skippydiesel

1 hour ago, IBob said:

You said the problem 'followed the EGT' when you moved the probe. Did you mean the problem remained at the same pipe.....or it moved when you moved the probe?

 

Moved with the probe/thermocouple

Some thoughts:
1.The EGT probes are a standard K type thermocouple, two dissimilar metals welded together at the tip, produce a small voltage when heated. So not hard to check with a multimeter set to mV. There will be lookup tables for temp vs voltage.

2. It is my understanding that those same metals must be must be used all the way back to the Dynon. Red and yellow I think they are. Asking the stupid question: you don't have a join where the red/yellow have been crossed up?

 

No system worked as expected, until I refitted the modified exhaust pipe. Blamed the pipe initially but found problem moved with probe - so not the pipe.

3. The exhaust gases will not pass down the pipe in a uniform manner, especially close to the heads. Are the probes installed as recommended, and fully into the pipe? Could there a be leak there resulting in a hot spot?

 

Probes installed as per Rorax manual (both exactly same distance from flange). How would a leak result in a hot spot?
 

4. If all that checks out, it does seem likely that it is associated with the remodelled pipe and/or anything that was disturbed at that time.

 

Problem moved from left to right when I swapped probes so unlikly to be exhaust pipe

Food for thought from correspondent in Rotax Owner Forum:

If we assume your probes are OK, and the high EGT is actually occurring, then the conditions you describe make perfect sense.  EGT represents a measure of energy wasted through the exhaust, and CHT represents energy used within the engine to produce thrust.  When you quickly reduce the prop pitch, this unloads the engine and you would expect to see an increase in EGT and decrease in CHT.  Once you increase RPM to fully load the engine at the reduced prop setting, the energy is once again directed to thrust, and EGT would decrease while CHT increases.  Think of it this way, the combustion heat has to go one place or another.  Unload the engine and the heat goes out the exhaust, load the engine and it goes into the heads and out to the radiator.  

Because we don’t have control of mixture, we tend not to think about these principles as much.  With conventional aircraft that have mixture control you see these effects more clearly.  It’s a common mistake for a pilot to unload the engine to attempt to reduce EGT, only to experience the opposite effect.

My response:

Thanks for that excellent reasoning .

There is one problem - the high readings followed the swapping of the probe from left to right.

Following your logic the low reading (assumed to be correct) probe must be the faulty one ??????

1 hour ago, Deano747 said:

Works a treat for marine pilot boats that see some pretty heavy seas.

Looked a bit further - Have written to company regarding difference between Industrial 114mm V  regular 114 mm Both $ 84.

Note: Another RAM ball will be needed to use with existing set up + $18-$30

Assume delivery + $10-$15

Total cost around $112-$129. Getting a bit steep for a suction mount . Have to think about it😈

25 minutes ago, BrendAn said:

pretty sure there are already magnetic fields in your cockpit.

Yeah! but already accounted /accommodated for within systems - probably OK to fit another but taking a chance never the less.

16 minutes ago, sfGnome said:

If the problem followed the probe swap, then it shouldn’t be related to the exhaust remodelling. Is it fair to assume that when you swapped the probes, you didn’t swap the wiring at the same time? That precludes noise spikes being picked up by the wires as they didn’t change while the reading did. Hmmm… I join you in your confusion. Correct
 

Out of interest, are the probes simple thermocouples that require correct thermocouple wire all the way back to the meter, or do they have inbuilt electronics so they can just be connected with ordinary wire? The probes & wiring has been  supplied by Dynon (compatible with their Dynon Skyview)

3 hours ago, BurnieM said:

Temperature cycling of the surface it is stuck to causes this. It will fall off more quickly in summer.

 

Take it off each time and replace it before flight. Naah! I set it up in just the right position to see and adjust the Garmin - take way too long to do before each flight.

 

Wet the cup with a small amount of water/saliva as well. Yes I do this - prefere water to saliva, which tends to leave a mark

 

A suction cup is not designed to be used as a permanent mount. Can't be true 😁

 

Putting it on and expecting it to still be there when you return in a week is possible but outside its design parameters. Lasts a lot longer than a week. Haven't actually taken ,note,  I recon 1-2 months is possible

 

I used to sell RAM mounts. Inside information Burnie????😈

 

Inside information Burnie

11 hours ago, BrendAn said:

velcro ?.    in the truck i use the magnetic phone mounts with success.

Yeah! I use Velcro elsewhere - The RAMS good it's just so unpredictable in its "release" timing.

Not sure about magnets in the cockpit - probably old school but I would be concerned about having a magnetic field anywhere near navigation systems.

13 hours ago, Deano747 said:

https://www.seasucker.com.au/114-mm-seasucker-black-vacuum-mount/

 

Little vacuum pump so you can see when suction is being lost.

Cost as much as the RAM mount but neat idea (if it actually works). 

14 hours ago, Red said:

Yep, The roads or rather the car drivers are terrible these days I'm probably quite capable of killing myself without everyone else trying to do it for me, I find young Ladies particularly dangerous..they simply dont seem to care all safe in their shiny metal boxes.

