I promised to respond to a thread that discussed the fact that the Jabiru Engine Manufacturer had closed his door. I ended up contacting Jabiru and they indeed confirmed that the company which Jabiru outsourced Engine manufacture, had indeed closed it's door due to reduced demand and increased overheads.
Jabiru is intending to assemble themselves and have hired some of the Staff and purchased some of the specialised equipment need for the task and they intend to outsource component manufacture. One of the Companies considered is ABCO who is well known and does excellent work, my neighbour is the Head Machinist there, but he's not 'in the know' in terms of negotiations.
The problem they had in Australia when the engines were grounded resulted from a change from push rods to Hydraulic Lifters, which set up a natural frequency on the Head Bolt housing threads, this was resolved with mods to the housing to off-set the Frequency - some extra stiffening I believe.
It seems these problems only arose in high end use like Flight Training when there is frequent power on and Power-off like in go-arounds. In normal everyday use it wasn't a problem. There were other instances of modified engines having problems, but those modifications weren't approved. I asked about the water cooled heads and that's not approved either, but personally I can't see an issue there, but that's their policy to keep the engine as simple as possible and air-cooled.
I was referred the Companies Web-site which contains similar information.
Hope that helps.
George (down under)
Jabiru is intending to assemble themselves and have hired some of the Staff and purchased some of the specialised equipment need for the task and they intend to outsource component manufacture. One of the Companies considered is ABCO who is well known and does excellent work, my neighbour is the Head Machinist there, but he's not 'in the know' in terms of negotiations.
The problem they had in Australia when the engines were grounded resulted from a change from push rods to Hydraulic Lifters, which set up a natural frequency on the Head Bolt housing threads, this was resolved with mods to the housing to off-set the Frequency - some extra stiffening I believe.
It seems these problems only arose in high end use like Flight Training when there is frequent power on and Power-off like in go-arounds. In normal everyday use it wasn't a problem. There were other instances of modified engines having problems, but those modifications weren't approved. I asked about the water cooled heads and that's not approved either, but personally I can't see an issue there, but that's their policy to keep the engine as simple as possible and air-cooled.
I was referred the Companies Web-site which contains similar information.
Hope that helps.
George (down under)