T-craft challenge.

[Sloanlow]

All

What would be the most desirable engine set up for a 1946 BC12D if the owner wanted the following specs? (modern technology can be used IE fuel injection etc.) alternator and starter desired but not critical.

Highest HP for high density altitude applications at max gross wieght (8500+)

Aircraft remains certified

Aircraft falls into LSA

Fuel consumption gives reasonable fight time on 6 gal wing tanks and 12 gal nose tank.

Aircraft remains appealing for future buyers.

Jim

[VictorBravo]

Re: T-craft challenge.

My guess is a C-85-8 engine, upgraded to the O-200 crankshaft, with a 337 for one of the new ultra-light small "brushless" alternators. Vortex Generator STC for high altitude operations. The C-85 had fuel injection available if there is any fuel economy benefit to that. I believe the Marvel-Schebler carburetor will allow a little more power to be made, as well as being able to control mixture more effectively at altitude.

This should give you themost available horsepower, yet you can always throttle it to achieve about 4 gallons an hour at a 90 mph cruise. This will yield about 5 hours of cruising after a full power climbout. The airplane is still EASILY certified, LSA compliant, and desirable to buyers.

Then, if you want to take it to the next step and still be "mostly" certified, you can start getting a little clever...

Mag timing advanced for testing between annuals
337 for LightSpeed electronic ignition
K&N air filter
Tuned exhaust
Timken bearings on rocker arms
Welded "repair" on camshaft lobes

[jgerard]

Re: T-craft challenge.

Bill is right about the stroker c85, but I would really want a c90. Also it would need to be a -12 to use an alternator. The best thing to do is make it as light as possible. I wouldn't even have an electrical system unless absolutely necessary. Forget fuel injection, waste of time and money. Stick with the carburetor and a good set of mags. Play with the timing if you think you need more hp. Electronic ignition will require an electrical system and add more weight. The best and fastest way to put a plane together for what your asking about is to make a BC12D-85 with the 0-200 crank STC. Short mount, non electric, light weight, Kick Ass plane. Properly done it can weigh in at 750lbs and have the 1280 gross weight and a claimed 97hp while still burning about 5.5 gal/hr. This combo will give you a plane with a service ceiling up to the floor of class A airspace. A very short takeoff run, and depending on the prop at-least a 110mph cruise.

Jason
N43643

[Dano"T"]

Re: T-craft challenge.

Jason and Bill are both right. I now have a BC12-D with C-85-8 no electrics....cruise is 105 at 2350 rpms and 5 gals/hr and spectacular climb. My dad and I just bought another...this one has the C-90-12F no electrics. What a rocket! with a CK76-2-40 prop it cruises at 97 TAS and climbs like a seriously homesick angel. We may put a lightweight skytec starter in it cause dad's getting on up there and hand propping is a little bit of a chore for him...but I think the C-90 has more usable power than an O-200 and is a bit lighter I think. I couldn't stay with him in a climb with my 85HP...he's got more of a climb prop than me though. Still, the C90 seems to really snort.

[paulp]

Re: T-craft challenge.

howdy Clan,

Just remember, that if you go with the electrics, you will have to have the longer engine mount. In addition, there will be a battery. This means that there will be a baggage compartment. This means a mod to at least a BC12-D-4-85. This means 1380 MGTOW. There goes the light sport cat weight limit.

About the only thing that I can see is to go with the 85-8. Get the 0200 stroker kit for a little more juice and go fly. I would however, check on the new gross with the 85-8. Will it still be 1200?

Another option, is to buy a new taylorcraft sport.(If Harry ever gets one finished-stop it bad paul, bad paul-Sorry, it was the voices again)

[crispy critter]

Re: T-craft challenge.

Paul,
Remember,the little pills are your friend...don't forget to take them or the little voices will take over .
Also, the data on the electrics is incorrect. I have Crispy signed,sealed, and finished in writing for an 0200 with a sky-tech starter and brushless alternator on the original short mount with a gross of 1280.

[Dick Smith]

Re: Question

Kevin, Which alternator are you referring to?? Dick

[Yellow Duck]

Re: T-craft challenge.

Like to add my wish list also. Like what Kevin did. Would also like to be able to land shorter. If I come in tight. ie: Very slow, steep angle of decent, I must round out flare, and land almost at the same time. If I make a "normal" approach 50-55 mph round out, flare and float a few hundred feet before putting wheels on turf. I end up using 1000-1200 ft.

This is coming over sixty ft or so trees.

I could land my L-2 much shorter, but take off would be a little longer.

[paulp]

Re: T-craft challenge.

Howdy Kevin,

How did you get that accomplished? Was it a field approval or an stc? I was under the impression that the tube size had to be upgraded for the larger engine.

[Jim Herpst]

Re: T-craft challenge.

Lee, I think my 13 foot wings will land a little qiicker !! Also think in spite of the shorter wings with something like 680 (or less) pounds empty and with a C-85 AND THE STROKER KIT it should get off ok too !! I can hardlly wait. (But alas back to work ).... someday....

[Yellow Duck]

Re: T-craft challenge.

Jim anxious for you to finish. Then you cancome down here and show me how it is done. Anyone else is welcome also.

[Dano"T"]

Re: T-craft challenge.

I have a C85-8 with the heavy type strut fittings and 11/16" spar bushings with a short mount 1280 gross done on a 337 from 1981 (no stc). The strut attach fittings have a plate welded to them which is shown nicely on rob lees web site. Go there and look at his pictures....I learned alot by just looking.

[crispy critter]

Re: T-craft challenge.

Dick,
I will be using a B&C alternator and sky-tech starter.

Paul,
No size difference in the tubing, it is all the same size of 4130. It is a field approval. I has taken me a year to get it done plus I had to cut brand new fabric off my wings and start over. I was told by several people that there was NO mods that had to be done to take Crispy from a BC12D to a BC12D-85.....WRONG . So figured if I have to do this all over then I'm going to find a way to put the 0200 on the short mount with or without electric LEGALLY! After lots of red tape,many hours on the phone,looking at original blue prints for the BC12D thru the F-19 I finally was able to submit something that the feds would accept.....it did help greatly that I have a couple of really great friends high up on the FAA's board of approvals both of which are strong supporters of the LSP and LSA.

[paulp]

Re: T-craft challenge.

Hey Kevin,

Thats great news. Hell, I've been waiting for 2 mos to get a field approval for installing strip lighting for the dash. And, I sent them an STC for the F-19 as a guide. Lord, you would think that I was adding a turbine.

I think the FAA should change their motto to: We're not happy until your not happy!

[zero.one.victor]

Re: T-craft challenge.

I was thinking about hotrod 4-bangers-- here's a whimsical idea: C-85-8,O-200 (stroker) crank, PLUS IO-240 pistons/rods in bored-out cylinders or in IO-240 cyl's modified for carb instead of injection. Injected the 240 puts out 125 horses, carburated it oughta be good for 120 or so. Should make for a nice light engine using the -8 case and no electrics. No idea what would be the best cam and prop to use.
The IO-240 uses the same top end as an IO-360, just 4 of them instead of 6, never looked at one up close and therefore don't know if converting to a carb is feasible. Anyways, it wouldn't be legal except on an experimental even if it were physically possible.But it's fun to day-dream!

Eric