A65 to A75 conversion

[tcart]

I just had my A65 majored and in the process we did the mods to convert it to an A75. Does anyone know how I can get my hands on a 337 for installing a Continental A75 on a BC12D?

[AndyDuke]

I ought to be able to because mine had an A75 before I swapped it for a C85. I'll take a look at my documentation and see what I can dig up.

[tcart]

Thanks for checking,

Alan

[AndyDuke]

The details are on microfiche at the moment, If you can wait a couple of weeks, I should be able to get the details in a format that can be emailed to you. If not maybee another member of the tribe could help you out.

[Robert Lees]

Andy, bring the fiche up on Thursday, I will copy and transcribe as necessary.

Rob

[AndyDuke]

Alan,

We have gone through the fiche documents and there is nothing on the A65/A75 conversion, sorry.

Interesting to note that there is no documentation for a whole host of other modifications either!!

[Carl Ellis]

A friend of mine bought a tcraft which had an A-75 swapped for a C-85 which went onto a J-5. He eventually obtained a one time STC for it through the Seattle FSDO. It was not big deal, just paper work. The swap was straight across with no additional work required other than weight and balance.

- Carl -

[Robert Lees]

Of course, an "A-75" is just an "A-65" running at higher rpm (albeit with a few minor mods inside the con rods) so if you keep it as a slightly-higher-revving A-65, but legally as still an A-65, then no paperwork change is required? Perhaps just a little 337 to run the 65 at higher rpm?

[AndyDuke]

I have also been told that the A75 had a different push rod so that it could take the higher stresses when running at 2600 rpm.

[tcart]

I know that it shouldn't be a big deal to get a field approval, but my local FAA office is notoriously difficult with these simple matters. My thought is that it would be hard for them to question the conversion if I present them with an approved 337.

Any ideas gentelmen?

Once agan, thanks for the replies.

Alan

[Carl Ellis]

The fellow who did this locally is a member of the form. You can send him an email to ask for a copy of his STC and maybe you can get the approval through the same FSDO. His name is
Allen Harstine and his forum login is "Allen".

- Carl -

[taylorcraftbc65]

A75 conversion

Hey guys, I'm back. On the A-75. My Engine was modified to
the A-75 specs when the engine and aircraft were restored. Out
here in west Texas the density altitudes get to be a bit much, so
the people putting the motor together changed the carb jetting,
put on the intake spyder that has the larger inside diameter, and
changed the connecting rods. The only thing that is in the aircraft logs is the con rod change. When I asked the IA that was doing the annual on the bird about it, he said "go fly the plane". Externally it looks the same, it seems to handle just fine, so I plan
on doing just that.
Sabrina

[allen]

One-Time STC for A-75

Hello Alan,

I am the person (mentioned above) that got the one-time STC for an A-75. I worked with the Seattle Aircraft Certification Office in Seattle, WA; the engineer assigned to my project was Richard McCauley. It took me about a year to research all of the information that I needed and about two months for them to do the actual approval. Richard and everyone else in the office were really helpful through the entire process. It is important to note that the airplane already had all of the modifications required for the C-85 and that made the process much easier. I sent you (Alan) a copy of my paperwork in a separate email.

Good luck,

Allen, N27599