Vev

Hi Evan,

Glad you enjoyed Tyabb ... come again but let us know when you are coming and we can show you around.

Cheers

Vev

The Mustang pilot is a she and not a he!

The incident has been reported and will be investigated.

I have to say very little of what I have read here aligns with the people involved!

Cheers

Vev

No secret recipe mate ... close enough to a 50/50 blend works fine..

All of the additives are compatible enough ... I would worry more about getting a dose of ethanol as this stuff needs a wide berth all round.

Cheers

Vev

I mostly run a cocktail of both Mogas (98) and 100LL avgas in my Jab ... I do this as 98 acts as a diluent on the lead content of 100LL and the lead has a synergistic interaction with the mogas and bumps the octane levels above the sum of the two parts. This reduces the overall lead depositions and takes advantage of the double dose of the additive treatment in 98 to keep things clean as well keep the octane levels up.

I agree that the laten heat of evaporation with mogas is slightly higher, however I really wouldn't get too excited about about its endothermic (or exothermic) values in relations to carby ice .... I have more of a concern with vapour lock, albeit it has a fair dose (99%) of the isooctane contained in Avgas and is somewhat remote in terms of vapour lock with a 50/50 blend.

Cheers

Vev

I have experienced carby Ice only once in over 600hrs in Jabs ... upon refection the condition were there, and I shouldn't have been a surprise. I simply went through the process and pulling on the carb heat and fuel pump and things came back to normal ops within 20 sec.

However when the lean burn kit was in place a few years ago there seemed to be more reports of carby ice in Jabs. Despite a number of service bulletins, I did come across many owners (including schools) still running on lean jets. I think the first AD was in 2007 and a second bulletin later in the year (mainly to stop detonation) ... it was resent again in 2009 to try and get owners to upgrade their jetting. I wouldn't be surprised to learn that many of these reports (still) would relate back to the lean jetting kits released in 2004.

I have a rule for myself .... 26 needs heat. That is, anything <2600 rpm pull on the carby heat.

Cheers

Vev

Wonderful to hear you have your new toy ... I think Brumby have a winner with this AC.

What about a couple of pic?

Cheers

Vev

If I need to fill out of a container, I have a bunch of 10lt containers which makes it much easier to manage on a high wing.

Cheers

Vev

Nice pics ... I guess the yacht club regatta is off then!

Hey Turbs ... I can relate to that story having spent quite a bit of time on various salt lakes myself ... although I've not always been as lucky to get the 4wd out back onto the hard stuff without a tow rope.

Cheers

Vev

Thanks for all of the responses guys... lots of wisdom!

I spoke with Sensenich in the US on Friday and asked them for their thoughts. They say there isn't much between their two props in terms of performance but they did say the 3 blade will feel smother and will be quieter.

Another point they made was about weight, stating that the 3 blade is 1lb lighter than the two blade owing to a new lay up technique and hub design ... this was not quite what I expected to hear!

Cheers

Vev

What is the advantage / disadvantage of a 2 or 3 blade prop .... which is better and why?

I'm looking to buy a new prop to stick on the front of a Rotax 914.

Cheers

Vev

Thanks for posting Merv.

I must say it was one of the most interesting aircraft at Temora at Natfly this year.

Does anyone know what the useable payload is with Lycoming and the Rotax? Do they offer the 914 Rotax too?

Cheers

Vev

Armstrongs last interview

http://thebottomline.cpaaustralia.com.au/

Cheers

Vev

Sad news to learn today that Neil Armstrong has died.

Truly one of the worlds greatest heros that played his part in advancing our first steps into space and brought the world together for one common moment of peace in 1969.

http://www.nytimes.com/2012/08/26/science/space/neil-armstrong-dies-first-man-on-moon.html?_r=1&hp

Mobil 1 series is a very high grade oil and as far as I'm aware may be suitable. I would refer to manufacturers specs to be sure - both engines' and oils'.One oil I would recommend at least looking into is the Dello 400 range - it is intended for 'mixed fleet' use and is formulated primarily for long service interval deisels.

Again, I'm not saying go out and use this stuff in your aeroplane... but its been good to me in my motorcycles and is certainly worth doing some research on.

 

Cheers - boingk

I don't mean to single you out, but systemically your comments concern me in relation to the use of lubricants.

Mobil 1 series is a catch all .... Mobil 1 racing 4T specifically is a product that is formulated for Motorcycles, and will be OK for a Rotax 4 stroke engine and is supported by the factory. One needs to very careful about which Mobil 1 they pick up as there are some that will not be suitable for a Rotax engine.

