Today's Message Index:
----------------------
1. 05:04 AM - Re: Horse Power? (Alex Peterson)
2. 05:35 AM - Re: Horse Power? (Denis Walsh)
3. 06:16 AM - Re: Horse Power? (Werner Schneider)
4. 06:22 AM - Re: Horse Power? (BobsV35B@aol.com)
5. 06:31 AM - Re: Horse Power? (BobsV35B@aol.com)
6. 06:33 AM - Re: Horse Power? (flyv35b)
7. 06:42 AM - Re: Horse Power? (flyv35b)
8. 07:11 AM - Re: Horse Power? (Denis Walsh)
9. 07:15 AM - Re: Horse Power? (Werner Schneider)
10. 07:18 AM - Re: Horse Power? (flyv35b)
11. 07:26 AM - Re: Re: AeroElectric-List Digest: 13 Msgs - 04/16/04 (Dale Martin)
12. 07:56 AM - Re: Horse Power? (Trampas)
13. 08:37 AM - Re: Horse Power? (Werner Schneider)
14. 10:11 AM - Re: Horse Power? (Alex Peterson)
15. 11:31 AM - Re: Aileron trim cable routing (GT)
16. 01:20 PM - Intercom/handheld wiring (Jack Kuehn)
17. 03:31 PM - Re: Horse Power? (James Foerster)
18. 03:44 PM - Re: Re: Horse Power? (BobsV35B@aol.com)
19. 03:56 PM - New thread about E.I. performance or lack thereof (czechsix@juno.com)
20. 04:33 PM - Re: Re: Horse Power? (David Carter)
21. 04:34 PM - Dumb Question (Randy Pflanzer)
22. 04:57 PM - Re: Re: Horse Power? (BobsV35B@aol.com)
23. 05:07 PM - Re: Dumb Question (Robert McCallum)
24. 05:22 PM - Re: Dumb Question (Randy Pflanzer)
25. 05:38 PM - Re: Dumb Question (Pat Hatch)
26. 05:41 PM - Re: Dumb Question (Robert L. Nuckolls, III)
27. 07:38 PM - Re: Horse Power? (Trampas)
28. 09:12 PM - PAR36 possibility (Troy Scott)
29. 11:53 PM - Re: Horse Power (James Foerster)
Message 1
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--> AeroElectric-List message posted by: "Alex Peterson" <alexpeterson@earthlink.net>
>
> --> AeroElectric-List message posted by: "Malcolm Thomson"
> --> <mdthomson@attglobal.net>
>
> Does anyone know the formula to calculate the %HP?
>
If you have an accurate fuel flow meter, you can get pretty close. Fuel
burn will range from something like 0.5 pounds/hour/hp if you run 100F
rich of peak to about 0.42 pounds/hr/hp if you are lean of peak. These
numbers are not hard and fast, obviously, and depend on ignition type,
prop type (rpm vs MAP), etc., but are probably as accurate as the engine
charts.
Others may know the algorithm that the commercially available engine
monitors with the percent hp use, I don't.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 458 hours
http://www.home.earthlink.net/~alexpeterson/
Message 2
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: Denis Walsh <denis.walsh@comcast.net>
Seems a little high to me
On Apr 19, 2004, at 6:01 AM, Alex Peterson wrote:
> --> AeroElectric-List message posted by: "Alex Peterson"
> <alexpeterson@earthlink.net>
>
>>
>> --> AeroElectric-List message posted by: "Malcolm Thomson"
>> --> <mdthomson@attglobal.net>
>>
>> Does anyone know the formula to calculate the %HP?
>>
>
> If you have an accurate fuel flow meter, you can get pretty close.
> Fuel
> burn will range from something like 0.5 pounds/hour/hp if you run 100F
> rich of peak to about 0.42 pounds/hr/hp if you are lean of peak. These
> numbers are not hard and fast, obviously, and depend on ignition type,
> prop type (rpm vs MAP), etc., but are probably as accurate as the
> engine
> charts.
>
> Others may know the algorithm that the commercially available engine
> monitors with the percent hp use, I don't.
>
> Alex Peterson
> Maple Grove, MN
> RV6-A N66AP 458 hours
>
> http://www.home.earthlink.net/~alexpeterson/
>
>
> _-
> =======================================================================
> _-
> =======================================================================
> _-
> =======================================================================
> _-
> =======================================================================
> >
>
>
Message 3
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "Werner Schneider" <wernerschneider@compuserve.com>
Agree, I had on my O-320 with 23/2300 in density 4000ft with 10 deg OAT 10.2
full rich and 7.4 peak.
Werner
----- Original Message -----
From: "Denis Walsh" <denis.walsh@comcast.net>
Subject: Re: AeroElectric-List: Horse Power?
> --> AeroElectric-List message posted by: Denis Walsh
<denis.walsh@comcast.net>
>
> Seems a little high to me
> On Apr 19, 2004, at 6:01 AM, Alex Peterson wrote:
>
> > --> AeroElectric-List message posted by: "Alex Peterson"
> > <alexpeterson@earthlink.net>
> >
> >>
> >> --> AeroElectric-List message posted by: "Malcolm Thomson"
> >> --> <mdthomson@attglobal.net>
> >>
> >> Does anyone know the formula to calculate the %HP?
