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Mag change

T

togaflyer

Well Known Member
Anyone running Bendix mags on an IO540D4A5. Im switching away from the Slicks to the Bendix S-20 or S-200 mags. Any starting issues with them. Im not ready to go to the electronic mags yet. Maybe down the road.

Reason for the change. With all the comments on the forum made about Slick impulse mag issues, I call TCM and spoke to the Tech Rep. He is the same person who spoke at Oshkosh. The issue with the impuse mag only affects the ones installed on the fifth counter weight crankshafts on specific Lycomings, like the D4A5 series. According to this rep, the fifth counter weight crank is causing some potential castitrophic failures with the Slick impulse mag. He made no hesitation telling me to pull the Slick impulse mag and go to something else. Joe (tech rep at TCM) said this is not a TCM issue, it is a Lycoming issue. He told me that they (TCM) are pushing the FAA and Lycoming to issue a 100 hour repetitive inspection AD on the impulse mags, and may go as far as requesting an AD requiring removal of Slick impulse mags from all fifth counter weight Lycomings. I was told, as of now, they have no upcoming fixes to resove the problem, other then an AD. Soooooo, bye bye Slick mags.
 
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Another option is to replace the left impulse mag with a Slick retard breaker mag (6393). That's what I have and I also have it paired with a SlickStart--no starting issues whatsoever.
 
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togaflyer said:
Anyone running Bendix mags on an IO540D4A5. Im switching away from the Slicks to the Bendix S-20 or S-200 mags. Any starting issues with them. Im not ready to go to the electronic mags yet. Maybe down the road.

Reason for the change. With all the comments on the forum made about Slick impulse mag issues, I call TCM and spoke to the Tech Rep. He is the same person who spoke at Oshkosh. The issue with the impuse mag only affects the ones installed on the fifth counter weight crankshafts on specific Lycomings, like the D4A5 series. According to this rep, the fifth counter weight crank is causing some potential castitrophic failures with the Slick impulse mag. He made no hesitation telling me to pull the Slick impulse mag and go to something else. Joe (tech rep at TCM) said this is not a TCM issue, it is a Lycoming issue. He told me that they (TCM) are pushing the FAA and Lycoming to issue a 100 hour repetitive inspection AD on the impulse mags, and may go as far as requesting an AD requiring removal of Slick impulse mags from all fifth counter weight Lycomings. I was told, as of now, they have no upcoming fixes to resove the problem, other then an AD. Soooooo, bye bye Slick mags.
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I was given a choice by my engine shop of new Slick, or either variety of overhauled Bendix. I chose the S1200 model because of its superior high altitude performance. The downside is that the mags are so much larger than the Slick or Bendix S6 models that clearance with the firewall and the crankcase breather line is minimal. Also had to remove right mag to attach the engine mount to the engine. Performance is excellent. Getting mixture right for hot start is somewhat tricky, but engine runs great. Mag drop on runup is pretty much 100 rpm plus or minus 10 when checked at 1700. I've been up to 13500 with smooth running. LOP is no problem.
Until there is a six cylinder P Mag with some operational experience, I would make the same choice again.
 
For what it's worth, in the near-ish future (4-6 weeks?) I will be selling two Bendix 1200-series mags (IO-540) freshly overhauled by Eagle Magneto with yellow tags.

They currently have zero hours on them since overhaul, but the plan is to run them for up to 5 hours on a dyno after my engine is built and first-run at the overhaul shop. I'm installing dual LSE's on the airplane, so I'll be looking to sell the mags when I receive delivery of the engine.

Let me know if you are (or anyone else is) interested. I'll post a BST ad when they actually become available too.
 
how about o-540 A4B5 engines

Question ?Slick impuse mag only affects the ones installed on the fifth counter weight crankshafts? does this also include 5th and 6th order O-540 A4B5 engines?
I once performed a spectral analysis and the 5th and 6th order IPS were negligible.
:confused:
 
counter example

Kellym said:
I was given a choice by my engine shop of new Slick, or either variety of overhauled Bendix. I chose the S1200 model because of its superior high altitude performance. I've been up to 13500 with smooth running. LOP is no problem.
Until there is a six cylinder P Mag with some operational experience, I would make the same choice again.
Click to expand...

