Vev

I would stick with the Shell Aerosport Plus 4 if you can get it. As Nev said, the key thing (but not only) you are looking for is the JASO MA or MA2 spec (latest spec) .. this is a japanese classification to indicate suitability for a wet clutch in motorcycles, which is required for Rotax gearbox clutch set up. The Shell Aerosport is approved by the Rotax OEM and you can rely on a consistent formulation and the correct additive packs which also carries the JASO MA spec. Cheers Vev

Hi D10, I could't agree more with your view on high frequency lube change ... this approach will cover a multitude of sins and is a great insurance policy. I am still in the camp that multigrades do help reduce wear at start up, albeit small in the context of Aust temperature environment... additionally there are other benefits offered in terms of better lubrication from a multigrade that I would pick over a mono-grade these days... like you that's my choice too. I am completely aligned with your rationale that soot and contaminate related wear is by far and away the biggest problem and does have a lot to do (but not all) with, as you indicated, with the quality and technology of the fuel used... again, early and frequent oil and filter change is a cheap and good thing to do and I like the 25hr approach. Cheers Vev

Hey Darky, Just in case you decide you need your ASIC card ... why not get it through the RAA as it's $160.00 and save yourself $30? http://old.raa.asn.au/docs/admin/asic-appn.pdf Cheers Vev

G'day Eric, My only additional comment is in relation to the lube oil level ... I would lean towards the very bottom end of the of the oil level marks, particularly on the finned 4 cylinder engines. (The non finned sumps have a deeper sump and don't have same issues.) There is a number of reasons to do this: It helps with oil drain back from the rocker chest in older 4 cylinder (finned) ... an extended dwell period in terms of lubricant retention in the rocker chest can cause the base oil to thermally crack from too much heat. If the base oil cracks it will quickly die and chemically fall apart and not do the job it was intended to do. Having a lower sump increase the sump/crankcase voids and reduces the crankcase pulse which affects the rocker chest drain back via the push rod tubes. More void = better drain back, thats why Jab went to the non finned sump. If you fill to the top of the oil level mark on the older finned engines you will find most of the lube oil ends up in the oil breather bottle. Seeing that you have a J170 I would suspect you will have one of the latest engine sumps, therefore things wont be so critical ... never the less, low end (of a dip stick) is better for your top end in a jab. Hope this helps? Cheers Vev

G'day Eric Jab produced the attached doc ..... This should help you work out the oil levels for each engines and the levels associated with each dip sticks in production. http://www.jabiru.net.au/Service%20Bulletins/Engine%20files/Dip%20Sticks%208A035A0D-1.pdf Cheers Vev

Sadly the CT impacts on Av-fuels will mean our flying will become slightly more expensive and will also cause a knock on effect into higher GST that most won't be able to recover in private use. Whilst some individuals will continue to argue the science is a nonsense, it is now clear, in my mind, that there are no credible institutions apposed to the mainstream scientific belief that, among other gases, Co2 is harmful to our atmosphere and is one of the key factors in causing global warming. I do not wish to debate this point as this is my belief based on my own research and understanding ... I am happy for you to have your opinion whatever it may be. I terms of tax .... There are some that will argue that the use of a tax impost is only locally effective and not as globally efficient as applying a commodity trading options in offsets credits ... some will argue that simply applying CO2 caps and penalties is even more locally effective than a CT. Personally I can see the point of all 3 different approaches dependent upon the various political landscapes and levels of capabilities of countries at any one point in time. As for us in Australia, the political influence has had more to do with which mechanism has been used and the CT has won out for now ... overtime it will evolve into (in my opinion) a more globally effective trading mechanism that will help change global behaviour and target the lower hanging technology fruit to assist in CO2 reduction in a more meaningful and cost effective way. Unfortunately, Av-fuels carbon taxes is here to stay.... it's a one way street and it's up hill from here on out, unless we find and use an alternative. Cheers Vev

I also bought a set of wheel covers for the front and main wheels ... the cover on the front is unaffected by the prop wash and you don't lose quite as much speed as you do without the any spats. Here's the link to the ones I bought. http://www.leggott.flyer.co.uk/extras.html#Wheel%20trims Vev

Hey Mardy, Just to share my experience with the front spat on my Jab. I found that the prop wash tended to favour the front wheel to turn left when flying, which turned the rudder to the left as they are interconnected ... you can increase the spring tension on the front wheel mechanism to over power the effect of the prop blast or fit a trim tab to the rudder, which most seem to do. My approach was to simply fit a very small trim tab on the back of the front spat, as sometimes I remove the spats if I am going in and out of dirt strips ... when you remove the front spat the wheel is unaffected by the prop blast and if you have use a rudder trim tab you end up with a bit of right rudder trim. Hope this makes sense? Cheers Vev

This is very sad news.... I offer my condolences to David's family and friends.

