jetboy

and all the while I thought it was the owners / maintainers fault when a valve drops or a piston breaks Jabiru still holding the line that the circlips are all perfect just someone doesnt install them proper. http://www.jabiru.net.au/images/Piston_Circlips_Iss2.pdf I suppose they expected those re-machined pistons to take the original sized circlips too? I like the move to the valve clearance recess in the pistons but really wonder if thats not going to lead to another issue later on. Will it alter the dynamic balance of the piston, and will it cause hot spots / preignition and is there any issue with weakness to the ring grooves or crown because of this machining? At 475 hours I'm nearing the time for a new set of rings and these discussions reveal many factors which are not published where they would be helpful to maintainers. I dont mind if the airframes are molded in SA and painted in Oz or the pistons come from China so long as this is not misrepresented (like the website probably still says Repco pistons) and the serial number change is stated so if an issue arises it has traceability

https://www.aircraftspruce.com/catalog/topages/diffpress12mm.php

just make sure its the model for small bore engines, there is a different sizing for P&W radials etc. I got the ACS one, brazed a fitting for the small plug

When I needed to choose for my 701 (max 80kg installed / 100 hp) the Diamond AE110R was my first choice. http://en.wikipedia.org/wiki/MidWest_AE_series This was to be a development of the Midwest Rotary which started as a BSA/Norton engine, but Diamond (Austro) nowdays only do the singe rotor versions - and they dont do that well if the SBs are anything to go by. I was also considering a single rotor "derivative of Mazda" NZ design based on the Kahu Gyro project - which was to be produced in China but had to be shelved. The idea of a single rotor does not appeal due to a single apex seal problem taking out 2/3 of the engine compared to 1/3 for a 2 rotor design - although a single rotor is likely easier to cool as both sides are available. Part of the appeal was the possibility of running on kerosene fuel although this doesnt appear to be successful for the Midwest. My wishlist included the smoothness of 120` firing (like a 3 cyl 2-stroke) and AVgas / Jet-A fuel in addition to the usual power/weight/reliability/cost factors. From then (2003) to now the scene has changed little, the compromise I made was a J2200 which has done OK in my application, however it may need replacement and I'd like to meet some of the original goals Wam 120, Diesel Air, D-motor and others like the Evinrude rotary have appeared briefly but not become available Bex's project has some interesting aspects, hope it progresses as planned. Nice to see someone actually doing it.

The ACS switch comes with instructions for starting with only one active mag, which is the usual configuration on lycoming engines. If I remenber correctly there is a link wire to connect to another terminal - so it earths out the unwanted mag when the key is turned to "start"

I have a couple of questions for the panel.... When I looked up the Jabiru engine TCDS it has been issued once and updated once, for the change to hydraulic lifters. This would seem to mean one can do a huge amount of modification without requiring any formal testing or paperwork or proof of continued product serviceability in compliance with its TC. Is maintaining a TC that simple? is the TC really still valid? The manufacturer claims they are ISO (I'm presuming here that the international certification he refers is ISO) - so there must be a traceable paper trail for all this within the company and all their suppliers would have to be ISO certified as well. I'd like to see the paperwork for the Chinese valves they supplied me which wouldnt fit their holes. Which leads me to question 2. There has been lots of rumour about where the engines are made nowdays and where the parts come from. Is the engine still assembled in Aus? There was a story about cast alloy cylinders being developed too.

At 2600 the carb would be delivering the leanest mixture. Simple diagnostic test is to operate carb heat to see if that helps by richening the mixture. Pulling the choke has the opposite effect, after a brief period of adding fuel it adds some air, leaning the mix. If any of this makes a difference, there is the mixture distribution ratio to individual cylinders, which may need trimming by rotating the carb, putting in a flow straightener - or finding an intake runner leak. The symptoms described seem more likely ignition related

and the 2 Tons of handheld radios of which about 400kg would be the LiPo batteries.....move along sir nothing to see here....

