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High Altitude operations (Turbo charge???)



 
 
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  #21  
Old July 7th 03, 10:15 PM
Ernest Christley
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RobertR237 wrote:

With all this talk of using a gas powered blower would someone please explain
how that blower is going to overcome the effects of altitude and maintain the
same velocity of air. It is going to drop off in power just as the engine will
and at altitude its effect will be nil.


Bob, they've told you already. They're going to put a turbo on the
blower. Sheesh! 8*)

--
----Because I can----
http://www.ernest.isa-geek.org/
------------------------

  #22  
Old July 8th 03, 12:08 AM
Robert Bonomi
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In article ,
Morgans jisumorgan@charterdotjunkdotnet wrote:

"RJ Cook" wrote in message
. ..
If your blower has an exhaust velocity of 200 MPH the maximum pressure
recovery in a diffuser would be about .7 pounds/in2, realistically about

.5
lbs/in2.

RJ


Sounds like a good swag. How does lbs/sq.-in relate to inches of mercury
(as in manifold pressure)?


30" of mercury is nominally 14.7 psi.

For rough approximations just use a factor of 2
  #23  
Old July 8th 03, 02:29 AM
RobertR237
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In article , Ernest Christley
writes:

RobertR237 wrote:

With all this talk of using a gas powered blower would someone please

explain
how that blower is going to overcome the effects of altitude and maintain

the
same velocity of air. It is going to drop off in power just as the engine

will
and at altitude its effect will be nil.


Bob, they've told you already. They're going to put a turbo on the
blower. Sheesh! 8*)



OK, and they are going to power the turbo with what?


Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)

  #24  
Old July 8th 03, 02:57 AM
Scott VanderVeen
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A teeny tiny leaf blower from the Barbie Collection.

" OK, and they are going to power the turbo with what?


Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)



  #25  
Old July 8th 03, 03:26 AM
Morgans
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" With all this talk of using a gas powered blower would someone please
explain
how that blower is going to overcome the effects of altitude and maintain

the
same velocity of air. It is going to drop off in power just as the engine

will
and at altitude its effect will be nil.

Bob Reed


"IF" you hook a leaf blower to pressurize the carb, and IF the carb was the
type that could deal with the pressure without building an airtight box
around it, and IF the CFM of the blower was high enough to be greater than
the CFM of the engine at WOT, and IF the blower had a carb that could adjust
to the altitude without going lean, and IF the blower still had a few inches
of mercury pressure left over after all of that, it would supply a sensation
of boost to the engine to raise the manifold pressure back up to what it was
at sea level while it was buzzing along at, say, 8,000 feet.

Yes, the blower wooould have lost some of its power compared to sea level,
but what I would propose is turbo normalizing, so the increased power is of
no use at sea level. Of course, it could be used to provide a boost for
take off and such.

Now, for all of the "IF"s !!! Not that many induction systems would
take the added pressure without modification. Then there is the regulating
valve for the turbonormalizing to deal with. I don't believe the CFM would
be enough to keep up with more than a small (40 -50 HP ?) engine. No one
has taken a pressure measurement from the home depot blower yet, so "I"
doubt that it could produce more than one or two inches of additional
pressure. (if that much)

More reasons why I doubt the validity of such a Rube Goldberg setup.

The superchargers that can do a good job of increasing manifold pressure use
more HP than a 31 cc motor could ever produce.

There is a reason the superchargers turn 80,000 RPM (some less, some more)
They have to, to produce enough boost pressure.

The superchargers also have very sophisticated impellers to deal with
airflow at these speed, and the home depot blower does not have any
sophistication.

Now I put out a disclaimer. This was not any of my idea, nor would I do
such a thing, but it is a semi-interesting mental exercise!

How's that? :-)
--
Jim in NC


  #26  
Old July 8th 03, 03:59 AM
Rich S.
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"Morgans" jisumorgan@charterdotjunkdotnet wrote in message
...
snip
Yes, the blower wooould have lost some of its power compared to sea level,
but what I would propose is turbo normalizing, so the increased power is

of
no use at sea level. Of course, it could be used to provide a boost for
take off and such.

