Mailing List flyrotary@lancaironline.net Message #64530
From: Neil Unger 12348ung@gmail.com <flyrotary@lancaironline.net>
Subject: Re: [FlyRotary] Re: Hey Neil,
Date: Fri, 14 Dec 2018 10:37:07 +1100
To: Rotary motors in aircraft <flyrotary@lancaironline.net>

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.

On 12/14/2018 10:21 AM, Todd Bartrim bartrim@gmail.com wrote:
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 

Todd Bartrim


On Thu, Dec 13, 2018 at 1:09 PM Neil Unger 12348ung@gmail.com <flyrotary@lancaironline.net> wrote:

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.

On 12/10/2018 8:48 PM, Andrew Martin andrew@martinag.com.au wrote:

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


On Mon, Dec 10, 2018 at 3:34 PM Neil Unger 12348ung@gmail.com <flyrotary@lancaironline.net> wrote:

Andrew,  Just what EGTs do you see at what revs?  Neil.

On 12/10/2018 10:03 AM, Andrew Martin andrew@martinag.com.au wrote:
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

On Mon, 10 Dec 2018 at 6:24 am, Charlie England ceengland7@gmail.com <flyrotary@lancaironline.net> wrote:
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

Virus-free. www.avast.com

On Sun, Dec 9, 2018 at 3:30 PM Neil Unger 12348ung@gmail.com <flyrotary@lancaironline.net> wrote:

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.

On 12/10/2018 8:08 AM, Bobby J. Hughes bhughes@qnsi.net wrote:

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.

On 12/5/2018 9:00 AM, Bobby J. Hughes bhughes@qnsi.net wrote:

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.

 

On 12/4/2018 2:30 AM, Jeff Whaley jwhaley@datacast.com wrote:

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.

 

Andrew

 

 



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