Guest Redair Posted March 31, 2008 Share Posted March 31, 2008 Greetings each, well, having almost made up my mind what aircraft I am going to buy, (Savannah) I now come across yet another puzzlement, namely, which engine to go for. Now I have made this a little easier for you, as I am decided on the Rotax 912, (watch everyone try and put me off!!) but my problem is, whether to go for the 100hp or the 80hp. I hear very different things from different people as to which way to go. Some thing the more horses the better, others say less horses, more money for fuel! Then there are those who think the that the max power is reuired for short take-offs and cruise perfomance, whilst others think economy and choice of fuel is the greater benefit. So, in short, I'm puzzled, and all thoughts/advice would be most welcome. Regards Redair. Link to comment Share on other sites More sharing options...
Flyer Posted March 31, 2008 Share Posted March 31, 2008 Hi Redair It's easy to throttle back a big engine but damn hard to get more ponies out of a small engine...... My 2 cents.... Regards Phil Link to comment Share on other sites More sharing options...
BigPete Posted March 31, 2008 Share Posted March 31, 2008 The 100hp Rotax is more powerfull by 25%. I very much doubt if you'll pick up more than 10% performance over the 80hp Rotax. (It's all to do with that wing - so I'm told) - but hey I'm a Jabiru Jockey. C'mon you Savannah drivers (sliders, shifters, slickers :big_grin:) What do you say? regards Link to comment Share on other sites More sharing options...
eastmeg2 Posted March 31, 2008 Share Posted March 31, 2008 Hi Red, Just my own impression here . . . the 100hp 912s seems to be having more reliability issues than the 80hp 912, ie, requiring heat paste on the spark plugs and the recent gearbox gears replacement AD which did not affect 80hp versions. The Carbon Sting which went down near Goulburn had a 100hp 912s, which if I recall the report correctly broke a conrod and sheared the crank. Just my 2c worth. Rgds, Glen Link to comment Share on other sites More sharing options...
cherk Posted March 31, 2008 Share Posted March 31, 2008 The Savannah ( and its design origin ,the CH701 ) are draggy, slo n' lo machines and the reliablity of 80 horses in the 912 is more than enough to provide the performance of the design........they both have other drag issues that could be addressed rather than add more pony power . A VG wing and 80horses..........sweeet Just my view of course.......might be worth what you pay for! ^ Link to comment Share on other sites More sharing options...
Guest disperse Posted March 31, 2008 Share Posted March 31, 2008 Not knowing a great deal about it all. I'm guessing that the main advantage for the savanna would be on takeoff. A bit more in the cruise, but you wouldn't buy a savanna for it's cruise. So if you want the best stol performance you can get 100hp, but if it's good enough already then 80hp But if in your heart your kinda set on the 100hp ...... then get it !!! you'll soon forget about the extra money. where if you save the money, you my find yourself regretting it every time you push the throttle to the firewall. Regards Troy Link to comment Share on other sites More sharing options...
markendee Posted April 1, 2008 Share Posted April 1, 2008 The 100 has the advantage of quicker lift off. We have flown 80 and 100hp Savvies side by side and the difference in cruise is minimal. The 80 runs well on unleaded fuel, uses less fuel and seems to have less problems. 9:1 is a lot less stress than 10.5:1 As a paddock basher there could well come the time that being able to burn unleaded is a big advantage - thinking of availability. Recreational flying is fun and affordable. The eighty makes it even more so. I remember super charged vehicles that had to run premium unleaded. Couldn't give them away. The eighty is a nice engine. Link to comment Share on other sites More sharing options...
Guest Redair Posted April 1, 2008 Share Posted April 1, 2008 Thanks each, I think this one will be giving me a headache for a while yet, although the 80hp does seem to be the better way to go, I think, oh I'm not sure, I can't make decisions!! It's taken me just over 2 years to narrow the type of aircraft down, now there are all these other options:loopy: Redair. Link to comment Share on other sites More sharing options...
Flyer Posted April 1, 2008 Share Posted April 1, 2008 Redair.... Dr Flyer prescribes a Bex, a good bottle of fine claret and a lie down while you ponder this wee problem. All will become clear when the bex and claret work their magic... Regards Phil Link to comment Share on other sites More sharing options...
hihosland Posted April 1, 2008 Share Posted April 1, 2008 With 350 hrs on my Skyranger a not dissimilar aircraft I am perfectly happy with the 80hp 912. Throwing more horses at a draggy airframe just makes more noise, more vibration, burns more fuel and does not get you there much earlier. Having said that with the relatively small price differential between the two engines most new builders seem to be going for the 100hp. Davidh Link to comment Share on other sites More sharing options...
vk3auu Posted April 1, 2008 Share Posted April 1, 2008 I have the 80 hp 912 in my CH701 and it is quite adequate for getting off the ground with a short strip. 200 metres between the diagonal corner posts of the paddock. The other advantage of the 80 hp is that it runs on standard unleaded mogas. I have flown in a 100 hp 701. It was a bit faster, noisier and used more fuel. You don't need the extra HP. The CH701 was originally designed to use a 503 although a lot of the early ones in the US used a 582. David Link to comment Share on other sites More sharing options...
Guest Redair Posted April 2, 2008 Share Posted April 2, 2008 Bex? Redair.... Dr Flyer prescribes a Bex, a good bottle of fine claret and a lie down while you ponder this wee problem. All will become clear when the bex and claret work their magic... Regards Phil Would that be Weet-bex? I would prefer milk with them! Edrair, hic! Link to comment Share on other sites More sharing options...
rick-p Posted April 18, 2008 Share Posted April 18, 2008 Hi Redair, I have it on good authority that the old 80hpUL motor is stronger and basically bullet proof. Engineered and manufactured stronger, overall. Don't take my word for it do a weight and measurement comparison on the crank case. Rick-p Link to comment Share on other sites More sharing options...
Guest Redair Posted April 19, 2008 Share Posted April 19, 2008 Thanks, seems that the majority are in favour of the 80hp, so that makes me happier about going for it. Redair. Link to comment Share on other sites More sharing options...
facthunter Posted April 19, 2008 Share Posted April 19, 2008 ALTERNATIVE Don't rule out the Continental 0-200D. Very price competitive and a very appropriate motor for a high drag machine, needing a fair sized propeller. Nev... Link to comment Share on other sites More sharing options...
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