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Hi Bruce, I would think balancing a prop would be a good thing. Whilst I don’t have any first hand experience with balancing, I have grown to appreciate the positive impact of getting the blades pitch the same in terms of achieving smoothness. I fitted a carbon fibre ground adjustable prop almost 200 hrs ago to my 160…. The adjustability aspect is great for performance set ups but it’s fabulous for reducing vibration with identical blade settings. I can’t imagine that prop balancing wouldn’t be a positive step forward..... I’m also keen to know if these gismos work too? Cheers Jack

I was with a mate a few weeks ago and he was pulling through the prop of the aircraft we were about to do some ribbon cutting in prep for a club comp…. A LAME came up and reminded us that if the magneto earths had failed (despite being turned off) for any reason we could be at risk of hand starting the engine with both of us in front of the prop. Ok nothing to do with a poor starting, but a safety reminder when pull over by the prop to make sure you do it safely. Check and make sure the mags are off Apply the brakes Stand to the side Keep a good clearance between you and the prop Cheers Jack

Hi Phil, You know, I think there is something in your LAME’s observation, although I think it could be related to the brand of filter used. When I replaced my original filter with the Ryco A360 I noticed the seal around the rim of the filter was slightly thicker than the original, which was a RAF17, I didn’t know it at the time but RAF17 is Repco filter (See previous post from JR) … I noticed that the new Ryco prevented me from tightening the cover home as I was causing distorting to the cover … this distortion would most certainly allow unfiltered air into the engine. In the end I settled to just tighten it down to the point I was happy I had a consistent seal. I’ve since checked it again and all seems to be ok. Never the less, I’m tempted to go down to the local Repco and measure the seal thickness on the RAF17 and see if it is in fact narrower in new condition and replace the Ryco filter at my next 50hrs maintenance schedule if it looks a better fit…. I’m not too keen on the idea of things not being completely secured, as in this instance it could also effect the carbie heat function if cool air can sneak in around the filter seal. While I’m mentioning the carbie heat … I was also wondering if this could be a source of concern for the supporters of oiled foam filters and why there have been reports of oil pooling in the air box? I wonder if the hot air from the carbie heat function is causing the oil to reduce its viscosity and fallout? I also wonder what effect the heat has on the foam too? I don’t know the answers to these questions but I thought I would mention and see if someone does? Regards Jack

Hi Nev, I wonder if the Bing is more of a problem regarding fuel mixture sensitivity than the engine … could the Bing be restricting potential performance and durability of a very nice engine. No not really interested in being anyone’s test pilot, hence the question to see if others knows the answers. Cheers Jack

There seems to be a number of Throttle Body Injectors available on the market... they all make a lot of claims about performace improvements. I did speak to a chap on the weekend who has a Aerocarb fitted to is Sonex, which has 4 cylinder Jab power plant, and said it provided better performance over the Bing. Keen to hear any opinions or exposure to these TBI's? AeroConversions Products -- Power to the Sport Pilot! Ellison Fluid Systems: Home Page TBI Regards Jack

My flter has been in service for the past 275 hrs and has been been cleaning each 50hrs. I spoke with the Jabiru engine guys and they did say that dirty filters has been the cause of some poor engine power issues and recommend replacing if the filter becomes dirty. I guess personal choice in terms of filter manufacture is up to the owner .... Ive bought a Ryco A360 as the replacement from Super Cheap for $16.50 and think for the peace of mind this cost is not worth trying to avoid to maintain performance and durability and above all safety. Regards Jack

Hi Nev, Thanks for the input. Just not clear on the reason you don't trust paper filters... can you please give me a little more detail behind your concerns? Regards Jack

How do you clean a K&N filter? Does it have a long service life or do you have to replace it after a couple pof cleans? Regards Jack

Hi Nelson, Recently I flew my 160 Jab from Melbourne to Lake Eyre and other iconic inland locations … by the way, I had a ball and the Jab didn’t miss a beat. On my return to Melbourne I found a fine layer of red dust on the filter. I’m not sure if I picked this up from the dirt strips I used along the way or if this was dust in the atmosphere?? Never the less, I thought a replacement filter a cheaper option to maintain durability and performance than attempt to clean it. Best regards Jack

