Today's Message Index:
----------------------
1. 05:09 AM - Re: Re: Horse Power (BobsV35B@aol.com)
2. 05:17 AM - Re: Re: Horse Power (BobsV35B@aol.com)
3. 06:05 AM - Re: Re: Horse Power (Jim Stone)
4. 07:11 AM - Re: Re: Horse Power (George Braly)
5. 08:43 AM - cell phone antenna (Troy Scott)
6. 11:42 AM - Fw: torque measurement (David Carter)
7. 05:03 PM - Thanks to all those HP contributors and (Malcolm Thomson)
8. 06:15 PM - Alternator blast tube cooling opinion (Rick Fogerson)
9. 06:25 PM - Automotive Spark Plugs (Speedy11@aol.com)
10. 06:35 PM - Just wondering........ (hausding, sid)
11. 09:17 PM - Re: Horse Power? (Mcculleyja@aol.com)
12. 09:34 PM - Re: Automotive Spark Plugs (mprather)
13. 09:50 PM - Re: Automotive Spark Plugs (Denis Walsh)
Message 1
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--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/20/04 1:54:11 AM Central Daylight Time,
jmfpublic@comcast.net writes:
I considered putting strain gauges on the mount, but in consultation with my
physicist cousin, it was clear that my mount would require both
tension/compression as well as torque gauges on each of 6 tubes, with significant
computation to make sense of all the moments involved.
Good Morning Jim.
First, let's recall that Al Hundere did not find the project to be
worthwhile considering the technology available fifty years ago.
Nevertheless, I do believe he was measuring movement with a
strain gauge at only one engine mount. He would then run the
engine at known power settings and extrapolate the data from
there. He was not as much interested in finding precisely
how much power was being developed as he was in finding
peak power.
It is somewhat analogous to his use of EGT to determine the
same point. He was the guru who gave us Alcor.
The idea of running at a particular EGT was not what Al had
intended. What he did was run an engine on a test bed and
determine what the EGT read at various mixtures. He found
that, on the average Lycoming or Continental, peak power
occurred at somewhere around fifty degrees Fahrenheit richer
than peak EGT. That was the information he wanted. He didn't
particularly care what the actual temperature was, he was trying
to locate peak power so that mixture adjustments could be
made with consistent results.
I guess he decided that it was a lot cheaper and easier to use
the relativity of the EGT to find peak power than it was to find
peak power directly from the torque applied to the engine mount.
One more off topic comment. He also found that best BSFC
generally occurred somewhere between peak EGT and thirty or
forty degrees F leaner than peak EGT. Since that is a very flat
curve, BSFC will be relatively constant throughout that range.
Any time that you are operating in that range, you can easily
tell how much horsepower is being developed by noting the
actual fuel burn.
Since we are, by definition, lean of peak EGT and well lean of
peak power, we know that there is more oxygen available than
is required to burn all of the fuel we are providing. If the engine
is a conforming engine and is not developing any unusual
internal stress, the fuel flow multiplied by a constant based on
the combustion pressures involved will be a very accurate
determination of power developed.
For an average lightplane engine using an 8.5 to 1 compression
ratio, you can multiply the gallons per hour times 14.9 and come
very close to the power that would be shown on a dynamometer.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Message 2
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--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/20/04 7:11:48 AM Central Daylight Time, BobsV35B@aol.com
writes:
For an average lightplane engine using an 8.5 to 1 compression
ratio, you can multiply the gallons per hour times 14.9 and come
very close to the power that would be shown on a dynamometer.
One additional comment if you don't mind. I should have noted that the above
formula only works when the engine has excellent fuel distribution to it's
cylinders and is operated between peak EGT and thirty to forty degrees F lean of
peak EGT.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Message 3
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--> AeroElectric-List message posted by: "Jim Stone" <jrstone@insightbb.com>
Do you happen to know the multiplier for 10:1 compression?
Thanks,
Jim
HRII
Do not archive
----- Original Message -----
From: <BobsV35B@aol.com>
Subject: Re: AeroElectric-List: Re: Horse Power
> --> AeroElectric-List message posted by: BobsV35B@aol.com
>
> In a message dated 4/20/04 7:11:48 AM Central Daylight Time,
BobsV35B@aol.com
> writes:
> For an average lightplane engine using an 8.5 to 1 compression
> ratio, you can multiply the gallons per hour times 14.9 and come
> very close to the power that would be shown on a dynamometer.
>
>
> One additional comment if you don't mind. I should have noted that the
above
> formula only works when the engine has excellent fuel distribution to it's
> cylinders and is operated between peak EGT and thirty to forty degrees F
lean of
> peak EGT.
