A-75 Engine ???

[Yellow Duck]

Was wondering ? What about just upgrading to an A-75, less work, and I don't believe we need to do any mods to the engine mount or wings (or do we?) What about fuel lines? Carb ? Mag Timming ?

Or anything else ?

This gives 16% additional HP, and may be enough for what I need.

Those flying with a standard BC-12D and an A-75 ? Talk to me. Tell me the difference you have found ?

[M Towsley]

Re: A-75 Engine ???

Hey Lee,

I just picked up an overhauled A-75 to replace the 65 when it gets too tired. My understanding is the carb has a bigger venturi, 1 1/4" to a 1 5/16" (I think) and larger main jet and the mag timing is staggered, 29 degrees and 32 degrees. You also run a shorter and/or smaller pitched prop to get the extra r.p.m., which is where the ten additional horsepower comes from. I am unaware of any changes to the fuel line, though I will digress to those who are running the A-75. Can anyone advise what the standard wood prop is for the BC-12D???

[Acroeric]

Re: A-75 Engine ???

I had the A75 on my first BC12-D. I would stick with the A65 if it were me. The additional hp comes from revving 100 additional RPM and changing the pitch of the prop. I could never tell the difference. Just my opinion. . . .

[d.grimm]

Re: A-75 Engine ???

I fly two of those yellow airplanes, one with a 65, and one with a 75. In my experience the 65 gets off the ground faster than the 75 because of 4 in more prop diameter and probably more static thrust.
Top speed is the same between the two.
Additionally, I did a top overhaul on the 75 and found out that the new Superior cylinders were not approved on the A75. Same cylinder, they just didn't include it when they did the approval. Ended up with old rebuilt.
If you flew one and then the other not knowing which was which I'm sure
you couldn't tell the difference.
Stick with a good 65 and change the prop pitch to get the desired results.

[Yellow Duck]

Re: A-75 Engine ???

After listening to several of you, I do believe that there is no apprecable difference between the 65 and 75. I have already repitchhed my prop to a 74 X 41. However my best static is about 2100-2150 and in level flight about 2300+ indicating about 100, best as I cant tell. The speed is just lightening ! (lol)

I will continue flying my trusty 65. It really runs great, starts very easy (that is always good for an old man)

I think one of the best things I have done was replace my Mags last annual with new Slicks. Made all the difference.

Solo, I love the T-Craft, and if I had 4 or 5 hundred more length to my runway, at gross it would be fine also. It is just getting over these trees in the summer time. And It is not that good in the winter either. Nowhere to go if it hic-cups shortly after breaking ground. Always a pucker factor. Oh well makes life interesting.

[NC36454]

Re: A-75 Engine ???

After listening to several of you, I do believe that there is no apprecable difference between the 65 and 75. I have already repitchhed my prop to a 74 X 41. However my best static is about 2100-2150 and in level flight about 2300+ indicating about 100, best as I cant tell. The speed is just lightening ! (lol)

I will continue flying my trusty 65. It really runs great, starts very easy (that is always good for an old man)

I think one of the best things I have done was replace my Mags last annual with new Slicks. Made all the difference.

Solo, I love the T-Craft, and if I had 4 or 5 hundred more length to my runway, at gross it would be fine also. It is just getting over these trees in the summer time. And It is not that good in the winter either. Nowhere to go if it hic-cups shortly after breaking ground. Always a pucker factor. Oh well makes life interesting.

Lee,
The way I see it, you have a number of options :

1. Cut down the trees (probably a bad idea...the environmentalists would be all over you!)
2. Change to a 72x42 wood prop (expensive)
3. Take everything out of the plane that is not required (makes it lighter...surprising how much quicker I get off by just removing my wheel pants)
4. Lose a few pounds (this is the best option...plane flies better and you will get to torment the skies MUCH longer!)
5. Run as much air as possible in your tires
6. If your runway is grass, cut it shorter (too much extra work!)
7. Last...always buy top grade underwear to compensate for the "pucker factor" (this is probably the most realistic option of all!)

Have fun (and Merry Christmas)
Ken
1941 BC12-65

P.S. I'm on a short strip too but bordered by a lake on three sides. (not too hard to climb high enough to get over water!)

[Yellow Duck]

Re: A-75 Engine ???

Ken, Lots of good options. Do you believe a 72x42 wood would preform better than a metal 74 X40 ? I have had wood props in the past, love them, looks great. But performance wise ? I don't know. They are lighter tho.

I always wear clean underwears when leaving out of here, just in case. Remember what mothers say, always have clean underwear, in case you are in an accident.

The trees at both ends ? Well I am certain my neighbors ,who own the trees may have something to say about that.

But, you are correct. Keep it light. Just put my wheel pants back on, may remove them, and any other non essentials. ie: more that half tank, unless going some place, charts,E6B,clip board, and any other junk that has accumulated in the baggage compartment. Great idea.

I have a 7amp 12 volt radio shack batt. and intercom, but really need that for instructions. Have two students. Also my hand held ICOM and portable GPS. Don't really use that most of the time. However once they learn pilotage and dead reconding, I do let them learn the GPS. And of course, my "Turbo Alternator" 5 pounds.

I have been considering Vortec Gen. Anyone have any installed ? Do they help ?

Thanks Ken, good ideas

[Dick Smith]

Re: RE: Turbo Alternator

Lee, what is your considered opinion re: the Turbo Alternator: Any vibration, excessive noise, problems that you've encountered? Does it keep your 7 amp battery charged, with the electrical load you have? Dick

[zero.one.victor]

Re: A-75 Engine ???

Lee, what if instead of asking neighbors to cut trees out of the goodness of their hearts, you offered to buy trees at "stumpage" rate (value of logs minus cost of logging).If trees are ornamental type, probably no go, but if they're just trees....might be worth a try. I know people with private strips here in WA who've had luck getting rid of obstruction trees like that-- with cold hard cash.

Eric

[Yellow Duck]

Re: A-75 Engine ???

Dick, love the Turbo Alternator. Can't tell it is even there. Works great.Weighs only about 5 lbs or less. Even the very inexpensive Radio Shack battery does the job. Guess I have had them on for 8-9 months now.


The trees ? They are in my neighbors yard. I live in the center of three subdivisons. Weren't there when I started, but they grew around me, the subdivisons. And, no there is no way they would allow me to cut or remove them. When I first got here , everyone would ask, why do you want to live so far? Now looks like the world has come to meet me. LOL Need to live with it or move. Not going to move, but may in the future move my plane to an airport. Hate that, but may well come to that. Until then, will play with ideas.