Tossing factory EGT, replacing with JPI or similar

[Ben Jackson]

I understand that if I had a CHT, and it had a redline (I don't have one
at all, probably because the PA-24 doesn't have cowl flaps) I would need
to keep my CHT or get something certified to be a primary CHT.

Are there any rules regarding EGT? The one I have is pretty useless. It's
an analog gauge that displays only relative EGT (it's marked in 100s of
degrees F, and a thumbwheel lets you adjust the position of the indicating
needle). I'd just leave it, except it's a 2.25" instrument right where
I'd like to put the digital replacement.

--
Ben Jackson
>
http://www.ben.com/

[Tom Sixkiller]

"Ben Jackson" > wrote in message
news:Xm1cc.181337$1p.2150841@attbi_s54...
> I understand that if I had a CHT, and it had a redline (I don't have one
> at all, probably because the PA-24 doesn't have cowl flaps) I would need
> to keep my CHT or get something certified to be a primary CHT.
>
> Are there any rules regarding EGT? The one I have is pretty useless.
It's
> an analog gauge that displays only relative EGT (it's marked in 100s of
> degrees F, and a thumbwheel lets you adjust the position of the indicating
> needle). I'd just leave it, except it's a 2.25" instrument right where
> I'd like to put the digital replacement.
>
Lycoming IO-540, right?

Definitely the EDM-700. http://jpinstruments.com/edm_700.html along with a
set of GAMIjectors.

You can probably get one cheaper, but not likely _better_.

[Ben Jackson]

In article >,
Tom Sixkiller > wrote:
>
>Lycoming IO-540, right?
>
>Definitely the EDM-700. http://jpinstruments.com/edm_700.html along with a
>set of GAMIjectors.

That's what I'm thinking, or possibly an EDM-800. I'd like to have
MP/RPM because the primary gauges for those are wayyy out of my scan.

Right now I'm trying to figure out if I can put it where I want: Right
where the stock EGT is now.

--
Ben Jackson
>
http://www.ben.com/

[Jay Honeck]

> That's what I'm thinking, or possibly an EDM-800. I'd like to have
> MP/RPM because the primary gauges for those are wayyy out of my scan.

The 800 looks cool. We've got the 700, and upon installation it rapidly
became a primary flight instrument.

We use it for leaning, we use it for diagnosis, we use it for early warning,
and we use it for peace of mind. It's a wonderful tool.
--
Jay Honeck
Iowa City, IA
Pathfinder N56993
www.AlexisParkInn.com
"Your Aviation Destination"

[Tom Sixkiller]

"Ben Jackson" > wrote in message
news:7P2cc.76725$JO3.41027@attbi_s04...
> In article >,
> Tom Sixkiller > wrote:
> >
> >Lycoming IO-540, right?
> >
> >Definitely the EDM-700. http://jpinstruments.com/edm_700.html along with
a
> >set of GAMIjectors.
>
> That's what I'm thinking, or possibly an EDM-800. I'd like to have
> MP/RPM because the primary gauges for those are wayyy out of my scan.
>
> Right now I'm trying to figure out if I can put it where I want: Right
> where the stock EGT is now.

That's usually where they go. I'd suspect that (??) some of the wiring would
already be in place.

How about the GAMI's?

[Ben Jackson]

In article >,
Tom Sixkiller > wrote:
>> Right now I'm trying to figure out if I can put it where I want: Right
>> where the stock EGT is now.
>
>That's usually where they go. I'd suspect that (??) some of the wiring would
>already be in place.

I don't think I'd want to re-use one mis-matched EGT probe with the other
five. I dug up a picture of a 'stock' 260 panel (mine is far from stock
on the left side) and lo and behold, no EGT at all. My EGT is where the
stock suction gauge was.

>How about the GAMI's?

I need the multi-channel EGT to know if I need those! :)

--
Ben Jackson
>
http://www.ben.com/

[G.R. Patterson III]

Ben Jackson wrote:
>
> I understand that if I had a CHT, and it had a redline (I don't have one
> at all, probably because the PA-24 doesn't have cowl flaps) I would need
> to keep my CHT or get something certified to be a primary CHT.
>
> Are there any rules regarding EGT?

