Constant speed props

Greg,

After all, he makes it perfectly clear
that you have to have an engine monitor, which makes it a
hole-in-your-wallet type of commitment for many.


One could (succesfully) make the argument that the information gleaned
from an engine monitor will save you more in money than it costs.

--
Thomas Borchert (EDDH)

On Sat, 26 Jun 2004 09:58:44 +0200, Thomas Borchert wrote:

Greg,

After all, he makes it perfectly clear
that you have to have an engine monitor, which makes it a
hole-in-your-wallet type of commitment for many.


One could (succesfully) make the argument that the information gleaned
from an engine monitor will save you more in money than it costs.

This is true. I read one such example where he had an 18gph engine
running at 15gph. Anyone have any idea what can be done with some of the
smaller engines? Say, something in the 9-11gph range? If we assume the
same ratio of savings, that puts us at 7.5 - 9.2 gph, right? At a savings
(unsupported assumptions here) of 1.65gph, on average, at $2.40/g, that's
$3.96 saved per hour. At, say, 100hr/year, that's $396 saved per year.
If we assume the 700 series JP Instrument, installed, that's something
like $1700 - $2000 installed (right?). So, that means we can recoup our
investment in 4.3 to a little over 5 years. Ouch.

Granted, the more you fly and the bigger the fuel rate of your engine, the
quicker it's going to pay off, but I think it's hard to justify it across
the board on a economy savings basis.

If we run with the demoed 3gph savings, at $2.40g, that's $7.20/hr
savings. If we assume 200hr/yr, that's $1440 savings a year, which makes
the cheap JPI monitor paid for in about 1 1/4 years. And that is still
assuming that it's a four cylinder. Realistically, it's probably going to
be a 6-cylinder, which is going to raise the price again. So, again, even
with 200hr/yr, we're looking at something about two years for a return on
our investment.

So, it doesn't look like quite the sweatheart deal after all. Now, if
there are some supporting numbers which indicate a return on TBO, then we
might have something to sing about.

Just some fun numbers for food for thought.

Cheers!

Greg

On Sat, 26 Jun 2004 10:53:43 -0500, Greg Copeland
wrote:

So, again, even
with 200hr/yr, we're looking at something about two years for a return on
our investment.

So, it doesn't look like quite the sweatheart deal after all. Now, if
there are some supporting numbers which indicate a return on TBO, then we
might have something to sing about.

Just some fun numbers for food for thought.

Cheers!

Ok, it may take two years to get your investment back in money saved
from fuel not burned. Isn't that better than not getting any
realization of savings ever?

Also, Deakin doesn't say you must have the JPI instrument, there are
at least three other multicylinder EGT guages that show you what's
happening in each cylinder, including one that is NOT a digital LED
type. That one costs less than $1,000.

Corky Scott

wrote in message
...
On Sat, 26 Jun 2004 10:53:43 -0500, Greg Copeland
wrote:

So, again, even
with 200hr/yr, we're looking at something about two years for a return on
our investment.

So, it doesn't look like quite the sweatheart deal after all. Now, if
there are some supporting numbers which indicate a return on TBO, then we
might have something to sing about.

Just some fun numbers for food for thought.

Cheers!

Ok, it may take two years to get your investment back in money saved
from fuel not burned.

And that's just fuel; it doesn't even take into account wear and tear due to
higher CHT temps.

Isn't that better than not getting any
realization of savings ever?

Let's see: About 40 cents a gallon time 15 gph = $6.00 and hour * 200 horus
a year = $1200 per year.

Figure in the amortized cost of a early TOH (two F33's I looked at had two
and three before they hit the 1700 TBO...one as early as 380 hours TTSN)
from running ROP (at least these two admitted such).


Also, Deakin doesn't say you must have the JPI instrument, there are
at least three other multicylinder EGT guages that show you what's
happening in each cylinder, including one that is NOT a digital LED
type. That one costs less than $1,000.

Quite. He merely says the JPI is _his_ favorite.

On Mon, 28 Jun 2004 08:19:21 -0700, Tom Sixkiller wrote:

So, it doesn't look like quite the sweatheart deal after all.
Now,
if
there are some supporting numbers which indicate a return on TBO, then
we might have something to sing about.

Just some fun numbers for food for thought.

Ok, it may take two years to get your investment back in money saved
from fuel not burned.

And that's just fuel; it doesn't even take into account wear and tear
due to higher CHT temps.

This is what I was hinting at. Does anyone know of any studies which can
associate an engine monitor with engine reliability, longevity, or reduced
TBO costs? Running engines past TBO?

I agree, common sense says, we'll see a happier engine resulting from
better managed temps, but is there anything that supports what a "happier
engine" translates into?

Greg

On Mon, 28 Jun 2004 10:39:31 -0500, Greg Copeland
wrote:

I agree, common sense says, we'll see a happier engine resulting from
better managed temps, but is there anything that supports what a "happier
engine" translates into?