> >>
> >
> > If you have an accurate fuel flow meter, you can get pretty close.
> > Fuel
> > burn will range from something like 0.5 pounds/hour/hp if you run 100F
> > rich of peak to about 0.42 pounds/hr/hp if you are lean of peak. These
> > numbers are not hard and fast, obviously, and depend on ignition type,
> > prop type (rpm vs MAP), etc., but are probably as accurate as the
> > engine
> > charts.
> >
> > Others may know the algorithm that the commercially available engine
> > monitors with the percent hp use, I don't.
> >
> > Alex Peterson
> > Maple Grove, MN
> > RV6-A N66AP 458 hours
> >
> > http://www.home.earthlink.net/~alexpeterson/
> >
> >
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > >
> >
> >
>
>
Message 4
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/19/04 7:36:50 AM Central Daylight Time,
denis.walsh@comcast.net writes:
Seems a little high to me
On Apr 19, 2004, at 6:01 AM, Alex Peterson wrote:
Good Morning Alex,
I think those numbers are very good though it results in horsepower,
not percentage of horsepower as was originally asked.
There are a few of our General Aviation engines that can get
a .38 burn when leaned about twenty or thirty degrees below
Peak EGT, but the .42 to .5 is a very good average number.
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: | Re: Horse Power? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/19/04 8:16:54 AM Central Daylight Time,
wernerschneider@compuserve.com writes:
Agree, I had on my O-320 with 23/2300 in density 4000ft with 10 deg OAT 10.2
full rich and 7.4 peak.
Werner
Good Morning Werner,
And what does a full rich number have to do with horsepower
developed?
The only thing we know when you are at full rich is that you
probably have enough fuel going into the engine to combine
with all of the air that is available to burn. If you are much
richer than the minimum amount of fuel required for that amount
of oxygen, you will lose a little bit of potential power. However,
most of our GA engines require a very rich mixture at takeoff
power to aid in positioniong the combustion event so as to
maintain reasonable temperatures.
If your 7.4 GPH figure was at peak EGT, you were probably
developing around 110 horsepower.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Message 6
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "flyv35b" <flyv35b@ashcreekwireless.com>
----- Original Message -----
From: "Denis Walsh" <denis.walsh@comcast.net>
Subject: Re: AeroElectric-List: Horse Power?
> --> AeroElectric-List message posted by: Denis Walsh
<denis.walsh@comcast.net>
>
> Seems a little high to me
> On Apr 19, 2004, at 6:01 AM, Alex Peterson wrote:
>
> > --> AeroElectric-List message posted by: "Alex Peterson"
> > <alexpeterson@earthlink.net>
> >
> >>
> >> --> AeroElectric-List message posted by: "Malcolm Thomson"
> >> --> <mdthomson@attglobal.net>
> >>
> >> Does anyone know the formula to calculate the %HP?
> >>
> >
> > If you have an accurate fuel flow meter, you can get pretty close.
> > Fuel
> > burn will range from something like 0.5 pounds/hour/hp if you run 100F
> > rich of peak to about 0.42 pounds/hr/hp if you are lean of peak. These
> > numbers are not hard and fast, obviously, and depend on ignition type,
> > prop type (rpm vs MAP), etc., but are probably as accurate as the
> > engine
> > charts.
> >
> > Others may know the algorithm that the commercially available engine
> > monitors with the percent hp use, I don't.
> >
> > Alex Peterson
> > Maple Grove, MN
> > RV6-A N66AP 458 hours
> >
> > http://www.home.earthlink.net/~alexpeterson/
> >
> >
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > >
> >
> >
>
>
Message 7
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "flyv35b" <flyv35b@ashcreekwireless.com>
Lycoming's Operator's Manual shows the O-360 A & E series engines (8.5:1 CR)
to have a BSFC of about .55lb/hp-hr at 2700 rpm, decreasing to .52 lb/hp-hr
at 2200 rpm. This is for full throttle and full rich mixture setting. The
propeller load curve (partial throttle) shows it to be about .46 lb/hp-hr
(min.) at 2300-2400 rpm. Info for a fuel injected IO-360A engine (8.7:1 CR)
shows a BSFC of about .42 lb/hp-hr at 2400 rpm and 65% power, best economy
(leaned out). This is the best you will get.
Cliff A&P/IA
----- Original Message -----
From: "Denis Walsh" <denis.walsh@comcast.net>
Subject: Re: AeroElectric-List: Horse Power?
> --> AeroElectric-List message posted by: Denis Walsh
<denis.walsh@comcast.net>
>
> Seems a little high to me
> On Apr 19, 2004, at 6:01 AM, Alex Peterson wrote:
>
> > --> AeroElectric-List message posted by: "Alex Peterson"
> > <alexpeterson@earthlink.net>
> >
> >>
> >> --> AeroElectric-List message posted by: "Malcolm Thomson"
> >> --> <mdthomson@attglobal.net>
> >>
> >> Does anyone know the formula to calculate the %HP?