My aircraft has a list of mandatory (AKA "standard") equipment and a list of optional
equipment. If you can get the same lists for your aircraft, and if the EGT is not
listed as mandatory equipment, it can be removed.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

[Tom Sixkiller]

"Ben Jackson" > wrote in message
news:eA3cc.182477$1p.2161124@attbi_s54...
> In article >,
> Tom Sixkiller > wrote:
> >> Right now I'm trying to figure out if I can put it where I want: Right
> >> where the stock EGT is now.
> >
> >That's usually where they go. I'd suspect that (??) some of the wiring
would
> >already be in place.
>
> I don't think I'd want to re-use one mis-matched EGT probe with the other
> five. I dug up a picture of a 'stock' 260 panel (mine is far from stock
> on the left side) and lo and behold, no EGT at all. My EGT is where the
> stock suction gauge was.

I wasn't thinking of the probe wires, but now that you mention it that's
makes sense.

In a Bonanza, it fits into the standard EGT readout slot.

>
> >How about the GAMI's?
>
> I need the multi-channel EGT to know if I need those! :)

(Oh believe me, if you have Fuel Injection, you NEED them. :~)

From what I gather, you can't get a proper reading from a multi-channel EG
with stock injectors. Check of John Deakin's articles in AvWeb about that.
What's more, better CHT's, fuel savings, SMOOTHER running...

Tom
--
Life is not a journey to the grave with the intention of arriving
safely in a pretty and well preserved body, but rather to skid
in broadside, thoroughly used up, totally worn out, and loudly
proclaiming - - WOW - - WHAT A RIDE!"

[Musky]

Bravo to Ben---the EDM 700 is the best $1800 we ever spent: $1500 for
the unit plus 6 hrs installation, but we had the engine out anyway.
Expect 8 hrs at your local shop rate. We just have Volts, EGT, and CHT,
didn't opt (yet) for OAT, fuel flow, or the other possibilities.

>>How about the GAMI's?
>>
>>I need the multi-channel EGT to know if I need those! :)
>
> (Oh believe me, if you have Fuel Injection, you NEED them. :~)

Lycoming already uses tuned injectors on the 4-bangers. Our Lyco IO-360
(in a Beech C24R) maintains CHT within 15 degrees for all cylinders, and
LOP is smooth as silk. Correct this last to read "if you have a
Continental engine, or a Lycoming 6-cylinder, you NEED them!"

best of luck

[Tom Sixkiller]

"Musky" > wrote in message
...
> Bravo to Ben---the EDM 700 is the best $1800 we ever spent: $1500 for
> the unit plus 6 hrs installation, but we had the engine out anyway.
> Expect 8 hrs at your local shop rate. We just have Volts, EGT, and CHT,
> didn't opt (yet) for OAT, fuel flow, or the other possibilities.
>
> >>How about the GAMI's?
> >>
> >>I need the multi-channel EGT to know if I need those! :)
> >
> > (Oh believe me, if you have Fuel Injection, you NEED them. :~)
>
> Lycoming already uses tuned injectors on the 4-bangers.

CMIIW but Lycoming's have tuned INDUCTION, not tuned injectors.

> Our Lyco IO-360
> (in a Beech C24R) maintains CHT within 15 degrees for all cylinders, and
> LOP is smooth as silk.

How about EGT's?

> Correct this last to read "if you have a
> Continental engine, or a Lycoming 6-cylinder, you NEED them!"

[G.R. Patterson III]

Tom Sixkiller wrote:
>
> CMIIW but Lycoming's have tuned INDUCTION, not tuned injectors.

If that's the case, you should be able to use Deakin's trick on a carburetted
Lycoming too.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

[jls]

"Tom Sixkiller" > wrote in message
...
>
> "Ben Jackson" > wrote in message
> news:eA3cc.182477$1p.2161124@attbi_s54...
[...]
> >
> > >How about the GAMI's?
> >
> > I need the multi-channel EGT to know if I need those! :)
>
> (Oh believe me, if you have Fuel Injection, you NEED them. :~)

On an IO-360 Continental? The engineer in our EAA chapter said gami's were
only for injected engines with the induction underneath the engine, NOT for
a cross-flow injected engine like a Continental IO-360 with the induction
system on top.

