rankamateur Posted July 15, 2012 Posted July 15, 2012 gee that would be nice... imagne the rate of climb you could get in a savannah with 140hp pulling you along http://www.customflightcreations.com/id26.html this is where Jason Parker ended up, the Extreme 914 predator engine in the Savannah XL does climb well, even with a big lump like me in the passengers seat.
bones Posted July 15, 2012 Posted July 15, 2012 http://www.customflightcreations.com/id26.html this is where Jason Parker ended up, the Extreme 914 predator engine in the Savannah XL does climb well, even with a big lump like me in the passengers seat. Yeah and try getting him to reply to an email after he's got your money, how do i know, well cause i had to sort out the crap and get one of the motors running, i got it to go, but not been flown yet, hopefully this week. So do you have one of these engines? or could you get access to one? i wouldnt mind getting a copy of all the maps to double check things ive done.
rankamateur Posted July 15, 2012 Posted July 15, 2012 Yeah and try getting him to reply to an email after he's got your money, how do i know, well cause i had to sort out the crap and get one of the motors running, i got it to go, but not been flown yet, hopefully this week.So do you have one of these engines? or could you get access to one? i wouldnt mind getting a copy of all the maps to double check things ive done. I wasn't sugesting that anyone deal with him, only that the fuel injected turbo with electronic mapping does make a savannah get up and go, with 19 rego of course. I know his engines aren't ready to run out of the box. I fly with Reg (Aerokits on here) in his XL behind one of these engines. PM me and I will give you his email.
jetjr Posted July 17, 2012 Posted July 17, 2012 Nice website, machine looks good too I have had dealings with Duc Helice and they ripped me off over $3000. They now have my propeller and wont refund ANY money. Been arguing for 3 years. Contact me if anyone want the full story Id suggest looking elsewhere for a reputable partner in propellers to match the gyros which look great.
Guest Maj Millard Posted July 17, 2012 Posted July 17, 2012 The 912s have a larger cylinder capacity than the 80hp, so taking a thou or three of the top of the pistons would increase the capacity even more, plus lower the compression-ratio to the point where it could be turboed. the P&W 985 9 cyl radial on the Beavers have huge pistons, and very low compression ratio (somewhere around 7-1 ?), with a supercharger hanging off the rear of the crank. More rpms more boost, but still only around 4-5 lbs at full rpms, as they only run a single carb. Point I'm trying to make is you don't need much heat-producing boost if you have the capacity, and only 4-5 lbs should produce suitable HP out of the 912s, without overstressing the engine internals and crank, and with out making lots of unwanted heat. Most 912s run on the cool side anyway, and I'm sure the cooling system would be capable of disapating a bit more heat if it had to Years ago a friend of mine built a huge Gyro. It had an EA81 Subaru on it that had 4 thou taken off the flat top pistons.. An ex-Starion turbo provided about 7 lbs of boost and the engine produced well over 100 hp without killing things in the process. We only need the HP boost for around a minute at take-off anyway. After that we are back at 70-75% rpms and low cool boost.....Gyros on the other hand go flat out all day if their working and need all the HP they can get to stay in the air most of the time....Personally I put long-term longevity and reliability ahead of gut-busting HP for the type of flying I do.......................................Maj...
rankamateur Posted July 17, 2012 Posted July 17, 2012 D Nice website, machine looks good tooI have had dealings with Duc Helice and they ripped me off over $3000. They now have my propeller and wont refund ANY money. Been arguing for 3 years. Contact me if anyone want the full story Id suggest looking elsewhere for a reputable partner in propellers to match the gyros which look great. Does constant speed have any application on Gyro propeller applications?