> >>
> >
> > If you have an accurate fuel flow meter, you can get pretty close.
> > Fuel
> > burn will range from something like 0.5 pounds/hour/hp if you run 100F
> > rich of peak to about 0.42 pounds/hr/hp if you are lean of peak. These
> > numbers are not hard and fast, obviously, and depend on ignition type,
> > prop type (rpm vs MAP), etc., but are probably as accurate as the
> > engine
> > charts.
> >
> > Others may know the algorithm that the commercially available engine
> > monitors with the percent hp use, I don't.
> >
> > Alex Peterson
> > Maple Grove, MN
> > RV6-A N66AP 458 hours
> >
> > http://www.home.earthlink.net/~alexpeterson/
> >
> >
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > _-
> > =======================================================================
> > >
> >
> >
>
>
Message 8
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: Denis Walsh <denis.walsh@comcast.net>
I would like to retract my previous post regarding seeming a little
high. I was timesing when I should have been gozintoing to get to gph.
Now I think it is exactly correct, and useful for estimating power,
assuming leaning is tended to.
Message 9
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "Werner Schneider" <wernerschneider@compuserve.com>
Good evening Bob (living a bit east of you (CH)),
> And what does a full rich number have to do with horsepower
> developed?
nothing, you can get the exact numbers only, if you lean peak and use the
fuel flow, and mine was more then the 0.5 on full rich). What would mean,
another kind of formula would help more.
> If your 7.4 GPH figure was at peak EGT, you were probably
> developing around 110 horsepower.
yeap, the table would tell that this would be around 65 % which means close
to 110HP. would help
A formula which would take MP and RPM into account would be easier to
calculate, but it might mean to have a lookup table and where to get this?
I've got once:
P = 2 * PI * M * n
P=Power
M = torque in Nm
n= rpm /min
or P = Vh * pe * n
Vh = cubic capacity in dm3
pe = medium piston pressure in bar
n= rpm/min
Power would be kW but how do I measure torque or piston pressure?
Thanks
Werner
Message 10
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "flyv35b" <flyv35b@ashcreekwireless.com>
> There are a few of our General Aviation engines that can get
> a .38 burn when leaned about twenty or thirty degrees below
> Peak EGT
The Continental IO-520 and IO-550 will do this good I believe.
Cliff
----- Original Message -----
From: <BobsV35B@aol.com>
Subject: Re: AeroElectric-List: Horse Power?
> --> AeroElectric-List message posted by: BobsV35B@aol.com
>
> In a message dated 4/19/04 7:36:50 AM Central Daylight Time,
> denis.walsh@comcast.net writes:
> Seems a little high to me
> On Apr 19, 2004, at 6:01 AM, Alex Peterson wrote:
>
>
> Good Morning Alex,
>
> I think those numbers are very good though it results in horsepower,
> not percentage of horsepower as was originally asked.
>
> There are a few of our General Aviation engines that can get
> a .38 burn when leaned about twenty or thirty degrees below
> Peak EGT, but the .42 to .5 is a very good average number.
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
Message 11
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| Subject: | Re: AeroElectric-List Digest: 13 Msgs - 04/16/04 |
--> AeroElectric-List message posted by: "Dale Martin" <niceez@cableone.net>
>BTW, two E.I.'s is not the most economic or lightest
> and it darn sure is not the best performance.
How do you support this claim?
*********************
Just as you said, you need two Batteries or two alternators to be safe with
dual E.I's..
Second - Check the Cafe Web page for the results. Two Mags beats two
E.I.'s.
I guess doing this for long enough you learn to raise your eyebrows at some
claims. There is more then LSE in the electronic ignition field and suspect
you'll find out the better unit in years to come. I have and now have a
Electro-Air unit. I have also need to used REM 37BY plugs all along due to
there further reach but was told it wasn't necessary by LSE..... Not
exactly accurate information.
>>>>>>>>>>>>
You Say-
The slight weight savings and
performance improvement of the second E.I. is an added bonus. No more
$$$ aviation spark plugs for me....
************
That is a big crock of ........ ?? waste!
Unless you have the long duration spark the performance is less and the E.I.
sparkplugs are more money then some that are available. The 386 sparkplug
has been working for many people. And when you get 700 to 900 hours from
aviation sparkplugs with the correct E.I. system it doesn't seem bad to
me....
Each to their own but have been there and done that and never to return.
******************
You Say-
>Agreed....my aux battery will be 3 ah capacity and cost about $10-15. In
>the unlikely event that the main electrical system fails completely, I
>will have about an hour of ignition operation to get on the ground.
Seems like more complication and weight to me then a mag that keeps running
without doing anything.... Just my opinion though.
Dale Martin
Lewiston, ID
LEZ-235
Message 12
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--> AeroElectric-List message posted by: "Trampas" <tstern@nc.rr.com>
First off I wanted to mention that some people are quoting burn rates in
lbs/hour/hp and some are using GPH, thus this could be some debate on the
number of 0.5 lbs/hour/hp.
