Today's Message Index:
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1. 05:49 AM - Re: JabiruEngine-List Digest: 2 Msgs - 09/24/06 (TELEDYNMCS@aol.com)
2. 06:19 AM - Re: JabiruEngine-List Digest: CHT Duct Mods for 3300 (JAPhillipsGA@aol.com)
3. 08:37 AM - Re: Re: JabiruEngine-List Digest: CHT Duct Mods for 3300 (vwknott)
4. 07:16 PM - Re: Re: JabiruEngine-List Digest: CHT Duct Mods for 3300 (gdh)
Message 1
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| Subject: | Re: JabiruEngine-List Digest: 2 Msgs - 09/24/06 |
In a message dated 9/25/2006 2:58:20 AM Eastern Daylight Time,
jabiruengine-list@matronics.com writes:
.....how important is
watching the EGT, especially of all six jugs?
Hi Tim,
Nice to see some activity on this list for a change. I'm certainly not an
expert, but I think I can answer your question. Monitoring all EGT's, as with
CHT's MAP, Carb Temp, Oil Temp, Oil Pressure, etc, will help point to issues
before they become problems. The issues I speak of in regard to EGT's are
things like loose intake connections, improperly adjusted valves, a burnt or
sticking valve, a loose spark plug, etc., anything that would lean out the engine
and cause harm over time. If you had a problem where the engine was running
too rich, this would also show up in EGT's.
I use a Grand Rapids EIS with a graphical display. Sometimes it is a
borderline distraction with all the info in provides, but as I've been breaking
in a
3300 on a Europa XS I've recently completed, I've found the monitoring of
all EGT's a great help.
All 3300's shipped after s/n 722 were shipped with an "economy cruise"
needle jet, along with a new Jabiru needle. The Jab needle is shaped with "steps'
along its length so that it corresponds more closely to the performance curve
of the engine. The stock Bing needle is a near constant taper and works, but
isn't optimum. This factory combo leans out the mixture at the right places
and the new needle allows the other portions of the carb to kick in when
needed. The result is fuel burn numbers similar to the 912S in cruise. I'm seeing
about 3.8 gph at 2900 rpm, resulting in a cruise speed of about 130 kts at
5000' on the Europa. I'm running a Sensenich hollow carbon ground adjustable
at the moment, but I intend to switch to an electrically adjustable hub as
soon as they are available for the Sensenich blades.
However, I found in the initial running of my 3300 that my EGT's were quite
high, >1450 F. After some searching, conversations with Andy Silvester of
Gulfcoast Sportplanes (where I got the 3300) and noodling out the problem I
decided that the economy needle jet was probably too small for break in,
resulting in a very lean mixture, as evidenced by the color of the plugs and the
high
EGT's. Taking Andy's advice, I switched to a 285 needle jet and the EGT's
dropped 150F and the plugs are now a nice tan color. Interestingly, I noticed
the other day while reading the most recent issue of "Jabba Chat" that the
factory has switched to the 285 needle jet in favor of the 278 as of April of
this year.
As the old saying goes, "An abnormally high EGT will tell you that you are
about to french fry your engine. An abnormally high CHT will tell you that you
just french fried your engine". This notion is probably more true for 2
strokes than 4 strokes, but the point remains the same.
In regard to preheating, I concur. I own a PA-25 Pawnee (0-540), a 7GCA
Citabria (0-320) and the Europa with a 3300. I preheat all three year round,
regardless of the ambient temperature. The Pawnee has both a Tanis block heater
and EZ-Heat oil pan heater. The Citabria has just the EZ-Heat oil pan heater.
My Europa has a heat pad similar to the EZ-Heat, but was obtained from JC
Whitney. The heat pad on the Europa is automotive, but is nearly identical to
the EZ-Heat, but about 1/3rd the price. I can usually get the oil temps to
140F before hitting the starter on any of the three , even on the coldest day.
(and yes, we can get some mighty cold days here in January and February)
One thing I'd like to know is how many Jab owners out there are running
carburettors other than the Bing? Aerocarbs, Ellisons? I'd really like to have
mixture control and the Aerocarb looks like a nice unit for the price. Comments?
Anyway, good luck with your project. The best part is yet to come!
Regards,
John Lawton
Whitwell, TN - TN89
Europa N245E - Flying - 33.5 hours
Message 2
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| Subject: | Re: JabiruEngine-List Digest: CHT Duct Mods for 3300 |
Jab Pals, I have made a combination of mods to air ducts and cowl outlet that
has reduced CHT on No. 4 & 6 by 70 degrees at max cruise. I have eight slow
dial up photos of the mods and will share with you all. How do I send photos
to the Jab site. Best regards, Bill
Message 3
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| Subject: | Re: JabiruEngine-List Digest: CHT Duct Mods for |
3300
Hi JA
Good to hear from a Jabiru engine owner.
I have a 2200 in a Zenith 701and am having air flou troble
EGT is high and RPM is only about 2650 I sure would like to
look at tour photos When I fly it, it acts like it is mising.
Vernon Knott
vwknott@cox.net
: jabiruengine-list@matronics.com
Sent: Monday, September 25, 2006 9:19 AM
Subject: JabiruEngine-List: Re: JabiruEngine-List Digest: CHT Duct
Mods for 3300
Jab Pals, I have made a combination of mods to air ducts and cowl
outlet that has reduced CHT on No. 4 & 6 by 70 degrees at max cruise. I
have eight slow dial up photos of the mods and will share with you all.
How do I send photos to the Jab site. Best regards, Bill
Message 4
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| Subject: | Re: JabiruEngine-List Digest: CHT Duct Mods for |
3300
Bill, Sure would like to see the photos.
Regards,
Dale
Europa XP/3300
----- Original Message -----
From: JAPhillipsGA@aol.com
To: jabiruengine-list@matronics.com
Sent: Monday, September 25, 2006 6:19 AM
Subject: JabiruEngine-List: Re: JabiruEngine-List Digest: CHT Duct
Mods for 3300
Jab Pals, I have made a combination of mods to air ducts and cowl
outlet that has reduced CHT on No. 4 & 6 by 70 degrees at max cruise. I
have eight slow dial up photos of the mods and will share with you all.
How do I send photos to the Jab site. Best regards, Bill
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