SureFly with EAREM37HE plugs? Slick failure?

[John Mininger]

On my way out to Oshkosh this year from eastern Pennsylvania, my engine started running a little rough. I initially thought it might be my leaning technique, but the slight roughness persisted. I finally did an inflight mag check and found that my left mag was dead. Long story short, I landed at AGC, rented a car, drove to Oshkosh, and had the Slick 4372 replaced with a SureFly which I bought from Spruce at Airventure and had overnighted to the A&P at AGC. The engine is a IO360-A3B6. In the interest of simplifying the away from home installation, I did not have the manifold pressure line installed. The timing is fixed at 20 degrees BTDC. So far, so good, but my CHTs are running higher even with the fixed timing. I can't get close to POH 75% power numbers without the CHTs going over 400 degrees. I have to be either way rich, or way lean. I'll play around with that in the coming colder months. 

Two questions:

My Slick 4372 only had about 400 hours on it since new. I bought the factory rebuilt IO360 A3B6 with the new mags in late 2019. Has anyone else experienced premature Slick failures? I talked to two other guys just on my airport alone that have. One guy had two failures! Both with lower time mags than what mine were!

And my other question is: Is anyone using Tempest EAREM37HE plugs with their SureFly SIMs? Those plugs were originally developed for Electroair, but SureFly will tell you that they're OK to use if "your engine is approved for them".

Frustrating stuff. I was planning to replace the Slick 4372 at 500 hours anyway. But not at the beginning of a trip, away from the home field at 400 hours.

Thanks, John

[Shadrach]

52 minutes ago, John Mininger said:

On my way out to Oshkosh this year from eastern Pennsylvania, my engine started running a little rough. I initially thought it might be my leaning technique, but the slight roughness persisted. I finally did an inflight mag check and found that my left mag was dead. Long story short, I landed at AGC, rented a car, drove to Oshkosh, and had the Slick 4372 replaced with a SureFly which I bought from Spruce at Airventure and had overnighted to the A&P at AGC. The engine is a IO360-A3B6. In the interest of simplifying the away from home installation, I did not have the manifold pressure line installed. The timing is fixed at 20 degrees BTDC. So far, so good, but my CHTs are running higher even with the fixed timing. I can't get close to POH 75% power numbers without the CHTs going over 400 degrees. I have to be either way rich, or way lean. I'll play around with that in the coming colder months. 

Two questions:

My Slick 4372 only had about 400 hours on it since new. I bought the factory rebuilt IO360 A3B6 with the new mags in late 2019. Has anyone else experienced premature Slick failures? I talked to two other guys just on my airport alone that have. One guy had two failures! Both with lower time mags than what mine were!

And my other question is: Is anyone using Tempest EAREM37HE plugs with their SureFly SIMs? Those plugs were originally developed for Electroair, but SureFly will tell you that they're OK to use if "your engine is approved for them".

Frustrating stuff. I was planning to replace the Slick 4372 at 500 hours anyway. But not at the beginning of a trip, away from the home field at 400 hours.

Thanks, John

Has anyone verified the timing by observing spark at the lead?  The Lycoming IO360 was certified at 25° of advance.  20° of advance was added to the TCDS at a later date. Many of us are running 25° with cool CHTs.  I can envision no scenario where 20° of advance would produce the symptoms you're experiencing. It seems unlikely that the increased spark energy of the Surefly would increase flame front propagation sufficiently to cause an increase CHT, ergo I would ensure it is properly timed.

As for the Slick failure.  Any magneto can fail. The question is what component failed. There are a number of component failures that would cause the scenario you describe.  If you ever again find yourself operating in on a single mag in flight, it is perfectly fine to adjust the mixture to increase the speed of combustion (flame front propagation).  This would entail leaning the mixture if ROP or enrichening the mixture if LOP. This will help to recapture lost power and reduce any roughness until the flight is completed.  Note that losing a mag while running LOP is more likely to result in noticeable power loss and roughness.

While it is getting harder to find A&Ps that will open a mag, there are still many that are willing.   

For future reference, a repair kit is available for the Slick 4370 through airpower for $175.00. Kit includes the following:

• Contact Point Kits
• Double Sealed Bearing
• Bearing Cap Assembly
• Condenser
• Rotor Gear
• Cotter Pin
• Coil
• Distributer Block and Gear
• Woodruff Key
• Oil Seal
• Washer
• Impulse Coupler

[PT20J]

First thing I would do is verify the timing. My Slicks that came with my rebuilt in 2018 have been fine. Coming up on 500 hrs. 

[John Mininger]

Good advice from both Ross and Skip. I should have followed their advice and verified the timing much earlier.

As it turned out, the A&P who originally installed the SureFly off field in 8/2024, installed it with the DIP switches positioned correctly to advance to 20 degrees BTDC. But he installed the unit as one would a mag, at the 20-degree BTDC mark on the front sprocket, not at 0-degree TDC. I was actually starting the engine at 20 BTDC and then at 400 RPM, the SureFly unit was than advancing the timing to another 20 BTDC! I was flying the plane at 40 degrees BTDC! The vacuum advance was never hooked up. I was well aware of the high CHT issue and kept them under 400 by leaning. But no wonder I was only able to get about 65% power without the CHTs going through the roof.

I finally took the plane to a SureFly dealer last Monday, 8/25 and they quickly found the problem. We borescoped the top of the pistons and saw no indication of detonation. 

I called SureFly and told them of my experience. They said that they used to hear of this happening when the units were first out on the market. But they haven't heard of it happening in a while.

So, the moral of the story? If you have a SureFly installed and you're seeing usually high CHTs, the first thing to do is verify the timing by making sure the unit was installed correctly.

John

[jetdriven]

Iver seen this before. A member had his Surefly installed at 25 degrees, and had the DIP set to 25 also.  After he put the gear up, the CHT continued to 600 degrees which was the gauge limit. He barely got back.  It can get you killed. 

[John Mininger]

30 minutes ago, jetdriven said:

Iver seen this before. A member had his Surefly installed at 25 degrees, and had the DIP set to 25 also.  After he put the gear up, the CHT continued to 600 degrees which was the gauge limit. He barely got back.  It can get you killed. 

I have a G3X with EIS. I never let the CHTs go much past 400 before I did something about it. They rarely went much past 400 with the cowl flaps open. With the cowl flaps closed however, about 8.8 GPH was about all the power you could make without the CHTs going crazy. I once let it go to about 425 before I started leaning. That was about 9.5 GPH. Maybe it would have gone to 600!

[KSMooniac]

Was this a case of the installer not RTFM?  (reading the manual)

I put in a dual ElectroAir kit in my -A3B6D J and the manual was quite explicit about setting the engine to TDC #1 when installing the timing housing (on the mag interface) or the trigger wheel on the crankshaft.  

[John Mininger]

20 hours ago, KSMooniac said:

Was this a case of the installer not RTFM?  (reading the manual)

I put in a dual ElectroAir kit in my -A3B6D J and the manual was quite explicit about setting the engine to TDC #1 when installing the timing housing (on the mag interface) or the trigger wheel on the crankshaft.  

SureFly is also about as explicit as it can be about installing the unit itself at TDC#1.