Newest J's with Two Independent Mags (not the D mag) ?

[DCarlton]

Curious.  What's the newest J production years that you could ever expect to find with two mags (not the D mag)?  Do they J's (MSE) produced in the early '90s have two independent mags?   Thanks.

Edited August 1, 2021 by DCarlton

[ArtVandelay]

My 78J was replaced A3B6 by PO, so you can’t tell unless you look.

[PT20J]

According to the IPC, the IO-360-A3B6 installation started with serial number 24-3374. That was the start of the 1996 production. So, 1996, 1997 and 1998 (last year J's were built) had two mags. from the factory (58 airplanes total). But a lot of earlier J's (including my 1994) have been converted.

Skip

[DCarlton]

17 minutes ago, PT20J said:

According to the IPC, the IO-360-A3B6 installation started with serial number 24-3374. That was the start of the 1996 production. So, 1996, 1997 and 1998 (last year J's were built) had two mags. from the factory (58 airplanes total). But a lot of earlier J's (including my 1994) have been converted.

Skip

How were they converted?  By Lycoming somehow?  Thanks.

[bmcconnaha]

my 1990 J had the single mag in it.  Serial 24-3146.  its not a split mag system with an IO390 with a surefly on the left mag spot.

[carusoam]

13 minutes ago, DCarlton said:

How were they converted?  By Lycoming somehow?  Thanks.

If you are familiar with the back of the IO360…

There is an accessory case…

All the drive mechanism for several accessory are related to the case cover and the gears behind it…

When the engine comes of the mount… the accessory case is most accessible…

Select your favorite engine shop for doing this level of work…

You want it done right the first time…

Replacing this many parts and doing the work gets expensive…

 

unlike adding roller bearing cam followers…. The case doesn’t have to be replaced…

PP thoughts only, not a mechanic…

Best regards,

-a-

[EricJ]

23 minutes ago, DCarlton said:

How were they converted?  By Lycoming somehow?  Thanks.

Generally during engine change/overhaul.   The accessory case and other components change enough that it is essentially a different engine, and generally not practical to make the change on an installed engine.   This has been done often enough, though, that it's worth checking on any candidate J model to see what is installed.

All that said, there's nothing wrong with the dual mag installations, either.   Some of us prefer them. 

[carusoam]

Important note for DC…

The biggest failures of Mags we have seen around here…

Re-use of star lockwashers… after maintenance.

They are a known failure device if used a second time…

Most trained mechanics are aware of this failure.

Keep a close eye on any hangar fairies that decide to do work on your engine… they may not be fully trained in the arts and sciences of fasteners…

Both styles of mags are equally susceptible to this failure…

 

Other Mag failures are related to hours since Mag OH… at 500hrs, they start nearing some quirky age/wear/exposure issues… bad capacitors, ozone exposed nylon gears… brittle failure, missing teeth…

Some people OH their mags based on a 500 hour schedule… and sometimes OH them on separate schedules…

Swapping in an electronic mag, might not be available for the dual mags yet….

The mechanical drive part of the mags isn’t usually part of a mag failure…

read potential target plane’s logs… look to see when the mags were OH’d last…

 

It helps to get to know the mechanics working on your plane… build a lasting relationship if you can…

 

PP thoughts only, not a mechanic… stuff I have read around here…

Best regards,

-a-

 

[PT20J]

1 hour ago, DCarlton said:

How were they converted?  By Lycoming somehow?  Thanks.

Engine replacement. There is no way to convert an A3B6D to an A3B6.

[KSMooniac]

Engine replacement. There is no way to convert an A3B6D to an A3B6.

Technically it is possible to convert one, but far easier to just exchange with Lycoming instead, especially since they no longer upcharge for a dissimilar core. They're motivated to get dual mags out of the fleet.

Sent from my LM-V405 using Tapatalk