Rotax 503 V's 582

[duongkhue84]

Just after some informed (or other) opinions on whether to replace an existing 503 (on a Thruster) with a new 503 or new 582 (which appeares to be approx twice the price).

 

+ I believe the cooling system in the 582 has some ongoing costs/issues

 

as opposed to the air cooled 503. Is the extra hassle + price of the

 

582 worth the extra 15hp??

 

 

[facthunter]

The 582 is the only motor available new from Rotax, in the 2 stroke range. Nev

 

 

[Head in the clouds]

I have quite a number of hours in the 2 seat 503 Thruster Gemini and just a few hours in one with the 582. About the only improvement with the 582 seemed to be a bit better climb rate.

 

I was talking to a friend the other day who has re-engined his with a 582 and he preferred the 503. His comments were about the extra weight and more forward CG chewing away the performance, and the even worse glide (if that is possible) due to the forward CG and the extra frontal area from radiator(s) increasing the drag. He found that he had to increase his approach and landing speed or would not have sufficient elevator authority for flare/round-out.

 

He said that he had tried adding weight aft to correct the CG but it didn't make any significant difference.

 

Last time I enquired, about 12 months ago, Rotax Rick in the USA was still supplying zero-timed 503s (long or short engine) and he seems to have an excellent reputation for quality as well as price and after-sales service. He could also re-build your own engine with new parts if preferred.

 

Welcome to the forum duongkhue84

 

 

[Cosmick]

If you could lay your hands on a 503 go for it but they are getting very hard to come by.

 

 

[Guernsey]

Have you tried Bert Flood as he may be able to supply a reconditioned 503 or rework yours.

 

Alan.

 

 

[Soleair]

I suggest you consider Compact Radial Engine's MZ202 here: http://www.compactradialengines.com/mz202.html

 

It is a very well built engine, which produces 25% more horsepower than the 503 at a weight saving in excess of 22lb. They are standard fit on the Mosquito light helicopter, so are reliable & well proven.

 

Give Leon Massa a call at CRE. You should pay less for the MZ202 than the Rotax 582. The 202 is fan air cooled like the 503, which means considerably less cooling drag due to reduced frontal area otherwise needed to accommodate the 583 radiator(s).

 

Bruce

 

 

[Don Arnold]

Back in the 1960's the moaning began about what to do when the supply of 65hp Continentals dried up. You can still get them, and any part you need. I wouldn't worry about the 503. It still the most reliable 2-stroke out there. My friend and I both tried Hirths, but went back to 503's. I hope the MZ's work out, but I'm done being a pioneer.

 

 

[flyerme]

Firstly the 582 including it's water cooling system is actually lighter by 200 grams than a 503... The 503 fan, dual carb dual ignition is the heaviest Rotax 2 stroke . I bought a brand new a Rotax 582 from bert a floods last year at a cost of $8000 for my lightwing. And I then had them rebuild the 503 for my nieuport at a cost of $ 6500.

 

It wasn't until after I had the 503 rebuilt that Gary at bert flood told me the 582 fully loaded was lighter than the 503. How ever I wouldn't want any ugly radiators hanging out the nieuport so still happy with rebuilding the 503.

 

I did my certificate In A 582 thruster T500 and have flown a t300 With 503.

 

I agree the climb was better with 582. But cruise was pretty much the same and the 582 used more fuel. !

 

As far as 582 cooling problems that was actually the 532. NOT the 582!

 

582 is a great engine but IMO. 503 hands down is the best 2 st. Out there.

 

Hope that helps.

 

And don't forget if it's 25 rego... You need an E/O. To change from 503 to 582...

 

 

[facthunter]

It's the bulky and draggy exhaust system as well as the radiators that make the two strokes so messy to install and ugly on the aircraft. The time will come soon if it isn't upon us now where the unsupported not available new, engines will be made of a collection of pretty tired parts, where you might build one good one out of three dead ones. The cranks are built up and if you get that done make sure it's done properly. Nev

 

 

[flyerme]

It's the bulky and draggy exhaust system as well as the radiators that make the two strokes so messy to install and ugly on the aircraft. The time will come soon if it isn't upon us now where the unsupported not available new, engines will be made of a collection of pretty tired parts, where you might build one good one out of three dead ones. The cranks are built up and if you get that done make sure it's done properly. Nev

It is upon us now Nev!!!!! I gave up on looking here and over seas for a 277 rotax. But have found the Aerochute engines are perfect for my invader project.

 

 

[howe]

When comparing a Kestrel - 503 + c box and a Bantam with a 582 + c box, both aircraft weigh about the same. The climb is better in the Bantam but at cruise 5500 rpm the 503 has so much less vibration, although the bigger prop on the 582 may contribute to more vibration.