[Robert M]

Does anyone know what a Lycoming O-320-A2B with the Conical mount becomes when the mount is changed to Dynafocal 1? An O-320-A2B with dynafocal mount? An -A2D?

Thanks

 

[Robert M]

Alrighty then! I've gotten the answer to my question.

For grins and giggles, I decided to look at the official Lycoming parts catalog for my engine to see if there was any references to crankcase types. Right there at the top of the parts index is a list of the many crankcase halves (Part No. 1) that are used for the various engines covered in this parts catalog. The first engine in the index is an O-320-A2B then an -A2C, A2D, etc. That's when I noticed that there are two possible crankcases available for the -A2B. Both of the crankcase numbers listed have either one or two cute little asterisks next to the numbers. Looking at the bottom of the page, there it was, two asterisks means that the crankcase assembly was setup in the "No. 1 dynafocal mounting provision"! So, even though the "mounting provision" has changed, it is still an -A2B!

 

[mahlon_r]

not so simple!

Look further into the book!
To change in into a TRUE dynafocal one A2B engine, you will also have to modify ( if experimental) or replace( if certified) the accessory housing and replace the oil sump assembly and intake pipes.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

 

[Robert M]

not so simple!

You are so right, nothing ever is - especially with aircraft. But, then, the question still remains. What type engine will I have?

I wanna believe that since the engine was born an -A2B, it will remain an -A2B. I'm not sure there's a good way to figure it. When the engine turns over for the first time, the mags will be different from the originals specified in the book - mags that aren't even IN the book. So even though the engine mounting provision is changed and the mags will be different it will still be an -A2B - I guess?!?!.

I don't know enough to fill a thimble when it comes to aircraft engines, (any engine for that matter).

Correct me if I'm wrong (I'll never admit it but), is the following data accurate?

-A2B:

A - Indicates change in Power Section and Rating from
Original Design - "A" being the original design - no change

2 - Indicates Nose Section and in this case fixed pitch - I will still be running a FP prop - no change.

B - Indicates Accessory Section - the only thing that will be different here will be mags.

If I choose to go with, say, Pmags. There is no alphanumeric for Pmags so how does this get classified.

Looking at the list of Lycoming engines and their designation labeling, the last of the 150 hp O-320's is an O-320-E3H. The H was because of a mag change from the previous model - "Same as ?E3D but equipped with S4LN -20 and ?21 Magnetos."

Overthinking this far more than I ever should (and always seem to do) - the label I will place on this particular configuration will be O-320-A2I

I'll send this information into Lycoming so they can make the necessary immediate changes to their paperwork for future reference. LOL