Vev

Well done Brett, great to watch ... how long did it take for you to go solo? Cheers Jack

I will be there with wings on from Tyabb

Nick, Have a read of the July Jab Chat ... they talk about the mid range torque reduction on the hyd version, which has a 150rpm reduction in egine speed in static performance. They also refer to a need to increase in leak down on the lifters too. Try this link and go to Jab Chat news .... July news letter Jabiru Aircraft&Engines Australia Cheers Jack

Good Ian, <?xml:namespace prefix = o ns = "urn:schemas-microsoft-com:office:office" /><o:p> </o:p> “Do learn Do” as suggested by Steve, is a powerful and pragmatic way to develop a programme …. Hopefully the feedback loop will ensure the right pace and resource is met ahead of the demand. <o:p> </o:p> Cheers Jack

Thanks for the info Ian, I called RAA today to asked about when and where courses will be held in Victoria. I was told there are >45 applicants for 10 spots on the 1st course in QLD ... the idea is great, but may be these courses need more resource to meet demand? Cheers Jack

Hi Cazza, Thanks for the feedback on my earlier post about food availability.... sounds more than enough catering. I was just wonder how the event agenda is looking in terms of lectures/activities for dates and times? ... I saw draft I think you (?) posted some time ago. Cheers Jack

Just after reading the Jan Jab Chat (on line now) about their star rating on fuels, it makes one wonder if one should be using a blend of Mogas 98 and LL Avgas. The LL Avags to keep the octane up and the mogas additives system to clean up the depositions ... combined both would stop posible detonation form low octane and incandescent ignition sources at the same time. Cheers Jack

This is one of those things where the process has overtaken the purpose… “tell them they’re dreamin” Cheers Jack

MM, I sooo glad it did come down anywhere near Dunnydoo (NSW) Poowong (Vic) Middle Intercourse Island (Qld) or Mt Buggery (Vic)

If ever I find a loose head bolt its always the bottom one (as per Big Pete's post) ... to access it you need to remove the rocker cover and then the grub screw, which requires a long allan key socket to reach the bolt head. I also agree with Nev's comments, you do need to ensure you use some anti-sieze or crack back and then torque.... the engine needs to be cold too. The guys at jab have told me over the phone to tension to 24 ftlbs which is higher then the manual, which is what I do every 50hrs. Just one issue for me out of the report is the leaking head causing detonation ... whilst this possible it does sound a little out of the ordinary? Does anyone have a real experiance with detonation via a head/cyclinder leak? What do you think Nev? Cheers Jack

Hi Garry, Great stuff ... nice to hear about a good outcome. Cheers Jack

Hi Bill, Not sure I would want to keep oil temp over 100 deg C an the Jab engine ... personally I would prefer to see it no more than 100 and not above. Cheers Jack

Hi Carol, Sounds great ... looking fwd to this event. Whats the situation regarding food if I camp on the field... I'm trying to keep my weight down, in the Jab that is ... I'm another story, but we wont go there :-) Cheers Jack

Hi Bob, Sorry to hear about your engine failure but thank you for taking the time to share this info. At what stage in the flight (climb/cruise/final?) did the engine fail and how long had it been in the air? I’m also interested to know if you have had high/low ground and flight temperatures and if/when this happens. I think that Walter’s point re “uneven thermal expansion” is quite plausible when you consider the different coefficient of expansion and different thermal conductivity of the engine materials… I wouldn’t be surprised if this is part of the failure mechanism. However for all our speculation here, it will be interesting to hear Jabiru’s thoughts on the reasons for the failure and what is their recommendation is in terms rectification and prevention. Cheers Jack

Hi Jack, Welcome aboard ... sounds like you will have a lot to contribute. Cheers Jack