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
Message 4
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--> AeroElectric-List message posted by: "George Braly" <gwbraly@gami.com>
Jim,
It will be slightly better, but only slightly. Maybe 15.0.
Regards, George
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Jim
Stone
Subject: Re: AeroElectric-List: Re: Horse Power
--> AeroElectric-List message posted by: "Jim Stone"
<jrstone@insightbb.com>
Do you happen to know the multiplier for 10:1 compression?
Thanks,
Jim
HRII
Do not archive
----- Original Message -----
From: <BobsV35B@aol.com>
Subject: Re: AeroElectric-List: Re: Horse Power
> --> AeroElectric-List message posted by: BobsV35B@aol.com
>
> In a message dated 4/20/04 7:11:48 AM Central Daylight Time,
BobsV35B@aol.com
> writes:
> For an average lightplane engine using an 8.5 to 1 compression
> ratio, you can multiply the gallons per hour times 14.9 and come
> very close to the power that would be shown on a dynamometer.
>
>
> One additional comment if you don't mind. I should have noted that
the
above
> formula only works when the engine has excellent fuel distribution to
it's
> cylinders and is operated between peak EGT and thirty to forty degrees
F
lean of
> peak EGT.
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
==
==
==
==
Message 5
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| Subject: | cell phone antenna |
--> AeroElectric-List message posted by: "Troy Scott" <tscott1217@bellsouth.net>
Richard said:
<<Get a headset and make an extension for it then lift the whole phone.
No coax loss, no designing an antenna.
My $0.02.
Dick Tasker>>
Richard,
That's a great idea for the "emergency, HELP!!" version. But I'm hoping for
a version that will let me receive calls. On camping trips I'm sometimes
accompanied by an MD who needs to remain in contact. What about an
amplifier to make up for the signal loss?
-Troy
tscott1217@bellsouth.net
Message 6
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| Subject: | Fw: torque measurement |
--> AeroElectric-List message posted by: "David Carter" <dcarter@datarecall.net>
I inquired at Alcor about Al Hundere's Twin Beech torque system - here's
their reply below.
David
----- Original Message -----
From: "Alcor Support" <alcorsupport@alcorinc.com>
Subject: Re: torque measurement
> Hello David,
>
> Most of that old data has been thrown away. As soon as,
> his son returns from vacation I will ask him if he has seen
> that data.
>
> Thanks for your inquiry,
>
> Rick Sonnen
> ----- Original Message -----
> From: "David Carter" <dcarter@datarecall.net>
> To: <support@alcorinc.com>
> Sent: Monday, April 19, 2004 6:50 PM
> Subject: torque measurement
>
>
> > Al [ Hundere ] successfully installed a torque measuring system on a
Twin Beech in the
> > '60s. Is there any technical info in the files on how he did that?
There
> > is continued interest in measuring torque on single engine homebuilts so
> > HP can be calculated and read out on the new engine instrument systems.
> >
> > David Carter
Message 7
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| Subject: | Thanks to all those HP contributors and |
--> AeroElectric-List message posted by: "Malcolm Thomson" <mdthomson@attglobal.net>
I am now trying to find the "Pilot Priority Relay Assembly" which is
referred to in Bob Nuckolls wiring book. Is this something that can be
purchased or do we fabricate them?
Message 8
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| Subject: | Alternator blast tube cooling opinion |
--> AeroElectric-List message posted by: "Rick Fogerson" <rickf@cableone.net> (by
way of Matt Dralle <nospam@matronics.com>)
Blast tube cooling for alternators has been a common discussion. Thought
everyone might be interested in B&C's opinion on their alternator.
Rick Fogerson
> Rick,
> There doesn't need to be a blast tube to the alternator. The L-40 has two
> cooling fans built into the rotor, now if you want to put a blast tube to
> the L-40 that is just fine, we do recommend that you put it at least 2
> inches away, so that if it gets clogged for some reason it won't hurt the
> purpose of the internal cooling fans.
>
> Thanks,
> Todd Koerner
> B&C Specialty Products, Inc
> 316-283-8000
> www.bandc.biz
>
> comments = I am building an RV-3 with B&C 40amp alternator.
> Does it need to have a cooling blast tube blowing cool air at it?
> Thanks, Rick.
>
> ------------------------------------------------
> Form processed at Sun Apr 18 15:36:24 MDT 2004
>
>
>
Message 9
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| Subject: | Automotive Spark Plugs |
--> AeroElectric-List message posted by: Speedy11@aol.com
In a message dated 4/19/2004 2:56:56 AM Eastern Daylight Time,
aeroelectric-list-digest@matronics.com writes:
> No more $$$ aviation spark plugs for me
Mark said he's using two EIs and thus using all auto spark plugs. I talked
to an engine builder at SnF who said the auto plugs are not holding up as well
as the aviation plugs. Does anyone have several hundred hours of flying on
auto plugs to substantiate or refute the claim?
