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RFguy

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Everything posted by RFguy

  1. RFguy
    Brendan, probably worthwhile doing some reading up on doing minimum radius valley turns. It is something a slow machine does well, AND there are techniques you can use to tighten up the turn (advanced) . Good to read up on it all anyway, approach, in, and exit. Practice in free space up high.
  2. RFguy
    suggest Samsung Galaxy Tab 8 Wifi. I got it, pretty good. 64GB I think. dont need a huge amount of memory if oz runways even with everything downloaded is all mostly it will do (IE you are not goigun to fil it with photos)
  3. RFguy
    that's for sure, I have heard VFR pilots get into IMC around canberra on at least two occassions, and ATC vectors them out of the radio.
  4. RFguy
    Sean, just FYI...... There have been a few Jabiru 230's pump the engine bay with fuel following the float valve seat coming out when subject to huge vibration bumping when the carb was touching the firewall. In J230s , depending on the rubbers and length of the mount tubes, the carby can be millimeters or closer to the firewall, (some are closer than others) and contact can occur, and this is known to dislodge the float seat (pressed in) and the engine bay fills with fuel, as does the airbox wquite a mess and at least one fire and loss of aircraft Just FYI- may not be anything to do with your kit -Glen.
  5. RFguy
    yeah but the cylinders are not in water jackets
  6. RFguy
    I see with the rotax installs front cylinders can get blast cooled while rear get not much airflow . It's not quite all bad, since hotter cylinders transfer more heat into the water cooled heads. But there is plenty of thermal resistance- the aluminium alloys used for these applications have relatively low thermal conductivity compared to pure ally (which peolpe look at for reference but it's not applicable) . A duct really will make a large difference overall - IE ducted inlet over the cylinder bores- avoids flooding and pressurizing the cowling (no good for radiators that are also being vented into the cowling) . I'd also like to see some blast air cooling around the carb bowls since that sit above the exhuast headers (or some heat shields ) . Skippy - are you taking care of any overflow from the carbies in a good fashion ? floats since, or seats come out, carb floods, fire ensues.
  7. RFguy
    but a bypass thermostat I think is part of any solution. and perhaps cowl flaps etc of sorts (IE airflow control) .
  8. RFguy
    Rotax installs vary enormously. Much of the problem is too much pressure inside the cowls (leading to loss of differential pressure across the radiators) , due to excessively sized nostrils. The cylinder bores DO need airflow though. (see rotax install manual) , but it really needs to be ducted from a low drag inlet like a naca rather than huge ram air foreced airflow which abotu 5% makes it across the cylinder bores and 95% just pressurizes the cowling without use. Oil and cooling radiators ideally need to be ducted out of the cowling separately to the nostril / cowling instake... and forward facing ram air flow facing radiators is a must unless you want to get very fancy with sealing. forget 'low drag' naca ducts, they can't produce any pressure to drive through the coress. They are good for general cooling ducts though (like cylinder bores, cabin airflow etc) where backpressure is minimal.
  9. RFguy
    LOL this has got to be the widest thread drift ever
  10. RFguy
    2nd paragraph "The Cessna had departed from Dalby toward forecast en route weather unsuitable for visual flight, despite the pilot only being qualified for flight in visual conditions." I stopped reading there...
  11. RFguy
    Yes, the LS might be one option for an RV10 if you couldnt buy a '540 anywhere. An IO540 is going to make 300 hp. You'd want a 450cu + LS if you were going there. not a job for a 350.......and it still wouldnt be as reliable as a IO540. looking at prices... it would be only worthwhile if you got the vehicle engine cheap. A new io540 is abotu 60kUSD. you might be able to get one yuu can bulk strip for 10-15k and spend 20 on parts to get it back the air Certainly VH-experimental buys a bit of flexibility there.
  12. RFguy
    (nev beat mne to it) The problem with a rear counterweight is that the whole system now has a higher (rotational) moment of inertia. IE just because you balanced it on a set of scales doesnt mean you put it the way it was.. IE take longer to recover from a spin. You've given a rotating object more rotational inertia. This would be , IMO , a hazardous change for an aerobatic aircraft that (was) permitted to do spins. The moment of inertia is proportional to weight times the distance to the centre of mass squared. Because it is radius squared, two bodies opposing do not cancel out because the square of anything is a positive number
  13. RFguy
    I'm assuming it weighs the same as a Lycoming+ a CS. Otherwise all flying quality and test data etc etc are all invalid But, it's experimental- " it is what it is "
  14. RFguy
    what people ask for an airplane and what they actually get are of course two different things.
