What's new
Van's Air Force

Don't miss anything! Register now for full access to the definitive RV support community.

P-Mags or Surefly (Lycoming EIS)?

bertschb

bertschb

Well Known Member
Friend
I've been following the recent thread on P-Mag vs SDS but I don't read much about Surefly. I ordered my 390 Thunderbolt engine last spring and initially selected Lycoming EIS (Surefly) for the ignition. Since then I've spent a lot of time reading about all the various EI choices out there and it seems each week I change my mind between Surefly, P-Mags and SDS.

I like the idea of being able to fine tune the SDS system but that comes with more complexity for the install.
I like the idea of the self powering feature of the P-Mags but don't like the idea of required annual inspections (not the inspection itself but the reason for it).
I like the idea of the Lycoming EIS with no maintenance required but don't like the fixed timing.

If I had a neighbor here at my airpark that was an expert with SDS and would help me install it, that's what I would choose. But alas, that isn't the case. I know there are several vocal P-Mag supporters here. Are there any equally passionate Surefly fans????
 
A few years ago, I did my personal evaluation of your subject. At that time, my choice was the SureFly / Lycoming EIS. The recent thread of P-Mag vs SDS now tells me that I would not want the Lycoming version because of no support from SureFly and no Lycoming support once I change dip switch settings.

After the P-Mag vs SDS thread, I now have a much higher opinion of SDS and am like you wanting to reevaluate.

I am NOT ready for the engine for the RV-8. When the finishing kit gets ordered, I will start thinking of engine configuration / ignition system.

In the past, I like EXPERIMENTAL aviation but tend to do things like factory certificated aircraft do. I only change to experimental systems when my comfort level is high because of a low risk level. I have done a lot of cross country flying in my RV-6 and have landed it in 49-states in the past 26-years. I alway want a plan to get back in the air quick when AOG away from home. A repair away from home can end up being expensive.

My RV-6 has the LASAR ignition system. I would NOT use it in a new airplane. I have all the service manuals and enough spares to keep one airplane flying the rest of my lifetime and then some. I have enough spares to use the LASAR system in the RV-8 but would not go that direction.

The plus for me is that the SureFly is FAA approved for factory certificated airplanes.
 
Have you considered actual Sure Fly units vs the Lycoming? Those have adjustable timing, although I currently don't utilize it on mine. I have one Sure Fly and one Slick, which I know is a fairly conservative setup, but it allows for a simple electrical system, easy maintenance, and still provides many of the benefits of EI. For me, there were diminishing returns with complicating things much more.

Chris
 
Like most things in our world it comes down to personal choice, I have a ECI 0-360 with two slick mags and approaching 900 hours since 2008. The slicks were built in the original factory and have had none of the issues that others have had since the relocation of the manufacturing. They were overhauled at 500 hours and have been basically solid performers. I have read many threads over the years and as I am approaching the next 500 hour IRAN/overhaul for the slicks and looked at the probable costs I finally bit the bullet and am currently installing a SureFly during my condition inspection. Setup is KISS, dip switches at fixed 25 deg setting based on the most recent thread on here on CHT temps etc. For me and my flying this will work fine and the lack of required maintenance, removal of the impulse mag, better starting, and ability to replace with a mag if I get stuck somewhere were all elements of the decision. The good news is that there are multiple choices depending on your desires/interests, I have a bit of a Frankenstein panel but I like to keep the motor part as simple as possible.
Figs
 
  • Like
Reactions: JGT
I've not owned one, but a buddy of mine has one. He likes it. It's just a straight mag replacement that depends on ship power.

Personally, the deal breaker for me is mechanical modes of failure and electronics bolted to the engine. I would go all the way to SDS (which I did) where you only have pickups on the engine and no mechanical parts other than magnets swinging past a pickup, or I would just install a mag.

One last thing that didn't come up in the last thread is the difference between 4cyl and 6cyl. The 6 cylinder lycoming has a 1.5:1 mag to crank drive ratio. This means that installing a pickup in the mag hole requires a 1:1.5 gear setup to get back to one revolution to crank revolution. In other words, the P-mag and surefly need additional internal gearing to work on the 6cyl engines. Place whatever value you you want on how that effects reliability.

Just my $.02.
 
The Surefly on the left side of my 320 has exceeded expectations primarily because it has transformed the way my engine starts and the years of difficult starts are now in the past. Admittedly that improvement is not unique to Surefly, so the other things I’ve appreciated about the Surefly are that it’s an easy install, has no ongoing maintenance requirements and the simple annual timing checks have shown that it stays where it’s put.

After running it for the first year in fixed timing mode I devised a way using simple tools to switch it over to variable timing without having to remove it from the engine. If you prefer simplicity it’s a good option.
 
Don't be on the fence, just run one of each! SureFly on the left with 470 hours, Pmag on the right with 756 hours. No problems with either, but I did change the SureFly over to the G3 plug wire harness for the NGK plugs.
 
MiserBird said:
Don't be on the fence, just run one of each! SureFly on the left with 470 hours, Pmag on the right with 756 hours. No problems with either, but I did change the SureFly over to the G3 plug wire harness for the NGK plugs.
Click to expand...
When you did the G3 conversion did you change the plug layout split between top and bottom plugs or leave it standard? How has it held up?
 
SureFly fires the bottom plugs, Pmag the top ones. No problems, mag check drops are very close. 430 hours on NGK BR8EIX plugs.
 
You must log in or register to reply here.
Back
Top