Fuel burn and things

[motzartmerv]

Hi fella's. Im considering buying a rag and tuber. Mabye a drifta or something of the like. I flew in a drifta once and if i had to sum the experiance up in one word it would be, FUN.. expletive deleted FUN..

 

Can some of you two strokers help me out with some stats.. Like, whats the average fuel burn for the 582 rotax and 502.. What is the drifta rated to g wise.. What sort of training acft do you guys think they would be?

 

cheers lads..

 

 

[Ultralights]

the 503 in my vampire uses approx 15 ltrs /hr at 5000 rpm.

 

 

[Guest Baphomet]

Hi Merv, I own a Bantam (582) and also fly a Drifter (582) from time to time (did my conversion in one). I plan on 18 lt/hr in either of them. The 503's I believe are a bit more economical but have lower rate of climb. They make excellent training aircraft, any student is going to be fully conversant with the effect of rudder by the time they're endorsed in it. Both aircraft are very strong, and properly maintained won't give you any cause for concern structurally. I think I heard that the wire-braced Drifter was good for 6G, but I could be wrong. in any case, you won't be pulling the wings off one anytime soon. My summary of a comparison would be, The Bantam has a wider performance envelope (stalls slower and has about the same cruise), is MUCH easier to land (tricycle undercarriage) and lands shorter, and is more social (pax is next to you, not behind you) and oh, you can open and read maps in the cockpit :-). The Drifter has better vis (Bantam is good, but nothing compares to the Drifter) and has more endurance (long range tank).

 

Hope this helps. send me a PM if you want more info.

 

Cheers

 

Ian

 

 

[farri]

Hi Merv,

 

My Maxair wire braced Drifter has had 1,Rotax 503 and 4 ,582 engines, I used it for instruction for almost 12 years,I`m retired from teaching and have now gone back to a new 503,hasn`t been started yet.

 

From experience,the first 503 was a bit under powered on a hot day with a heavy guy in the front seat,on an anaverage day,doing circuits at sea level it would use anywhere between 13 to 15 lts phr.

 

For instructing the 582 is the way to go,in 2 strokes,again, at sea level with standard jet needle and needle jet in the carby,doing circuits on an average day I would get between,12 and 14 lts phr.

 

Keep in mind that fuel burn is determined by the jeting of the carbies,the way the throttle is used and air density on any particular day,there are other factors also and it is better to be running a bit rich than too lean because lean will burn the pistons.

 

Cheers,

 

Frank.

 

 

[Guest TOSGcentral]

This is probably going to be controversial!

 

 

Motz – a Drifter! Gawd Man grow some hairs on your chest and get a Thruster. You want to instruct then get something that you will not get bored with (Sorry Farri!). But more to the point something that you can turn out really great students from that really are equipped to fly ‘anything’ around that weight.

 

 

Fuel burn? 13 years of flying Thrusters now so the figures are kosher. 503s I cannot say – would not give one house room in a Thruster for instructing. It can be done, has been done often, but the 582 gives far more teaching flexibility as well as safety.

 

 

R582 on standard jets and needles and a 16 degree pitched 3 blade Brolga gives 16 ltrs per hour at 55 knots under intensive school training work being mainly circuits and low level emergencies (5600 rpm).

 

 

Cross country 60 knots (6000 rpm which is hardly flogging the engine) gives 20 ltrs per hour.

 

 

Aye

 

 

Tony

 

 

[Yenn]

The 503 in a Thruster gave me a consistent 16 l per hour, except for when the float pins wore and I suddenly used 22.

 

It would appear that there is little saving using a 503 compared to a 582. The 503 is always working hard.

 

 

[farri]

G`Day Tony,

 

No controversy at all, and I`ve never had many hairs on my chest and now I don`t have many on my head either.

 

Boy you`re using some fuel, with every 582 I`ve had, I`ve turned a 60 inch, 4 blade Brolga prop with 17 degrees of pitch.

 

Taking it easy I would use, on average 12 lts phr,and on a cross country I would flight plan for 14 lts phr, this always proved well on the side of caution.

