WHICH J's have -A3B6D engines vs -A3B6 - year numbers or model numbers?

[OZMOONEYMAN]

Anyone know which J's have -A3B6D engines vs -A3B6 - year numbers or model numbers?  

 

[ArtVandelay]

My 78 has a A3B6, many like mine were retrofitted, pretty easy to do with only a few minor changes.

[PT20J]

According to the IPC, S/N 24-3374 and above were built with A3B6.

EDIT: That serial number range is for 1996, 1997, 1998 (last year built)

[MisfitSELF]

My J (1984, S/N 24-1425, I think) got a factory re-manufactured engine in 2013.  It got a A3B6.  I think it had a A3B6D prior to that.  (I purchased it in 2017)

[haymak3r]

my 79 J has an A3B6D currently. S/N is 24-0843

[OR75]

The TCDS is a good source of information for this type of question 

A3B6 or A3B6D or A1B6D can be found on any J model ( independently of the serial number) 

No specific indication of when the factory switched 

[DCarlton]

I investigated this recently too.  It looks like less than 40 were made during or after 1997.  An experience broker estimates that less than 10% (older than 1997) have been converted.  My conclusion was you've gotta have deep pockets to buy a newer one, get lucky or go with the D mag engine.  I'm curious what it takes to convert the D mag engine if you buy one with a run out engine and plan to overhaul.  Will Lycoming still do it at a reasonable cost, etc.  

Edited December 29, 2021 by DCarlton

[PT20J]

3 minutes ago, DCarlton said:

I investigated this recently too.  It looks like less than 40 were made during or after 1997.  An experience broker estimates that less than 10% (older than 1997) have been converted.  My conclusion was you've gotta have deep pockets to buy a newer one, get lucky or go with the D mag engine.  I'm curious what it takes to convert the D mag engine if you buy one with a run out engine and plan to overhaul.  Will Lycoming still do it at a reasonable cost, etc.  

Lycoming will give you a discount for a D core on a rebuilt A3B6.

There is no way to "convert" an engine as there are a great many internal differences -- it's not just the accessory case. Lycoming told me that the IO-360-A3B6D was built in lesser numbers than other IO-360 variants and shares fewer common parts. Lycoming would like to accelerate the retirements so that's what's behind the lower cost to get an A3B6 from the factory.

Skip

[DCarlton]

19 minutes ago, PT20J said:

Lycoming will give you a discount for a D core on a rebuilt A3B6.

There is no way to "convert" an engine as there are a great many internal differences -- it's not just the accessory case. Lycoming told me that the IO-360-A3B6D was built in lesser numbers than other IO-360 variants and shares fewer common parts. Lycoming would like to accelerate the retirements so that's what's behind the lower cost to get an A3B6 from the factory.

Skip

So basically it's an exchange for a different engine at a discounted price?  Thanks.  

[jaylw314]

I still have the receipts from when the previous owner of my '86J converted from a factory A3B6D to a rebuilt A3B6 at Dugosh in TX, it was about $50k in 2012.

[OR75]

Lycoming accepts the A3B6D as a core for the A3B6 as well as for the IO-390-A3A6

converting from the A3B6D to the A3B6 or to the IO-390-A3A6 is the same process ( governor ratio, brackets, hoses …) . The accessories panel is the same 

but I guess it has to be a factory overhaul 

 

[jaylw314]

7 minutes ago, OR75 said:

Lycoming accepts the A3B6D as a core for the A3B6 as well as for the IO-390-A3A6

converting from the A3B6D to the A3B6 or to the IO-390-A3A6 is the same process ( governor ratio, brackets, hoses …) . The accessories panel is the same 

but I guess it has to be a factory overhaul 

 

There have been conversions from A3B6 to A3B6D that have been field overhauls.  IIRC, that does not include the replacement with roller tappets, but not 100% sure

FWIW, if the A3B6 serial number ends with an "E", it is roller tappet motor.  

Edited December 29, 2021 by jaylw314

[OR75]

23 minutes ago, jaylw314 said:

There have been conversions from A3B6 to A3B6D that have been field overhauls.  IIRC, that does not include the replacement with roller tappets, but not 100% sure

FWIW, if the A3B6 serial number ends with an "E", it is roller tappet motor.  

I guess they can procure the accessories panel or get it from an other mothballed engine but by then , I am not sure what the saving can be.