I have the medium size - probably F3. It tips around a bit so I think the F8 size would be easier to use - less chance of splash. When pouring, you have to miss the middle area for a splatter free fill

Oscar, is there a place I can see the technical details of what this latest "problem" with Jabirus is? As reading these forums from an outside perspective - in NZ I'm not a RAA member - just part of the Great Unwashed whom simarly dont get much response from our own 3 microlighting organisations, a notable exception is the RAANZ work done on the flywheel bolts issue of way back, so rely on whats being said or not said over here.........I worry a bit for my own engine and like to keep up with any accusations - good or bad - in order to evaluate the best course of action. PM me if thats more appropriate Thanks

I'm told the heads on Camit engines are not the same as the Chinese made engines which Jabiru has now switched to: rather they are more similar to the earlier thick finned heads. UL power make a similar engine - wait - thats a clone of the Jab too.... The certification aspect has always interested me. Before I bought my 2200 I checked what cert. it held compared to others. Their Type certificate has been updated only once in 2008 to include the change to hydraulic lifters. Ironically it should have been cancelled as a result of the introduction of them, if reliability has anything to do with the validity of a Type Certificate. I've had a fairly good run with my 2003 engine, but would not want to replace it with the later designs. The Camit option seems more sensible, and I dont need any certification for my application, fortunately. Jabiru engines were Certified to JAR 22-H (now called EASA CS-22 subpart H) standards for JAR-VLA category aircraft. This test requires an engine to complete a 50 hour endurance test with 25 hrs being at max continuous power. It doesnt seem much needs to be done once the initial paperwork is filed. The ASTM F2339-04 is even simpler to achieve. Most other engines are Certified to JAR-E or FAR-33, which require 150 hrs running - not a lot really - but FAR 33 includes vibration tests with propeller at worst vibration case with the worst cylinder not firing for 10 million reversals.

J170 and Evan, I wanted to do something similar starting 5 years ago, before NZ microlights were required to carry a PLB. Have run APRS tests, both VHF, HF and TETRA tests on a 900 MHz network to obtain real world experience. For a system to be worthwhile it needs to have large uptake by the non-commercial aircraft, or at least be inexpensive for those who would use it - either for their own 'flight following' or for awareness of other aircraft nearby. FLARM is really only useful as a collision aviodance scheme, and only does that job if all the other aircraft have it. Because transponders are more prevalent, buying a PCAS would be the best way to do this function. The reason the APRS works so well is the internet backbone, so once a position report has got into the system the track is searchable from any PC or connected smartphone, not just those aircraft in direct range. In NZ it should be possible to use the UHF CB data channels for this, however I doubt there would be high uptake with owners, similarly each pilot would need to obtain a ham licence in order to use an APRS radio in the ham bands, and this equipment would cost much more than a CB. 3 things are needed for an APRS system: the APRS encoder/GPS board which assembles the position reports, the transmitter, the network of ground receivers/internet connected PCs. The APRS system itself is patented, but its likely to be allowed to be used in this application non-commercially. The APRS tracker boards are available at around $50. Ground receivers and PCs situated at club fields would not be expensive to set up. If the VHF aero band was to be used (there are already channels used for ACARS) then the transmitter can be either an aero band handheld, or better still the installed VHF com. This could be best achieved with a simple software revision to the Aussie made radios so that when the APRS tracker board wants to send the packet burst, connected via the "copilot" ptt and audio input connections to the radio, the radio switches to the data frequency for the period of the burst, then returns to normal operations. This function obviously would be inhibited if the radio was already in use at that moment. It remains for someone to convince the radio manufacturer to make the software revision. In NZ there has been little interest in doing this, pilots have already bought their PLBs so the project has been shelved somewhat. It didnt help when the CAA prohibited submissions on any alternatives to the 406 systems when 'consulting' on the rules.

I have had Continentals dynamic balanced and that was a worthwhile thing, recommended if a static balanced prop has any vibration - such as rudder pedal, instrument shaking etc. I've only flown in one Jab aircraft that in my opinion was out of whack, the owner took it to a dynamic balance outfit but they said it was in limits. I dumped my Jab prop of 200 hrs because one blade had a degree more pitch than the other. You say the engine is brand new. Exactly how old is it? I would be reluctant to open up an engine and remove the crank just on suspicion that your one might have missed being balanced in the first place, passed thru the dyno run and sat in the crate. If its an older one (without the roller camfollowers), then there are many and various compulsory SB which need doing for the privilege of putting a spanner to it. In many cases such work becomes uneconomic, if not seriously questionable. Then there is the other matter, which way do you refit the pistons? the Jabiru way, or the Holden way? According to some, who have reversed the piston offset on more than 1 engine, its noticeably smoother. Your choice, but go for the prop first, the more times you strip a Jab, the more likely it has used up all its 'cycles' Ralph

The original MS nuts are friction locking and have a torque setting of 30 lb/ft The 12 points have no friction locking and are assembled with loctite 620 to 30 lb/ft loctite 620 is classed as a lubricant similar to light machine oil for assembly purposes. ARP will specify what the difference is to torquing 'wet' vs 'dry' anyone spot the difference to the finished job here? I wouldnt speculate if this had any bearing on the engine in question. After all, it had an overtemp, all sorts of things can go bad Ralph