bones Posted July 17, 2012 Posted July 17, 2012 We only need the HP boost for around a minute at take-off anyway. After that we are back at 70-75% rpms and low cool boost.....Gyros on the other hand go flat out all day if their working and need all the HP they can get to stay in the air most of the time....Personally I put long-term longevity and reliability ahead of gut-busting HP for the type of flying I do.......................................Maj... Yes and No Maj, the gyro is not that much different to any other machine once its up and flying, then we are back on the power too, the machines i deal with, are capable of 70kts full fuel ect at only 5000rpm, so at those rpm the turbo is only putting in about 4.5-5 PSI, so yes very low boost really in cruise flight, obviously there is limtis to full boost. But if you fluffing around 15 kts hanging on the power curve then obviously your using every bit of power you got, even with the 914 i got on the single seat, it is only in boost maybe 2 mins(combined) every hr, 2 mins is a damn long time in reality. Never seen the caution or warning lights on yet.
wannafly Posted January 17, 2014 Posted January 17, 2014 I was looking at a youtube clip that Hongie posted on the "what are your favourite youtube clips" thread. The highlander was a very impressive performer. I read the comments and, after someone asked the Highlander owner what made his engine so powerful, he wrote this comment:"It's a 912S (100hp) with the compression lowered to 9-1 and then turboed exactly like the 914. It's about 150cc bigger than a regular 914 and it makes something around 140 hp. A 914 makes 115 hp." I know that the Rotax 914 is really a turbo-charged 80 hp motor. However it had never occurred to me that the 100 hp (912S) motor could have the same turbo gear fitted to this to increase the performance to 140 hp ...once the compression has been lowered somewhat. This probably means that you don't need premium unleaded to run either. Does anyone know others that have done this (possibly in Australia). I for one would like to know the expected engine life of this arrangement. I would also be very interested to know if anybody else has done this particular conversion??
wannafly Posted January 17, 2014 Posted January 17, 2014 Well ok i import a brand of aircraft(that im not allowed to mention cause its in breach of rules) that has a 80 hp rotax that has turbo that produces 135hp of course this is for only a couple of minutes, but it is about 110 hp 100%, and the only real difference between it and the 914 is no computer crap, it is absolutely great performance and good fuel econ. i have one machine in Oz that has about 800hr mustering time and still going strong, the simplisity is so well simple it beg to wonder why rotax did the crap they did with the 914.I will have another brand new machine in town this coming week end so they are definately popular. Sounds great, could you please tell me more info on this motor eg: what sort of turbo are they running, who did the conversion and an approx cost.Thanks
Kyle Communications Posted January 18, 2014 Posted January 18, 2014 Reg Brost has a "Predator" motor in his Savannah.. It is a modified 914 I believe. Not sure on how much HP but more than 115 for sure. The guy used to make the engines for the predator drones…he doesn't sell them anymore..I don't know why
Guest Maj Millard Posted January 18, 2014 Posted January 18, 2014 I've heard the drone 912s are replaced every 100 hrs.....maybe regs' has some combat history. The 912 100 HP with lowered compression and a MANUALLY controlled turbo waste gate would be good..........without all the eltronic rubbish and computer control that's on the 914, to cause unnecessary dramas.. You find most turbos on GA aircraft are mechanically linked to the throttle without any computer control................Maj....
rankamateur Posted January 18, 2014 Posted January 18, 2014 Reg Brost has a "Predator" motor in his Savannah.. It is a modified 914 I believe. Not sure on how much HP but more than 115 for sure. The guy used to make the engines for the predator drones…he doesn't sell them anymore..I don't know why Jason Parker was building Rotax extreme engines in America from ex-drone 914 engines an adding fuel injection. US military changed their policy and all drone engines now get scrapped instead of sold off as surplus, so the supply dried up. He was quoting 140 Hp but he made lots of claims.
eightyknots Posted January 28, 2014 Author Posted January 28, 2014 US military changed their policy and all drone engines now get scrapped instead of sold off as surplus, so the supply dried up. I am not surprised at this waste. The US government never runs out of money because they simply keep printing more.
fly_tornado Posted January 28, 2014 Posted January 28, 2014 More like Rotax added the destruction clause to its contract.
Yenn Posted January 28, 2014 Posted January 28, 2014 There is a write up in the latest EAA magazine of an Italian Turbo charger for Rotax 912. Give an extra 41h.p. The pics look OK.
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