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Old 19th Jan 2014, 20:20
  #16 (permalink)  
rutan around
Join Date: Jul 2005
Location: Queensland
Posts: 686
In September last year a post entitled 'Two more Jabirus down' may be of interest to contributors to this current Jabiru engine problem post if they missed it at the time. I think the following is still relevant.

I attended a forum at Oshkosh on Jab cooling presented by Robert Gutterage. Maybe most of Jabs problems are insufficient cooling going undetected due to incorrect CHT information being presented to the pilot. Certainly Robert presented a very well researched forum backed up by hard data. Note :- He had data - not a bunch of 'I thinks'. He showed slides of what he did to solve the problem in his aircraft, as well as the 'before' data.

Apologies to Tim Juhl for pinching the following from a forum on Jabs.
(Remember-stealing articles from one writer is plagiarism----stealing from many is research.)

I attended a forum at Oshkosh where a fellow discussed his research on cooling a Jabiru 3300. He had compared the spark plug washer type CHT sensors to ones directly in the head and showed that they pretty consistently indicated CHT's about 70 cooler than actual temperatures! If this is the case, Jab operators could be cooking their engines while thinking that their CHT's were within safe limits. He ended up designing a cooling baffling system that is nothing like what comes from the factory and claimed that was the only way he was able to get the CHT's under control.

I wonder what the rest of you Jabiru 3300 operators have to say about this? I'm not flying mine yet but will be getting ready to hang it soon.

For a summary on the fellow who made the presentation check out EAA AirVenture Oshkosh - The World's Greatest Aviation Celebration
EAA AirVenture Oshkosh - The World's Greatest Aviation Celebration

It's worth looking at the last web site outlining Robert's qualifications. He's the right man for the job.

For all those who want to junk the Jab engine for as yet no clearly defined problems it would be good if you reflected on the Wright R3350 turbo compound engine used in the B29 and in the Super Constellation. When those engines were first used their TBO was typically 200 to 600 hours. Ouch
After they learned to operate them properly (essentially by running them lean of peak) they were often getting TBOs of 3,600 hours all with 1940s technology. Lycoming and Continental should hang their heads in shame.
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