Greg

This will be extremely difficult to quantify, because if you've read
all Deakin's columns, you will know that he feels that both Lycoming
and Continental have lost the ability to put together a long lasting
engine any longer. Also, there is a URL out there that describes the
problems the parallel head Lycoming 6 cylinder engine has in terms of
producing too much heat at the exhaust valve guide due to improper
original design back when they began installing hydraulic lifters.

This last piece of information is not from a Deaking column, it's from
two AP's who have done EXTENSIVE research on the problem of 6 cyl.
parallel valve Lycomings and why they can't seem to make TBO without
loosing compression because of excessive valve guide wear.

These guys traced it to the lack of oil flow to the valve guide, it's
that simple. Other engines that have MUCH more flow to the exhaust
valve guide do not suffer the same excessive valve guide wear.

See: http://egaa.home.mindspring.com/engine1.htm

What Deakin HAS said, and frequently, is that there are no engine
development engineers at Lycoming anymore. They've all retired.

Lycoming doesn't manufacture it's own parts anymore, they just
assemble what's sent them from outside sources.

But they still charge you plenty for them.

Corky Scott

On Mon, 28 Jun 2004 16:30:08 -0400, charles.k.scott wrote:

On Mon, 28 Jun 2004 10:39:31 -0500, Greg Copeland
wrote:

I agree, common sense says, we'll see a happier engine resulting from
better managed temps, but is there anything that supports what a "happier
engine" translates into?

Greg

What Deakin HAS said, and frequently, is that there are no engine
development engineers at Lycoming anymore. They've all retired.

Lycoming doesn't manufacture it's own parts anymore, they just
assemble what's sent them from outside sources.



Okay. I've read enough to see Deakin really tear up two
engine manufacturers. Just the same, if people want to assert that using
an engine monitor is going to (greatly?) extend an engine's life, let's
see some data. If we accept Deakin's arguments at face value, that there
are fundimental design issues and no expertise to fix, then we should be
having a serious problem with any of the two manufacturer's engines
reaching TBO. Yet, many are reporting TBO and beyond. Likewise, if engine
monitors are really adding life back to an engine, surely someone (engine
monitor manufacturer?) can say, x% of engines which had monitors, on
average, lasted y% longer then those that did not. Until there is some
supporting evidence, I think Mr. Campbell (George?) makes a good stand on
his position about LOP, and by extention, engine monitors.

Do we have direct evidence to support that LOP adds life to an
engine? Do we have dirrect evidence to support that an engine monitor
will increase longevity? From what I'm hearing, in spite of Deakin's very
interesting reads, the answer is no.

Please, feel free to correct as needed!

Cheers!

Greg

On Mon, 28 Jun 2004 08:45:15 -0400, charles.k.scott wrote:

On Sat, 26 Jun 2004 10:53:43 -0500, Greg Copeland
wrote:

So, again, even
with 200hr/yr, we're looking at something about two years for a return on
our investment.

So, it doesn't look like quite the sweatheart deal after all. Now, if
there are some supporting numbers which indicate a return on TBO, then we
might have something to sing about.

Just some fun numbers for food for thought.

Cheers!

Ok, it may take two years to get your investment back in money saved
from fuel not burned. Isn't that better than not getting any
realization of savings ever?

Also, Deakin doesn't say you must have the JPI instrument, there are
at least three other multicylinder EGT guages that show you what's
happening in each cylinder, including one that is NOT a digital LED
type. That one costs less than $1,000.

Corky Scott


Thanks. I've been meaning to look at the others. Have any urls to offer?

Greg

On Mon, 28 Jun 2004 10:31:59 -0500, Greg Copeland
wrote:


Thanks. I've been meaning to look at the others. Have any urls to offer?

Greg

I'll have to look em up. They are usually displayed in the Homebuilt
mags like Sport Aviation and Kitplanes. I should be getting the new
SA shortly.

Corky Scott

On Mon, 28 Jun 2004 16:21:11 -0400,
wrote:


Thanks. I've been meaning to look at the others. Have any urls to offer?

Greg

I'll have to look em up. They are usually displayed in the Homebuilt
mags like Sport Aviation and Kitplanes. I should be getting the new
SA shortly.

When I arrived home last night, the July "Sport Aviation" was on the
table.

Electronics International is another alternative to JPI
www.Buy-EI.com

There is also Vision Microsystems Inc. which produces a multi cylinder
EGT as one part of a number of displays: www.visionmicrosystems.com

The company I mentioned that produces an analog EGT is KS Avionics:
http://www.ksavionics.com/

There are a few others offering EGT's within their glass panel along
with just about every instrument needed for flight, but those, like
the Microsystems version are a bit pricey. Or not, if you brave the
brave and use just that system and eliminate all analog instruments.
We're talking homebuilts here though, not sure how these will get into
certified airplanes.

Corky Scott