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  #16  
Old 05-03-2005, 02:51 PM
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ok, ok, ok jon - i hear you and me for that matter, heh heh heh

hows about taking the ss tube from the turbo outlet tube and wrapping it, with spacers, around the 1400 degree exhaust manifold

still simple, but hot all the time and pressurized so i am guaranteed flow
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  #17  
Old 05-03-2005, 02:57 PM
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Default Water cooling rulez

I wish I could feel smug, but all I can feel is sorry for all my friends in cold climates freezing their b...s off in their air-cooled engine planes. Come to rotary or diesel country. If president Bush and the Congress can see the light, at long last, why can't you?
http://www.cnn.com/2005/POLITICS/04/...sel/index.html
What I find especially amusing is the last paragraph of the report, where the reporter has to explain the operating principle of a diesel as opposed to an Otto cycle engine; how ignorant does he think his public is? Is he right? I hope not.
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  #18  
Old 05-03-2005, 03:05 PM
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Kumaros - you couldn't pay me to move to a boring warm climate, i might pay to move further north.

if i went liquid cooled, i would still use boost heat, don't want radiaters in my cabin and i hear they are hard to get allot of heat out of, remember i am designing for -30 OAT
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  #19  
Old 05-03-2005, 03:29 PM
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Quote:
Originally Posted by Dust
snipped...
if i went liquid cooled, i would still use boost heat, don't want radiaters in my cabin and i hear they are hard to get allot of heat out of, remember i am designing for -30 OAT
Mike, there's no accounting for taste of cource, but if you are toasty warm in your huge SUV with a radiator and blower, why don't you want the same arrangement in your far smaller Cozy?
I personally have stashed away a couple of car blowers I found in the garbage of a local car dealership, left-overs from retrofitting air-conditioning.
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  #20  
Old 05-03-2005, 03:35 PM
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I view the radiator in the cabin as soo much plumbing to go wrong, have you never had one go bad. A pipe wear out, the core leak.

the turbo, in my opinion, is a simpler solution
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  #21  
Old 05-03-2005, 03:44 PM
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Default Bleed air

I think Dust's idea will work fine if he has some type of mixer valve to control temp of air going to the cabin. We typically see compresor discharge temps of 50-65C at only 30 inches and 6500 feet. It just gets warmer as altitude is increased. At 15000 feet, we are up around 80-85C at 30 inches and over 100C in the climb up there at 35 inches. Real world temp rise is higher than theory predicts due to conduction effects from the turbine section through the center section into the compressor backplate. Bleeding off 50 SCFM from a properly matched compressor is nothing as far as engine power goes although this can affect surge margins and compresor efficiencies a bit.

Alternately, air from the intercooler matrix could be ducted into the cabin. This does not affect charge air to the engine and is not as hot but could be potentially easier to do and more reliable.

I'm not aware of any piston aircraft using charge air heating exclusively. Most twins use Janitrol gasoline heaters in conjunction with traditional exhaust heat muffs. Obviously the pressurized turbo ones use turbo air to pump up the cabin which is hot so they need a/c as well so they don't fry everyone inside but the small volume of air fed in cools considerably when fed in through the inlet valve or duct. Dust is thinking about feeding lots of hot air in right off the compressor.
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  #22  
Old 05-03-2005, 03:50 PM
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Default Free heat

Quote:
Originally Posted by Dust
I view the radiator in the cabin as soo much plumbing to go wrong, have you never had one go bad. A pipe wear out, the core leak.

the turbo, in my opinion, is a simpler solution
No Mike, in thirty years of automotion I've never had a coolant leak in a properly maintained car. On the other hand, I've heard lots of terrifying stories of carbon monoxide poisoning etc., all too easy to happen when you get your breathing air from the engine, through a sleeve around the exhaust pipes, a turbo or whatever. For me anyway it's a one-way street, since the diesel engine is slightly heavy, I'll have to put the radiator up front for balancing, therefore why not use the heat available ?
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  #23  
Old 05-03-2005, 03:52 PM
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Quote:
Originally Posted by Kumaros
Mike, there's no accounting for taste ..... your huge SUV
Kumaros
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I DO NOT OWN A HUGE SUV. I gots a huge pickup truck, i would not buy a huge SUV, unless i could get my hands on a real humvee, not the yukon gm one. A pickup is useful, the big SUV's are silly, oh, don't get dirt on my carpet, itsa clean suv - clean and suv don't go together

I might buy a small old jeep for fun and park it at an airport in the UP. thats the upper peninsula of michigan for you non michiganders
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  #24  
Old 05-03-2005, 03:59 PM
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Quote:
Originally Posted by rv6ejguy
snipped ...
Alternately, air from the intercooler matrix could be ducted into the cabin. This does not affect charge air to the engine and is not as hot but could be potentially easier to do and more reliable.
Now that would be an elegant solution.

[/quote]
I'm not aware of any piston aircraft using charge air heating exclusively. Most twins use Janitrol gasoline heaters in conjunction with traditional exhaust heat muffs. Obviously the pressurized turbo ones use turbo air to pump up the cabin which is hot so they need a/c as well so they don't fry everyone inside but the small volume of air fed in cools considerably when fed in through the inlet valve or duct. Dust is thinking about feeding lots of hot air in right off the compressor.[/quote]
This whole 50's and 60's technology mess reminds me of skyscrapers designed in that era, no switches for lighting, air-conditioning and heating on all the time, balanced against each other with no concern for wasting energy. On what planet did the designers live on?
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  #25  
Old 05-03-2005, 04:11 PM
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Default Same difference

Quote:
Originally Posted by Dust
I DO NOT OWN A HUGE SUV. I gots a huge pickup truck,
snipped...
Same difference

Quote:
Originally Posted by Dust
I might buy a small old jeep for fun and park it at an airport in the UP. thats the upper peninsula of michigan for you non michiganders
There was a time in the early '70's you could buy an original 20-30 years old ex US army, ex Greek army jeep for less than a hundred bucks at the government agency auctioning off military surplus material. Farmers used to buy them and fit more modern and efficient engines. I remember almost buying one back then, but I bought a Fiat 600 instead.
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  #26  
Old 05-03-2005, 06:08 PM
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Default Waste that fuel!