Stan Sutterfield
RV-8A
Tampa
Message 10
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| Subject: | Just wondering........ |
--> AeroElectric-List message posted by: "hausding, sid" <sidh@charter.net>
If I buy a 28 volt comm radio how can it be utilized in a 12 volt system?
What needs to be done to the 12 volt system to power the radio, or can the
radio be "fixed" to detune it to the existing system?
Thinking outloud, but wondering if its a deal, or steal??????? :-)
Sid
Message 11
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--> AeroElectric-List message posted by: Mcculleyja@aol.com
Alex,
On the assumption you are probably looking for a reasonably accurate way to
determine the percentage of engine maximum continuous rated horsepower during
flight using the RPM, and MAP (manifold pressure) that you see on the gauges,
here is a method that works to within about half to one percent accuracy for
naturally aspirated engines similar to Lycoming, Continental, etc , when leaned
in the conventional manner.
100% minus [(Max rated RPM in hundreds minus actual RPM in hundreds) times
2.5 plus (29 inches MAP minus actual inches MAP) times 3.5)]
This can be done in your head with a little practice or carry along a simple
calculator.
An example: Assume you are at 2450 RPM and 24" MAP at a pressure altitude of
4,000 feet, with an engine having a rated maximum horsepower of 180 at 2700
RPM at sea level. The solution becomes (27-24.5) X 2.5 or 6.25 plus (29-24) X
3.5 or 17.5. Adding the 6.25 to the 17.5 gives 23.75 which is then
subtracted from 100 to show 76.25 % of Rated Power.
The most accurate method is of course to look up the horsepower on the engine
manufacturer's data plots. In the above example, a Lycoming would show 138
HP, which is 76.7 % of the 180 Rated HP. This is correct for an ambient intake
temperature on a standard day (44.7F) at the example altitude. If the actual
intake temperature is different, a calculation can be made to correct this,
with higher temps reducing the HP--and lower temps increasing HP. The
approximate correction is 1% HP for each 10 degrees Fahrenheit difference from
the
standard.
Jim McCulley
Tailwind
AeroElectric-List message posted by: "Alex Peterson"
<alexpeterson@earthlink.net>
> Does anyone know the formula to calculate the %HP?
Message 12
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| Subject: | Re: Automotive Spark Plugs |
--> AeroElectric-List message posted by: mprather <mprather@spro.net>
I wonder if the engine builder meant that the auto plugs are having
failures, or
that they are burning out faster.... If they wear out faster, I don't
see that as a big
deal. I put 4 new NGK's in my O-200. Total cost: ~$6.00. I bet if
you run the
right heat range, they will survive just fine.
Regards,
Matt-
Speedy11@aol.com wrote:
>--> AeroElectric-List message posted by: Speedy11@aol.com
>
>In a message dated 4/19/2004 2:56:56 AM Eastern Daylight Time,
>aeroelectric-list-digest@matronics.com writes:
>
>
>
>>No more $$$ aviation spark plugs for me
>>
>>
>
>Mark said he's using two EIs and thus using all auto spark plugs. I talked
>to an engine builder at SnF who said the auto plugs are not holding up as well
>as the aviation plugs. Does anyone have several hundred hours of flying on
>auto plugs to substantiate or refute the claim?
>
>Stan Sutterfield
>RV-8A
>Tampa
>
>
>
>
Message 13
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| Subject: | Re: Automotive Spark Plugs |
--> AeroElectric-List message posted by: Denis Walsh <denis.walsh@comcast.net>
I have been running Jeff Rose (Electroair) system on left drive for
about a thousand hours. No significant problems. I used auto plugs as
recommended by him for most of that time, but have used REM 37BYs for
the past few hundred hours, at his (changed) recommendation.
Never had any problem with the 386 or C86 Auto plugs lasting a hundred
hours or several hundred with cleaning and regapping. I did quit
regapping them and started discarding them when I discovered I was
probably damaging them when gapping them. At a buck apiece it was
smarter.
The airplane REM 37 BYs that I am now using are certainly sturdier, but
in my normal aspirated O-360 A1A, the auto ones were just fine, too.
Hope this helps your research.
Denis
> I talked
> to an engine builder at SnF who said the auto plugs are not holding up
> as well
> as the aviation plugs. Does anyone have several hundred hours of
> flying on
> auto plugs to substantiate or refute the claim?
>
> Stan Sutterfield
> RV-8A
> Tampa
>
>
> _-
> =======================================================================
> _-
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> _-
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> >
>
>
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