reaches 500h, we can simply replace it by by this one and so on.
There is no breaker required under the STC, just an inline fuse close to the battery. With the Mooney the battery is located in the tail cone, so running the wire is a bit of work. That’s why I ran the cable while the interior was removed for refurbishment.
Dan wrote:
Be sure to have the EI fire the bottom plugs.
Would you mind explaining to an absolute ignorant the reason for this? Thank you :)
Not sure what the engine monitor’s got to do with the mag or EI
The engine monitor gets its RPM information from the magneto. There’s a sensor (magnetic perhaps?) on the case, like this:
Bottom plugs are generally more prone to fouling, so with the EI giving a better spark, the same fouling is reduced by installing those on the bottom.
AFAIK all EI systems have an RPM output. On the Pmags upgrade I mentioned above, we just added 1ea wire for the RPM, from 1 Pmag to the EMS (GRT in our case).