Quote:
Originally Posted by Kumaros
Now that would be an elegant solution.
I'm not aware of any piston aircraft using charge air heating exclusively. Most twins use Janitrol gasoline heaters in conjunction with traditional exhaust heat muffs. Obviously the pressurized turbo ones use turbo air to pump up the cabin which is hot so they need a/c as well so they don't fry everyone inside but the small volume of air fed in cools considerably when fed in through the inlet valve or duct. Dust is thinking about feeding lots of hot air in right off the compressor.[/quote]
This whole 50's and 60's technology mess reminds me of skyscrapers designed in that era, no switches for lighting, air-conditioning and heating on all the time, balanced against each other with no concern for wasting energy. On what planet did the designers live on?
Kumaros
It's all Greek to me[/quote]


With a bit of time in P Navajos many years ago, it does seem silly to add a gasoline heater when you have two 425hp Lycs on each side pumping out XXXXX BTUs/ killowatts of waste heat. The Janitrols were not all that reliable either, leaving you with very cold feet on occassion at 24,000 feet. Could have used bleed air, intercooler air, heat muffs or oil cooler air to heat the cabin. I'm guessing that the engineers at Piper had their reasons, possibly easier to route pressurized air from the turbos to the janitrol in the nose for the pressurized cabin, otherwise long ducts and another heat exchanger needed somewhere which might have been heavier. The Janitrol used a few gallons an hour at max output if I recall. Cracked pipes and heat exchangers along with bad ignitor plugs caused some downtime and they are quite expensive.
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  #27  
Old 05-03-2005, 07:07 PM
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Quote:
Originally Posted by rv6ejguy
I think Dust's idea will work fine if he has some type of mixer valve to control temp of air going to the cabin.
The common way to do that is just pipe the air through a seperate intercooler that is enclosed in a plenum with a flapper on the intake. Look at the leading edge of a C421 wing root and you will see what I mean.... better yet, I'll take pictures tonight/tommorow.

Quote:
Originally Posted by rv6ejguy
We typically see compresor discharge temps of 50-65C at only 30 inches and 6500 feet. It just gets warmer as altitude is increased. At 15000 feet, we are up around 80-85C at 30 inches and over 100C in the climb up there at 35 inches. Real world temp rise is higher than theory predicts due to conduction effects from the turbine section through the center section into the compressor backplate. Bleeding off 50 SCFM from a properly matched compressor is nothing as far as engine power goes although this can affect surge margins and compresor efficiencies a bit.
You may have hotter air at those points, but you are also working the turbo harder and harder as you get higher. 50 scfm might not be much for a turbo at low altitude, but the higher you go the more likely you are to overspeed trying to keep up your bleed air as well as 30 inches in the manifold.

It is a very real solution to do, however I'm not sure it is worth the extra engineering time when you can just pipe air through an oil cooler and get the same effect without risking your turbo(s).
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  #28  
Old 05-03-2005, 09:54 PM
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Quote:
Originally Posted by rv6ejguy
Alternately, air from the intercooler matrix could be ducted into the cabin. This does not affect charge air to the engine and is not as hot but could be potentially easier to do and more reliable.
this is easier in a tractor than a pusher, not to say it cannot be done, but significantly more complex with the air behind you, leaving you
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  #29  
Old 05-04-2005, 07:22 AM
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Default Its a shame.. BUT...

Quote:
Originally Posted by Kumaros
how ignorant does he think his public is? Is he right? I hope not.
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I hate to admit it, but as a whole 1) the public is ignorant of technical matters and 2) the public is indignant and offended when you remind them of #1. Honestly, the media guy is wasting his time. Those who care already know how a diesel works. Those who dont, wont bother to pay attention.

People in America are remarkably ignorant of world events, world geography, politics and technology. I have coworkers who work in nursing as a degreed profession who asked me for advice on how to use their computer for an online class. They did not know how to "Cut and paste" in order to add something to email (because their prof didnt want attachments - well founded virus fears). This is someone with a college degree and responsible for intensive nursing care... and they are good at that role.. but they are still technophobes. The vast majority of folks only know that their car/truck/bike takes gas/diesel and you fill it up when the gauge says "E" (and lament the current price of fuel) and you change the oil when the jiffy-lube sticker/penzoil sticker on the inside of the windshield says its time.

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  #30  
Old 05-04-2005, 11:08 AM
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Quote:
Originally Posted by rv6ejguy
Obviously the pressurized turbo ones use turbo air to pump up the cabin which is hot so they need a/c as well so they don't fry everyone inside but the small volume of air fed in cools considerably when fed in through the inlet valve or duct. Dust is thinking about feeding lots of hot air in right off the compressor.
the mixing of this air will be a bit tricky, the higher the less charge air and the more fresh air and on my docents - no heat and they should take about an hour at 500 fpm. that is why dave got me thinkin about wrapping a few coils around the hot side of the exhaust for times when the turbo is not putting out much heat

aint experimenting fun
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