jetjr

Theres only a few models, many variations within each

Dont think speeds changed much

Try asking what you want to know and an owner will help

the back compression on a false start or the accidental double press of starter were seen as possible reasons for bolt breakages

I thought they said it was more prevalent on frequently cold started engines and wasn't around on early models with smaller torque starter.

They also tended to not start more often...…….like cold weather.

I think CAE did some work on prop end starter, I saw one somewhere with starter drive shaft to prop end

Was all part of the work to stop flywheel bolt breakages, they thought is could be related to larger torque starters and warned LiPO4 could give problems with flywheel bolts on std Jab designs

Also thought, as Nev said, the two "flywheels" might be working against one another causing vibrations or harmonics.

They ended up redesigning flywheel to crank attachment system

Everyone is going to get covid 19, now, July, Dec or in years to follow

some will die as a result, we can do very little to stop this

Best we can do is slow the spread to give ICU more capacity

Whilst doing that we are crippling the economy that provides all those services

In AU there are many ways to die and viruses make up very few, even at worst predictions it wouldnt be the highest

A 10% increase in suicides will kill more than the flu so far.

If you think being jobless or bankrupt and locked at home indefinitely wont achieve that?

Essential is Commercial Aviation.

Says who?

Id have thought if the issue is pushed the best result you could hope for is to added to a list of unsecured creditors

The aircraft wasn't paid for so it cant be burdened.

So why is the guy with BFR due after 30/3 safe to keep flying for 3 months and those not renewed before then now grounded indefinitely

Currency is key so by that rationale not flying regularly raises the risk

Same health officials say its Ok to sit in full Saab for 2 hrs.

Not sure anyone has said cant perform flight training if essential, have they?

That's because the regs are far from clear.

If someone flys for commuting to remote work (Ag or mining both essential) and needs a BFR -why is that not allowed

Medical advice is that 1-2 hr commercial flights in full aircraft are Ok due to short duration and cleanliness measures

Exemptions for work crews in vehicles, theist goes on and on.

Then the odd way CASA have granted 3 mth extensions for those BFR lapsed after a 30/3 whilst those before are unable to even sit a BFR, single seat or otherwise.

Somehow not having a review makes flight unsafe?

Simpler would be a path for supervised single seat BFR rather than extensions.

Are you watching EGT?

Chasing economy in Jabiru engines is a slippery slope

Was a series of low time failures from a Jabiru supplied economy kit

Fuel is used to cool Jab engines and also remember fuel distribution within the engine can be terrible. Some cylinders cool with others at destructive temps

I just bought an aircraft 4 weeks ago, so what’s to worry about? I made a decision and this Virus is not going to be here for ever. Sure, I hope my flying school weathers the storm and I can continue training. IF this Virus destroys the flying schools and I can t train:-( Guess what? I have good friend in the far west Qld with an airstrip! I will trailer my aircraft out there and ’log’ hours with no instructor:-). Who’s watching!!!

Now youve declared on the web probably CASA and RAA

19 reg you can alter MTOW - owner can modify under Marap if necessary

BUT unlikely to be accepted without support from manufacturer of kit

With J2/400 this is fairly simple (rated to 700kg anyway) - just slow down its stall,

Others like SP Im not sure but recall it being tried without success as Jabiru couldn't/ wouldn't support it

4.5" replacements?

Wont fit Jabiru setup I don think?

Cht probes on a screw between plugs was 20 deg cooler than down the hole, with CAE blast shields fitted the screw placement was pretty much the same as deep in the head

Air passing probe cooled a lot

"Cool as possible" was typically a safe statement as that wasn't very cool, there are some getting very cool running engines however care needs to be taken comparing numbers as theres several cht measuring points and methods too

Metallurgical limits (ie where alloy changes irrecoverably) are not too far from max cht published. Not much info on these limits and how they were measured

And people whos BFR expired on 27 feb? do what?

I recall talk, when Camit working on upgrades, that bore corrosion was a significant problem, more than given credit for, with low time failures and stuck rings etc

In a Jab, you can feel scaping noise when hand turning prop, only on first rotation

Only one cyl will have open valve so mostly be only one cylinder, once you feel it once you will notice it on every one that hasn't run for a while

A borescope will show it for sure

The Camit inhibitor system works a treat to stop this

I get plenty of air entering at door seals

2200 have strong inherant vibration/harmonics, several nasty problems with aftermarket props over the years. Wood absorbs these but has its problems.

More rigid carbon props cant handle this well hence why Jabiru version is actually fibreglass

the 3300 doent have this harmonics problem as much and many CF props like those from Patroney and Bolly work well

Caution seems to be needed with over propping for speed as can load engine too highly, causes temp and fuel problems that's why Jabiru pin the pitch

Ive run several types on a 3300, 5x, and the pick is Bolly 2 blade adjustable (ive not had Jabiru fibreglass one)

I believe Rob Patroney no longer makes props, they are good however heavy Ive been told.

And no definitive break between the "Gens" although the latest is by far the biggest change in one move

Very sad, 

Some reports of structural failures in C 130 in USA in similar applications - ABC

https://www.abc.net.au/news/2020-01-23/large-air-tanker-c-130-water-bomber-crash-cooma/11894892

Inspection and measurement of catch oil is a key thing to monitor on Jabiru I think.

Subtract volume in can at service to what was added and you get real oil burn

That's whats going past rings etc

Colour of and water in there important too.

Reckon they are 1/2 ali tube ,bent into a right angle (slow radius)

Come out the back of the duct and end sits just above coils and pump, just flocked in.

Yes, CAE recommended blast tubes to coils and fuel pump

I recall they had problems getting fuel pressure correct to limits and once springs correct there was some incidents of pump plunger binding - probably linked to heat

Efforts spent on ensuring max gravity flow , see 60lpm ?? required without any pumps (std Jabiru gets around 30lpm) and they had special jigs to realign fuel pump on assembly.

The extra blast tube does make getting duct on and off tricky

there were problems with cylinder cracking

Well supported and all replaced  - THIS is a big improvement

Not yet convinced they are that much better than older solid lifter versions