As far as the original question, the percent horse power calculation is
based on estimating the air flow into the engine. So we can go back to the
text books and find the air flow equations which are a function of air
temperature, manifold pressure, RPM and displacement. Then we estimate the
power of engine based on the engine efficiency.
Then since you are doing a percentage you will find that the air
temperature, efficiency and displacement cancel out in the percentage
calculation leaving you with estimated percent horsepower.
Regards,
Trampas Stern
www.sterntech.com
Message 13
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "Werner Schneider" <wernerschneider@compuserve.com>
Hello Trampas,
so if I understand it correct we could get %HP out of a formula with MP and
RPM?
Would you be so kind to post this formula? I had to do some flighttesting
and therefore had to go through the tables of lycoming to find a pair of MP
and RPM for 75%/65%/55% HP in different density altitudes.
Thanks a lot
Werner
----- Original Message -----
From: "Trampas" <tstern@nc.rr.com>
Subject: RE: AeroElectric-List: Horse Power?
> --> AeroElectric-List message posted by: "Trampas" <tstern@nc.rr.com>
>
> First off I wanted to mention that some people are quoting burn rates in
> lbs/hour/hp and some are using GPH, thus this could be some debate on the
> number of 0.5 lbs/hour/hp.
>
> As far as the original question, the percent horse power calculation is
> based on estimating the air flow into the engine. So we can go back to the
> text books and find the air flow equations which are a function of air
> temperature, manifold pressure, RPM and displacement. Then we estimate the
> power of engine based on the engine efficiency.
>
> Then since you are doing a percentage you will find that the air
> temperature, efficiency and displacement cancel out in the percentage
> calculation leaving you with estimated percent horsepower.
>
> Regards,
> Trampas Stern
> www.sterntech.com
>
>
Message 14
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--> AeroElectric-List message posted by: "Alex Peterson" <alexpeterson@earthlink.net>
> so if I understand it correct we could get %HP out of a
> formula with MP and RPM?
This would also require temperature of the induction air. In cold air,
a given MP and RPM will deliver more power than in warm air (more air,
by mass, into the engine).
Air at 90F will be only about 84% as dense as at 0F, barometric pressure
the same. So, with identical MAP and RPM, the power at 90F will be
about 84% of what it would be for the same settings at 0F. It is all
about how much air mass goes into the cylinders. There are other
variables, but not as important.
Alex Peterson
Maple Grove, MN
RV6-A N66AP 458 hours
http://www.home.earthlink.net/~alexpeterson/
Message 15
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| Subject: | Re: Aileron trim cable routing |
--> AeroElectric-List message posted by: "GT" <Gilles.Thesee@ac-grenoble.fr>
>
> Good Morning Gilles,
>
> Is there room to run the wire parallel to the hinge line for a little way?
>
> I have used that method to give a wire adequate flexibility when a
> loop would not be practical. The length of wire can even be lightly
> supported along it's length if that need be. All you have to do is run
> it through a support that does not bind it down solidly. As long as
> the wire is free to twist, all of the motion will be absorbed by the
> torsion of the wire instead of as a bending moment. A six inch length
> of number twenty or twenty two can stand a lot of twisting without
> any damage at all. The longer, the better.
>
> Works for me!
>
> Happy Skies,
>
> Old Bob
Hi Old Bob,
Thank you for responding. The aileron trim is located at the outboard end of
the aileron. The hinges are offset but I'll try to have the wires come out
of the wing into the winglet and back into the aileron end, in a spanwise
direction. So the motion will be mainly twisting.
Regards,
Gilles
Message 16
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| Subject: | Intercom/handheld wiring |
--> AeroElectric-List message posted by: "Jack Kuehn" <jkuehn@uiuc.edu>
Has anyone used a Softcomm ATC panel mounted intercom with a handheld
transceiver like the Icom A23? Does anyone know how to wire them together?
Thanks,
Jack
Message 17
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "James Foerster" <jmfpublic@comcast.net>
Malcolm,
What do you want the information for? If you want to determine that your engine
is putting out normal power on takeoff, with a variable pitch prop, you would
need to measure torque in the prop shaft, then calculate HP using rpmXtorque/5252,
then dividing by the standard HP to get a percentage. If you just want
the % HP in a modestly accurate way for setting up in the engine in cruise at
altitude, then using the charts as given by the engine maker gives a rough idea.
Using MP and temperature, you can calculate relative mass airflow into the
engine. The problem is that the efficiency of the engine, based on fuel flow,
varies depending upon leaning of the mixture. You may find that a calculation
based on mass airflow is more accurate than one based on fuel flow, but some
data from a well-instrumented aircraft engine sure would be nice to check this
notion.
Most likely, this has been done in the 1940's and early 1950's, but the knowledge is not well known. John Deakin writes about this, the last time I saw this was at www.avweb.com/news/columns/182146-1.html I don't recall that he addressed this topic based on mass air flow.
It may have been Saab in the 1970's that used a "luftmengenmesser" to measure
air mass to adjust fuel injection. This was a Bosch item if memory serves.
