Vev

Hi DK, Yes heard about new manifolds for both 4 and 6 ... I understand they are out on trial now (at least thats what I was told 2 weeks ago) in some ac off-shore and at some flying schools for testing. However the stop gap (6 cyl only) while this is being done is to put the round defuser in the manifold which works well. Also of interest is Jabiru engines are currently being fitted with EFI ... these are the Israeli Army UAV engines. They adjust mixture via an EGT sensor, all reports suggest there isn't a huge improvement and is just adding complexity. Cheers Jack

Fantastic video Michael ... thanks for posting. Cheers Jack

Thanks guys .. glad if this helps. Andrew, The k-line value guide inserts are available at almost any auto head re-conditioner ... I believe they are an Al/bronze material. I have run with std clearance and these seem to be working fine, although, as I said, it will take a few more hours to confirm their durability, but others have obtained great improvements. The answer I believe is all to do with the spiral cut inside the insert which provides better lubrication between the valve stem and guide... The spiral simply hold the lubricant and prevents dry contact. In terms of the carby mod ... I checked my notes and I have the "Air Density Sense Port" is drilled out to 3/16" and the emulsion tube holes is increased to 3mm from 2.5mm (not 4 mm as I said in my previous note). The guys at Jab in Bundy are well aware of this mod for the 6 cyl so I suggest you talk to them as I haven't done this to my jab. The only other thing I should mention is your EGT should not exceed 1250 deg F ... some even say 1200 f as max. Whilst EGT's have their limitations in terms of accuracy, there is a direct correlation between reaching TBO and not. Putting in the recommended jetting and using plenty of throttle will take you a long way to managing engine temp at a good level. Cheers Jack

Improved engine life G’day Andrew, After rebuilding my top end at 350 hrs I went out and spoke to a number of Jab engine experts around the world (mostly Jab Distributors) and found a number of things that I think will help extend the life of the jab engine. Most of the problems in Jabs is due to overheating ... sticking rings, worn guides, exhaust value pitting/breakage, broken through bolts (detonation) etc etc is all heat related. The new fine fin heads have 50% more surface area along with a wider setting between the valves .. there is also a lot more finning material around the exhaust port which make quite an improvement in terms of getting heat away from the top end. Additionally the new hollow push rod and rocker gear has greatly improved lubrication system and will help extend the rocker gear life many times. One mod I have come across and have implemented into my own engine is to use K-line valve guide inserts, whilst I haven't done enough hrs on them yet to personally give them the thumbs up, the South African Jab Distributor has done thousands of hrs and say they are the bees knees. The new piston and ring set up provides more clearance in the ring groves which should help stop ring sticking and the new piston have larger drain slots in the oil ring grove too ... this combo is a good step forward to reduce ring and bore wear. Jab have also changed the cylinders in the last few months; these are now 0.5m longer to lower the compression to overcome detonation and stop thru bolts breaking. As I said, most problems in Jab engine relate to getting too hot ... the biggest factor to fix over heating is fuel mixture. It is imperative that you have the latest jetting (including needle) in your carby .. Without the right jets you will most certainly run lean and do damage. Fuel distribution in the 6 cylinder is a problem and has also claimed the life of many engines ... however there is a simple fix for the 6 cylinder (not the 4). In the induction track of the manifold there is an aerofoil which acts as a divider to direct flow inside the manifold … this aerofoil doesn’t work. The factory has discovered if you remove this and simply replace it with a 12mm round tube it improves fuel distribution and EGT becomes balanced across the cylinders… it really does work!:big_grin: There is another mod to the Bing Carby, although I have not done this myself, .. the South African Jab Distributor has increased the emulsion air induction size and drilled the emulsion tube air holes to 4mm … I believe this as improved things in terms of better atomisation. I know Jab in Bundy have verified this and suggest you talk with them to get the exact details. I have also tried exhaust wrap for 250 hrs and came to the conclusion that this didn’t provide any real benefit .. it reduced the inside cowl temp but think it may have put heat stress on the exhaust valve. Lastly, fly them hard, particularly during run-in to ward off glazing … they love heaps of fuel going through them to cool thngs down. Hope this helps … Jack

Hi Chris, I have fitted a few of these before on my jab as well as mates. It sounds like u have just a little too much air in the tube at assembly as the halves should push together enough to put the std bolts in ... make sure you soap up the tyre bead and powder the tube. If you put too much air in the tube you run the risk of pinching... you just need a very small amount air to get the tube away from the split joint but still allow you to push them together. If you need to put longer bolts in you will probably pinch your tube as you bring the rims together. hope this helps Cheers Jack

G'day Phil, Well done on your GFPT :dance3: Cheers Vev

G'day Dazza ... good to see you here. Cheers Vev

Got one at Repco for $80.00 this morning .. thx Michael Cheers Vev

Thanks Michael, I spoke with Jab but they don't stock these unfortunatly. I will give Repco a try and see how I go. Cheers Vev

Does anyone know where I can buy a VDO manifold/vacuum gauge that will match the standard Jab engine gauges? Cheers Vev

Tomo Thanks Glenn and Chainsaw

Hi Darky, Fancy meeting you here? Good to see you :biggrin: Cheers Vev

G'day All, Currently flying a Jab J160 out of Tyabb, Victoria, but will fly anything I can get my hands on. I enjoy fly aways around the country with friends whenever I can get away. Hope to learn and share anything to do with airframes and engines. Cheers Vev

Well done FG ... like so many things in life, practice and determination to win will get you there ... you are well on the way. Cheers Vev

One of the key points in the article was its affordability over other amphibious aircraft, but they failed to say what it was???… this feels disingenuous to me and spoilt my first impressions. I hope their new marketing manager repositions their offer to meet our intelligence in their future marketing campaigns. Cheers Jack

