Constant speed props

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 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

Howdy!

In article ,
C J Campbell wrote:

"Tom Sixkiller" wrote in message
...

"C J Campbell" wrote in message
...
I think Deakin is worth reading, but some of what he says should be
taken
with a grain of salt. His columns are mostly based on experiments with
his
own highly modified Bonanza, a few high performance radial engines, and
some
theory. In fact, a careful reading of his columns will show no test data
for
the most common engine and propeller combinations in use today.

You've not read hiscolumns about the test beds they've run at GAMI?

I merely point out that his theories are controversial -- they are hardly
universally accepted, as even this thread amply demonstrates. As I said, I
think he has a point, but I have to consider that the engine manufacturers
and aircraft manufacturers might know at least as much about their products
as GAMI does.

No. You do not "merely" point out... You do it in a manner that, intentional
or no, suggests that he is blowing smoke up your backside. You further
appear to completely disregard the supporting data and arguments, both from
GAMI testbeds and from historical operating practices for piston engined
aircraft. He does offer credible arguments that the engine manufacturers
offer recommendations contrary to good engineering and operating practices.

Let's be honest here.

yours,
Michael

--
Michael and MJ Houghton | Herveus d'Ormonde and Megan O'Donnelly
| White Wolf and the Phoenix
Bowie, MD, USA | Tablet and Inkle bands, and other stuff
| http://www.radix.net/~herveus/

"Michael Houghton" wrote in message
...

No. You do not "merely" point out... You do it in a manner that,
intentional
or no, suggests that he is blowing smoke up your backside. You further
appear to completely disregard the supporting data and arguments, both
from
GAMI testbeds and from historical operating practices for piston engined
aircraft. He does offer credible arguments that the engine manufacturers
offer recommendations contrary to good engineering and operating
practices.

Let's be honest here.

All right, let's be honest. I am not disregarding the data that he as
presented in his articles. I will also not disregard the anecdotal evidence
that I have from several engine shops that engines consistently run LOP
generally do not make TBO, nor do they last as long as engines run according
to manufacturers' specifications. When Deakin comes up with hard evidence
that applies to anything other than GAMI's special setups then I will
welcome it. If there is anything that drives me up the wall, it is these
vague references to "historical operating practices." It is really just a
substitute for "bull****."

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 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

"C J Campbell" wrote in message
...

"Michael Houghton" wrote in message
...

No. You do not "merely" point out... You do it in a manner that,
intentional
or no, suggests that he is blowing smoke up your backside. You further
appear to completely disregard the supporting data and arguments, both
from
GAMI testbeds and from historical operating practices for piston engined
aircraft. He does offer credible arguments that the engine manufacturers
offer recommendations contrary to good engineering and operating
practices.

Let's be honest here.

All right, let's be honest. I am not disregarding the data that he as
presented in his articles.

That's exactly what you're doing. You're also ingoring the parameters he
sets (that standard fatory injectors are so poorly done and out of spec that
LOP with standard injectors would cause one or more cylinders to run
excessivly hot (400 degrees plus).

I will also not disregard the anecdotal evidence
that I have from several engine shops that engines consistently run LOP
generally do not make TBO, nor do they last as long as engines run
according
to manufacturers' specifications.

Odd. Most of the anecdotal evidence shows that engines run according to
manufactureres specs (ie, ROP) DON'T make TBO. This is supported by the
DATA.

When Deakin comes up with hard evidence
that applies to anything other than GAMI's special setups then I will
welcome it.

Well, the test stand has data for all sorts of setups and configurations and
you ignore THAT, so cut the crap.

If there is anything that drives me up the wall, it is these
vague references to "historical operating practices." It is really just a
substitute for "bull****."

"Vague" reference?

Talk about bull****, and talk about shoving ones foot in mouth and playing
"pay no attention to that man behind the curtain...".

"Tom Sixkiller" wrote in message
...

"C J Campbell" wrote in message
...

If there is anything that drives me up the wall, it is these
vague references to "historical operating practices." It is really just
a
substitute for "bull****."

"Vague" reference?

Talk about bull****, and talk about shoving ones foot in mouth and playing
"pay no attention to that man behind the curtain...".

When someone tells me that 'historical operating practices' are different
from what has always been done, it automatically fails the baloney test.

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