 

As you say,the 582 is the better engine for instructing, in the Drifter,a good burst of power and you get sudden rudder response which makes it easy to correct students mistakes.

 

The 503 may well use more fuel, because it`s working harder to do the same thing, but if the extra power is not needed the purchase cost is much less and the saving buys a lot of fuel even with the increase in fuel price

 

Regards,

 

farri.

 

 

[Guest brentc]

You won't able to buy 503's any longer so stick with the 582 as a minimum.

 

 

[Guest TOSGcentral]

Yup Farri - big difference between the two types.

 

I reckon that is down to drag. The Thruster has a massive cross sectional area compared to the Drifter (shows up well in how much better the Drifter glides). Just putting aerofoil section lift struts on a Thruster gives you 6 knots more cruise.

 

But hell! I just like the Thruster ambience, so it is worth paying a bit more for

 

Tony

 

 

[farri]

Rag and Tube

 

Tony,

 

You`re doing a great job in trying to keep rag and tube flying

 

Good onya.

 

Cheers,

 

Frank.

 

 

[motzartmerv]

Thanx for the info guys.. Ive only flown the one thruster and ive posted previously about my experiance in that machine.. Its probably unfair to judge them all on one aeroplane (that was dangerously U/S), but, there we have it..

 

I would probably move guys up into the J160 after they solo the drifta and teach nav and some advanced stuff in the jab.. I think a true rag and tuber is needed in the sydney area, no-one'd doing it anymore, and i reckon we need to keep the spirit of the ultralight thing going because its what attracts alot of ppl to the game in the first place.. High performance stuff like the jabs and tecnams are fine, but the diff between them and the lighter ga stuff has narrowed to practically nothing i feel..

 

if anyone knows of anyone operating a drifta (or thruster, dare i say it) in the sydney area let me know. I'd like to tee up a flight to suss it out further..

 

Thanx guys (sorry about the thruster comments tony)..lol

 

cheers

 

 

[farri]

You won't able to buy 503's any longer so stick with the 582 as a minimum.

Hi Brentec,

 

What do you know that I don`t?.

 

Why won`t the 503 be available ?.

 

Frank.

 

 

[motzartmerv]

1 more silly question... obviously the fuel needed is 2stroke...How is that organised at airfields , i mean can u add the oil to avgas??...or do ya just rock up to the servo and ask for some mower fuel (that sounds scarrrrry)..

 

cheers

 

 

[Guest TOSGcentral]

Farri - the goss a few months ago was that Rotax was discontinuing production of R503s although the R582 would continue and parts for R503s would continue.

 

That is not much help with the price hike and restriction on parts that Rotax engineered a few years ago, making a rebuilt Rotax so close to a new motor that it was not really worth re-building any longer.

 

This is a bit of a body blow for 95.10 where the R503 was really the main engine that was reliable and proven. Most of those real ultra light types cannot cope with the power or weight of a R582 (I put one on a Glasshouse two seater and was using full stick to counter the torque until I got it down and we started re-organising the trim of the aircraft and it flies OK now.

 

But there are a lot of types it simply has too much power for. OK the Volkswagon four stroke goes successfully on a Tyro and you do not get much more 95.10 than that - but there is a woeful lack of knowledge combined with too much freedom out there that could lead people into difficulties.

 

I dunno! Looks like this 'evolutionary mentality' that we have to re-invent GA is in full swing now and I personally am really ticked off that several thousand people will suffer as a result of the way we have been led - and what for? To get more membership that in turn is shoving up prices and reducing services?

 

Guess I will stick with my Thrusters - at least they can be remanufactured and enhanced with another 20 years of life in them plua you can fix them at home. The view out of the window is the same and does not go past that much slower.

 

Aye

 

Tony

 

 

[Guest TOSGcentral]

Motz - did not Bill teach you anything other than how to wash your jocks?

 

You do not use Avgas in 2 strokes (even LL100) it sludges up the combustion chambers and bores - thereby reaming out your engine.

