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Rotax 503


Barcy

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Without knowing the model, the history, and the condition of the engine, it`s impossible to comment accurately and compare the Rotax 503 to the 582, not only that! you need to know the aircraft ( single or twin seat ) and performance expected from the aircraft.

 

503 versus 582.

 

503: Is it single carb, single ignition or dual carb, dual ignition, new or used, if used how many hrs has it done, what type of gearbox and prop is it driving? The 503 is fan, air-cooled, it has fewer working parts than the 582, grey or blue head, oil injected or not, therefore, fewer things to go wrong.

 

582: is it grey or blue head, oil injected, new or used; if used, how many hrs has it done; what type of gearbox and prop is it driving? The 582 is water cooled, therefore, it requires a radiator and all the things that go with that, also, Rotax now recommend that the Crankshaft be replaced every 300 hrs.

 

Hopefully! I`ve outlined some of the questions that, need to be answered, to be able to make an informed decision.

 

I`m on my second 503 and I went through four grey head 582, purchased new, when I was instructing...I`m currently running the 503 DCDI, purchased new, with the E-type box turning a 60-inch ground adjustable, 3 blades, Ivo prop, on the certified twin seat Austflight Drifter! from memory, the engine has done close to 500 hrs and so far it hasn`t missed a beat but I`ve fitted new rings and gaskets twice and all the parts in the carbies, once.

 

At the moment, parts for the 503 are still available from Bert Flood Imports, Pty Ltd.

 

Franco.

 

 

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I fly a Trike & a Drifter, both with a 503. I love a 503. Why? With the Trike, I can overhaul it in one day sitting on the Trike. A decarbon? About 3 hours by myself.

 

Try that with a 582. What you'll have first of all is anti-freeze all over you & your hangar floor then 10 times the crap to remove & replace....make a mistake at an early stage of reassembly & you get to do it all over again.

 

Yes, I've owned 582s also. Great motors but the trade offs for 13 more horsepower, to me, is not worth it. Parts are easily avaiable in the U.S. & why they stopped making this bullet proof motor is beyond me. More money in 912s etc. Is my guess.

 

If you want to see a 503 work out watch my two YouTube videos "Drifter Flying by William Catalina." I've got another one coming soon. Will post.

 

P.S. The float portion in Part II was with a 582.

 

plenty of aftermarket parts for the 503, some an improvement but yeah they are an old aircooled 2 stroke engine

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It's not a like-for-like changeover, far from it. Although the 582 has more power, with it's rads and other ancillaries plus being a bigger, heavier engine to start off with, some of that is lost just hauling the extra weight around. Plus you must also be aware of potential CoG problems (sorry, I don't know the specific aircraft you mention). I bought a Weedhopper AX3 with a collapsed undercarriage and tube damage that had previously had a 582 fitted. One of the reasons why I bought it was because I already had the parts needed to repair it from my old AX3 plus its low hours 503 engine. When I came to fit the 503 I had to move the engine brackets quite a way forward to get the CoG within limits so it's worth doing the calcs.

 

I while back I saw a single seat Weedhopper for sale over here on which some clever s*d had fitted a 582. It comes as standard with a 447. It was obvious that the clever bugger hadn't moved the engine brackets at all and I reckon anyone buying that aircraft would have been heading for an early death - that's if they had enough upward pitch control to get the nose up to take off.

 

I also have a blue top 582 powered X-Air which comfortably cruises at 90 kmh and 15 litres/hour. I couldn't get a '503' prop for my French Weedhopper but found one off a 582 engine. Then I did some sums and cut a wee bit off each end but, of course, it still had the same courser-than-standard pitch. I was pleasantly surprised that take off with the 503 was hardly affected but I can cruise at the 'standard' AX3 speed of 80 kmh at 5200 rpm using an amazingly low 10-11 litres/hour (solo). And by upping the revs to 5500, I could match the speed of the X-Air and still, probably, be under the 582 X-Air's 15 l/h.

 

So there are a few things to consider. The 503 is pretty bullet-proof if looked after, especially the DCDI. Mine isn't fan cooled either - you only need that on a flexwing or a pusher 3-axis and then not always (eg the Shadow). Someone once told me that 582 stators fail quite often. I didn't believe them until mine did after I'd also viewed another X-Air some time before that was also suffering from a huge mag drop which typically tells you its stator is naff.

 

 

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I take it then that you like 503s Roller?

 

Sometimes I miss that bit more punch when getting out of a tight 'landing area' in the middle of nowhere....then I think how easy it would be to fix if stuck 'in the middle of nowhere' with the tools & spare parts I carry.....as compared to the nightmare repair I would have with a 582.... anybody carry anti-freeze & hoses in their onboard parts kit? :)

 

But hey! If you like 582s, more power to you. They're great motors too! I've just gotten older (and lazy-er!)....and don't want to be stuck somewhere.

 

It's not a like-for-like changeover, far from it. Although the 582 has more power, with it's rads and other ancillaries plus being a bigger, heavier engine to start off with, some of that is lost just hauling the extra weight around. Plus you must also be aware of potential CoG problems (sorry, I don't know the specific aircraft you mention). I bought a Weedhopper AX3 with a collapsed undercarriage and tube damage that had previously had a 582 fitted. One of the reasons why I bought it was because I already had the parts needed to repair it from my old AX3 plus its low hours 503 engine. When I came to fit the 503 I had to move the engine brackets quite a way forward to get the CoG within limits so it's worth doing the calcs.I while back I saw a single seat Weedhopper for sale over here on which some clever s*d had fitted a 582. It comes as standard with a 447. It was obvious that the clever bugger hadn't moved the engine brackets at all and I reckon anyone buying that aircraft would have been heading for an early death - that's if they had enough upward pitch control to get the nose up to take off.