Now that easily programmed microprocessors are available, such as the Basic
units from Parallex and others, calculation of mass flow is practical in real
time based upon MP and temperature. If you want to do this, a look-up table is
the easy way to go, of course.
I asked this question some time ago, and looked into strain gauges on the wing
struts! The strain gauge on the prop shaft scares me, as it could mess up
the engine, and sounds hard to design. I dropped the whole idea in favor of
just completing the airplane.
Jim Foerster Jabiru J400, 80% done.
----------------------------------------------------
This mailbox protected from junk email by Matador
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Message 18
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/19/04 5:33:02 PM Central Daylight Time,
jmfpublic@comcast.net writes:
I asked this question some time ago, and looked into strain gauges on the
wing struts! The strain gauge on the prop shaft scares me, as it could mess up
the engine, and sounds hard to design. I dropped the whole idea in favor of
just completing the airplane.
Good Evening Jim,
If you really want to check the torque output, put strain gauges on the
engine mounts. Al Hundere made up a device to do just that on a Twin Beech many
years ago. I understand that it worked OK, but needed a lot of TLC to retain
accuracy.
I suppose you are familiar with the torque meters used on many radial engines
of the forties and fifties. They worked by measuring the force on the
planetary gear reduction system.
More than one way to skin a cat.
The nice thing about using a fuel flow to figure out what power is being
developed is the simplicity of the idea. The bad thing is that it won't tell you
if the engine is developing an unusual internal drag. The engine could be
tearing itself up and the fuel flow indication would not reflect the power loss.
A torquemeter will show that power output has been lost even though the
engine is using the amount of fuel that it should be using to develop the indicated
HP.
In smooth air, a change in airspeed gives an excellent indication of power
output and, if the airplane has a fixed pitch prop, you can easily note power
changes by the change in RPM. That is how Lindbergh did it. Still works just
fine.
Any help?
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Message 19
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| Subject: | New thread about E.I. performance or lack thereof |
--> AeroElectric-List message posted by: czechsix@juno.com
>Subject: Re: Re: AeroElectric-List Digest: 13 Msgs - 04/16/04
>From: Dale Martin (niceez@cableone.net)
>Date: Mon Apr 19 - 7:26 AM
>
>--> AeroElectric-List message posted by: "Dale Martin" <niceez@cableone.net>
>
>BTW, two E.I.'s is not the most economic or lightest
> and it darn sure is not the best performance.
>
>How do you support this claim?
>*********************
>
>Just as you said, you need two Batteries or two alternators to be safe with
>dual E.I's..
>
>Second - Check the Cafe Web page for the results. Two Mags beats two
>E.I.'s.
I'm familiar with the Cafe reports on E.I. because I studied them before ordering
my LSE units. I don't think you can look at the reports Cafe did and make
a blanket statement that "two mags beats two E.I's". The report clearly demonstrates
that with either one or two E.I.'s, there's a significant improvement
in performance at higher altitudes and lean operation (as well as better idle
and other marginal improvements). This jives with the expected results based
on the physics of hotter spark and timing advance. The "Ignition Dynamics II"
article does note a few conditions in which the the test results contradict what
you'd expect.....that is, the performance of the mags was a bit better. The
article notes that the difference was "slight" or "small" in such conditions,
and speculates that the timing curve used in the subject Electroair system
was to blame for the difference, over-advancing the spark causing some power
loss compared to the mags (see second paragraph in t
he right column of page 8 of this article at www.cafefoundation.org/aprs/ignition2.pdf). This theory makes perfect sense. In all fairness to Jeff Rose, the timing is hard to nail down without extensive testing, and impossible to optimize based only on RPM and manifold pressure. Having other sensors like cars (or the Aerosance FADEC) is required to perfect it under all operating conditions. But I recall hearing that Jeff improved the timing curve after the Cafe results came out....might have been hearsay. I know when I talked to Klaus Savier at Oshkosh a couple years ago he was aware of the article and said that the LSE system did not advance the spark as much as the tested Electroair system in the conditions where the mags were showing better performance than the E.I. The paragraph mentioned above notes that Cafe talked to Klaus at the time of writing and he was already aware that less spark advance was needed for more power under the conditions described there. And
Bart Lalonde at Aerosport Power told me that there was a measurable increase
in HP on the dyno with both single and dual LSE systems installed, which should
translate into better low altitude performance than mags in addition to the
well-established high altitude lean mixture operations.
>I guess doing this for long enough you learn to raise your eyebrows at some
>claims.
I'm not new to aviation either and frequently raise my eyebrows at all kinds of
claims out there. The great thing about this forum is we can debunk the claims
that are bogus, and share information for the benefit of our fellow builders/pilots.
I don't believe everything Klaus claims for his LSE system, but nor
do I believe the evidence supports a statement that "two mags beats two E.I.'s",
simple as that.
>There is more then LSE in the electronic ignition field and suspect
>you'll find out the better unit in years to come. I have and now have a
>Electro-Air unit.
I've heard good things about Jeff Rose and Electroair. Just curious though, why
are you using an E.I. at all if, in your opinion, two mags are better? Or are
you saying that one mag and one E.I. outperforms either dual mags or dual E.I.'s?