I have the standard Slicks (retard, no impulse coupling) and have been to 17,900', LOP, no issues. (Plane would go higher but I dislike O2 masks).

I think the better high altitude performance doesn't show up until you're higher up in the flight levels, and/or have worn plugs.
 
Mags

Do yourself a Favor and go with the EMAG PMAG electronic ignition. I can promise you, you will not be disappointed.
-Self sustaining during an electrical failure
- Superior performance
- Fuel savings
-can run auto plugs which saves big bucks
- Super easy to time
-lighter
-Extremely easy cold and hot starts. <--- Big plus for me! starts like a car.
- if you need it overhauled it will cost you a whopping 135 bucks. not that there is a time requirement. anything over 500-600 hrs in a bendix I start getting nervous.
 
AttackPilot64 said:
Do yourself a Favor and go with the EMAG PMAG electronic ignition. I can promise you, you will not be disappointed.
-Self sustaining during an electrical failure
- Superior performance
- Fuel savings
-can run auto plugs which saves big bucks
- Super easy to time
-lighter
-Extremely easy cold and hot starts. <--- Big plus for me! starts like a car.
- if you need it overhauled it will cost you a whopping 135 bucks. not that there is a time requirement. anything over 500-600 hrs in a bendix I start getting nervous.
Click to expand...

There is no 6 cyl pmag
 
Auburntsts said:
There is no 6 cyl pmag
Click to expand...

Well, there is, sort of...............

They are now promising (?) deliveries "soon" like they have for the last 3 years. I think the 4 cylinder version was a great leap forward but the P200 has been an ongoing disaster for whatever reason. I ended up with Slicks with the left retard breaker and SlickStart - works great.
 
So after talking with my engine guy, Im switching to the Bendix S-20 series mag. putting impulse mags on both sides for easy start up. They have snap ring impulses so no rivet issues, and a typical 500 hour service. I will fly these for the first 500 hours and then see whats going on in the E mag world.
 
It is interesting with all of the conflicting data regarding the impulse mags on some of the engines we use on the RV-10. The gentleman (Joe) in the Slick booth at OSH was quite outspoken that they need to come off due to the potential for a catastrophic failure. However, some of the engine shops were not so adamant. Not knowing who to believe, and not wanting to be the one to find out, I replaced the 6351 impulse mag on my IO-540 with a 6350 straight mag, and now start only on the Lightspeed electronic ignition. I've actually not noticed any difference in starting.
If you have switches on the ignition it is easy to do this---just enable one ignition for starting. And don't forget to turn the other ignition on after starting! If you have a key switch, don't forget to install a jumper on the key switch to disable the non-impulse mag for starting, otherwise you will get a kickback, especially if you are using the Lithium batteries which spin the starter quite rapidly.

Vic
 
I am thinking of replacing the Slick mag with one of these.
http://www.surefly.net/
I would like to see a few more field reports before I go down the surefly road.

Vic's idea is also being considered especially since I have toggle switches installed for my one Slick and one LSE ignition.
 
More info after the engine shop spoke to the Lycoming people. When a three blade prop is hung on this engine series, the harmonics change at the rear of the engine. This causes an unusual wear on the mag parts, which can eventually cause a failure with the rivet in the impulse assembly. Some issues have also occurred with the mag due to engine mods. My engine guy said he has not personally came across the mag failure issue, but has heard about it from other shops. I agree with Vic, there is nothing wrong with the Slick non-impulse mags, I went with the Bendix impulse mags vs the Slick Start unit. Its all about what you want to start the engine. Once the engine is running, a mag is a mag. As Vic said, I don't want to be the one to find out. Under Murphy's Law, I would be the one to have a castitrophic failure with the Slick impulse mag set up.

