OH Bendix magnetoes

Rowebird · #1 02-25-2012, 04:27 AM

My Bendix Magnetoes is due for OH acc. Service Bulletin every 4 years.
A quiet expensive operation that?s not needed on Slick. So I?m looking at changing to Slick for nearly the same money as OH of my Bendix. Has anyone of you out there any opinion on this?
Can I use Bendix drive gear on the new Slick for instance?

I?m also considering two P-mags... Would that be a better choice? PLS give me some input.

curtis · #2 02-25-2012, 07:05 AM

Keep in mind that like the engine, overhaul periods are just recommended, not mandatory for FAR part 91 aircraft. The same holds true about SB's.

speyers · #3 02-25-2012, 07:27 AM

Roland, I see that you are in Sweden. What does the governing aviation body there say about experimental aircraft? Having worked in South America for 5 years, I know that different countries have different regulations, ie Mandatory Overhaul of engines once they reach TBO. If you did not comply you were grounded and fined. What are the rules like where you live?
If you do not have to legally overhaul the magnetos then I would consider what Curtis said. How many hours to the mags have on them? Are they failing to perform well in any way? What model of Bendix, are they S-20 or S-21 of the much larger S-1200?
-Cheers

cajunwings · #4 02-25-2012, 08:31 AM

If your country does not require a mandantory overhaul find a mechanic that is familiar with Bendix and inspect and replace worn parts as needed. If you need lots of parts of if your mags are ancient and tired a full overhaul or swap to Slick may make more sense. If not then relubricate with the specified Bendix lubes and continue to fly them with inspections every 75-100hrs. Factor in that going to Slick may require a harness swap as well.

Don B

Rowebird · #5 02-26-2012, 03:45 AM

Thank you for your inputs about the FAA requirement. I?ve just had my 4?
in for the 5 year EAA inspection and and the inspector noted that I have to comply with the 4 year OH for my S4 LN-20/21 magnetoes. Even if they were OH 2004 and has less than 100 h of time since. The riveted impulse coupling has to be inspected every 100 h, but that is not a problem, as I see it.
There are Champion Slick kits for sale for USD 2100 so I guess I should go for one of those. I?m not clear about the drive gear, can I use the gear from my Bendix on Slick 4370 /-73, does anyone know?

My other option is two P-mags full kits with auto spark plugs, I haven?t read anything negative on those....?

jrs14855 · #6 02-26-2012, 08:45 AM

Factory overhauled Bendix mags are way less than $2100. Aircraft Spruce has good price, around $650 each exchange. Unless the Bendix mags are antiques you should be able to overhaul for less than factorry reman. I peronally prefer the Bendix to Slick.

jrs14855 · #7 02-26-2012, 09:30 AM

Same drive gear fits Bendix or Slick. Impulse and no impulse drive gears are different so if you change from one impulse mag to both impulse you will need one new gear.

RV Jerry · #8 02-26-2012, 09:59 AM

I JUST BOUGHT TWO REBUILT 6 CYL. MAGS FROM SPRUCE LESS THAN 500 EACH

terrye · #9 02-26-2012, 11:53 AM

Have a look at the EAA Webinar on magnetos by Mike Busch. He explains the technical differences between the various Bendix and Slick mags. He favours the Bendix as a more robust mag.
http://www.eaavideo.org/video.aspx?v=1367499350001

chaskuss · #10 02-26-2012, 02:07 PM

Quote:

Originally Posted by Rowebird

Thank you for your inputs about the FAA requirement. I?ve just had my 4?
in for the 5 year EAA inspection and and the inspector noted that I have to comply with the 4 year OH for my S4 LN-20/21 magnetos. Even if they were OH 2004 and has less than 100 h of time since. The riveted impulse coupling has to be inspected every 100 h, but that is not a problem, as I see it.
There are Champion Slick kits for sale for USD 2100 so I guess I should go for one of those. I?m not clear about the drive gear, can I use the gear from my Bendix on Slick 4370 /-73, does anyone know?

My other option is two P-mags full kits with auto spark plugs, I haven?t read anything negative on those....?

Roland,
What does this 4 year "overhaul" actually entail? Does it require mandatory replacement of certain parts? Or is it more of an inspection, with repairs as required? If the later, your low time magnetos should breeze right through with little expense. Besides the cost of replacement units, be they Slick, Bendix [now TCM] or experimental EI units, you need to factor in shipping costs and any taxes or import duties required.
Charlie