Your recommendation to use Dello 400 (A diesel engine oil) is one I would not support in anyway for a Rotax 900 series engine. Oil companies work very closely with OEM's and spend huge amounts of research time and cash to test lubricants to ensure they not only meet the test standards required but also meet backward compatibility with old formulations and a whole bunch of things not obvious to the average punter.

I strongly suggest that you don't become a research horse but stay within the OEM's recommendation ... for a few bucks more you can rest assured that someone has spent many years formulating a good product that will do everything you need.

Cheers

Vev

I've been using Valvolene Durablend 15w50 now for three years with no dramas. Generally available at my local Repco..It's on Rotaxs' recommended list if your using a bit of avgas occasionally..........................................................Maj...

You talked about using this product on another post and though I would respond and here and stay in topic ....

I don't doubt you haven't had an engine problem with this product, however it might be worth considering that by formulation chemistry it has a lower gear loading capability compared to a well blended motorcycle lubricant vis a vis Shell Aerosport 4, which is formulated to cope with an integrated engine gearbox arrangement.

I'm not suggesting Durablend isn't a good product ... I just think Rotax's primary recommendation for Shell Aerosport 4 is very hard to beat.

By the way I don't work for Shell either.

Cheers

Vev

Why the hell don't these things start in the cold???.

This is the link to Jabs published recommendations for cold starting .... as stated in the attached doc, (most important) make sure the fuel bowl levels are correct and throttle butterfly is closed at start up ... if the throttle is open (even just cracked) the idle and choke system in the carby wont work. I presume you have dne the starter motor earth lead mod as per the starter motor bulletin too??

http://www.jabiru.net.au/Manuals/Cold_Start_Checklist.pdf

Good luck

Vev

http://www.eaavideo.org/video.aspx?v=1674033150

Cheers

Vev

Hi Jetjr,

This may help answer your question.

http://www.eaavideo.org/video.aspx?v=3735936001

Cheers

Vev

Hi Turbs,

Of course there are no header tanks in Jab's but other engines do. One could do what is called a patch tests (look for wear debris), crackle test (check for water) and may be a fuel dilution test (looking for fuel and help indicate soot levels) which are cheap and quick to do. You would still need to buy some specialist gear and need a little bit of training to really know what you are looking at, albeit it's not very hard to learn.

However, I think there is plenty of process to ensure one is keeping an eye on the engine if we follows all of the required maintenance and running procedures to alert us to any potential problem... not wanting to tell you how to suck eggs of course, doing pull throughs each day, running an engine frequently at full operating temp, doing leak downs etc etc will go a long way to making sure all is good and one is ahead of the curve.

I'm still in the camp of changing lubricants early, I'm not suggesting this is a requirement but saying it's a good insurance policy... examining the filter debris content each time is a great way to manage wear and very easy to do.

However, to your point, big diesel engines, turbines, industrial gear boxes etc etc are a different kettle of fish and I wouldn't hesitate in plugging in a full oil condition monitoring programme... crazy if one didn't.

Cheers

vev

[quote="turboplanner, There's no problem at all with deciding to change oil earlier than the manufacturer's recommended intervals, but it can be expensive depending on the oil cost. In the example of a certain 4x4 I gave earlier, changing at 25 hours would cost $7,200.00 by the end of 200, 000 km.

Oil Analysis is an alternative to this, since this shows when the oil is starting to break down and need replacement, rather than just being discoloured.

Hi Turbs,

I'm not completely aligned with your alternative suggestion in using oil analysis on economic grounds. In this context, a Jab 2200 engine only hold 2.2lt (really only 2lt) oil lubricant and costs about $30 to do an oil change. The most basic oil analysis will cost a min of $25 to Joe Blogs in the street and more likely $50. It's in my view, it is far cheaper to just change your lube earlier and a whole lot more convenient, as you are not waiting on the return of the results to make a call.

In reality base oils only break down when subject to extreme use, that is very high and sustained temps ... the additives likewise, but more likely to suffer from depletion in their protective properties. If your oil is breaking down, there is without doubt, something else going on in that engine.

I think D10 made a good point ... it's not so much oil breaking down, its contamination in the way of combustion particulates is the problem. Soot related wear is real and will cause wear long before the detergent and dispersants become saturated. Easiest way to deal with this is to change the lubricant.

Lube oil analysis will provide some insight into wear in the engine, but it really requires a lot of discipline to get a good trend (trend is the key) and very accurate records need to be kept and used to interpret the details... this is even more critical in a small engine... large diesel engines are much easier to do, which I suspect is were you have experience.

In terms of managing wear debris in a Jab engine, it really only takes a small amount of training to read the particulates in an oil filter ... this is a very simple and very acceptable way to read the tea leafs on an engines condition and future.

Cheers

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