I'm not poking fun at you, just trying to understand your position which
appears contradictory to me.
> I have also need to used REM 37BY plugs all along due to
t>here further reach but was told it wasn't necessary by LSE..... Not
>exactly accurate information.
What is inaccurate about this? Lots of RV'ers are using automotive plugs as supplied
by Klaus with the LSE system. Haven't ever heard a complaint on the RV
List about them, but that doesn't mean someone out there hasn't experienced trouble
with them. Can you elaborate a bit for my benefit? Should I throw out
the auto plugs and put aviation plugs in my engine instead? Does this have anything
to do with engine type (i.e. you are running an O-235 and I've got an
O-360)?
>>>>>>>>>>>>
>
>You Say-
>The slight weight savings and
>performance improvement of the second E.I. is an added bonus. No more
>$$$ aviation spark plugs for me....
>************
>
>That is a big crock of ........ ?? waste!
>
>Unless you have the long duration spark the performance is less and the E.I.
>sparkplugs are more money then some that are available. The 386 sparkplug
>has been working for many people. And when you get 700 to 900 hours from
>aviation sparkplugs with the correct E.I. system it doesn't seem bad to
>me....
>
>Each to their own but have been there and done that and never to return.
Ok....you've been there, done that and had a bad experience and won't do it again.
Can you tell us what happened to you so that others don't repeat your bad
experience? If my research on the LSE system has missed something important,
I'd like to understand it. I know there's been some starting kickback issues
(different subject entirely, all in the archives) but I'm not aware of spark
plug problems or other operational/performance issues that would cause the kind
of regrets you have experienced. Please share your experiences and data with
us.
>******************
>
>You Say-
>Agreed....my aux battery will be 3 ah capacity and cost about $10-15. In
>the unlikely event that the main electrical system fails completely, I
>will have about an hour of ignition operation to get on the ground.
>
>Seems like more complication and weight to me then a mag that keeps running
>without doing anything.... Just my opinion though.
Actually the aux battery arrangment is not complicated, it's quite simple and light
if you size it to the task. But anyway, there's nothing wrong with your
approach (single mag, single E.I.) There's pros and cons to dual mags vs dual
E.I. vs the combo approach you're using, just depends on one's priorities.
>Dale Martin
>Lewiston, ID
>LEZ-235
--Mark Navratil
Cedar Rapids, Iowa
RV-8A N2D finishing....
Message 20
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: "David Carter" <dcarter@datarecall.net>
Hey, Old Bob, about measuring torque in a planetary gear reduction system.
I have a 2.85 to 1 planetary gear reduction to hang on front of my RX-8
Renesis engine on an RV-6. Have any idea how one could find out how to put
a strain gage on such a gadget to get torque?
The Lone Star Flight Museum at Galveston, Texas, has an excellent research
library with lots of tech data on WW II aircraft. Maybe I could spend some
time in there and find out how they did that torque thing - if they had
started doing it by WWII. I don't remember fighters having torque meters -
seems like that was something for the 4 engine transport and bomber guys
with a flight engineer monitoring lots of stuff.
David
----- 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 4/19/04 5:33:02 PM Central Daylight Time,
> jmfpublic@comcast.net writes:
> I asked this question some time ago, and looked into strain gauges on the
> wing struts! The strain gauge on the prop shaft scares me, as it could
mess up
> the engine, and sounds hard to design. I dropped the whole idea in favor
of
> just completing the airplane.
>
>
> Good Evening Jim,
>
> If you really want to check the torque output, put strain gauges on the
> engine mounts. Al Hundere made up a device to do just that on a Twin
Beech many
> years ago. I understand that it worked OK, but needed a lot of TLC to
retain
> accuracy.
>
> I suppose you are familiar with the torque meters used on many radial
engines
> of the forties and fifties. They worked by measuring the force on the
> planetary gear reduction system.
>
> More than one way to skin a cat.
>
> The nice thing about using a fuel flow to figure out what power is being
> developed is the simplicity of the idea. The bad thing is that it won't
tell you
> if the engine is developing an unusual internal drag. The engine could be
> tearing itself up and the fuel flow indication would not reflect the power
loss.
> A torquemeter will show that power output has been lost even though the
> engine is using the amount of fuel that it should be using to develop the
indicated
> HP.
>
> In smooth air, a change in airspeed gives an excellent indication of power
> output and, if the airplane has a fixed pitch prop, you can easily note
power
> changes by the change in RPM. That is how Lindbergh did it. Still works
just
> fine.
>
> Any help?
>
> Happy Skies,
>
> Old Bob
> AKA
> Bob Siegfried
> Ancient Aviator
> Stearman N3977A
> Brookeridge Airpark LL22
> Downers Grove, IL 60516
> 630 985-8502
>
>
Message 21
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--> AeroElectric-List message posted by: "Randy Pflanzer" <f1rocket@comcast.net>
You'd think I'd know this stuff by now. However.....
My starter solenoid from Van's has two small terminals on it. One is marked "S"
and the other is marked "I". I assume that the "S" goes to the starter switch
to energize the coil. I also assume that I just ignore the other terminal.
