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Todd,
Your temps are more like mine were, although I did
manage upwards of 1830 degrees. I am hoping that with a richer
mix I will be able to hold them down similar to yours. Obviously
your turbo is surviving these temps?? What turbo have you
fitted? Great thermocouples!! Neil.
I built my own thermocouples for my EGT's and
they are still in great shape after a 100 hours. There are 2
of them less than an inch from each exhaust port and another a
few inches further at the turbine inlet. A fourth one is about
24" downstream of the turbo. I regularly expose them to 950C
(1750F). I recently removed them for inspection and only one
needed a light tap to free it up for removal, so they don't
jam up and get stuck or melt and bend. They don't show any
signs of wear.
They were easy to make and long ago I wrote up a full
description on how to do it. Unfortunately I didn't include
pictures but the description is quite thorough. I was
fortunate to have all the materials on hand so it didn't
cost me anything, but I can't imagine the supplies would
cost that much then you could make as many as you need for
cheap, and likely not have to replace them again.
It is own my google drive and can be viewed here
Andrew,
yeah, my probes were only 2 inches from
the port and melted quite nicely. All with the microtech
ECU which was a fair "illegitimate" to tune. I tend to
suspect that the min dist should be 4 inches or more.
That turbo you suggest -- it was fitted to nearly all IH
machinery, even the old 1480! Does that go back! Do you
have any idea as to its weight? Neil.
Neil. others will know lots more than me as I'm
still trying to work this engine out.
I don't really have enough data to quote
reliable numbers, But last flight the data
recorder showed egt 850-950c upto 1030c all at
same rpm's 2200-2300 prop rpm (2.85:1 reduction),
seems the egt's are more a factor of Afr's than
rpm with the cooler temps when afr <12.5, mid
range when afr > 16, high temps afr between
13-16:1
Have now lost 3 egt sensors, originally all
placed 50mm from port. just too close me thinks.
next lot will be further away but this will place
them in the tube where gas from both rotors are
mixed so not sure if I'll get individual rotor
temps or if that really matters anyway.
Andrew
Andrew, Just what EGTs do you see at what revs?
Neil.
Neil, In Aus I’ve found
Justraceparts.com in Qld good for quality
sensors, their Egt sensors are $26 rated to
1300c. Have not tried their instrument display
though as I just connect to my Efis & Em2.
Andrew
Who was it on
the list that was using a Maximite for
instrumentation? Shouldn't be too
difficult to add a temperature reference
& order Chinese probes from ebay.
Charlie
Bobby,
Only reason for
an addition to the fueltech is
neatness, but at that cost a stand
alone EGT is attractive.Currently
investigating as freight is the
killer from the USA. Need a local
supplier,
Neil.
Neil,
I
have flown an Eaton MP90 4th
gen super charger for a little
over 500 hours. No intercooler
with the super charger. Turbo
FWF is in the works and will
have an intercooler. I needed
a wider compressor map at a
lower PR for takeoff than the
TO4-50 . I ended up purchasing
a Garret GT3076R w/ Tial 1.06
SS housing. I would have
preferred a journal bearing
turbo but this one is ball
bearing.
Do
you have a reason for added
EGT’s to the fueltech vs an
aircraft engine monitor /
efis?
Bobby
From:
Rotary motors in aircraft
[mailto:flyrotary@lancaironline.net]
Sent: Saturday,
December 08, 2018 2:47 AM
To: Rotary motors
in aircraft
Subject:
[FlyRotary] Re: Hey Neil,
Bobby,
Yes I have
the wide band 02, but when I
used the microtech which was the
reason I ditched it it was to me
impossible to tune properly.
Then Microtech refused to answer
phone calls or were gone to a
drag race somewhere--- all
queries were to be done by
internet. With microtech as I
said before the mixture knob did
nothing except occupy another
hole in the dash. EGTs in
excess of 1850 degrees were
easily reached.
Long story short I left
Microtech and bought the
fueltech. Much easier to tune
and actually have backup as
required. Did not add an EGT as
nothing seemed to change with
the microtech, so simply slept
better not knowing what the
EGT's actually were.
Can add EGT to the fueltech but
another $1000 AUD. May have to
go that way as intend to get to
8000 RPM if required
Today at low 30's degrees my
water was on the thermostat at
95 degrees C and oil around 90.