Thanks Gary I don't recall the valves they supplied me having any machined down area It will be interesting to see which type last the best BTW your collets look upside down in the picture or is that the Northern hemisphere version

Nev, can you be a bit clearer about what youre saying. Its my understanding that the original valves, pre 2009, have the semicircle section collet / stem grip grooves. these collets meet without gap, allowing the valve stem to suspend loosely and able to rotate when opened. Now they changed the valves and collets to a different type in 2009. the ones they supplied me , when fitted, had a residual gap with the collet halves gripping the valvestem firmly. I assumed they know what they doing when they make these changes. I didnt like it but all the valves come from a different supplier now. I say these are the valves which dont rotate. I emailed them about this, after the advisory was issued due to 2 cases of washers wearing thru and dropping valves recently. I'd actually be worried if these new valves do rotate, given the square edges on the grip. no thanks, i'm staying with the round gudgeon pin clips too! Jabiru say they do rotate, if not the collets are faulty. So who is correct, did I get a faulty batch from them? The engines been running 140 hrs since, so I think I might have assembled them correctly. has anyone else seen their collets in action? I will have another look when doing the tappets Ralph

I had a look at the skycraft pictures. they look like the Chinese valves, if they have the square section stem grips rather than the earlier 'half round' grips, then please tell us , when the two collets are fitted to the stems, do the collets have a clearance in the gap, and are the valves free to rotate within the collets clamped together? Nobody around here seems to have the new valves fitted - except me - and what I saw seems at odds with what Jabiru are saying in their latest service advisory on failing valvegear. Ralph

have a serious talk to Roger over there - if you are replacing rings you want to hone all bores out to the new limits and fix the base nuts issues if you have any - and make sure you get them torqued NO loctite and heated evenly. if you are going to this amount of trouble consider doing all the rings. And be wary about what valves you are changing too the Chinese ones dont have as much horse as the UK ones - your choice - My opinion, based on real experience of an O-200 new cylinder set which got 'run in' on normal aero oil and then required all rings replaced, fresh honing and a hard run-in on straight oil, to fix the issue, best to use S80 or S100 oil for at least 50 hrs. Ralph

Speaking of oil filters I've picked up some Repco ROF21 now that the gen-4 Ryco ones look a bit shoddy. Used to be that Repco stocked both Ryco and their home brand, and at that time both filters were made by GUD SA, the only difference being colour and a $. The ROF21, which also bears Z386 as equivalent on the can, looks identical inside to the Rycos I used a couple of versions back and I had no issues with those. and they are used on many Toyotas such as RAV-4. was there a new recommendation for oil coming out "soon" - or have I missed that announcement? Still holding my breath with Rick-P on the other revelation further up this thread..... Ralph

I was expecting to see some sort of announcement by now, maybe the testing hasnt gone well, looks like roller camfollowers are the answer for 2013 www.facebook.com/JabiruAircraft

I have the 701SP airframe and J2200 with the factory "low speed" larger air ducts. - I dont know if they are still available With a large exit area it makes the required cylinder pressure differentials at 1.3 VS and runs all day with relatively cool CHTs But if youre expecting to ever see 80 kts you must be contemplating a 3300 up front Ralph

I described an airflow straightener earlier which I made with 6 vanes and fitted years ago. have no photos but it was modeled from a similar one pictured here http://groups.yahoo.com/group/jabiruengines/photos/album/867968529/pic/list there is plenty of other mentions around the net http://usjabiru.com/Gallagher_601.html Ralph

On my 2200 I had some early issues with EGT, made a few different 'smooth' bends and cobra head type angle, by far the most effective fix was an aluminium sleeve on front of carb containing cross vanes making 6 segments, the vanes about 50mm long ( 1 straight across, plus 2 half height pairs, riveted to the tube wall). The tube clamped to carb, and to scat hose. No further issues - did try Sceet hose as well which made no difference except the worry that the internal layer might come adrift and terminate flight one day Ralph

depending on engine and w&b they can differ. To some extent its adjustable by either adding droop or reflex to the aileron neutral position. I have the j2200 up front therefore tend to have cg nearer the aft limit, and a slower cruise speed than some. Flies better with a few degrees down on the ailerons. This model has the 16 deg flap (not original 30) Ralph

yes if they do this it will be a major change http://www.recreationalflying.com/threads/new-jabiru-engine.32531/ not holding my breath or anything though. For me its a 2yr stand-down period before any 'improvements' become acceptable proposition