[Musky]

> How about EGT's?

One cylinder typically reads 40 degrees hot, otherwise they are all very
close. I'll get some data next time I'm up and post.

[Tom Sixkiller]

"G.R. Patterson III" > wrote in message
...
>
>
> Tom Sixkiller wrote:
> >
> > CMIIW but Lycoming's have tuned INDUCTION, not tuned injectors.
>
> If that's the case, you should be able to use Deakin's trick on a
carburetted
> Lycoming too.
>

Elaborate, please, for those of us that are not 100% mechanically inclined.
:~)

[Tom Sixkiller]

" jls" > wrote in message
...
>
> "Tom Sixkiller" > wrote in message
> ...
> >
> > "Ben Jackson" > wrote in message
> > news:eA3cc.182477$1p.2161124@attbi_s54...
> [...]
> > >
> > > >How about the GAMI's?
> > >
> > > I need the multi-channel EGT to know if I need those! :)
> >
> > (Oh believe me, if you have Fuel Injection, you NEED them. :~)
>
> On an IO-360 Continental? The engineer in our EAA chapter said gami's
were
> only for injected engines with the induction underneath the engine, NOT
for
> a cross-flow injected engine like a Continental IO-360 with the induction
> system on top.

AFAIK, GAMI's have nothing to do with the induction. At the least, GAMI has
them listed on their availability list.

http://www.gami.com/gamimodellist.html (and the note: NOW AVAILABLE FOR
"TUNED INDUCTION SYSTEMS" ENGINES!)

....
Lycoming Engines

----------------------------------------------------------------------------
----


All models of fuel injected "IO" and "TIO" engines (and left turning
versions thereof, except the TIO-541 engines), as follows:

IO-360
A1A, A1B, A1B6, A1B6D, A1C, A1D, A1D6, A1D6D, A2A, A2B, A2C, A3B6, A3B6D,
A3D6D, B1A, B1B, B1C, B1D, B1E, B1F, B1F6, B2E, B2F, B2F6, B4A, C1A, C1B,
C1C, C1C6, C1D6, C1E6, C1E6D, C1F, D1A, E1A, F1A, J1AD, J1A6D, K2A, L2A

[G.R. Patterson III]

Tom Sixkiller wrote:
>
> > If that's the case, you should be able to use Deakin's trick on a
> carburetted
> > Lycoming too.
>
> Elaborate, please, for those of us that are not 100% mechanically inclined.

There are a couple of interesting things that Deakin recommends. One is running
substantially lean of peak EGT. Running about 50 degrees rich of peak is generally
recommended by other people. Another trick is leaving the throttle wide open and
controlling rpm with the mixture. I've seen both discussed here. I've also seen
running lean of peak discussed elsewhere.

In all of these discussions, everyone seems to agree that this can only be done with
a set of GAMI injectors because the mixture and the distribution of fuel to the
cylinders is uneven with every other system. Well, the entire purpose of a tuned
induction system is to ensure even distribution and mixture of the fuel charges to
the cylinders. It doesn't matter whether you have injectors or not, if you have a
tuned induction system, the fuel charge distribution and mixture will be the same at
every cylinder.

So. If Lycoming has tuned the induction on their engines half as well as Holley or
Shelby used to do for V-8s in the 70s, you should be able to run consistently lean of
peak with, for example, the basic O-360.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

[Marc J. Zeitlin]

G.R. Patterson III wrote:

> So. If Lycoming has tuned the induction on their engines half as well
as Holley or
> Shelby used to do for V-8s in the 70s, you should be able to run
consistently lean of
> peak with, for example, the basic O-360.

I don't know jack about Holleys or Shelby, but I do know that while I
can run 50 degrees LOP with my COZY MKIV with an O-360 A2A and Ellison
throttle body, that's about the extent of it. If I try to lean it out
more than that, it starts running pretty rough, and the vibration is
annoying as hell.