Hi Leonie, These are excellent ... whilst you say you have a disability it certainly is not with a brush. Love the Nanchangs! Cheers JV

Hey Brian, I knew that 3300 would be fast in the 160 but that was a quick trip Good stuff guys. Cheers Vev

Locks .. I say let's close this thread.... This is not a proper discussion! Cheers Vev

You know what ... I don't care! There is nothing to be gained, what's the point... leave the guy alone! Vev

Nev, I am sure you are correct over all with this thinking.... as I am aware that making some small mods (wont bother with detail here and now) to the manifold you can improve things a lot. However I also think the Bing has its problems too, that is, if you tilt the carby a couple of deg to one side when mounting it you can get a better EGT balance and less variation.... the US jab distributor worked this one out. Additionally if you pull the carb heat on you will get an almost even EGT temp across the instruments, however not a good idea to do under power owing to an increased risk of detonation. Lastly, increasing the emulsion air bleed holes in the Bing on the 6 cylinder will also improve EGT balance too. My point is the carby has some poor atomisation characteristics too and fixing the EGT balance is a combination of both. The other interesting thing is the African Jab guys have developed a fuel injection ... I believe it gives much better EGT balance and 30% more power. Cheers Vev

Nev, An interesting observation was shared with me when I spoke with the South African Jab distributor 2 years ago ... he said that Jab engines flying out of Johannesburg would easily make TBO +, yet engines in Durban were only making 350 hrs and needed a topend refresh. He said the altitude at JHB is approx 5250 ft and the thinner air made the Bing run rich (despite pressure compensation) and therefore cooler, whereas in Durban, at sea level, engines that are run at around 2800rpm ran lean and got very hot, which consequently cooked the top ends. The lesson learnt was to run the Jab engine hard and ensure that the Bing was operating on the pointy end of the needle jet to get the fuel into the engine. He said the best indicator is EGT and it must remain below 1250 deg F as anything above this means a shorten life on the top end ... Don at Jab in QLD also says "fly them like a fighter" and never baby them. If you operate the engine around 2800 rpm you will cook the top end without you knowing it as your CHT will indicate normal temps but your EGT's will be 1400 deg F and making a mess of the top end. Personally I fitted EGT's and use this to set my throttle position when in cruise ... so far my top end looks as good as the day I put together and all of my temps are sitting down in the lower quarter of the heat range :-) Cheers Vev

What could possibly go wrong with that Willie?

From what Dead-stick has already said from his preliminary inspection ... the engine had done 1370 hrs, 3 topends and was supplied before the thru-bolt upgrade was put into production. Several people here have tried to ask the question in a subtle way .... forgive me for being direct but I can only draw from DS statement that this engine was not compliant with the Manufactures Safety Direction and was still running parts that are known to fail. The attached Service Bulletin... it says it all ... I hope all Jab owners have read this and make sure they have implemented these Safety Directions http://www.jabiru.net.au/Service%20Bulletins/Engine%20files/JSB031-1_JSD031-1_Engine_Through_Bolts.pdf

The Jab engine does use an o-ring between the barrel and crankcase. Silicon is used when the spacer have been added to lower the compression on early barrels by raising the barrels 0.5mm, which was an interim fix (during 2010) while the new barrels where being designed and put into production. When you raise the barrel with shims the o-ring no longer has the same interference fit to squish it into the machined grove in the crankcase... it seals ok but its not as good without the shims. The current engine has 0.5mm longer barrels and therefore doesn't have spacers and relies entirely on the o-ring to seal between the barrel and crankcase.... Essentially Jab have addressed this issue. Cheers Vev

In terms of the thru-bolt failure, is there any evidence that the new longer bolts and nuts are failing? In my mind this is the real acid test, everything before this upgrade is past events and falls into the history bucket and already known. There was an AD out to upgrade the bolts and/or nuts which had timed out for mandatory completion on the 14th April 2012... this AD also included crankcase dowels in some prescribed circumstances. We know Jab have added 0.5mm to lengthen the barrels or have fitted 0.5mm of spacers on earlier barrels to lower the compression to help manage the detonation .... to the best of my knowledge this has not been mandated to owners but has been a standard process during factory rebuilds since 2010 inclusive of new production engines. On the current production engine they have increased the thru-bolt dia as well as the longer 12 point nuts, along with a higher interference fit on the crankcase dowels ..... this is a significant improvement but it can't be preformed on old engines easily. In terms of retrospective upgrades today ... is there any evidence of the new longer thru-bolts with 12 point nuts failing???? Cheers Vev

Thanks Deadstick, Wasn't the new through bolt AD deadline 14/4/12 and all engines required the upgrade by then? http://www.jabiru.net.au/Service%20Bulletins/Engine%20files/JSB031-1_JSD031-1_Engine_Through_Bolts.pdf Cheers Vev

Hi Motz, Where is the engine in terms of the through bolt and dowels ... what is its current status? Helpful to know the facts on the through bolts and nuts to help getting a better understanding of the issue? Glad all worked out for everyone. Cheers Vev

This has some good info on how to survive a forced landing according to the FAA... it's little long but worth your time. Cheers Vev