Many thanks JR ... this is great. Regards Jack

Thanks Guys I'm mindful some brands are better than others as I dont want to get caught out with a cheap poor quality copy... any ideas? Regards Jack

Does anyone know what the (quality) replacement air fliter is for a 160 from the local auto parts shop? Part number will be useful too. Regards Jack

I’m keen to know if anyone out there in Jabiru land has fitted an Throttle Body Injector to replace the Bing on either a 4 or 6 cylinder engine and what was the result... good or bad? Regards Jack

I also believe the GME MT410 EPIRB also complies with the standard, albeit without the GPS function, and is around $150.00 cheaper (approx $450.00) than the MT410G model … not a large saving but something to consider when on a limited flying budget. Jack

Hi Walter, My cruise speed was very simply measured by setting the same RPM that I normally cruise at (2900 – 3000 rpm) @ 15.8 lt per hour (I have a flow meter too) which gives me around 104 – 105 knots in solo configuration with 60-80lt of gas in the wings. I tend to use the fuel consumption rate as more of an indicator for cruise configuration as this is a bit of a sweet spot for CHT management. With the VG’s fitted at the same power settings and weight as above I was pulled back to 100 – 101. After I removed the VG’s off the tail plane I recovered most of my cruise at 103 – 104 knots, again with the same power/weight settings, but I had still lost 1-2 knots. I was of the view that the VG’s improved the air flow over the tail plane (which is an inverted wing) and was requiring more forward trim to compensate for this effect causing drag. Once I removed the VG from the tail plane my trim went back to normal settings and the speed went up. Interestingly too, I find when I am fully loaded close to MTOW I can added a small amount of flap 2 or 3deg and my cruise will jump up around 2-3knots as well, however this doesn’t work in solo configuration … I presume when adding flap it lifts the tail slightly and reduces the drag. The guys at Jabiru gave me this tip at a fly-in last year…. I’ve also heard others confirm the same experience too. Regards Jack

Just let you know I tried fitting the Land Shorter VG’s to my J160 and thought I would provide some feedback. Firstly, I fitted them as per the suggested instruction both on the wing and the underside of the horizontal tail… the following was observed: Pros Improved stall by about 5 knots It gave a more positive feel at slower IAS Gave more elevator authority at lower speeds Shorter take off Cons Reduced cruise speed by 4-5 knots for the same power setting Reduce max S&L speed by 5 – 6 knots No real detectable improvement in climb Had an negitive impact on normal trim settings and increased drag I then tried various adjustments to the placement of the VG, within the limitations of the instructions, which made some small differences to the stall characteristics but still caused an unacceptable loss of speed. I reduced the amount of VG’s and then eventually I removed them from the horizontal stabiliser as there was a noticeable increase in forward trim with the VG's fitted to maintain S&L flight.. I presume the improved air flow efficiency over the horizontal stab needed to be off-set by trim which was causing drag… the removal of the VG off the horizontal stab did improve the cruise by 2-3 knots. In the end I went through the process of increasing the spacing of the VG’s on the wing and then eventually removed them altogether as I could not find a spot or spacing combination to recover my speed loss. On a more esthetical note, the VG’s don’t do very much for the nice clean lines of the Jab smooth wing and look somewhat ugly…. Which was a shame to spoil such a clean looking a’craft? In my view, (after many hours) the Land Short VG’s do improve stall as claimed but at a significant cost to speed and economy on the J160. I think these VG’s are only useful if you have a requirement to get in and out of a short runway regularly and don’t do a lot of cruising and fuel economy isn’t a big factor in your flying consideration. Hope this is of use? Regards Jack

There has been some previous discussion on exhaust insulation and ceramics were in the mix.... it doesn't answer your question but may help add some additional thinking and context. http://www.recreationalflying.com/forum/jabiru-users-group/10826-exhaust-insulation-wrap.html Cheers Jack

I thought this paper by the ATSB may be of some interest to Jab owners (and others) as it offers some insight into composite materials that are used in aircraft. http://www.atsb.gov.au/publications/2008/pdf/AR2007021.pdf Best regards Jack