Agreed standard is extraordinarily poor. As for "0" road deaths its easier to spend tax payers $$$$$ on stupid /meaningless adverts than do anything practical about the appalling driving standards.

14 hours ago, Red said:

tbh the Instructors seem really poor quality these days too, I had one tell me you don't need to indicate if there is nobody in the vicnity...wtf?? how about the guy you didnt see and just pulled out in front of?..idiot

My guess - driving examiners are held to a certain code/standard dictated by the State - no room for discretion - they most likly know that they are passing incompetent drivers.

On my way home this morning with horse float full of hay,e up  climbing a long straight hill,, speed down to 80 kph - came up behind a Range Rover, behind a truck (70kph) - moved into right lane to pass as I derw abeam the RR it suddenly decided to pass truck - jammed on brakes, hit horn, RR kept coming - RR continued up hill at 70-75 kph - I recovered to catch him again on level ground - continued at 75-80 kph in 100 kph zone, no further passing opportunities for next 20 k. To say this drivers is an ignorant illegitimate would be an understatement.

I have two EGT probes on my Rotax 912ULS (just went 90 hrs) read by a Dynon Skyview.

About 10 hrs ago, one of them started to peak at over temp. This coincide with a remodeling of the exhaust pipe that the probe is in. 

Checked and double checked everything, including carby balance - no apparent cause.

Swapped EGT probe from left to right exhaust - problem followed EGT - problem must be defective EGT (In my limited experince defective EGT's under read or fail).

Replaced probe (today) with new Dynon supplied part. Most of the time the EGT's read one a little higher than other, Unfortunatly still have problem.

Took note of when it overreads - Happens when Airmaster CS, switched from Cruise to Climb  and rpm reduced for a gradual descent (wiered) EGT went into the red (again). Increase rpm -  EGT temp drops. Reduce rpm further, to say 3500. EGT drops

Any suggestions???

I have a RAM mount for my Garmin handheld GPS.

The mount is great except for one small problem: The suction part seems to stick very well and for several weeks at a time (think this varies a little with ambient temperatures).

There is no indication of when the suction is about to fail. Secure one moment in your lap the next - can be a bit disconcerting, if happens at a high concentration section of the flight (on final).

Anyone got any Tried -& -True suggestion for longer stick? (please don't say make it a permeants mount) 

"Well, you can discuss all you like. CASA have decided what’s the correct procedure. Less calls. "

Yes and I do way less calls, compared with how I was trained in the late 1989 -90s.

While a pilot can make too many calls, this is preferable to insufficient/calls. Aside from the 10 mile Inbound, the calls are at the discretion of the PIC, who I would hope, has the courtesy and safety awareness to do at least 3 calls - just in case.

Yeah! the 50 kph rule on main arteries is crazy. If absolutely indicated, it should be just on the stretch (centre of town) where risk highest.

1 hour ago, Blueadventures said:

Skippy you are making at least two unnecessary calls once you have joined the circuit, which clutters the air waves and therefore you could miss and hinder another call or priority call that you may need to hear.

How is - Overhead, Joining, Base -  to many calls??? The rest, that I mentioned, are optional( thats why they are in brackets)- depending on conditions (traffic/confusion).

I said minimum three calls for TO/Landing. There is no possible way that this "clutters" the airwaves. Bear in mind that my calls are spaced by many minutes of silence. My communication model is as for a controlled airfield - I don't employ all the (many) calls, just what I feel will keep me and any other aircraft safe.

How is another aircraft supposed to know, where you are (location) and what your intentions may be, if a few calls are not made??? None & one is clearly insufficient.

As always - Go with the engine makers advice/recommendation ( 80-90 C still seems very low to me)

"i did say before my engine is clean. "

I agree that if the drain oil is "clean" it is likly that the engine internals are also clean. Having spent a good portion of my life servicing diesels, I doubt that the look of the oil is an absolute guarantee of the internal condition.  

12 minutes ago, Blueadventures said:

He said all fastenings and parts were marked for where they went so I assume that was how it was.  The labelling would have been great for him.  (I was brought up and still label parts and fastenings for future reference) He corrected the matter immediately before its first flight so nuts comply with rules for thread protrusion.  They are not bolts through the engine frame as I checked there and longer bolts would have been good to fit; but the thread is part of the frame so cannot be changed without welding new thread pieces.  All good now.

Yes its  threaded rod on the engine frame bolts is just an easier description.

There were labeled packets of parts, not individual fitting instructions.

The engine frame was mounted - ready for repair - on a heavy plywood "jig" that I made up. No clear recollection but likly did not use the same washers/nuts on the jig, as when mounted in aircraft - this may be where the confusion arises (use of automotive suspension washers???)

"Making all 3 calls can jam up the radio. Especially when it’s busy. I believe the original CASA change was brought about by one or more incidents where less calls would have reduced the risk of collision."

No offence Mike  - the above is bovine excrement. Look at the calls that I make - by doing these, any non transmitting aircraft will hear me and know my location & intention. My calls enhance safety. There is a world of difference between making a small number of courtesy/just in case there is someone out there, calls and blocking the airwaves with unnecessary verbiage.

