Which magneto?


Overhauling TSIO-550-E

New Slicks or overhauled Bendix? 
(assuming both are available for this engine)

PS I have a electronic ignition but for now, going with mags.

Generally I prefer mags that can be repaired in future.

 Thanks for opinions.

Whoa.  The TCDS only lists

Whoa.  The TCDS only lists Slicks.  Unless I am missing something.

"Note 10. The following magnetos are suitable for use on these engines.
Continental/TCM S6RSC-25P or Slick Champion 6220 or 6320 pressurized with appropriate pressurization system and ignition harness available for TSIO-550-A, B, C, E, G, K and N models.
Continental S6RSC-25 un-pressurized magnetos with Continental ignition harness is the only ignition system approved for the TSIO-550-J engine model."


rpastusek's picture



I've successfully run Slicks on N437RP, my IV-P with a TSIO-550E, for 2500 hours since 2008. I overhauled the original set myself at 900 hours and replaced them at about 1300 hours. I had the current set overhauled by a local shop at 2200 hours two years ago. 
I always intended to replace the Slicks w electronic ignition when it became available for the TSIO-550, but when I found that all currently available have fixed timing, I lost some enthusiasm for changing. 
My engine starts reliably hot or cold, and runs smoothly past 100 degrees LOP, 

I think 6 cylinder P-MAGs

I think 6 cylinder P-MAGs support variable timing? The way I understand it, a problem with variable timing for boosted engines is that it has a very nasty failure mode - if manifold pressure sensing line fails the mags advance the timing so much that it will ruin your day big time. Which is especially dangerous with a highly boosted engine like 550E on takeoff. It's somewhat alleviated in PMAGs because you can switch them between fixed and variable timing, so it is possible to keep them on fixed timing for take-off and landing.

Why would you NOT want to use

Why would you NOT want to use the electronic ignition?
What type is it?
I do not understand why anyone would go for 1912 Mags when they can have spark advance and retardation and a longer spark duration. 
Please explain.

I am interested if you would

I am interested if you would like to sell your electronic ignition or trade to Two 6320 pressurized mags with only 70 hours on them?


One (or two) Sureflys are a

One (or two) Sureflys are a good compromise, you have to add a power wire but you are able to select fixed timing so it acts no different than a mag but less maintenance and no impulse coupling.  If I had to buy new mags i'd consider that.

I am replacing my mags with

I am replacing my mags with the https://www.flyefii.com/products/ignition-systems/  as it will provide better fuel economy and be easier on the engine at lean settings. My friend had ONE Surefly and said it offered no value until he had TWO, and he can lean without issue as much as he wants without the pre detonation issues and picked up 2 GPH.  Just my 2 cents.     

Lancairmikees's picture

I looked at Flyefii but his

I looked at Flyefii but his delivery date kept sliding back until I pulled the plug after about 6 months. I went with 2 PMags. I did not see 10% gain in speed or drop in fuel flow, but the engine runs smoother, starts easier, and runs LOP better. I kept the Bendix mags for a year just in case, but then sold the pair. PMags do have variable timing, plus generate their own power once spinning. The aircraft electrical system isn't as critical with these.