Username Protected wrote:
Is it just me or is someone announcing a new diesel application every six months?
What keeps them away from on GA?
Weight?
Cold weather ops?
Gearing issues?
It seems these same issues pop up and stop progress.
Weight, TV and the FAA.
The power pulse of diesel is significantly more violent then traditional ICE. In order to contain/manage the pulse you need a much stronger block which leads to a heavy case. Which leads to weight problems.
Next issue is torsional vibration; the power pulse if unchecked will tear up a prop. To reduce the issue, common solutions are weighted flywheels, gear boxes, and inline TV dampers. All of these items are heavy; and that adds to the weight problems.
Pure hearsay; but a few companies I know going for certification of engines has stated the FAA, small airplane department has taken to literal meaning of the regulations; not the intent. For example, if the engine says 8-12qts of oil, the oil tank cannot hold more then 12. This is really a new requirement, take any old CMI IO-540 and I bet you could put in 20 qts of oil even though the max is 12. I have a few more examples, but this is all anecdotal.
Tim