Still better than ROP, but I don't think that Lycoming's got a perfect
induction system tuning going :-). If I ever have a few thousand $$
fall on my head, I'll install injection and GAMI's. But that's after
the Lightspeed electronic ignition.

--
Marc J. Zeitlin
http://marc.zeitlin.home.comcast.net/
http://www.cozybuilders.org/
Copyright (c) 2004

[Tom Sixkiller]

"Marc J. Zeitlin" > wrote in message
news:66occ.192794$_w.1894074@attbi_s53...
>
> Still better than ROP, but I don't think that Lycoming's got a perfect
> induction system tuning going :-). If I ever have a few thousand $$
> fall on my head, I'll install injection and GAMI's. But that's after
> the Lightspeed electronic ignition.

Lightspeed? I've heard of headphones under that name but not electronic
ignition.

How does it vary from PRISM? http://www.gami.com/prism.html

[Tom Sixkiller]

"G.R. Patterson III" > wrote in message
...
>
>
> Tom Sixkiller wrote:
> >
> > > If that's the case, you should be able to use Deakin's trick on a
> > carburetted
> > > Lycoming too.
> >
> > Elaborate, please, for those of us that are not 100% mechanically
inclined.
>
> There are a couple of interesting things that Deakin recommends. One is
running
> substantially lean of peak EGT. Running about 50 degrees rich of peak is
generally
> recommended by other people.

From what I remember (am am too lazy to look up at 10:30 at night) is that
running that rich is a good way to wind up with lead fouling and other
disasters that lead to a premature top overhaul. What's intersting is the
data the the folks at GAMI got from their test bed contradicts so much
"conventional wisdom".

> Another trick is leaving the throttle wide open and
> controlling rpm with the mixture. I've seen both discussed here. I've also
seen
> running lean of peak discussed elsewhere.


> In all of these discussions, everyone seems to agree that this can only be
done with
> a set of GAMI injectors because the mixture and the distribution of fuel
to the
> cylinders is uneven with every other system. Well, the entire purpose of a
tuned
> induction system is to ensure even distribution and mixture of the fuel
charges to
> the cylinders.

CMIIW, but a good induction system can be wasted if the QC on the injectors
sucks?

> It doesn't matter whether you have injectors or not, if you have a
> tuned induction system, the fuel charge distribution and mixture will be
the same at
> every cylinder.

See above question.

>
> So. If Lycoming has tuned the induction on their engines half as well as
Holley or
> Shelby used to do for V-8s in the 70s, you should be able to run
consistently lean of
> peak with, for example, the basic O-360.

In the 70's...or the 60's? By 72' all the pollution equipment threw it all
in the dumper, TMWOT.

[Viperdoc]

GAMI injectors are a great addition for the big Continentals, but I'm not so
sure if the same is true for Lycomings. My Lycoming AEIO 540 has a lot more
even temperatures across the board than the IO-470's in my Baron that's
equipped with GAMI injectors.

Didn't Deakin's articles pretty much say the same?

[Russell Kent]

Marc J. Zeitlin wrote:

> Still better than ROP, but I don't think that Lycoming's got a perfect
> induction system tuning going :-). If I ever have a few thousand $$ fall
> on my head, I'll install injection and GAMI's. But that's after the
> Lightspeed electronic ignition.

Tom Sixkiller replied:

> Lightspeed? I've heard of headphones under that name but not electronic
> ignition.

Klaus Savier's company.
http://www.lsecorp.com/

> How does it vary from PRISM? http://www.gami.com/prism.html

Uh, by being available for experimentals now? :-)
Seriously, GAMI's PRISM is cool and is expected for STC/377 in the (near?)
future. I don't think it's shipping yet. I believe that Light Speed
Engineering's ignition is intended for the experimental market only (no plan
to pursue any FAA certification).

So, different target markets.

Russell Kent

[Chris Kennedy]

Tom Sixkiller wrote:

[snip]

> CMIIW but Lycoming's have tuned INDUCTION, not tuned injectors.

This is manifestly not true with _all_ Lycomings, but it may be true for
four bangers (but even then perhaps more as a function of marketing spin
than concerted engineering effort).