Now, for all of the "IF"s !!! Not that many induction systems would
take the added pressure without modification.

resnip

But Jim. . . If the engine is just returned to sea level conditions, where
is the pressure? At your given example of 8000', the manifold pressure would
still be less than atmospheric pressure, would it not?

Rich S.


  #27  
Old July 8th 03, 04:23 PM
RobertR237
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In article , "Morgans"
jisumorgan@charterdotjunkdotnet writes:


ANOTHER leaf blower, silly! :-)
--
Jim in NC



And another to help that one and another to help that one and.......

Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)

  #28  
Old July 8th 03, 04:23 PM
RobertR237
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In article , "Morgans"
jisumorgan@charterdotjunkdotnet writes:


Now I put out a disclaimer. This was not any of my idea, nor would I do
such a thing, but it is a semi-interesting mental exercise!

How's that? :-)
--
Jim in NC



I think you hit it with the Rube Goldberg comment. Like going around the world
to get across the street.



Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)

  #29  
Old July 8th 03, 06:15 PM
Big John
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I've got a electric (110VAC) leaf blower. If you put a converter on
your dc and came out with 110VAC you could use the electric leaf
blower and not have to worry about the gas leaf blower having altitude
problems (reduced power output) G

Where theres a will, theres a way.

If the leaf blower don't give any engine boost, then it could be used
for pilot cooling on the hot muggy days like we have here in Houston
vs A/C in the bird.


Big John
Pilot, ROC Air Force


On 08 Jul 2003 01:29:29 GMT, osit (RobertR237)
wrote:

In article , Ernest Christley
writes:

RobertR237 wrote:

With all this talk of using a gas powered blower would someone please

explain
how that blower is going to overcome the effects of altitude and maintain

the
same velocity of air. It is going to drop off in power just as the engine

will
and at altitude its effect will be nil.


Bob, they've told you already. They're going to put a turbo on the
blower. Sheesh! 8*)



OK, and they are going to power the turbo with what?


Bob Reed
www.kisbuild.r-a-reed-assoc.com (KIS Builders Site)
KIS Cruiser in progress...Slow but steady progress....

"Ladies and Gentlemen, take my advice,
pull down your pants and Slide on the Ice!"
(M.A.S.H. Sidney Freedman)


  #30  
Old July 8th 03, 07:03 PM
Big John
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Rich

Let me try to talk in lay terms (close enough for Government work as
they say) for the great unwashed masses G

1. Engine does not suck mixture into cylinder.
2. Piston comes up on exhaust stroke with exhaust valve open. At top,
exhaust valve closeses and intake valve opens. As piston descends it
creates a volume in the cylinder and ambient air pressure pushes
mixture into cylinder to fill that volume.
3. At sea level the air pressure is 14+ psi and puts 'X' amount of
mixture into cylinder.
4. At 18,000 ft (used because I remember from my Air Force altitude
training) the air pressure is 7.5 psi (half the sea level pressure).
5. With half the amount of mixture pushed into cylinder you get
reduced power out.
6. If you put a mechanical or turbo blower in system you can bring the
amount of (fuel-air) mixture back up to the same amount in cylinder
you get at sea level and will get sea level horse power.

A normally aspirated engine, not designed for a blower, has a higher
compression ratio than a engine designed for a blower. So if you add a
blower (mech or turbo) you are limited to 30 inches of MP (sea level
MP) to maintain engine longevity.

How does this fit in this thread?

No way will a leaf blower provide enough 'boost' to even offset the
weight of installation.

As some posts have said, "been a diverting subject to kick around". If
anyone can make it work they can make a fortune.

Big John
Pilot, ROC Air Force


On Mon, 7 Jul 2003 19:59:53 -0700, "Rich S."
wrote:

"Morgans" jisumorgan@charterdotjunkdotnet wrote in message
...
snip
Yes, the blower wooould have lost some of its power compared to sea level,
but what I would propose is turbo normalizing, so the increased power is

of
no use at sea level. Of course, it could be used to provide a boost for
take off and such.

Now, for all of the "IF"s !!! Not that many induction systems would
take the added pressure without modification.

resnip

But Jim. . . If the engine is just returned to sea level conditions, where
is the pressure? At your given example of 8000', the manifold pressure would
still be less than atmospheric pressure, would it not?

Rich S.


 




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