skippydiesel

2 hours ago, Thruster88 said:

What did you get skip, is it a Sonex???????

Yes. In the words of my consulting engineer "95% complete, 30% to go"

I know you ae all enjoying this BUT what has his occupation got to do with anything in this matter? Further he has not been convicted of the possible crime. Possible because no bodied have been found or evince of an actual crime other than a burnt camp site. Could have been a murder suicide/suicide pact or as you are all alluding, third part involvement. My guess  - no aviation connection here.

On 21/11/2021 at 7:59 PM, jackc said:

I do have a 68 litre tank as it is, maybe I will add a 20l Turtlepac for added range, strap it in the Pax seat?

 

Turtle - Pac are pretty pricy . The 20 L is a collapsible "jerry can" - go the 40 L and you get the full in flight transfer capability.

Chip?

What ?? no one has engaged the services of a custom upholsterer to fit out their aircraft ???????.

8 hours ago, IBob said:

It's surprising (to me) how many elect to change the 912 oil at 50hrs.

I assume that Rotax built in some margin when nominating the 100hr change.

 

This isn't intended as a criticism.......clearly it is for every operator to decide what suits them....but I am just curious.

Agreed 110% however Rotax/Shell forgot to accommodate the emotional needs of the anally retentive. I do 50 hr oil changes (nothing else) to satisfy the itch. All other items are serviced according to the Rotax recommendations at 100 hrs

No matter the oil used (within reason) the engine is very very unlikely to stop (in flight failure) due to the oil used. 

The quality/formulation of the oil impacts on engine longevity ie use the wrong oil and the expected operational life of the engine is likely to be reduced - this may counteract the short term financial savings referred to by Wee wee.

Shell Sport Plus 4 is expensive but a 912 uses only three litres per oil change, every 100 hrs (if using ULP) - personally I like to change the oil every 50 hrs but that is to satisfy my own emotional need.

Hi all -I am located near Camden NSW -  anyone care to recommend the services of a custom upholstery service provider in the greater Sydney area,  including The Gong, Southern Highlands ?  

34 minutes ago, kasper said:

Agree with 3000rpm as my ignition check setting ... can't do 4000 as that's enough to take off and on wet grass all braked wheels will skid at that much power 😀

Well expect to have inconsistent/less significant, ignition rpm drops

21 hours ago, Rodr said:

Who can I call in regards to ign problems with a 912uls  ie large rev drop on mag under 3000rpm but all ok on higher revs 

what to look for??

thanks

As per JG3 - I do my Rotax 912 RPM checks at or above 4000 rpm

I like the idea of IBob's 5 way splitter.

Just a thought; you can create the return line & fuel pressure manifolds by using brass T fittings - just solder up one outlet and then using a 1mm drill bit,  drill out a small exit hole. Could probably do the same with "plastic" T piece, substituting the solder with one of the fuel resistant epoxy resins.

Hi Marty_d, 

My Rotax installation uses T pieces/connectors to achieve the 5 way split you are referring to.

Hose clamps: I am a strong believer in using fuel injectors style clamps. There are 2-3 designs but all have common features;  360 degree pressure (no pinching) ; smooth edges (sharp edges can cause damage) ; can be reused indefinitely (if not overtightened. ; redilly available from the better automotive stores (eg Repco - purchase by the box, way cheaper).

No experience with fuel taps in aircraft, however there is a good selection available for mower/stationary engine applications in "plastic" & metal.

Hope I have been of assistance.

It seems to me that using "off the shelf" fasteners in non structural applications can have little, if any, additional risk. A smidgeon of common sense will guide most people in this sot of scenario. I agree with Bruce on this.

14 minutes ago, onetrack said:

One must always keep in mind that when using automotive fuels from servos, the older underground tanks are steel, coated with bitumen. After 20 years, the high levels of moisture in the soil, that is carrying either acidic or alkaline components in solution, gets under the bitumen and corrodes the steel. This then develops into pinholes in the steel tanks, which allows entry of dirty, rusty water, which settles on the bottom of the tank.

 

Even though the suction spears for the bowser pumps are placed a distance from the bottom of the tank, swirling fuel from recent underground tank fills, makes the dirty rusty water move within reach of the suction lines for the bowser pumps, thus pumping up the rusty dirty water with the fuel. The filters on the bowsers are only mesh screens (about 20 or 30 micron from memory), they do not have elements than can stop water.

 

Many older servos also have fill points for underground tanks that are poorly positioned and poorly designed, and which can allow floodwaters to enter tanks.