Completely agree with Nev’s assertions re oil temp .. if too low (< 80 deg c) you run the risk of not flashing off free water and causing corrosion problems.. alternatively temp spikes up to 100 deg c in the sump is not going to harm things either. Base oils normally won’t begin to thermally crack until temps > 160 – 180 deg c, however consistent elevated temps or short excursions into extreme temps will produce a greater likelihood of oxidation and eventual break down in the base oil and additive system. Once oxidation starts it’s like a cancer that will generate a molecular auto decomposition of the hydrocarbon chain … in simple terms the oil is cooked and engine damage is assured to follow! Outside of thermal breakdown, maintaining lubes within the right temp range also assists in the lubricant performance in terms of viscosity and hydrodynamic lubrication as well as the additive system to support anti-wear and dispersants. The moral of the story … it’s a bit like the Three Bears … not too hot, not too cold but just right. Cheers Jack

Not sure if this helps but here's a link? Cowl Plugs from Aircraft Spruce Cheers Jack

G’day Rocketdriver, Nice to hear a positive story … I’ve known Brent for a couple of years and he is always ready to promote flying and help out anyone in need. Glad you enjoyed your fly with him … I sure you will enjoy the guys down at the Tooradin Flying School too... welcome back to the big blue. Cheers Jack

G'day Turboplanner, Re exhaust bandage. I had spoken with a number of experts as well as had quite a bit of feedback from a few on this forum before I tried it. In addition to this I ran an oil condition monitoring programme and did an oil test every hour to track the impact for 50 hrs to look for wear metals and oxidation levels ... I also shared the results with a couple of very good engineers that have a lot of experiance in this area. I persoanlly didn't run temp probs in the engine compartment but a lame in SA did and reported the temp reductions on this site. It's now been in place for a bit over 200hrs and i'm still doing condition monitoring ever 25 hrs and not seeing anything to be concerned about, however I am enjoying a lower engine bay temp which is kinder to all things electric. Btw... I also reported the mode to the RAA to put it on the record. As I said ... If i had to pick one performance improvement I would do the adjustable prop hands down. Cheers Jack

Steve, I did a couple of simple things to my 160 to get it to perform a bit better. 1. I fitted a ground adjustable prop and made sure I could get 2900 rpm static run up and 3000 on take off and climb. Letting the engine rev really makes a difference. 2. Fitted NGK Iridum plugs .. these seem to give me may be 25 rpm more on static. 3. I wraped the exhaust in bandage .. not completely sure if this made a huge difference but it did helped keep the temps down. 4. Fitted the recommended richer jets in the carby In my experiance the adjustable prop is the go .... the trick is to let the engine rev and develop the HP. You hold higher revs on cruise but the Jab Engine guys tell you that's a good thing. Cheers Jack

The Jab 6 cyclinder (120hp) is 178 lb and the Honda 199 lb ... the Jab is close enough to 10kg lighter. Cheers Jack

Looks interesting ... great price at US$12k Cheers Jack

Yes you are right, but your take off and climb rpm will always be lower than max rpm in S&L flight.... in S&L flt you will see the engine speed increase if you held full power. I have a varible pitch prop on my 160 and pull 2900 in static mode, 3000.3050 rpm in climb and 3300 in S&L flight at full power. I tend to cruise around 3000/3100 @ 100/105 knts. Cheers Jack

If you take a look at the "JabChat News Letter" (July 2009) on the Jab site they have listed fuel burn per RPM for the recommended carby jetting ... the attached is a cut and paste from Jabchat. RPM Litres/hour 2600 13.4 2700 14.1 2800 16.5 2900 17.4 3000 24.3 Full Power (3175) 28.5 In terms of max RPM, I beleive this to be 3300 RPM for the 2200/4 engine. The guys at Jab always tell you not to baby the engine and drive it hard, therefore I really wouldn't think 3050 rpm as being too hard on the engine. Cheers Jack

yes .. sorry guys I had stuffed up that part number ... it is in fact DR9EIX. By the way, on the weekend I took a look at my HT plug leads and noticed some rubbing between the leads where they cross over between the distributors. I was wondering, if this was left unchecked could this be the source of shorting between the leads and be a cause for plug fouling? Could it also explain why one would still experiance a missfire on both mags? Just a thought? Cheers Jack