  15. RFguy
    IMO you want to keep the exit coolant temp at least 10% below the boiling point of the coolant at the operating pressure. Bubbling, gassing will upset the flow and lead to coolant being ejected into the expansion bottle (bad ish) . Vapour spots 'hot spots' have a higher potential heat removal capability than liquid water conduction regions, depending on flow.. It's hard to know how big the hotspots would be because they would vary with flow and viscosity which beleive it or not, varies quite a bit for common coolants. Remember , Ally Alloy has a fairly high thermal conductivity so hot spots are unlikely because they'll just conduct the heat to the cooler spot. **Plenty up for chance and speculation without accurate physical modelling !** so just keep the coolant 10-15 deg below the boiling pt I'd keep the temps below boiling pt for an atmospheric pressure of 50/50. IE below 106C. Anyway, I dont think you have coolant temp issues, you need to get the oil temp down. 80-90 deg C hottest.
  16. RFguy
    Sounds like you need to change the balance of oil cooler airflow and coolant airflow. Skip what size ID hoses did you end up running between tank and oil cooler and engine ? I'd keep the coolant below 110C, despite being an anti boil mix. rates of corrosion increase at higher temperatures. If you can measure coolant rise across the radiator or across the engine, that will give you lots of extra info.
  17. RFguy
    My Kluger.. on my OBD in hot summer, never seen the oil go higher than 90 deg C. and i have never seen my Lycoming above 85C, sits a round 80-82C But, yeah I agree 90C-110C is probably fine, my point is that you are leaving some cooling on the table - that oil cooling is the low hanging fruit to cool stuff in your engine.
  18. RFguy
    that's all crap about oil having to be 100deg C. water doesnt suddenly start vapourizing at 100C. rapid evap is well and truly underway at 80 deg C. It does take a little more to evap water out of suspension/solution but not that much. Atmo pressure also falls with altitude, makes evap water easier...
  19. RFguy
    Skip, in my opinion, that oil is still too hot. by about 10 deg C.... but, getting there. water temps seems OK, something is wrong with your oil cooling... or biased too much one way., IMO.
  20. RFguy
    this is the easiest https://www.flightstore.com.au/aviation-headsets/plugs-jacks or, buy from clearprop, ozpilot, or mobileone .. I get mine from Mouser but you need to know all the cryptic Switchcraft numbers.
  21. RFguy
    BTW yesterday I installed a FUNKE ZATR833S in a friend's aircraft. It is superb ! easy to setup, everything is controllable, adjustable from the panel, wiring it is highly adaptable, real nice kit . good ext audio input options, adjustable sidetone level s indpenendent of mic gains etc dont forget to set it to 25k channel spacing once installed. sounds good on air, also. https://www.ozpilot.com.au/product/funke-zatr833s-vhf-transceiver/?utm_source=Google Shopping&utm_medium=cpc&utm_campaign=Ozpilot Products&gclid=CjwKCAiA1fqrBhA1EiwAMU5m_0bZoX14nmGoZrjP0sMxGlTzcim12-uPIdLPcLhAhz692YI7X07znhoCq1MQAvD_BwE
  22. RFguy
    I have already made my conclusion. And it is harsh ! Pilot became unconscious. Passengers were not sufficiently briefed on activating the CAPS system (shutdown engine, activate CAPS). Should have been with so many souls on board. It is a terrible ending to a what should have been survivable situation. Pilot only accumulated 800 hours in 38 years which for me is a question mark. For whatever reason he failed to provide duty of care to that family through his own errors.
  23. RFguy
    This concept is covered regularly in science fiction.
  24. RFguy
    mmm a couple of things 1) on points of fault / incident reporting. seems the biggest reason for not getting fault/ error reporting is people thinking someone will get in trouble or it will adversely affect them for whatever reason. Need to figure out a way to change that mindset to the right sort of no blame/ no fault. Of course- no blame no fault cant be unbounded - so that's the sticky bit. I've heard of two Jabiru oil filters splitting, (could be the high pulsing PRV or could be mfr defect or steel too light or ????? ----but they have not heard of this- this is an example of owner/operator reporting defficiencies. 2) With regards to the meat of the discussion, my concerns with a certain manufacturer's behaviour - there has been an ownership change , and broadly issues I have raised as a company culture problem will get addressed, but it wont be overnight. -glen
  25. RFguy
    back on topic. skippy please dont bring yout sonex and soneri talk into the Van's forum. We're tired of it. Van's will be fine, YES VERY TRUE - they make a NICHE and HIGHLY SOUGHT AFTER product- which is a good commercial recipe to be able to put your prices up (as necessary) . I doubt a 30% extra cost of kit would change anyone's buying habits...
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