 

So the chances of acquiring petrol contaminated with dirty rusty water, particularly from older servos, are reasonably high. Cars and trucks have better fuel filtering than bowser pumps, so they stop a lot of this crap from reaching your car or truck engines critical fuel components.

 

Newer servos utilise fibreglass tanks, and are better designed, so the chances of corrosion and contamination are greatly reduced. Most servos have fuel leak tracing spears sited in the ground around the tanks. but these are designed to catch fuel leaks into groundwater aquifers, and they're behind the curve when it comes to fuel contamination, as they only catch holes in tanks when there's a serious outflow of fuel from the tank into the soil.

 

There's a reason why avgas is delivered in sealed containers with strict traceability. Automotive fuels have multiple points of entry for contamination and adulteration. More than one dodgy servo owner/operator has been done for fuel adulteration, adding a number of cheap, readily available, discarded industrial chemicals, ranging from products such as toluene, discarded parts cleaning fluids, to paint thinners. 

 

If you must buy petrol for your aircraft from servos, buying from the newest servos is critical, buying from large company-owned servos means less chance of servo owner fuel adulteration - but you still must be aware that fuel companies can add ethanol in any percentage up to 10% in 91 RON automotive fuel, without advising users.

 

https://www.fcai.com.au/environment/can-my-vehicle-operate-on-ethanol-blend-petrol

With reference to your Ethanol comment: Unlikely from major distributers. Why ? because they advertise E10/(10%) as a distinct product, separate from their non ethanol blended petrol. Why would they jeopardise their customer trust when there are other competing brands only to happy to take disgruntled ex customers.

Adulteration stories have been around for just about ever - rarely is their proof that the bigger more reputable companies do any such thing. Smaller "independents" well that's something else.

At the end of the debate, it is still Rotax recommendation that ULP/MoGas/Unledade is the preferred fuel.

5 minutes ago, Yenn said:

i recently tried BP super or whatever it is called in my Jab 2200. I didn't fly for a couple of weeks and had terrible trouble starting it. It would not run properly and no matter what I tried, the only way to get that motor going was to revert back to Avgas. NO more mogas for me.

Yenn -to have your start problem,  there must be something else going on - its not the unladed fuel (unless you got a bad drop), 

1 hour ago, Cosmick said:

So out there you have the Skippys and the Turbs, KGs Nevs and Wals (sorry to take liberties) and others who will investigate the intricacies of fuels and then there is the rest of us who ask advice and get good feedback and some individual biases. Personally I use 95 like an Insurance cover that I know nothing bad should come of that fuel and I store in airtight metal containers (good condition jerry). Reading the above feedback does give us (me) the uneducated some satisfaction of good practice.

 

I think this guy is funny, sometimes too much and I tire of him but this Vid seems to cover technically.

https://www.youtube.com/watch?v=3Sl5KqF4AM8

Your man (video) explains the fuel rating scale very well.

16 minutes ago, facthunter said:

....................Start Ya Bastard has ether in it but I would not use that on an aero engine.but it starts my Dexta at 1500 ft on a frosty morning in about one turn of the crank Saves batteries and starter motors. Nev

Nev ! Nev ! As a confirmed diesel freak (your Dexta is a diesel ?), for at least the last 50 years, this (Start Ya bastard) is a blasphemes suggestion. I would only resort to such a perverse action/substance in a dire emergency such that I cant even conceive of (I have never owned a can of SYB). Does your Dexta not have cold start system/mechanism? 

Cosmick; The Rotax 9 (912/80 hp 912/100 hp & 914/115 hp) range of engines preferer to run on unleaded(ULP/MoGas)  fuel of 95-98 RON (Australian). 

They can run on AvGas (leaded aviation fuel) however you will have to halve the recommended oil change interval, from 100 hrs to 50 hrs and there is a gear box strip/clean/inspect required at (from bad memory) 900 hrs. The two requirements are  both related to lead fowling of the inside of the engine/gear box.

There is no performance benefit in using higher than 95 RON below 10,000ft AMSL.

Higher octane fuels (RON) do little if anything for engines not optimised to use them. I see a lot of people pulling up at the 98 RON bowser in vehicles that will run perfectly well on 91-95 RON. Use the fuel your vehicle/engine is designed to run on.

