So you would rather use logic (however derived) rather than company
specifications to dictate how you use a product? Sounds very "British" to
me! Check the Rotax specs, As stated "max continuous speed 5,500RPM".
Look carefully at the bore to stroke ratio on a 914 and do the math.
Somebody stated a Lycoming was in it's "sweet spot" at 3,000RPM? What makes
you think an engine with close to 1/2 the bore and about 1/2 the stroke
would be happy at only 4,000RPM? I know your WALLET is happier at 4,000RPM
but that has no logical bearing on what keeps the engine happy. Most owners
don't run their birds like a flight school Katana either now do they? Read
the good book my friend. And of the three different 914 Europa's I flew
with a combined total of around 2,300 hours on them we can throw Jim Browns
914 into the mix and we have 3,000 operating hours on 914's. Garry Stouts
bird also has close to 500 hours last I knew and he isn't easy on his
either. There is a little "proper evidence to the contrary" not dictated by
gas prices.
Best Regards
Jim T.
--> <ami@mcfadyean.freeserve.co.uk>
But I've not experienced that for the short durations that I've used 100LL
and would have expected that to have occurred logically at any engine speed;
more so at higher power settings when there is more lead going into the
engine.
In fact logic is my guiding principle in the absence of proper evidence to
the contrary!
How's your 1000 hours at 5000rpm going? Will you make TBO? Katanas don't!
Duncan McF.
----- Original Message -----
From: "Jim Thursby" <jthursby@tampabay.rr.com>
Subject: RE: Europa-List: Rotax 914 question?
> <jthursby@tampabay.rr.com>
>
> Don't know about your source but the person I trusted (as did many others
> including Rotax) to keep me informed about the Rotax engines always stated
> "the 912/914 series engine is happiest and will get the best longevity
> ABOVE
> 5,000 RPM in the cruise". He is now gone as of July of this year but his
> experience was trusted enough that Kodiak research and Rotax called him to
> assist in product development. Glen had forgotten more about Rotax
> engines
> than most of us could ever learn. He never steered me or anyone I know
> wrong, and I trusted his opinions and ideas about these engines with my
> life
> on more than one occasion.
> Oh, and you WILL foul plugs on 100 LL and reduced power settings
> eventually. Or put up with the auto gas smell. Or have to add TCP all
> the
> time. When you have 1,000 plus hours on a 912/914 come back and let us
> know how you're doing. Keep an eye on the gearbox too.
>
> Jim T.
>
> -----Original Message-----
> From: owner-europa-list-server@matronics.com
> [mailto:owner-europa-list-server@matronics.com] On Behalf Of Duncan
> McFadyean
> To: europa-list@matronics.com
> Subject: Re: Europa-List: Rotax 914 question?
>
> --> <ami@mcfadyean.freeserve.co.uk>
>
> OK, I'll bite!
> I cruise at about 4,000rpm. And have done for over 200 hours of use,
> excepting climb-out at 4,800 and the odd spurt to see how fast it will go.
> The plugs are squeaky-clean. The piston crowns are quite clean. There is
> no
> loss of compression or performance that suggests that the piston rings are
> coked. The engine uses virtually no oil between changes and the oil
> discolouration is mid brown colour at 100 hours.
> Our local Rotax dealer commented flippantly that at these speeds the
> engine
> would 'last forever'!
>
>
>
|