Saw your temps and had a heart
attack until I realised you are
farenheit.
What turbo do you run and have
you an intercooler?
Will get to check out the ag
turbos shortly as there are
hundreds of them around here.
Will get to weigh one shortly.
Neil.
Neil,
Do
you have a wideband O2? I
have to run in the low 11’s
at full power and under
boost for takeoff. 7000 rpm
/ 30-48” MP to keep egt’s
around 1600F. Typical cruise
between 4800 – 5200 rpm /
<30 “ MP with F/A 15.8:1
brings EGT’s into the
1500’s. With an intercooler
I would expect F/A in the
12’s will keep egt’s below
1600 but that’s just a
guess. I have seen EGT’s at
or below 1475F on cold days
at altitude. The only time I
run stoichiometric is in the
pattern and low MP.
Information
from Pro Formula Mazda
Engine
Vitals: Exhaust Gas
Temperatures Exhaust
Gas Temperatures (EGTs) are
the second most important
tuning and troubleshooting
channel next to Lambda. EGTs
reflect on the injector
balance between the front and
rear rotor Reflects misfires
through high readings
accompanied by normal lambda
Decline in engine performance
can be evidenced by the rate
of temperature acceleration
between the rotors during a
long pull – gapping Emphasis
needs put on the condition of
the EGTs – low reading sensors
are beginning to fail. In
order to have an accurate
assessment of the performance,
EGT sensors must be replaced
often. Generally, one EGT
sensor is used per rotor. One
sensor bung should be welded
on the each the outer exhaust
pipes 3” from the header
flange (the center pipe
usually does not receive a
sensor). The sensor depth
should be enough to where the
tip of the sensor is in the
centerline of the exhaust
flow. Operational Range:
Front Rotor: 1450F – 1600F,
Rear Rotor: 1400F – 1550F
Engine
Vitals: Lambda
Lambda
is the measure of the amount
of oxygen in the exhaust
stream. The value expressed is
a percentage of the
stoichiometric air/fuel ratio
14.7:1.
Air/fuel
ratio can be calculated by
multiplying the lambda value
monitored by data system by
14.7
(ex:
.90 Lambda translates as (.9 x
14.7 = )13.23 Air/fuel ratio
Operating
Range = .87 - .91, aim for
.90
Bobby
From:
Rotary motors in
aircraft [mailto:flyrotary@lancaironline.net]
Sent: Tuesday,
December 04, 2018 1:30
PM
To: Rotary motors
in aircraft
Subject:
[FlyRotary] Re: Hey
Neil,
Ok, interesting stuff, but
how do you keep the exhaust
temp below 1600 degrees
without losing a lot of
power? I no longer have an
EGT as it just worried me with
1800 degrees and the cost of
burnt off egt probes. From
memory 1600 degrees goes out
the window at about 6000 rpm
or less?
Neil.
Hi
Andrew, I know next to
nothing about turbo
technology so have stayed
clear of them; IIRC this
is the first time I’ve
heard of using a turbo
from the agricultural
industry and advice to
stay clear of the
automotive type ... seems
to make sense – tractors
use turbos that last for
decades.
Jeff
(13B, RD1-C, 144 hrs)
From:
Sent:
December-03-18 5:14 AM
Subject: Re:
[FlyRotary] Re: Hey
Neil,
Neil,
Type Turbo selection
Into search of
flyrotary archives,
you’ll get about 30
posts from 2002 to 13
that are worth reading,
other searches will give
more.
Basically
you want something the
size of a T04 60-1, keep
the A/R >1, something
like 1.15 or 1.30
T04’s
are plentiful from all the
older diesels like 2wd
tractors from last
century. you probably got
a few parked up around you
that will still be
servicable. If you can
find one without a
intercooler on it, chances
are that it might have the
right compressor.
Otherwise they are easy to
change.
Steer
clear of automotive
turbo’s, they will
overspeed at altitude
& disintegrate, need
waste gates & blow off
valves. Stuff thats not
required on an aeroplane.
When
installing. Put a normally
open solonoid valve in the
oil supply line. Allows
you to close the oil
supply if the turbo blows
its seal.
Always
bugged me why turbo shops
charge so much for such a
simple part.
--
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Regards
Andrew Martin Martin Ag
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