Is that correct? Should I ground the "I" terminal?
Just asking. My brain isn't working that great tonight.
Randy
F1 Rocket
http://f1rocket.home.comcast.net/
Message 22
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| Subject: | Re: Horse Power? |
--> AeroElectric-List message posted by: BobsV35B@aol.com
In a message dated 4/19/04 6:34:28 PM Central Daylight Time,
dcarter@datarecall.net writes:
I have a 2.85 to 1 planetary gear reduction to hang on front of my RX-8
Renesis engine on an RV-6. Have any idea how one could find out how to put
a strain gage on such a gadget to get torque?
Good Evening David,
The old torque meters did it by measuring the movement of the
ring gear. It was mounted so that it moved back and forth very
slightly in a set of angled grooves when torque was applied. The
movement was resisted by a few small oil filled cylinders. The
pressure of the oil in those little cylinders was calibrated to read
in torque which was generally presented as an equivalent BMEP
number. I think the easiest thing would be to measure the torque
somewhere in the engines mounting.
Happy Skies,
Old Bob
AKA
Bob Siegfried
Ancient Aviator
Stearman N3977A
Brookeridge Airpark LL22
Downers Grove, IL 60516
630 985-8502
Message 23
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| Subject: | Re: Dumb Question |
--> AeroElectric-List message posted by: Robert McCallum <robert.mccallum2@sympatico.ca>
Don't ground it. That might tend to let the smoke out. The "I" terminal
becomes live while the solenoid is engaged. It's original purpose was to
bypass the ballast resistor in automotive applications. In your aircraft
it can be used to signify "starter engaged" if you wish. Or just ignore it.
Bob McC
Randy Pflanzer wrote:
>--> AeroElectric-List message posted by: "Randy Pflanzer" <f1rocket@comcast.net>
>
>You'd think I'd know this stuff by now. However.....
>
>My starter solenoid from Van's has two small terminals on it. One is marked "S"
and the other is marked "I". I assume that the "S" goes to the starter switch
to energize the coil. I also assume that I just ignore the other terminal.
Is that correct? Should I ground the "I" terminal?
>
>Just asking. My brain isn't working that great tonight.
>
>Randy
>
>
>
Message 24
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| Subject: | Re: Dumb Question |
--> AeroElectric-List message posted by: "Randy Pflanzer" <f1rocket@comcast.net>
Thanks.
----- Original Message -----
From: "Robert McCallum" <robert.mccallum2@sympatico.ca>
Subject: Re: AeroElectric-List: Dumb Question
> --> AeroElectric-List message posted by: Robert McCallum
<robert.mccallum2@sympatico.ca>
>
> Don't ground it. That might tend to let the smoke out. The "I" terminal
> becomes live while the solenoid is engaged. It's original purpose was to
> bypass the ballast resistor in automotive applications. In your aircraft
> it can be used to signify "starter engaged" if you wish. Or just ignore
it.
>
> Bob McC
>
> Randy Pflanzer wrote:
>
> >--> AeroElectric-List message posted by: "Randy Pflanzer"
<f1rocket@comcast.net>
> >
> >You'd think I'd know this stuff by now. However.....
> >
> >My starter solenoid from Van's has two small terminals on it. One is
marked "S" and the other is marked "I". I assume that the "S" goes to the
starter switch to energize the coil. I also assume that I just ignore the
other terminal. Is that correct? Should I ground the "I" terminal?
> >
> >Just asking. My brain isn't working that great tonight.
> >
> >Randy
> >
> >
> >
>
>
Message 25
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| Subject: | Re: Dumb Question |
--> AeroElectric-List message posted by: "Pat Hatch" <pat_hatch@msn.com>
Randy, your assumptions are correct. The "I" terminal could also be used
for a starter-engaged light. If not, just ignore it.
Pat Hatch
RV-4
RV-6
RV-7 Finishing Kit
Vero Beach, FL
----- Original Message -----
From: "Randy Pflanzer" <f1rocket@comcast.net>
Subject: AeroElectric-List: Dumb Question
> --> AeroElectric-List message posted by: "Randy Pflanzer"
<f1rocket@comcast.net>
>
> You'd think I'd know this stuff by now. However.....
>
> My starter solenoid from Van's has two small terminals on it. One is
marked "S" and the other is marked "I". I assume that the "S" goes to the
starter switch to energize the coil. I also assume that I just ignore the
other terminal. Is that correct? Should I ground the "I" terminal?
>
> Just asking. My brain isn't working that great tonight.
>
> Randy
> F1 Rocket
> http://f1rocket.home.comcast.net/
>
>
Message 26
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| Subject: | Re: Dumb Question |
--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" <bob.nuckolls@cox.net>
At 08:04 PM 4/19/2004 -0400, you wrote:
>--> AeroElectric-List message posted by: Robert McCallum
><robert.mccallum2@sympatico.ca>
See http://www.aeroelectric.com/Pictures/s702wire.jpg
>Don't ground it. That might tend to let the smoke out. The "I" terminal
>becomes live while the solenoid is engaged. It's original purpose was to
>bypass the ballast resistor in automotive applications. In your aircraft
>it can be used to signify "starter engaged" if you wish. Or just ignore it.
