Robert Posted May 22, 2014 Share Posted May 22, 2014 Hi All Just wondering what a time expired 100hp 912 rotax would be like to use in a 50 to 80 hrs a year aircraft Worth it or not any info on this matter would be good Cheers Link to comment Share on other sites More sharing options...
facthunter Posted May 22, 2014 Share Posted May 22, 2014 Be quite variable as to the condition. Some people don't log all the engine time. You would want to know IF it had had a prang or prop strike so the log book should be done properly. There's work required on the redrive at periodic intervals. Someone has to write something in a book for the "on condition " use. One thing about the engines they don't get corrosion in the cylinders but can on valve stems . The exhaust particularly. Nev Link to comment Share on other sites More sharing options...
LJS Posted May 22, 2014 Share Posted May 22, 2014 So just slightly off topic here, a timex engine is one that is time expired, to be overhauled/rebuilt or one that is to be relegated to the 'never to fly again' use for ground fun pile? Link to comment Share on other sites More sharing options...
facthunter Posted May 22, 2014 Share Posted May 22, 2014 Zero timing an engine is a complex argument . The only real one is NEW. Others are an inspect NDT parts. and restore where needed to be within dimensional tolerences. Some parts may have a specified life and others may be able to be reused with a minimum dimension stipulated Ie Deck Height of crankcases. Nev Link to comment Share on other sites More sharing options...
LJS Posted May 22, 2014 Share Posted May 22, 2014 Thanks Nev, so like anything else in life the determining factor is cost, ie which is more cost effective, REbuild or REplace. Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted May 22, 2014 Share Posted May 22, 2014 Hi AllJust wondering what a time expired 100hp 912 rotax would be like to use in a 50 to 80 hrs a year aircraft Worth it or not any info on this matter would be good Cheers I know a few people who run them until the compression is too low for easy cold starts or to the mandated life, whichever comes first. Generally it's the rings that lose compression, and rebuilt in accordance with Rotax specs, a 2nd life engine is - not new, but a fair bet. Not cheap, mind... As Nev said, a fully overhauled engine has old bits in it. 3rd life (overhauled twice) Continental 6s, and a few Lycs I think, have blown barrels off the case due to crankcase overaging... amongst zillions of engines... i'd be willing to run a time-ex 912 VFR by day, if I could get it to start! For a while, anyway... Link to comment Share on other sites More sharing options...
LJS Posted May 22, 2014 Share Posted May 22, 2014 So what would a 912's timex be, 1500 hrs?? Link to comment Share on other sites More sharing options...
facthunter Posted May 22, 2014 Share Posted May 22, 2014 You are completely correct. I would rather replace a GA motor with a new one completely and sell the original with a few hundred hours left on it. The Rotax can sit unused better than a lot of engines which MUST be inhibited for storage. This is OK if you are doing a lot of hours. Parts for a Rotax are expensive. I would suggest they are worth pulling down and inspecting to evaluate whether it is economical to refurbish it somewhat and put it back in service . I'm not aware if Rotax will do it and recertify it.. If someone else does it I don't know where you would stand for "school" use. To answer you question re condition. a lot of 1500 hour Rotax engines would look pretty good inside but I think they are "lifed past that.. Exhaust valves rings gaskets and seals and inspect drive clutch etc and you might easily get another 1200 hours or more There's things like starter drives an electrics too. You can spend the money once you start with this brand. but they do last well. Nev 1 Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted May 22, 2014 Share Posted May 22, 2014 So what would a 912's timex be, 1500 hrs?? depends on the model.... earlier ones were shorter... not sure at which model the life went up from 1,200 or so... I run my 503's "on inspection", with plenty of inspections! But not in flying school use... Link to comment Share on other sites More sharing options...
LJS Posted May 22, 2014 Share Posted May 22, 2014 So what sort of hours do your 'well inspected' 503's rack up? Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted May 22, 2014 Share Posted May 22, 2014 A points-ignition single carb, with good oil and a wooden prop that doesn't hum, can see 600 hours with good compression and minimal play on the bearings - haven't gone past this. A dual-carb (solid state ignition) in a two-seater will go at least 500 hours, if you keep the throttle well open. If you treat it like a 4-stroke, you can get bearing problems before the compression gets low... Be aware - I have not racked up this amount of time on my own; it's a combination of the second-hand aeroplanes with known histories I have/use, and the records of TOSG on which I base this advice. The 582 with good oil, in the right hands - even in training use - can go 1,000 hrs; but your warranty will be void! Link to comment Share on other sites More sharing options...
LJS Posted May 22, 2014 Share Posted May 22, 2014 Thanks Bob, Good useful information that! Sorry for the Thread Hijack Robert! Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted May 22, 2014 Share Posted May 22, 2014 Thanks Bob,Good useful information that! Sorry for the Thread Hijack Robert! No worries. The Rotax lifing is mainly based upon the very variable life of ball bearings, but modern synthetic oils - esp. methyl silicone - and keeping the throttle either fairly open or quite closed seems to beat that. Link to comment Share on other sites More sharing options...
