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RFguy

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Everything posted by RFguy

  1. RFguy

    Rotaxaru

    Hi Ken, I dunno where a 'sonex turbo' would go. I would use a Garret GBC 14-200. but, worthwhile consider is this : https://www.recreationalflying.com/topic/38647-the-ideal-modified-jab-engine/
  2. I have come to a conclusion that the best engine combo for J230, 160, 170 all of them....is : 2200 Gen3 upgraded engine with LCH ( liquid cooled heads) (series 2 rotec) the new high temperature fancy exhaust valves ($75 a pop) The marle forged pistons (need very slight overbore) and a turbo charger... maybe up to 38". ideally, an Airmaster IFA Prop. why ? 1) LCH provides the thermal margin for higher power operation 2) The turbo can work well with an 8:1 compression engine. gets you that extra 20-30h you always wanted , or needed when operating from Jindabyne in summer (DA 5k-6k) 3) The new valves can take the extra heat , espesh in conjunction with the LCH 4) Those pistons are a good upgrade and what do you have ? you have a 914 rotax equiv (80hp engine with turbo) ........ I am wholly convinced now that Jab engine troubles are mostly inappropriate/ unfamiliar /unsuitable mechanical staff operating on them, and in many cases, a lack of CHT/EGT on all cylinders, which thus operators, not faced with red flags on their panels, are oblivious to their inappropriate engine control styles. Yes, the factory are responsible for some clangers, like the flywheel. Jabiru would have saved alot of bad press on themselves by putting all cylinder EGT/CHT on all engines. Jabiru's secrecy and lack of communication has not done them any favours, either.
  3. Yes, there are many RAAUS aircraft that become E24 (experimental) when their rotaxes run out of time. Still requires an AP (authorized person) to do the paperwork. But no big deal.
  4. My fuel pump has 8mm barb on input, 6mm barb on output. Not being near the pump, does anyone know the thread in the fuel pump body ?
  5. Hi Nev. Thanks for the comment and info about what others have done. yeah dumping the flow directly out of the exhaust collector would seem to be to most simple option. IE open a flap with a cable. (and I think you meant to post in the Rotaxaru forum- you can post it there and that will get the knowledge into that forum topic)
  6. from all the crash picture I saw they look like big bore VW copies or aerovees.
  7. No, that's a specific manufacturers rule. If RAA brought that in I think we'd all get together and change the entire board of RAA in one go with an extraordinary general meeting.....
  8. RFguy

    Rotaxaru

    yeah only looking at a pressure ratio up to about 1.5. Which is laughable territory for enthusiasts. I've asked garrett if the wastegate can bypass enough flow to reduce the boost to almost zero at 5-8 lbs/min. (since we have to observe the maximum engine ratings at sea level) - other solution would be just to bleed or bypass the inlet compressed air... If the turbo isnt doing any work (except for flow losses) it wont chew much power but could overspeed I guess. anyway, plenty of options there., could dump air directly out of the exhaust collector so its just going out another pipe.
  9. RFguy

    Rotaxaru

    Hi Nev. fortunately the turbo will be away from EVERYTHING. seems that even the smallest garret is almost too big. But, the pressure ratio/ exhaust mass flow is inside the curve... too low though and it will take time to spool up. mind you that aint much of an issue, this is to get one's horsepower back to sea level at high DA. Ha. I can have an N2 turbine RPM indicator. There's quite a few turbos designed for 2-3L engines suitable. One must remmeber not to compare direct to vehicle use because the engine is running 100% WOT and th evehicle is not, so have to conservately rate the turbo. actually a Garret GBC14-200 or GT2052 at 40% rotor speed would fit spec well (I think) 6kg. Qu for the MFR is that will the internal wastegate dump enough to bring boost back to zero ? and need to do back pressure calcs for it
  10. RFguy

    Rotaxaru

    yes ultimately there will be fuel injection, electronics ignition etc.... its a while away. I'm just making sure I have room for various things. The turbo should be pretty easy. though the wastegate will need to be something a bit different. There's a waste gate built into most low end chargers I see just designed to limit boost, like 15psi.....call it the valve that stops overboosting. But in this case I want to hold a specific MAP, So I'll need to drive the wastegate (another waste gate? separately ) dunno, far in the future. maybe an actuator on the built in automatic wastegate. wonder if enough gas can be diverted to get zero boost. . I dont know too much about this stuff (yet). I only want a pressure ratio of around 1.25 to 1.3- right down the bottom LHS of most compressor maps. but I dont want a tiny turbo small small S/A running red hot. Many water+oil cooled bearing types. Hmm there are standard flanges. rightio.... Wow variable geometry turbos. golly. I'll certainly look for choosing a high turbine A/R . etc etc This is really small roots-blower supercharger territory, but its painful getting the engine direct coupling for it.... ANyway, no more talk abotu turbos right now ! 🙂 unless you have advice, turbo sizing suggestions. etc
  11. RFguy

