BC12D A-65 to A75

[lfries]

Anyone have paperwork going from an A65 to an A75.
Not coming down from an 85

[marc]

Re: BC12D A-65 to A75

my engine was a a65 now a75 i far as i know there is no paper work and the engine was ported and balance jason gerard did the rebuild.iam swinging a MCauley 1b90 cm74-43.marc n43643

[jCandlish]

Re: BC12D A-65 to A75

I am also running an a75 + 1b90 7445. This combination will rev to 2550+ where the motor tends to run quite lean. Unless the carb is rejetted and has the correct venturi it is inadvisable to run for long periods at full rpm.

Regards.
jCandlish

[M Towsley]

Re: BC12D A-65 to A75

Mr. Fries,

I have a spare A-75 I plan on installing someday. My local FSDO said they would approve if it was around a 10% increase. You do need to get a field approval, from what I understand, along with the paperwork.

[fearofpavement]

Re: BC12D A-65 to A75

one of our t-crafts had gone from an A-65 to an A-75 and then later back to an A-65. There were only log entries.

[Ragwing nut]

Re: BC12D A-65 to A75

Nothing more than a log boook entry to convert the motor from an A65 to A75. It will require a 337 to install.

Mike

[cpirrmann]

Re: BC12D A-65 to A75

I have an A-65 to overhaul. Is an A-75 conversion desirable?

[M Towsley]

Re: BC12D A-65 to A75

Use the search function for a-65 to a-75 or something similar. You will find this information in past discussions.

[marc]

Re: BC12D A-65 to A75

my a65 was converted to a a75 staying with the a65 keep the a65 just pump it up no need ad weight marc n43643

[Ragwing nut]

Re: BC12D A-65 to A75

I have an A-65 to overhaul. Is an A-75 conversion desirable?

The only way you actually get the extra 10 hp is to turn the rpm's up to 2600. You get no gain by just changing the internals.

Mike

[jCandlish]

Re: BC12D A-65 to A75

The A75 will burn 5+ gal/hr. Not very efficient at all.

[astjp2]

Re: BC12D A-65 to A75

The Carb venturi is the same for the A-65 and 75, per the type certificate....My O-200 burned 4.5 gph this last weekend when I had the rpm's down to about 2050 cruise but I was using about 2500 rpm's for take off. The A-75 gets its power from the rpm increase, my parts manual claims to use all of the same parts as the A-65, but I have seen another manual that was a different revision that required different pistons and rings. The A-80 uses different pistons and Compression ration but the extra weight of the pistons makes it a moot point.

http://www.bowersflybaby.com/tech/fenton.htm

Good reading for general info. Tim

[Ragwing nut]

Re: BC12D A-65 to A75

The Carb venturi is the same for the A-65 and 75, per the type certificate....My O-200 burned 4.5 gph this last weekend when I had the rpm's down to about 2050 cruise but I was using about 2500 rpm's for take off. The A-75 gets its power from the rpm increase, my parts manual claims to use all of the same parts as the A-65, but I have seen another manual that was a different revision that required different pistons and rings. The A-80 uses different pistons and Compression ration but the extra weight of the pistons makes it a moot point.

http://www.bowersflybaby.com/tech/fenton.htm

Good reading for general info. Tim

The internal differences are stellite exhaust valves, waffle head pistons, and rejet of the carb. All parts carry different part numbers.

mike

[jCandlish]

Re: BC12D A-65 to A75

The wristpins are of smaller diameter, and the rods are setup to splash oil on the skirts.

continential parts .pdf --> http://www.candlish.net/taylorcraft/...ntal_parts.pdf

[lfries]

Re: BC12D A-65 to A75

I hope this works. I went to the FAA Registry today and found
1 BC12-d in Alabama listed with an A-75, 8 In Alaska and 4 in California.
Any chance some may have been delivered from the Factory with an A 75.
None of the Names showed up in the members list.