Tuning an intake system usually implies two goals: Near identical
mixture distribution and tweaks to manipulate the torque curve. For
engines that do not use port or direct injection the former more or less
requires identical runner lengths, something that may be a happy
accident on four bangers but certainly isn't the case on my O-540.
Manipulating the torque curve consists of futzing with the length and
diameter of the runners such that one of the pressure peaks in the gas
column (the gas column has inertia but is perpetually being asked to
stop and start as the intake valve opens and closes, resulting in
standing waves in the gas column) coincides with the intake valve at the
time the valve is open for a particular engine speed, such that there is
a relative overpressure during some portion of the intake valve being
open. I _might_ believe some of that was done, but lacking intake
balance pipes and other weird juju I'd be skeptical of the efficacy of
same -- and even then it wouldn't contribute to mixture distribution.

Don't even get me started on Lycoming plumbing the intake runners
through the oil pan to "improve" the mixture. If the runner design is
so bad that the intake manifold needs to be heated to assure that the
mixture from the carb remains vaporized the only reasonable conclusion
is that the runners are too long or have too many kinks and that the
overall intake system blows hairy goats. It's the mechanical
engineering answer to documenting a bug and calling it a feature.

[G.R. Patterson III]

Tom Sixkiller wrote:
>
> What's intersting is the
> data the the folks at GAMI got from their test bed contradicts so much
> "conventional wisdom".

Yeah, a recent article in AOPA Pilot about that contained the statement "In fairness
to both Lycoming and Teledyne Continental Motors, the engine-operating instructions
in POHs … appear to have been the result of marketing decisions taking precedence
over engineering recommendations." I wrote back that it would have been more
accurately phrased as "In fairness to both Lycoming and Teledyne Continental Motors,
their engineers are competent, but the companies apparently lie through their teeth
to get you to trash your engine and buy a new one sooner." They didn't print the
letter.

> CMIIW, but a good induction system can be wasted if the QC on the injectors
> sucks?

True. That wouldn't apply to carburetors, however, so we still should be able to pull
some of Deakin's tricks with them (and, apparently, one poster is doing that).

> In the 70's...or the 60's? By 72' all the pollution equipment threw it all
> in the dumper, TMWOT.

Not in the South, it didn't. About the only piece of anti-pollution gear you had to
leave on the car was the PCV valve. Holley was still doing a good business in tuned
intake manifolds and Shelby's exhaust systems were still in demand in 1980. Then I
sort of lost track of it for a while (went back to school). A guy I worked with in
'72 actually rodded a new Vega. He got unbelievable performance out of it for a
while, but the engine only lasted about 6 months.

George Patterson
This marriage is off to a shaky start. The groom just asked the band to
play "Your cheatin' heart", and the bride just requested "Don't come home
a'drinkin' with lovin' on your mind".

[kage]

Doc,

GAMI doesn't claim, and never did, to even EGT's. Further, on a flat engine,
they don't. Deakin, with whom I have flown, would NEVER say they even EGTs.
They do even the fuel flows to each cylinder and even the horsepower
developed by each cylinder. EGTs will vary, due to the geometry and
installation of a flat engine.
Karl
"Curator" N185KG


"Viperdoc" > wrote in message
...
> GAMI injectors are a great addition for the big Continentals, but I'm not
so
> sure if the same is true for Lycomings. My Lycoming AEIO 540 has a lot
more
> even temperatures across the board than the IO-470's in my Baron that's
> equipped with GAMI injectors.
>
> Didn't Deakin's articles pretty much say the same?
>
>

[Tom Sixkiller]

"Russell Kent" > wrote in message
...
>
> > How does it vary from PRISM? http://www.gami.com/prism.html
>
> Uh, by being available for experimentals now? :-)
> Seriously, GAMI's PRISM is cool and is expected for STC/377 in the (near?)
> future. I don't think it's shipping yet. I believe that Light Speed
> Engineering's ignition is intended for the experimental market only (no
plan
> to pursue any FAA certification).
>
> So, different target markets.

I was speaking of _operationally_.

