Jabiru longevity

[biggles5128]

I have heard from a number of sources that the J3300 will only log up about 450hrs before the pistons and cyl get out of round. I understand there may be a problem with some engines that don't pull down square and this causes the problem.

 

Like all you guys out there we have invested considerable sums into aviation, is there any truth to this being an issue to all owners or is this the old Ford V Holden scenario.

 

I would be interested to here from others who have gone through to TBO without these issues.

 

Biggles

 

 

[Guest brentc]

All Jabiru engines will usually make TBO or close to it if they are looked after properly and the mixture is correct. I believe the out of round barrels you are referring to were a manufacturing defect and not something that 'happens' over time, nor are all engines affected, but I stand to be corrected if others have credible information.

 

From the engines I've seen that have and haven't reached TBO (including my 3300) the main issues with durability usually relate to:

 

- Lean running, which has been mostly overcome now (you need to be burning more than 22-23 litres per hour to be safe @ 2,800rpm (causes burnt valves and other head damage otherwise)

 

- Prop out of balance and vibrations causing fretting of the crank case journals, which won't stop it reaching TBO, however will cause issues after the cylinders are re-attached and torqued.

 

There are a number of other issues that occur but they also happen in other engines. For those that are interested I came across a 912S in an Esqual recently that required a number of new valves at only 400 hours and had head damage too. A very expensive repair for an essentially new engine with absolutely no explanation from the Rotax people as to what caused other than manufacturing defects.