>
>Bob McC
>
>Randy Pflanzer wrote:
>
> >--> AeroElectric-List message posted by: "Randy Pflanzer"
> <f1rocket@comcast.net>
> >
> >You'd think I'd know this stuff by now. However.....
> >
> >My starter solenoid from Van's has two small terminals on it. One is
> marked "S" and the other is marked "I". I assume that the "S" goes to
> the starter switch to energize the coil. I also assume that I just
> ignore the other terminal. Is that correct? Should I ground the "I" terminal?
> >
> >Just asking. My brain isn't working that great tonight.
> >
> >Randy
> >
> >
> >
>
>
Bob . . .
-----------------------------------------
( Experience and common sense cannot be )
( replaced with policy and procedures. )
( R. L. Nuckolls III )
-----------------------------------------
Message 27
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--> AeroElectric-List message posted by: "Trampas" <tstern@nc.rr.com>
I found all the formulas for calculating the mass air entering the cylinders
from a website for an open source EFI,
http://www.megasquirt.info/manual/mfuel.htm
You can use the formulas for calculating the mass air flow and realizing
that the mass of the air is proportional to the fuel entering the engine, of
course assuming a constant fuel mixture. Then the horse power will be
proportional to the fuel, which is proportional to the air entering the
engine.
Again if you assume the air temperature is constant and the fuel mixture is
constant then all you are left with is MAP and RPMs. Now if you are using a
fixed pitch propeller then you can actually remove the MAP from the equation
is that the horsepower required to turn prop is dependent on the RPMs and
the air density, again since we want percent horsepower we assume constant
air density and thus only have RPMs in the equation.
Regards,
Trampas Stern
www.sterntech.com
-----Original Message-----
From: owner-aeroelectric-list-server@matronics.com
[mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Werner
Schneider
Subject: Re: AeroElectric-List: Horse Power?
--> AeroElectric-List message posted by: "Werner Schneider"
<wernerschneider@compuserve.com>
Hello Trampas,
so if I understand it correct we could get %HP out of a formula with MP and
RPM?
Would you be so kind to post this formula? I had to do some flighttesting
and therefore had to go through the tables of lycoming to find a pair of MP
and RPM for 75%/65%/55% HP in different density altitudes.
Thanks a lot
Werner
----- Original Message -----
From: "Trampas" <tstern@nc.rr.com>
Subject: RE: AeroElectric-List: Horse Power?
> --> AeroElectric-List message posted by: "Trampas" <tstern@nc.rr.com>
>
> First off I wanted to mention that some people are quoting burn rates in
> lbs/hour/hp and some are using GPH, thus this could be some debate on the
> number of 0.5 lbs/hour/hp.
>
> As far as the original question, the percent horse power calculation is
> based on estimating the air flow into the engine. So we can go back to the
> text books and find the air flow equations which are a function of air
> temperature, manifold pressure, RPM and displacement. Then we estimate the
> power of engine based on the engine efficiency.
>
> Then since you are doing a percentage you will find that the air
> temperature, efficiency and displacement cancel out in the percentage
> calculation leaving you with estimated percent horsepower.
>
> Regards,
> Trampas Stern
> www.sterntech.com
>
>
Message 28
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| Subject: | PAR36 possibility |
--> AeroElectric-List message posted by: "Troy Scott" <tscott1217@bellsouth.net>
Gentlemen,
Are any of you familiar with this bulb?:
50Watt PAR36 5 degree spot 12V 19878 GE Halogen Lamp 50PAR36/NSP
I bought one just to compare it to the "standard" 4509. It is just about as
bright in the center spot, which is about the same size spot the 4509 makes.
The area just outside the spot may be slightly brighter compared to the
4509. Of course the current required is just half that required for the 100
watt incandescent 4509. I have no idea how well this bulb would hold up on
an airplane. It seems robust to me. The price is $9.95 each, which seems
reasonable considering it's rated at 4000 hours. The incandescent 4509 is a
25 hour bulb and sells for $7.94.
These prices are current at www.atlantalightbulbs.com
Thoughts?
Regards,
Troy
tscott1217@bellsouth.net
Message 29
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--> AeroElectric-List message posted by: "James Foerster" <jmfpublic@comcast.net>
On 4-19-04 Bob Siegfried wrote: If you really want to check the torque output,
put strain gauges on the engine mounts. Al Hundere made up a device to do just
that on a Twin Beech many years ago. I understand that it worked OK, but needed
a lot of TLC to retain
accuracy.
Good evening Bob,
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. If I were to rebuild the mount, with
a design that had a bearing with the axis pointing forward which would allow
measurement of a "pure" torque, the job would be easy. I also considered putting
strains gauges on the longerons attached to the firewall, but I'm not sure
about the stability of that location in a composite aircraft. Eventually,
I put the project on the future list. I do appreciate your description of the
torque measurement in the planetary gear system on those big radials.
Jim Foerster
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