 

I also have a blue top 582 powered X-Air which comfortably cruises at 90 kmh and 15 litres/hour. I couldn't get a '503' prop for my French Weedhopper but found one off a 582 engine. Then I did some sums and cut a wee bit off each end but, of course, it still had the same courser-than-standard pitch. I was pleasantly surprised that take off with the 503 was hardly affected but I can cruise at the 'standard' AX3 speed of 80 kmh at 5200 rpm using an amazingly low 10-11 litres/hour (solo). And by upping the revs to 5500, I could match the speed of the X-Air and still, probably, be under the 582 X-Air's 15 l/h.

 

So there are a few things to consider. The 503 is pretty bullet-proof if looked after, especially the DCDI. Mine isn't fan cooled either - you only need that on a flexwing or a pusher 3-axis and then not always (eg the Shadow). Someone once told me that 582 stators fail quite often. I didn't believe them until mine did after I'd also viewed another X-Air some time before that was also suffering from a huge mag drop which typically tells you its stator is naff.

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Hey, that looks like what was a Mustang over here in France. Not sure if it had wires or not though.

 

I knew a guy who bought a Mustang with a 582 and thought that the little oil tank that lubricates the butterfly valves was an oil injection system (no comment please). So he just put neat mogas in the tank and flew it home for over an hour. Then he added some more and flew it for a little bit longer before the error of his ways was pointed out to him. From then on he added 50:1 and flew it for another couple of years with no ill effects except he crashed it and knackered the main tube in front of the main wheels as you'd expect.

 

So France being France, he got hold of another smashed Mustang, cut the main tubes of both aircraft and joined them with an enormous bloody sleeve with thousands of pop rivets. You'd never have got me up in it but he flew it for some time before selling it on to a punter who happily handed over the cash and flew it off to its new home 037_yikes.gif.f44636559f7f2c4c52637b7ff2322907.gif

 

 

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Callahan's pic reinforces my views on CoG. Just a straight replacement of the 503 with a 582 would move it back quite a lot I'd say and depending on the elevator authority could lead to a potentially dangerous situation. Be interesting to hear from someone flying a 582 Drifter about whether that's so or if a nose weight had to be added to keep the CoG within limits. If so, that would also tend to negate the 582s advantages over a lowly little 503.

 

BTW I found a pic of the French Mustang that I mentioned that's a bit too big to post here. It didn't have wires - it had lightweight round struts plus a nose wheel and the main gear a little bit further back. Otherwise looked almost idetical to the Drifter.

 

 

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Roller!

 

Quick one! I never did a 503 to 582 conversion but I did do a low mount 582 to a top mount 582. Negligable CG change of course but it did tend to force the nose down on takeoff as power was added. It was something you get used to quickly though. I did it to swing a wider prop. More later.

 

Interesting friend you have! We'd get along great. I'm much the outlaw & "rigger" too!

 

 

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hmmm... I dunno

 

Here's that pic of the Mustang I was talking about after I've cut it down a bit and you can see the repair sleeve I mentioned on the main tube.

 

 

His 'hangar' consisted of an ancient old marquee tent that someone had given him and when I took the shot it had just been ripped to pieces by high winds winter 2011/12. Otherwise that's just about as tidy and organised as it ever was. We've all lost touch with him now. The word was that as in all things, he preferred to fly well under the radar and despite claiming to have an ultralight licence, could never produce it 'because he'd lost it'.

 

 

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Roller,

 

You've got to have him contact me if you ever meet up with this guy again. He's my hero & I'd probably be his. Birds of a feather & all that. I keep wondering when the landlords here are going to throw me off the train for posting some of the stuff I do!

 

It does resemble a Maxair....with a nosewheel. Interesting but looks kinda'....kinda'....kinda'.....Homespun? That's the best adjective I can come up with. Maybe it's the environment it was photographed in? I liked the tent idea but winds can be a bit testy on canvas! All in all, I like odd things like this & even odder personalities. His. Not yours. You seem perfectly sane.

 

By the way, what are you doing in France if I may be so bold? Retired Aussie or American expat or a Frenchie who happens to type excellent Engllsh? Just curious is all.

 

Anyway, thank you for the interesting story on that chap & his forlorn aircraft....probably spelled that wrong too!

 

Let's see how long they let this remain viable! Ten minutes? Twenty? Ten seconds? My studio.1013753681_Heather-23Sept.shoot006.jpg.eb78eb55b018783203dbac6c49c56e66.jpg

 

hmmm... I dunnoHere's that pic of the Mustang I was talking about after I've cut it down a bit and you can see the repair sleeve I mentioned on the main tube.

 

His 'hangar' consisted of an ancient old marquee tent that someone had given him and when I took the shot it had just been ripped to pieces by high winds winter 2011/12. Otherwise that's just about as tidy and organised as it ever was. We've all lost touch with him now. The word was that as in all things, he preferred to fly well under the radar and despite claiming to have an ultralight licence, could never produce it 'because he'd lost it'.

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