G’day Nick, I can’t recall what I set my pitch at and I don’t have access to my notes which are in the hanger. I found it more important to focus on the static ground RPM to achieve a min 2800 rpm … I’ve been thinking about making a slight adjustment to fine the pitch off a little and may shoot for 2850 rpm to assist my climb during summer here. My cruise set up now is around 2950 - 3000 rpm which gives round 105knts at 15.7 lt per hr burn with one up … with two people and gear I drop about 3-4 knts. Just as a side comment …. I got a good tip from the Jabiru guys at the Cowra fly-in who suggested that if I drop about 2% of flap in at cruise, when fully loaded, I will improve my cruise speed … I tried this on the way back and picked up about 3 knts. This of course dropped the nose a little but seems to pick up the tail from dragging??? Durability in the wet is without question … I don’t try and fly through rain and avoid it when possible…. however with this prop, damage isn’t a consideration as it’s unaffected. I have fitted some prop tape to protect the leading edge against stone damage and replace when needed. I’ll let Brent comment on Revolution OEM as he knows way more than me about the manufacture and props as he put me onto them about 18 months ago when he fitted his prop to his J400. Cheers Jack

Hi Nick, I fitted a 2 bladed (don't believe there is a 3 blade for the 2200 engine) carbon fibre ground adjustable prop about 120hrs ago to my 160. In terms of performance improvement, it’s very hard to say as I don’t have any firm data to give you other than my perception. However having said that, I did record before and after performance in terms of CHT and Oil temps to make sure these were still nominal vis a vis Jabs specs and my previous numbers… which they were. In my view I think the cockpit noise is lower along with a very noticeable reduction in vibration. I did achieve a much higher cruise speed initially; however I slowly reduced the pitch and pulled the cruise speed back to find the best climb/cruise compromise. The other good thing about this prop is its durability, which is way better than the orginal wooden prop. It's basically impervious to rain and grass cutting … it’s also very good in terms of stone chip resistance and very easily repaired if you pick up a stone, which I have managed twice in the last 50hrs. If you asked me what I like about it the most, I would have to say the lack of vibration … its turbine smooth and quiet. Hope this helps. Best regards Jack

Hi Biggles, I feel somewhat surprised to hear that you are experiencing higher temps with a multigrade lubricant, as generally speaking it should have a better thermo exchange than a mono grade SAE50 viscosity. The multigrade should absorb more heat from the engine and dissipate it better through the cooler…. I can’t really see why this viscosity change would have a negative impact, if anything I would expect to see an improvement. For what it’s worth, I Personally I think that a multi grade is always more superior to mono grades in terms of lubrication characteristics…. I won’t go in to details about why but there is a great deal of proven science to support my view. Whilst polymers are used to improve the VI (viscosity index) in multigrade, which allows the lube to change its viscosity to better suit to temperatures in the engine, they are “shear stable” and don’t break down like they did 30 years ago. What’s more, as you top up the oil you give it a fresh dose of IV improver as well as a bunch of new additives which helps maintain the health of the lubricant as well as dilute suspended particulates that are too small to be caught in the filter…. These particulates (soot) cause a lot of problems, therefore top up is good. In terms of synthetics, this is a term that is a little over used … in the context of the majority of piston aviation lubes we are talking about these are a blend of ordinary mineral oils (group 1 base stocks) and hydrocrack mineral oils (group 2 base stocks)… they are not quite a synthetic and really more a term developed by marketers and not the petro-chemist. Lastly, anti corrosion, antifoaming, wear resistance, detergency and dispersancy etc etc are overwhelmingly influenced by the additive system blended into the lubricant, oil base stock do play a part but in the scheme of things this is small beer. Not sure if this helps, but I suggest you look a little deeper into your problem as I somehow think the lubricant isn’t the problem. Regards Jack

Hi Steve, Thanks again ... great result. It's too late to test my before and after under cowel temps without taking off the wrap, although I'm very pleased to see a good reduction in my CHT, which has made the effort all worthwhile. Best regards Jack

Hi Steve, That's a great result... well done! Sorry about all the questions, but was the 12deg C reduction during ground testing or in flt? Cheers Jack

Hi Steve, This sounds like an excellent outcome. When you say 5 deg lower CHT is this F or C??? Regards Jack

Hi Ross, Will do some pics but won't be able to do until the weekend. I think you're right in terms of my configeration re air flow over the sump... I'm quite sure the fitment I have will provide very good oil cooling. Regards Jack