Savannah 80hp against 100hp

[Robert]

Hi All

 

Can anyone comment on savannah performance 100hp verses 80hp

 

Much differance and if so what ?????

 

 

[eightyknots]

Performance figures for the 100hp Rotax are easy to obtain. For instance, they're summarised on this thread: http://www.recreationalflying.com/threads/the-zenith-ch-701-ch-750-and-icp-savannah-vg-xl-and-s-comparison.36408/

 

Getting 80 hp figures are a bit harder because I don't think there are many around in this neck of the woods. In Europe, where many countries have imposed a 450 kg limit on their ultralights, there are probably quite a few. You'll probably have to search around on European websites and use an online translator to figure it out.

 

I may be wondering aloud here but how many 80 hp Savannahs are there Down Under?

 

 

[rankamateur]

100Hp compared to 115Hp maybe becoming a more relevent comparison in current Australian built Savannah planes and before we know it we will be comparing 912iS installations with standard 912S and 914 installations.

 

It will still be a power to weight to price to installation hassle argument and it will always be an individual decision based on how much pain the individual is prepared suffer for the precieved gains.

 

 

[Kyle Communications]

I wish I had the option of the 912IS....I think they will sell a heap of them

 

 

[Guest Maj Millard]

The 100 Hp as opposed to the 80, will definitly lift a bigger load, out of a shorter strip when you need it, which is what many Australian Savannahs will end up doing most. They have the long range tanks with 160 lts, and most often would be two-up with baggage and camping gear, all of which they are more than capable of handling.

 

The 80 hp on the other hand is certainly suited to the lighter loaded versions, and would possibly offer better cruise fuel consumption, if thats what you are after.

 

The big difference between the two in my opinion are the gearbox ratios. The 100 hp with it's 2.43 ratio allows one to use a larger range of prop options, which really allows you to convert the 100hp into some serious thrust come take-off time.

 

The fuel-injected 912iS is just a finer and more capable version of the current 100hp engine, and will make a very fine engine in many types of machines once they arrive...............................................Maj...

 

 

[winsor68]

As a contender to the Savanah how about a Bingo with a 80hp 912? I believe the Bingo is a little lighter... perhaps more in keeping with the original design?

 

 

[Guest Maj Millard]

I'm sure the 80hp would be the ideal engine for the Bingo......don't know if it is approved for them though...................................................................Maj...

 

 

[Robert]

I own a Savannah Bingo with HKS engine. Airframe is the same as other savannahs

 

A bit lighter because mostly people dont paint them also limited to 450kg due to engine size

 

Great fuel economy about 9ltrs per hr but I do think it looses a lot of it stol capability because of engine HP.

 

Cruises about 60kts

 

Must go for a ride in a 100hp one of these days to compare

 

 

[Guest Maj Millard]

Robert, yes the Bingo is a nice little plane. Do watch that climbout capability, and how much you load though, we had a HKS Bingo come to grief recently because it was overloaded, and run out of puff. OK if you respect the limitations................................................................Maj...

 

 

[naremman]

This reply does not relate to the Savannah directly, but some parallels with the Airtourer may be applicable.

 

Victa initally introduced the Airtourer in 1961 with a 100 hp engine, with a Max All Up weight of 1650 lbs (750 Kg). In winter at sea level it was a fair performer. In Australia we don't always fly in the winter, and not always at sea level, and performance at a Density Height of 4000' does not show up too well on a VSI. It was not too long before the 115 hp variant was put into production, and a choice was available for either 100 or 115 hp. Same airframe, same MTOW, just different engines and props. The benefit was in the climb as the extra 15 hp went into the climb. Usefull load and range went in the 100s favour.

 

In cruise the 115 was faster of course, but probably not as much as was anticipated. Most of my experience has been in then 100 and I have not experienced any 115s getting any better than a five knot advantage, and using an extra 2-3 litres a hour to achieve it. Alan Wood and I did a formation flight for nearly two hours together in 1987 when Woody had VH-MUL still flying, and he was surprised at how little he had to back off the throttle.

 

The 100 hp variant of the Airtourer has always been acknowledged as the nicest model to aerobat, that is if you are prepared to accept the altimeter unwinding at a fair rate!!

 

Once again how much power you are comfortable with is a matter of owner, or pilot choice. Some are comfortable not having their socks blown off, others want a world beater. Having some Scottish blood, I am far happier funding the 21 litres for an hours flight in a 100 hp Airtourer than 32 litres for a 150 hp model at todays Avgas prices!! Ditto, I imagine between a Jab 170 or 230. Are there any 80 hp Foxbats in Oz?

 

 

[eightyknots]

The fuel injected Rotax may eventually become the 'standard' 912: give it a couple of years. I reckon they'll eventually cease production of the carby versions.

 

 

[facthunter]

It gets down to the weight at which you operate. An overpowered plane will leap off the ground but waste fuel if you want to use it to up the cruise speed, particularly when considering a plane like the one here. At the lighter weights the 80 HP Rotax is enough. ( already been said) It is the most proven motor of the range and will operate on the lower octane mogas fuel. If you operate at high ambient temps regularly that would make you be inclined to the higher power engine option, but generally, don't overpower a plane. Nev

 

 

[Powerin]

I know of one 80hp Savvy. The owner was very happy with it, especially the economy and the wider availability of fuel (regular unleaded).

 

 

[Guest Maj Millard]

The 80 Hp engine is quite nice. It generally runs a bit smoother due to the lower compression ratio than the 100hp. It is also the engine that they put the turbo on and turned into the 115 hp 914, so that shows just how strong they are. Fuel economy is very good and a little less than a 582, and often 9-11 Lph if your good.

 

The 80hp 912 now has a good record with a great in-service reliability history.....................................Maj...

 

 

[rankamateur]

I thought they had aluminium pistons which had to swapped for cast iron pistons to make them just how strong thay are as a 914.

Edit: maybe they don't?

[facthunter]

Sheesh. Cast iron pistons went out with the rotaries. ( the real ones where the engine went round and the crankshaft didn't) Nev

 

 

[Guest Maj Millard]

Not aware that the 914 has cast iron pistons ??.........................the standard 912 pistons are quality Cima Marhle forged alum pistons, that are also used OEM in Porsche engines and others. Theres' not a lot of boost on the 914 somewhere around 7 pounds max I believe.

 

They used the 80 Hp as it is a low compression engine, Vs the 100 Hp which is a high compression engine.................................................Maj...