Geared engines, why?

Bill

Touchdown! Greaser!
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Ok, so that 175 has a geared engine, as does another nifty plane, the Travel Aire. But, getting them re-done is near impossible. So, why did the manufacturers use geared engines to begin with? Get more HP out of a smaller engine by spinning it faster, then gearing down to prop speed?

Just wondering.
 
Bill Jennings said:
Ok, so that 175 has a geared engine, as does another nifty plane, the Travel Aire. But, getting them re-done is near impossible. So, why did the manufacturers use geared engines to begin with? Get more HP out of a smaller engine by spinning it faster, then gearing down to prop speed?

Just wondering.

Good guess.
 
Bill Jennings said:
Ok, so that 175 has a geared engine, as does another nifty plane, the Travel Aire. But, getting them re-done is near impossible. So, why did the manufacturers use geared engines to begin with? Get more HP out of a smaller engine by spinning it faster, then gearing down to prop speed?

Just wondering.

Yes, that and the fact that props work more efficiently at lower rpm's. What is a Travel Aire and what geared engine does it use?
 
Henning said:
Yes, that and the fact that props work more efficiently at lower rpm's. What is a Travel Aire and what geared engine does it use?

I meant the Beech Travel Air, I thought it used a geared engine, but maybe I'm thinking of the twin Bonanza? I thought one of the Beech twins was a geared engine plane. Then again, I could be talking out my a$$ :dunno:
 
Bill Jennings said:
I meant the Beech Travel Air, I thought it used a geared engine, but maybe I'm thinking of the twin Bonanza? I thought one of the Beech twins was a geared engine plane. Then again, I could be talking out my a$$ :dunno:

Could be thinking of a Grumman Widgeon after the Ranger engines.
 
They are also very quiet. My 310 makes Bose earn its money for my headset. In contrast, I have friends (421C drivers) who tell me that they cruise at 1800 rpms and don't even need a headset.
 
Bill Jennings said:
I meant the Beech Travel Air, I thought it used a geared engine, but maybe I'm thinking of the twin Bonanza? I thought one of the Beech twins was a geared engine plane. Then again, I could be talking out my a$$ :dunno:
Yeah, the T-bone used GO-435 IIRC and teh Queen Air used a GO-480 again, IIRC. Been a long time since I've worked on either. Love the T-bone though, such a good flying airplane, and roomy, wouldn't mind a runout one and stick some aluminum small block Chevies on it and go experimental. Most of the ones still in action have the Air Stair as well. Quite a few of the remaining Queen Airs have undergone the Excalibur conversion and have the IO-720 8 cyl 400hp engines. I have grown to really like that engine, it can be pricy to maintain, but when operated properly and kindly, they hang in there.

The Travel Air came with O-360 and IO-360 Lycomings. Riley provided a turbo package with either cable control or electric control wastegates. I had the latter. Good airplane though. About as economical of a twin there is, however is not a known Ice plane. However, no geared engine, although I dont understand why all engines aren't geared, especially now with the advances in metalurgy and precision tolerance manufacturing. Props should be slowed way down. Who's the engineer? What's he most efficient speed for an aerodynamic prop? 500rpm? Problem is for one that slow, the diameter would be too big. Personally I think a 1400-2000 rpm prop would work out pretty well.
 
All of which reminds me of the Continental Tiara, a bad idea that went noplace....
 
RobertGerace said:
They are also very quiet. My 310 makes Bose earn its money for my headset. In contrast, I have friends (421C drivers) who tell me that they cruise at 1800 rpms and don't even need a headset.

All the 421 models I've flown have been like that, just use Walkman style head sets. Bring that tip speed down just a bit and it makes a big difference.
 
Henning said:
All the 421 models I've flown have been like that, just use Walkman style head sets. Bring that tip speed down just a bit and it makes a big difference.

I used to do the same thing when I drove the C421B. However, it was old enough to be a little louder. I used to use earplugs and then put the Telex on over them and just crank up the volume. Worked great.

Our boss/owner at the charter is so worred about hearing over time in the learjets that he bought all four planes a set of Bose. I don't think they need them but I sure didnt try and talk him out of it. :)

Brent
 
Whats a t-bone? I'm assuming the chevy's would mate with the factory reduction gear? Sounds like an interesting idea.



Henning said:
Yeah, the T-bone used GO-435 IIRC and teh Queen Air used a GO-480 again, IIRC. Been a long time since I've worked on either. Love the T-bone though, such a good flying airplane, and roomy, wouldn't mind a runout one and stick some aluminum small block Chevies on it and go experimental. Most of the ones still in action have the Air Stair as well. Quite a few of the remaining Queen Airs have undergone the Excalibur conversion and have the IO-720 8 cyl 400hp engines. I have grown to really like that engine, it can be pricy to maintain, but when operated properly and kindly, they hang in there.

The Travel Air came with O-360 and IO-360 Lycomings. Riley provided a turbo package with either cable control or electric control wastegates. I had the latter. Good airplane though. About as economical of a twin there is, however is not a known Ice plane. However, no geared engine, although I dont understand why all engines aren't geared, especially now with the advances in metalurgy and precision tolerance manufacturing. Props should be slowed way down. Who's the engineer? What's he most efficient speed for an aerodynamic prop? 500rpm? Problem is for one that slow, the diameter would be too big. Personally I think a 1400-2000 rpm prop would work out pretty well.
 
pete177 said:
Whats a t-bone? I'm assuming the chevy's would mate with the factory reduction gear? Sounds like an interesting idea.

A T-Bone is a Twin Bonanza BE-50 I believe, actually it looks like a Travel Air on Steroids. The factory gear reduction would not work well from a practicality stand point, and also from a crnk/prop offset point. It would work out much better to just make a new housing and gear reduction to bolt onto the bellhousing flange, or modify the set off a Continental GTSO 520. There is also a good belt drive reduction already made for it. I think 1.75:1 would make a good ratio for that engine. I can build a 400hp 347ci engine that would have a 4000 hr TBO. Engine and reduction for $14,000 a side. If you want twin plug heads, that's $7k extra.
 
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