Fuels I don’t think we are at risk of Avgas being pulled for some time. There was a plan presented 3 weeks ago to the US EPA by the Industry Avgas Coalition to develop a programme called “FAST” (Future Avgas Strategy & Transitional Plan) to develop a viable “drop-in” fuel solution. In terms of the near future … It’s reasonably clear we will see a lead reduction (may be 50%) on the current LL100 to move towards meeting the 2006 Friends of the Earth Petition to outlaw lead. It’s also clear that aviation engine designs will increasingly accept high octane zero lead fuel formulation to also reduce the lead demand. In my view, there is still a heap of data needed to understand the impact of lead on society from avgas (notwithstanding the fact that lead is harmful) and a bunch of petrochemistry research to develop a suitable “drop-in” fuel product that will provide safety with engine durability at an affordable price. Avgas will be around for a while yet! Cheers Jack

Diesel Waxing Hi Brian, Excellent question re Diesel Fuel Waxing … In my view, Diesel Fuel will never be suitable for aviation use in its current formulation because of the risk of waxing. Diesel fuel "Cloud Point" varies around Aust from state to state throughout the year … what works in one geography will not be suitable in another. If you were to fill your tanks and fly south …. leave fuel in your tank from a warmer month and then use in a cold month … fly at an attitude that chills down the fuel in your tanks … you could end up with wax forming in the fuel lines or blocking filters. As an example, over a 30 day period between say Gladstone and Brisbane there is as much as a 12deg C difference in Cloud Point by government regulation. If you were to fill in Gladstone and fly South to Bris 30 day later you could easily find you are operating beyond the safety parameters of the fuels temperature design limits. On the other hand, Jet A1 makes a very good alternative to Diesel fuel as it is designed to operate over an extreme range of temperature and will happily run in a diesel engine application, that is, so long as the engine has been designed to use it. Cheers Jack

Hi 80knts, Seriously.. do you mean that? I'm no expert in metallurgy but I would think the current 4140 chrome moly single billet cylinder is miles ahead of an aluminum/stainless combo any day.... wouldn't your suggestion just add weight, complexity and cost on a cyl that works fine? Cheers Jack

Please explain? Hi Ozzie, Don't get your statement about high pressure injected moulded heads and cylinder? The cylinder are machined out of a slingle billet of steel.. what wrong with that? Cheers Jack

Through bolt failures is hardly a Jabiru only problem … this was happening on aero engines before Rod Stiff ever consider building an engine and still is. In any case, Jabiru has done quite a lot to fix these failures over the past 18 months which has reduced the incidence significantly. They have modified the engine in a number of ways to engineer out the problem and reduce the propensity of fuel detonation, which is the primary cause of through bolt failure in Jabs. Take a read of the attached “Case Check” in Jabachat for some helpful hints on maintenance procedures, albeit 99% of tool boxes won’t have the tools do the 200 hr checks on the through bolts as prescribed… you will most likely need to enlist an L2 or LAME to perform the checks. http://www.jabiru.net.au/Jabachat/Jaba%20Chat%20August%202010.pdf Cheers Jack

Hi Ian, Thanks for this ... Rod did make mention of the discussion last year and was aware of the road blocks. However, after talking with him today he seems to think there is an alternative or a new approach to get this over the line. It may be best you have a chat with him directly and talk though his thinking and test it with you own understanding and help him shape it for the RAA Board meeting? Cheers Jack

Michel, Did you see the Aug Jabachat ... attached link http://www.jabiru.net.au/Jabachat/Jaba%20Chat%20August%202010.pdf Cheers Jack

I spoke with Rod Birrell (Victorian RAA Board Member) today and I asked where things are in terms of the introduction of a Plain Language Weather Reports for recreational pilots. Rod said, he is very enthusiastic to make this happen and will champion the issue on behalf of the RAA membership. He said he intended to table the motion earlier but the RAA elections had been a personal distraction which slowed things up. Never the less, he said, he will be tabling this at the next board meeting in a couple of weeks. Rod seems to think there is a reasonable opportunity to develop an interim solution around the legislation to move this along with some pace, although it will still take time relative to many things involving bureaucracy. He said, this work sits mainly in the domain of the RAA Operation Managers but he is very supportive and prepared become directly involved in this project to help drive the change. If any of you out there feel supportive of moving to a Plain Language Weather Report it wouldn’t hurt to inform your state board member to help motivate this along… just drop them a short email. Rod said that he will get back in touch with me as soon as he has introduced this at the next Board meeting and let us know the next steps. In my view, if this change can make flying safer through reduced complexity and clearer information we have had a win. Cheers Jack

G’day Tomo, Yes you’re correct, oil does “wear out”. Essentially the lubricant is made up of two parts, one being the base oil and the other the additive system. The additives do a number of things to enhance the lubrication performance in terms of anti-wear, soot and viscosity control etc etc. Over time the additive system gets over loaded (soot, acid etc) and the oil itself begins to oxidise and break down .. therefore oil (lubricant) “wears out”. However, the response posed by BlackRod in terms of lubricant dwell periods being safe at the manufactures recommendation is something I would assume to be spot on… I would expect the OEM’s recommendations would have been supported by quality data from oil and wear metal analysis over an extended period of time. Not withstanding all of the facts produced by the OEM... I say, oil and filters are cheap and I’m a 25hr oil man. Cheers Jack

I see not only has Lowrance has pulled the pin on the manufacturing of the 2000c but they are not providing update services on the Jeppesen map data... no reason given other than there is a "situation" ... which i think is code for don't sue us yet! LEI Extras - Jeppeson Database Updates It's not right these guys can promote and sell a product and then dump it without warning as well as continue to allow their distributors to sell the old stock knowing there is no software map back up. Shame on Lowrance Jack