"Another thing that particular  instructor brought up yesterday was aircraft naming and it really doesn’t need to be in every call..... "

Personally, I hear/register the type of aircraft far more readily than the registration - Rylstone Traffic Cessna KZS joining X wind for Runway XXX  - Cessna is what makes an impression on me - if needed, I can call back immediately Cessna Rylstone..... and make the connection . Of course if here are multiple Cessnas in/entering the circuit, I have to step up to the mark and use the rego (KZS) to differentiate.

Being able to identify the more common aircraft aids in location eg  calling you will be number two to an RV, places you in the circuit que for all other circuit aircraft. 

"......It’s for situational awareness of performance. We know a 172, warrior etc will be around 100kn downwind. We hope an RV has slowed to a reasonable circuit speed from their 160-180kn descending approach. We will notice  a warbird calling because it’s likely to be fast and wide. We got that on their first call."

Since when is a pilot supposed to have an understanding of other aircrafts performance characteristics?  How does this assist safety? It's the flying pilots job, to fly the circuit suitable to his/her aircraft.

90 C might just be okay in crusie  - better 95C ++ . Still need to get that elevated temperature, preferably above 100C , usually in Climb Out, to get rid of as much of the volatile fractions as possible.

I have seen the inside of car & stationary engines, which for some reason or other, rarely achieved a sustained temperature, during their service life. GUNK!  Back in the days, before high detergent oils, this was common. Pre drain flushing oil/chemicals were often used to try and rid the engines of GUNK

25 minutes ago, Red said:

90C is a good operating temp for a Jab on an XAir, the engine is exposed and the sensor will be under reading actual temperature

Not if you get calf scour (water/oil emulsions) coming out of the crankcase breather. Something needs to be done to raise the oil temp. It's quite likly that the inside of that engine is coated in a thick film of "gunk" - Leave it long enough and it will reduce the flow of oil through distribution galleries.

27 minutes ago, Neil_S said:

Hi Skippy,

 

Easier to see. The fuel can dry very quickly and it's sometimes hard to see exactly where it was on the stick. Keeping a finger on the end of the tube until read is just more precise.

 

Cheers,

Neil

That would work (stick has the level marks) but seems a tad over complicated, simplified if marks can be transferred to tube (no stick needed)

Rotax recomend oil temps reach above 100C  for a sustained period, specifically to drive of water & other volatile contaminants. I aim for mid to high 90C in Cruise and hope to see over 100C during climb out.

90C is far to low.

On 21/05/2024 at 1:56 PM, Neil_S said:

Hi IBob,

 

I have some narrow plastic tubing I bought from an aquarium shop  - I was thinking just use zipties to attach a length to my wooden dipstick.

 

Cheers,

Neil

Would the wooden dipstick  have the levels - if so why both a stick & tube??

The hollow plastic tube type: I have one of these (never used)

How can it give an accurate measure/level in any tank that is not perfectly linear (is that the right descriptor?)

The best it can do is;

Full - you would see that without a stick & hopefully know the capacity of the tank

Between Full & Empty - this would be guess work.

I make a minimum of three calls.

If there does not seem to be any other aircraft (no transmissions) in or approaching the circuit, it's just the three.

If I am aware of other aircraft, I will make calls according to circumstance - I don't have a rule beyond the minimum. When there are many aircraft I may make additional calls, to ensure other pilots have "found"  my aircraft.

Joining the Circuit; Overhead The Field /thousand ft descending on the Dead Side, Joining X wind for runway??,  (Established Downwind Runway?? T&G number two to Foxbat????), Turning or Established On Base for Runway ?? T&G). ( Optional). I would only call on Final if I felt there was a point in doing so eg an aircraft /vehicle on the runway.

Departing; Taxi for ?? Runup Bay (Backtracking Runway??) Entering & Lining up Runway?? One POB, Departing Upwind for airwork to north of field. , Rolling (Additional calls  on Climb Out if circuit bussy) 

17 minutes ago, turboplanner said:

From memory, horse riding has more injuries than flying.

 

I think you're probably correct.

It's interesting, at least to me, how biased statistics (in this case recreation, death & age) can be used to sway/influence people.

The statistics may be correct but that they reflect a very limited/biased view of the dangers inherent in activities in question.

In this case using the fear that we all have of untimely death, would lead people to believe that certain activates are so dangerous that they should be avoided.

I suspect that if the risk of  injury (resulting in a visit to an emergency department) was the criteria being studied, flying a small aircraft would likly be very low on the scale, horse riding (I have been a rider all my life) on the other hand likly to be high on the scale.

24 minutes ago, spacesailor said:

There is one overlooked " grease " , by the name of Lanolin.  

It is the oil from sheep's ( wool ) hair .

I have used it on rubber & it hasn't damaged it , after five years . It still has a little

Shine left .

Not ' animal ' fat , as it is only in the fleece. 

spacesailor

Yeah! I have only occasionally used it (Lanox) but like the idea that its of organic origin and is therefore likly to have very low toxicity (if any) is appealing. I would steer away from the pressurised spray cans and go with the liquid applicators (less likly to be thinned with hydrocarbon)