[Tom Sixkiller]

"Viperdoc" > wrote in message
...
> GAMI injectors are a great addition for the big Continentals, but I'm not
so
> sure if the same is true for Lycomings. My Lycoming AEIO 540 has a lot
more
> even temperatures across the board than the IO-470's in my Baron that's
> equipped with GAMI injectors.
>
> Didn't Deakin's articles pretty much say the same?

I don't think so (IMW), but GAMI's are not the only factor in even CHT's one
way or another. (I "assume" you're referring to CHT's when you speak of
temperatures.

[Russell Kent]

Tom Sixkiller wrote:

> "Russell Kent" > wrote in message
> ...
> >
> > > How does it vary from PRISM? http://www.gami.com/prism.html
> >
> > Uh, by being available for experimentals now? :-)
> > Seriously, GAMI's PRISM is cool and is expected for STC/377 in the (near?)
> > future. I don't think it's shipping yet. I believe that Light Speed
> > Engineering's ignition is intended for the experimental market only (no
> plan
> > to pursue any FAA certification).
> >
> > So, different target markets.
>
> I was speaking of _operationally_.

Both systems use capacitive discharge systems to make longer duration, hotter
sparks. The GAMI PRISM system uses a pressure sensor in the cylinder (part of
the spark plug assembly I believe) to measure the cylinder pressure during the
combustion event. It uses that information to alter the timing of the spark for
best performance. This also makes it compatible with varying grades of fuel.
The LSE Light Speed has no such pressure feedback, but does use manifold
pressure and RPM to affect the timing and duration of the spark. I do not know
if the PRISM uses MAP or RPM for timing curve manipulation.

Russell Kent

[Tom Sixkiller]

"Russell Kent" > wrote in message
...
> Tom Sixkiller wrote:
>
> > "Russell Kent" > wrote in message
> > ...
> > >
> > > > How does it vary from PRISM? http://www.gami.com/prism.html
> >
> > I was speaking of _operationally_.
>
> Both systems use capacitive discharge systems to make longer duration,
hotter
> sparks. The GAMI PRISM system uses a pressure sensor in the cylinder
(part of
> the spark plug assembly I believe) to measure the cylinder pressure during
the
> combustion event. It uses that information to alter the timing of the
spark for
> best performance. This also makes it compatible with varying grades of
fuel.
> The LSE Light Speed has no such pressure feedback, but does use manifold
> pressure and RPM to affect the timing and duration of the spark. I do not
know
> if the PRISM uses MAP or RPM for timing curve manipulation.
>
Thanks...that increased my knowledge of ignition system immensely!!

I notice that GAMI's PRISM system offers/recommends a digital tach, so it
may be (guessing) that it's based on RPM.

I've heard that STC certifications are running wayyyy behind, so it may be
over a year.

[James M. Knox]

"Tom Sixkiller" > wrote in
:
>
> I notice that GAMI's PRISM system offers/recommends a digital tach, so
> it may be (guessing) that it's based on RPM.
>
> I've heard that STC certifications are running wayyyy behind, so it
> may be over a year.

PRISM went through several variations of the algorithms during the
design cycle, as you would expect, learning what was needed (and a
surprising amount of stuff that wasn't needed). I believe you will find
that it is not quite described by either of the typical MAP or RPM
approaches. It's inputs are the cylinder timing (TDC) and the cylinder
pressure *curve*, plus those things that can be derived from TDC (like
RPM). The timing of the spark is adjusted to produce the desired
pressure curve relative to TDC, further adjusted to offset any
unacceptable variation in the curve shape itself (i.e. stop any
detonation before it happens).

Works amazingly well, and is independent of fuel - in that if (for
example) you switch tanks in flight and the octane rating of the fuel in
one tank is lower than the other, the PRISM system notices the changes
in the combustion pressure curves and moves the timing to compensate.
You, the pilot, may notice a slight change in the "sound" of the engine,
and a slight change in power output, but otherwise it just keeps humming
along.

Certification -- ah, there's the rub. Anyone got the schematics for a
good electric FAA-prod? Maybe two years ago when the Light Sport Plane
proposal is approved. {:<(

-----------------------------------------------
James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
-----------------------------------------------