P.S. No expertise in this area, just passing on the info I was told.
 
Been running a NON-Impulse S-20 on the right side location along with a Lightspeed ignition.

The ignition is configured to use the Lightspeed for starting then bring the Bendix online after running.

Works good now for over 1000 hrs with no impulse coupler to fail.
 
Auburntsts said:
For future reference for anyone that does a thread search on this topic, IAW with Lycoming SI 1443K, the only approved Slick mags for an IO-540-C4B5 or D4A5 (the 2 most prevalent 540 models on RV-10s) are the 6393 retard breaker mag on the left, and the 6350 plain mag on the right.

http://www.lycoming.com/Portals/0/techpublications/serviceinstructions/SI1443K Slick Magnetos.pdf
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Good reference. The date is 2015. Most of the RV's have been built prior to this SI and the engine shops made it a practice to put an impulse mag on the left. I did check mine every 250 hours, and even replaced it at 800 hours just for piece of mind, before I finally removed it and installed the 6350 since OSH 2016. And though it probably shouldn't matter, I did remove the impulse mag from the left side and installed the 6350 on the right side.

Vic

Vic
 
vic syracuse said:
Good reference. The date is 2015. Most of the RV's have been built prior to this SI and the engine shops made it a practice to put an impulse mag on the left. I did check mine every 250 hours, and even replaced it at 800 hours just for piece of mind, before I finally removed it and installed the 6350 since OSH 2016. And though it probably shouldn't matter, I did remove the impulse mag from the left side and installed the 6350 on the right side.

Vic

Vic
Click to expand...

Yeah but it is version "K". I did an quick internet search and was able to find version H dated Feb 7, 2012 and the approved Slick mags are the same.
 
More info after the engine shop spoke to the Lycoming people. When a three blade prop is hung on this engine series, the harmonics change at the rear of the engine. This causes an unusual wear on the mag parts, which can eventually cause a failure with the rivet in the impulse assembly. Some issues have also occurred with the mag due to engine mods. My engine guy said he has not personally came across the mag failure issue, but has heard about it from other shops. I agree with Vic, there is nothing wrong with the Slick non-impulse mags, I went with the Bendix impulse mags vs the Slick Start unit. Its all about what you want to start the engine. Once the engine is running, a mag is a mag. As Vic said, I don't want to be the one to find out. Under Murphy's Law, I would be the one to have a castitrophic failure with the Slick impulse mag set up.

P.S. No expertise in this area, just passing on the info I was told.
 
BobTurner said:
I have the standard Slicks (retard, no impulse coupling) and have been to 17,900', LOP, no issues. (Plane would go higher but I dislike O2 masks).

I think the better high altitude performance doesn't show up until you're higher up in the flight levels, and/or have worn plugs.
Click to expand...
See what performance you have at 700 hours on your mags. Slicks don't generally do well after 500 hours, and by 1000 hours need so many parts that you can do better with new. Bendix are more durable and can cost effectively overhaul indefinitely. The S1200 mag is far more resistant to crossfire than any Slick will ever be.
The only reason Lycoming switched to Slick is that they are owned by Textron, and Bendix is owned by Teledyne and they weren't going to buy from their corporate competitor. Same reason Cessna switched from Continental engines to Lycoming.
 
Kellym said:
See what performance you have at 700 hours on your mags. Slicks don't generally do well after 500 hours, and by 1000 hours need so many parts that you can do better with new. Bendix are more durable and can cost effectively overhaul indefinitely. The S1200 mag is far more resistant to crossfire than any Slick will ever be.
The only reason Lycoming switched to Slick is that they are owned by Textron, and Bendix is owned by Teledyne and they weren't going to buy from their corporate competitor. Same reason Cessna switched from Continental engines to Lycoming.
Click to expand...

I think that's why Slick recommends overhaul at 500 hours. And I agree, overhaul is expensive enough to seriously consider just going new.
 
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