Graeme
I totally agree with Kingsley's appraisal. AC has the standard 912 UL
with a CAP 140 variable pitch prop. This allows me to get 5,600 rpm at
start of roll, so getting as much power as possible out of the engine.
Acceleration and climb out are no problem. The only time I would like
more power is at max weight (1,300 lbs) on a hot, cross windy day, we
then get a closer look at the far hedge that I like. Initial climb when
clean is around 800 to 1,000 fpm. Cruise is 120 kts at 14 to 15 litres
per hour, depending on weight. You can wind it up to 130 but the fuel
consumption increases.
Just worth checking I seem to remember that when the weight increase mod
to 1,370 lbs was introduced that the PFA would only approve it with an
80 hp engine if using a variable pitch prop.
Pete
G-RMAC Classic mono #109
On 12/01/2019 23:49, Kingsley Hurst wrote:
> <kingsnjan@westnet.com.au>
>
> Hello Graeme,
>
> I have a Mono Classic with the 912 80HP engine with 3 tapered Warp
> Drive blades and an Airmaster CS hub.
>
> Whilst I cannot directly compare the 80 HP 912 to the 100HP 912S, I
> can say that I (along with others) am amazed how well it performs.
> The only thing that would make me consider replacing it with the 100HP
> engine is that part of flight between lift off and 90 kts. I am
> perfectly happy with the ground run but after lift off in the high
> drag configuration (flaps and gear down), 60 kts is about all I can
> get. I therefore progressively start raising the gear/flaps very soon
> after lift off and put them fully away at 60 kts. Climb rate at this
> time is minimal as it fairly slowly accelerates. At 80 kts it starts
> to climb quite nicely but by then I am well past the end of our 700m
> strip. (Exacerbating this situation is the fact that we almost always
> have a cross wind) I like to climb at 90 kts IAS and at AUW of 621
> kg, I am astounded how well it climbs to altitude averaging around 500
> fpm and sometimes more to 8,000 ft etc.
>
> A mate of mine had a tri gear with the 80 HP engine and a fixed pitch
> wooden propeller. It couldn't look at mine performance wise. I'm
> therefore of the opinion a CS prop is a necessity with the 80 HP
> especially in the hot conditions we have to endure over here.
>
> I suppose this has told you very little Graeme but I wouldn't go to
> the expense of purchasing a 912S without first trying the 912 you were
> supplied. If need be, swapping them over is a very simple exercise
> once you have forked out the $$$!!
>
> Best regards
>
> Kingsley in Oz
>
>
> On 12.01.19 8:57 pm, graeme bird wrote:-
>> I received an unused 80HP 912 with my recent part built kit with a
>> thin three blade warp drive; my own Europa is a 100HP 912ULS, can
>> anyone comment on what difference in performance I might expect. I
>> recall on my previous plane, a C42, the 80HP was less violent and
>> more economical with marginal difference in performance but that
>> might have been because it was cloth and draggy.
>>
>
>
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