Facthunter/Nev's comments regarding quality control/assurance, AvGas V ULP, re absolutely correct . However I, along with most Rotax 9 drivers have never had a a problem with ULP. This may be due to following some simple common-sense rules when purchasing fuel:

• Use dedicated ( for your aircraft only) fuel containers - they must have air tight lids and preferably no tendency to internally rust or shed lining /paint.
• Purchase from name brand, high turn over servo,s - this minimises the chances of the fuel becoming adulterated and becoming "stale"
• Do not store fuel for more than 6 months and then only in a genuinely air tight container that is 75% or better, full of fuel (best to use fuel as soon as practical after purchase).
• I always refuel with a filter funnel - You can purchase a Mr Funnel - I dont much like them but they do work. I made my own for a fraction of the cost and it fits my vertical fuel filler point.
• Personally I prefer to purchase 98 RON on the basis that if there has been some adulteration/shandying, the actual RON is most likely to be 95 or better. This may be a bit of wishful thinking. There is a slight down side ;98 RON does not seem to have the shelf life of 95 but if stored as I have outlined you should not have a problem (Note: an aircraft fuel tank is not airtight so fueling just befor flight is a good practise - seems a good dollop of fresh 98, pretty much restores the in tank fuel to near 98 standards).

In 10 years I have never had a contamination (water/dirt)  problem with ULP - Years ago,  did fuel up with 95 from a no name brand establishment (only fuel place in town), engine definitely down on power, drained remaining fuel when I got home - smelt awful !!. refuelled with fresh and my engine delivered all that I expected.

Turbs - I was specifically addressing engine cold start & run - I agree with your tangential statements.

Sounds/reads like its a top notch treatment.

My aircraft has been treated using Desoto 51x319 on external surfaces and Alodine BMS 10-11 internal. Finish coat , yet to be decided, but probably Glasurit 68

BUT

Composite bits are as supplied by Sonex (untreated) - should I do a UV resistant undercoat befor applying finish coat?

Kg - so no specially "treatment" for glass/composited bits. Was this an oversight or intentional?

On 28/05/2021 at 4:50 PM, Bruce Tuncks said:

Yesterday I tried, from a cold start, opening the throttle a few seconds after the engine started with choke, and sure enough it stopped. 

In nearly 20 years of avgas, I had fallen into the habit of opening the throttle early on to get the revs over 1000 when the engine runs much smoother than with the 600 rpm idle I have it set to. Not once did it cause the engine to stop, so this is the only difference between mogas and avgas I have noticed so far.

The slow idle is in order to shorten the ground run after landing, and yes it is marginal. But on a warmed up engine, there is no more tendancy for stoppage than before the change to mogas.

So thanks again guys for the help.

All engines should be warmed prior to loading (flying/driving/mowing the lawn/ plowing the paddock/ etc)

Petrol, in particular, need to be warmed before a smooth running/power delivery can be expected.

Recent computer management/fuel injected systems may not appear to need the warm up period but I suggest this is the computer masking the symptoms of a cold stat rather than actually preventing them.

Two strokes seem to get over the warm up chugs quicker than 4/

Diesel engines appear to not have the problem at all however good engine management still calls for a warm period.

So the type of fuel (even the grade/RON of petrol) may impact on the time taken to warm up - should not be an issue for any pilot, unless expecting to conduct an emergency take off due to attacking enemy🤣

Great job JG3.

I have an addendum to my original question; I want to paint an all metal aircraft (no real problems here) however it is fitted with a number of composite bits (cowling/tail & stabiliser/tail ends, wheel fairings). Would the "brains trust undercoat these, UV susceptible, parts with a UV resistant undercoat? If so what brand would you suggest?

58 minutes ago, turboplanner said:

" You can make a major safety improvement by not developing the habits. In this case you could make a major improvement to your future by not going anywhere near Katoomba.

 

 

 Its like this Turbs; The only way out of the Sydney Basin, that does not involve flying over very rugged/extensive urban development, is south, towards you. So no matter what aircraft you fly, getting out of the Basin, N, & W is going to involve additional risk. The challenge is to mitigate that risk (its unavoidable). For all my west & north west trips, exiting as high as I can go, CTA steps permitting, via Katoomba (the only potential emergency landing area actually in the mountains) is my usual plan.

59 minutes ago, JG3 said:

Just finished some painting with Protek Polyurethane 4:1.

Excellent results and easy to spray, good finish.

Costs $160 - $200 for 5 litre kit of paint and hardener depending upon colour.

Great! At last someone responds with real/recent experience. Thank JG3.

Any chance of some photos?

Why did you choose this particular paint? 

What are you painting on to metal/composite/fabric/wood ?

If composite bits - did you use UV resistant undercoat ?

Oh! & I could do with some idea of your your methodology: ie spray gun type & nozzle, pressure settings, number of coats, temperature, mix by weight or volume, etc