Riley Posted May 22, 2014 Share Posted May 22, 2014 Thanks Nev, so like anything else in life the determining factor is cost, ie which is more cost effective, REbuild or REplace. Just last week I was given a budgetary quote to factory-rebuild a timed-out R912 80 HP at between 16 & 17 thousand. Picked myself off the floor, took three nitroglycerine tablets and requested a new price on the same unit. Immediate reply - $18 thousand! Have to guess that management policy of selling new engines for a few points more than a rebuild keeps their factories working. Anway, who needs economy - it's aviation, and everybody knows we're all rich! cheers Riley 2 Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted May 22, 2014 Share Posted May 22, 2014 Just last week I was given a budgetary quote to factory-rebuild a timed-out R912 80 HP at between 16 & 17 thousand. Picked myself off the floor, took three nitroglycerine tablets and requested a new price on the same unit. Immediate reply - $18 thousand! Have to guess that management policy of selling new engines for a few points more than a rebuild keeps their factories working. Anway, who needs economy - it's aviation, and everybody knows we're all rich! cheers Riley Struth! well I know I'm rich, that's why I know about 503s... and Thrusters... 1 Link to comment Share on other sites More sharing options...
LJS Posted May 22, 2014 Share Posted May 22, 2014 "Anway, who needs economy - it's aviation, and everybody knows we're all rich! cheers Riley" Hahahaa Yes we have all made our '2 Mil' Link to comment Share on other sites More sharing options...
Robert Posted May 25, 2014 Author Share Posted May 25, 2014 Thanks for the replies guys So whats your thoughts on what a time expired 912 is worth ????? The way i see it is that due to the colossal cost of repairs to Rotax engines one could be buying an expensive boat anchor!!! Any comments ?? Link to comment Share on other sites More sharing options...
facthunter Posted May 25, 2014 Share Posted May 25, 2014 You would need to know the engine's history. You should get 1500 hours out of a 912 easily. You have to allow about $11/hr for engine cost. They stopped making any two stroke bar the 582 a few years ago, so I guess getting bits for the smaller ones will be difficult. Nev Link to comment Share on other sites More sharing options...
slb Posted May 25, 2014 Share Posted May 25, 2014 The 582 with good oil, in the right hands - even in training use - can go 1,000 hrs; but your warranty will be void! ... not to mention your Insurance too 1 Link to comment Share on other sites More sharing options...
facthunter Posted May 25, 2014 Share Posted May 25, 2014 For every one that makes 1,000 hours there's piles that stop suddenly, long before that. Piston rings through exhaust ports . Holes through the tops of pistons and Big ends going blue with cage failures. I think Rotax give you 300 hours which if you know how to run 2 strokes is pretty conservative, but that's the legal figure (unless it has changed) Nev Link to comment Share on other sites More sharing options...
alf jessup Posted May 25, 2014 Share Posted May 25, 2014 How did we get 582's and 2 strokes on a 912 thread??? Alf Link to comment Share on other sites More sharing options...
aj_richo Posted May 26, 2014 Share Posted May 26, 2014 'How did we get 582's and 2 strokes on a 912 thread???" Osmosis? and what ever you do don't mention L2 or you'll get "that" bloke on here. 1 2 Link to comment Share on other sites More sharing options...
cscotthendry Posted May 26, 2014 Share Posted May 26, 2014 So what would a 912's timex be, 1500 hrs?? You can find this by looking in the Rotax service bulletins which are freely available. Just find out the serial number of the engine and check against the lists. Link to comment Share on other sites More sharing options...
Bob Llewellyn Posted May 27, 2014 Share Posted May 27, 2014 ther How did we get 582's and 2 strokes on a 912 thread???Alf There's a parallel between a two-stroke of any age and a timex 4-stroke, of course! Gee whizzz... Link to comment Share on other sites More sharing options...
pylon500 Posted May 30, 2014 Share Posted May 30, 2014 So whats your thoughts on what a time expired 912 is worth ?? From what I've seen in the adds, prices generally seem to be; Expired 912A (80hp) 1200hr (some 1500hr) basic motor =$3~4K Expired 912UL (80hp) 1500hr (pre 2000hr extended) basic motor =$4K Expired 912UL (80hp) current 2000hr model, basic engine =$4~5K Expired 912ULS (100hp) mostly 2000hr, basic engine =$5~6K These are generally run out engines from schools and depending on how they operate, either pulling just the basic core and replacing it (about $15K I think?), or doing a firewall forward change ($LOTS), the buyer of the old engine will then need to chase up all the extras. I read 'Basic' engine to be engine with ignition packs, inlet manifolds, carbi's, coolant hoses with pressure cap tank, starter motor and maybe the old exhaust system? To get a running engine into your 'non-certifed' aircraft, you will also need the following; Exhaust (you may need to mod to suit your application...) Oil tank, Oil cooler, Radiator, Coolant expansion chamber. If the above bits are included, you could ad at least $1K to the above figures. Have a good read of the log books to be sure, general feeling is that most 912's will run at least another 50% of their TBO time... 1 1 Link to comment Share on other sites More sharing options...
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