And I am not sure how that works with the part and serial number plate. 
does the data plate remain the D engine one ? unless there is a SB that allows for a conversion path. Probably only lycoming service centers can do would be my guess. 

[EricJ]

2 hours ago, OR75 said:

The TCDS is a good source of information for this type of question 

A3B6 or A3B6D or A1B6D can be found on any J model ( independently of the serial number) 

No specific indication of when the factory switched 

The TCDS just shows what's authorized to be installed via the type certificate.   As mentioned previously, the IPC tells what got installed per serial number.   In this case (in my IPC):

-A1B6D,  Ser Nos 24-001 to 24-0083, 24-0085 to 24-0377

-A3B6D,  24-0084, 24-0378 to TBA

-A3B6, 24-3374 to TBA.

Converting -A1xx to -A3xx is an authorized field modification that reclocks the propeller 120 degrees.

I'm wondering if separate mags was an option at some point given the TBAs in the serial number categories.

[PT20J]

25 minutes ago, EricJ said:

I'm wondering if separate mags was an option at some point given the TBAs in the serial number categories.

I don’t think so. I think Mooney just switched beginning with the 1996 model year. TBA shows up a lot in the IPC. I think that’s because the last IPC revision was before production ended and they didn’t yet know what the last serial number would be. 

[EricJ]

12 minutes ago, PT20J said:

I don’t think so. I think Mooney just switched beginning with the 1996 model year. TBA shows up a lot in the IPC. I think that’s because the last IPC revision was before production ended and they didn’t yet know what the last serial number would be. 

In this case the TBAs would indicate that they were shipping both at the time since there's a TBA for both the -A3B6D and -A3B6?   Or they just didn't bother to fill it in, which is always possible... 

[OZMOONEYMAN]

20 hours ago, ArtVandelay said:

My 78 has a A3B6, many like mine were retrofitted, pretty easy to do with only a few minor changes.

Thanks Tom cheers

[OZMOONEYMAN]

17 hours ago, MisfitSELF said:

My J (1984, S/N 24-1425, I think) got a factory re-manufactured engine in 2013.  It got a A3B6.  I think it had a A3B6D prior to that.  (I purchased it in 2017)

Thanks

[OZMOONEYMAN]

16 hours ago, OR75 said:

The TCDS is a good source of information for this type of question 

A3B6 or A3B6D or A1B6D can be found on any J model ( independently of the serial number) 

No specific indication of when the factory switched 

Copy thanks

[A64Pilot]

This is my second airplane with a (D) mag. As long as parts are available for the mag I see no real difference between the two including safety.

Its my understanding that there is no conversion path, the only way to get dual mags is to replace the engine which is most often a very expensive proposition.

If I have to overhaul my current engine, I’ll keep the (D) mag, the cam and whether or not it has DLC lifters is way more important to me.

(it’s my understanding that rollers are essentially another engine change) and therefore beyond my financial resources.

If I had a run out engine and wanted a Lycoming exchange, then I’d certainly be interested

[skykrawler]

Its a question not worth asking because a specimen airplane could have been converted.

I don't think its a discount for the non-D engine, its more like a premium for the D type engine.  The quote I got from Air Power in August is now reflected in the Lycoming mailers:  Factory Overhaul (includes roller lifters) is $39,888 for the D and $37,830 for the non-D.   If you have to ask... then likely when you 'convert' the expenses for that will probably easily exceed the difference in prices - and you better have a mechanic or shop that knows what they are doing in that regard.

There are plenty of dual mag engines around - including 6 cylinder 540s.   There is nothing unsafe about the dual magneto - if there was there would be an AD to eliminate it. From what I hear there is more maintenance expense/problems with the Slicks.  But, whatever....

[Mad Mikey]

A3B6D is in my 1979 M 20J.  24-0893. 

[MisfitSELF]

Indeed, the Slick Mags that come with the A3B6 suck hard.  Take my several data points.  I've had them replaced 4 times in two years according to the logs before I owed the aircraft, and I had to send them in once to get an "SB" performed because the timing would drift with temperature changes.  Since Champion took over the brand, they've seemed to have a lot of problems.

However, the advantage of having the A3B6 is that you can change out a mag for an electronic ignition like the Surefly which I will do in the next couple months.  You may also be able to install a Bendix mag instead.

[ArtVandelay]

There seems to be a period (late 90s to early 2000?) where slicks had a quality problem.
My 1st pair lasted 2200 hours, from mid 90s.
After overhaul, My new pair has 3 years and 300 hours on them.