 

What you do is rock up to the local servo brandishing a 20 ltre jerry can or two, or a 60 litre drum, to which you have already added the oil (which should be a good quality 2 stroke racing oil - mineral seems best these days) and enter a measured amount of fuel to compliment the oil in a 50:1 ratio. and refuel with Premium unleaded (ordinary unleaded is too low an octane).

 

Now doubtless others will argue with me and I do not give a stuff! Been there and done that and use what I know works and looks after my engines!

 

Tony

 

 

[farri]

Howdy,

 

I`ve tried synthetic oil and it doesn`t burn well and makes a mess out the exhaust.

 

With the 582 which is water cooled I`ve used Valvoline outboard oil with good results,

 

burns pretty well.

 

I`m not sure about Premium unleaded as I havn`t used it but I tried Super when it was around and found that the engine was running 10 to 15 degrees hotter,I`ve used unleaded ever since.

 

With 503 make sure the oil is for air cooled engines and with the 582 that it`s for water cooled or what is described as WAO approved.

 

Hope you can afford a whole 20 lt drum of fuel, these days.

 

Frank.

 

 

[motzartmerv]

hmmm...so its a servo job...thats a bit of a bumma...

 

Tony, i won't go on about what Bill did and didnt teach me (but washing jocks was deff in the syllabus)...

 

So how do you guys organise the refuelling on trips??...land at a servo??..walk into town with a jerrycan??...hmmmm

 

Can someone fil me in on some stats...whats the stalling speed of the drifta and thruster?? what sorta crusie do they get and so on

 

cheers lads

 

 

[farri]

Re-Fueling.

 

Merv,

 

Re-Fueling away from home with a 2 stroke certainly is a challenge,needs some imagination.

 

Regarding the stall speed of a Drifter,I think we`re going to have to be more specific with which Drifter we`re talking about,from now on.

 

For starters There`s the Maxair Drifter,single and twin seat,wire braced,503 and 582 powered, then there`s the Strut braced, 582 or 618 powered, then there`s all the ones that have been modified by the owners.

 

We then have the Wayne Fisher Drifters, which are different again,to my knowledge Wayne has one with a 912,Take you`re pick,which do you want?

 

Have fun choosing.

 

Cheers,

 

Frank.

 

 

[motzartmerv]

lol..ok fair enough (told u it was a stupid question).. the one im looking at is a 95 model, 2place with the large pod, wire braced with a 582

 

cheers

 

 

[farri]

Sorry Merv,

 

But furthermore when talking about Stall speed we need to define, IAS with power on or power off and at MTOW or otherwise.

 

Stupid is relative,never be afraid to ask questions.

 

Frank.

 

Don`t complain to me you put yourself in it.

 

 

[motzartmerv]

lol...ok...power off stall speed i spose, being a pusher doesn't that negate the effects of power on Vs?? perhaps the quoted Vs at MOTW would be a good place to start..

 

cheers

 

 

[farri]

Re-Inventing the wheel.

 

Tony I agree,

 

What will have to happen, somewhere down the track is that the re-invented wheel will have to be re-invented again, if there`s anyone left, prepared to do so that is.

 

Frank.

 

 

[Ultralights]

when i enquired about buying a new 503 for the vampire, i asked about running LL100 Avgas in it, the burt flood rep said it is fine, just you have to change the plugs twice as often, and use mineral 2 stroke oil...

 

 

[farri]

lol...ok...power off stall speed i spose, being a pusher doesn't that negate the effects of power on Vs?? perhaps the quoted Vs at MOTW would be a good place to start..cheers

Merv,

 

You`re getting warm but I`m not sure what you mean by, " being a pusher ,doesn`t that negate the effects of power on Vs?"

 

Will you explain,please.

 

Frank.

 

 

[motzartmerv]

Farri, the drifta is a pusha, the engine faces backwards and the prop blows over the tail section and not the wing.. The reason power reduces stalling speed (Vs) on conventional aircraft is due to the extra airflow over the inboard sections of the wing when power is applied.. ,the wing doesn't care where the extra airflow comes from..so an acft that has the engine behind the wing won't have a reduced Vs when ya add power..

 

So, how are we going with that stalling speed??;)