    Rotaxaru

    yeah ...10.8:1 there is no headroom.. but it's to be a normalizing turbocharger- 100% wastegate until significant altitude... never more than 30" of MAP. Turbo will be stage 2..... but it will be designed with location etc in mind....
  12. RFguy

    Rotaxaru

    The exhaust ill be custom- that's just what I got. some weird phone camera image distortion in the side view The oil and water cooler will be underneath. The exhaust and turbocharger will be under and forward of the ring mount. That pipe is heavy. 30mm OD, 1.6mm wall. Wil use corrugated SS hose to connect collector, and maybe see how the collector goes paper thin. the turbocharger has to mount to something. The front cylinder cheeks will need to be made a bit wider in the case I reduce compression with cylinder shims.
  13. RFguy

    Rotaxaru

    progress. as known, engine is about 30mm further forward, and the front of the top and bottom cowling needs modifications. thrust line and centre is all good.
  14. I measured mine at 10 watts.... but, its designed to be a short range device, so no probs. I reckon there is enough rooom for a reduced bolt size 4 bolt SMA, if the flange is on the outside. I will get some tails made up. The 3/8" square flange (0.25" square holes), I reckon no issue with room... One man's micro surgery is another man's day to day.... While there are smaller connectors, It's probably the smallest and most reasonable connector to use.
  15. Only reasonable and reliable solution IMO is a soldered down RG178B or RG316 coax cable and 4 bolt mount SMA female on the case . -glen
  16. they are bastards to remove at the best of times. It's why we all have oil filter wrenches...... suggest painting it half black, half white, easy to see if it has moved. Doesnt hurt to put ur hand onto it with cowls off and check tightness.
  17. The hammering with Jabirus killing VDO sensors is due to the PRV (not the pump) is know to be bad, and there have been several PRV mods by users . here is the Jab oil pressure std PRV on a solid state sensor as required by Bob Panther. probably a bit off topic.
  18. suggest this sender- compatible with most EFIS , for fuel and oil). 100psi for Oil, 15 psi for fuel pressure. (Thanks MarkDun) https://www.ebay.com.au/itm/175192533261?mkcid=16&mkevt=1&mkrid=705-154756-20017-0&ssspo=_ZjsKGYLT-6&sssrc=2047675&ssuid=yHPQZk7zRBi&widget_ver=artemis&media=COPY many sites with the same things, some have full model stock, some not.
  19. The wings (90kg) were sitting in the rear third, and the fuselage was in the front third (200kg) . all the plane weight is on the mains. nose has to be pulled down without engine inplace. probably 100kg on the ball. Noone sat in the plane while it was in transit.
  20. robbenfred50 probably another scammer , most likely
  21. IMO, Aly is fine if you use gal (heavy zinc) fasteners, (avoid stainless) and if you really want to go to town, use Aluminium electrical jointing compound , which I think is some zinc based compound. If you must joint copper and ally etc or ally and something, use a nice fat gal washer between the metals.
  22. sounds like a scammer trying to get access to the membership base.
  23. Bathroom scales are fine, and often have more resolution (0.1kg instead of the 0.5kg resolution weighing setups I have come across) however I feel the calibration must be verified before use- at least two points (like near expected weights, and 50% of that) to determine absolute calibration and linearity . The levelling is doesnt have to be controversial. On the most recent system I looked at, the RAAUS scales, which I might add- the system is VERY NICE , nice it, have 0.5kg resolution, and given they'll likely round to nearest, is an uncertainty of 1kg.. So for 30kg on the nosewheel, that is a 3% uncertainty error..... This has to be understood. I determined that the error due to the remaining inclination (imperfect levelling) amounted to a bias of 0.3kg.... Bubble gauges do have mm versus degrees, you can look it up. Then it's a simple sine table lookup to calculate whether the error due to levelling is less than the intrinsic uncertainty of the weighing system.
  24. January I think . maybe December for the first versions of the enclosures.... the enclosure is the tricky bit to get right, that needs a bit of attention right now. Currently parts shortages mean the hard to get parts get used on (more) profitable products.... contact me directly...
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