T300 cruise rpm

[Guest Johnny B]

With a cruise speed of 55 Knots what rpm would you expect the 582 to be turning at? Some say rotax 582 cruise is 6200 others as low as 4600 I was thinking 5200 would be a good compromise between speed and fuel consumption. Can any Thruster flyer out there tell me what they cruise at and at what revs.Still getting an idea of the correct pitch for my prop.The prop supplier says a 56 pitch, which would give 70 Knots with a 3-47 ratio at 5200 revs.Assuming its a geometric pitch value and a slip of approx 25% leaves it at about 52 Knots.Still a bit stab in the dark though.Would like to hear from someone who runs that ratio.

 

Cheers

 

John B

 

 

[pudestcon]

With a cruise speed of 55 Knots what rpm would you expect the 582 to be turning at? Some say rotax 582 cruise is 6200 others as low as 4600 I was thinking 5200 would be a good compromise between speed and fuel consumption. Can any Thruster flyer out there tell me what they cruise at and at what revs.Still getting an idea of the correct pitch for my prop.The prop supplier says a 56 pitch, which would give 70 Knots with a 3-47 ratio at 5200 revs.Assuming its a geometric pitch value and a slip of approx 25% leaves it at about 52 Knots.Still a bit stab in the dark though.Would like to hear from someone who runs that ratio.Cheers

John B

Well JB, I dunno if you want to take my figures, what with the prop/RPM issues I have, but at 5200 1 up I cruise at 55kts. For the record, 68" Brolga prop with 12* pitch blocks powered by a Rotax 582 blue head engine through a B reduction box with 2.58 reduction.

Pud

 

 

[skyfox1]

You Might be better off running a 4 blade with that ratio box

 

 

[SAJ]

G'day John B

 

My T500 cruises 50/55 kts at 5200 revs 1 up, 5400 revs 2 up, My max revs is 6200, I have 15* pitch blocks and a C type gearbox not sure of the ratio. I use about 17 to 18 Lph at these settings.

 

SAJ

 

 

[propfarmer]

Hi John, the TST E that I am doing a bit of flying in cruises at 5400rpm 55kts, two up. I think it has a B type box? Not sure though. It acheives 6500rpm on climb.

 

 

[robinsm]

Xair with blue head, 16 degree pitch on 3 blade brolga prop with c box (3:1). 5500 revs cruise. 55 knots (only problem is 18 - 20 lts hr).

 

 

[corky450]

t300 with 16 degrees, 68 inch brolga prop, e gearbox,blue top 582 getting 55 kts at 5500 rpm.6300 rpm flat out

 

 

[robinsm]

Corky450. 6300 flat out is what I get as well. Thank goodness someone else gets that, I was worried I couldn't get the quoted 6800 although everything seems to run ok. Is the e box a 3:1 ratio?

 

 

[corky450]

Robinsn ,yeah i'm pretty sure it's 3:1 ratio & i'm burning about 18 lts an hour also

 

 

[Guest Johnny B]

You Might be better off running a 4 blade with that ratio box

Thanks Syfox.The motor did come off a Trike that ran a 4 blade but it's cruise was 40 Kt.I am trying to find someone with a Thruster or something that cruises at the same speed. Cheers JB

 

 

[Guest Johnny B]

Hi John, the TST E that I am doing a bit of flying in cruises at 5400rpm 55kts, two up. I think it has a B type box? Not sure though. It acheives 6500rpm on climb.

Great to get So many replies.Most of the numbers are looking about right .Unfortunately no one has the same 3.47 ratio.I am still rebuilding the Thruster and it is a long way off from finished so I have plenty of time to sort something.

Cheers and thanks to everyone.

 

JB

 

 

[pudestcon]

Robinsn ,yeah i'm pretty sure it's 3:1 ratio & i'm burning about 18 lts an hour also

I reckon my fuel burn is closer to 15l per hour but I wouldn't say that is definitive just yet!! Maybe that is my problem - running a bit lean.

Pud

 

 

[flyerme]

Corky450. 6300 flat out is what I get as well. Thank goodness someone else gets that, I was worried I couldn't get the quoted 6800 although everything seems to run ok. Is the e box a 3:1 ratio?

the quoted 6800 rpm is max which means RED LINE,all rotax up to 582 should have a max of 6300 rpm in climb out and ground run should be 6100-6200..some will say 6500 on climb out but according to Rotax (Austria) it all about the torque range,,anyway all seem to be within range,I max at 6200 on climb out and 6000 om ground running a 447 - b type 2:24 with a power fin ground adjust 56" x 10deg ..

 

 

[skyfox1]

the quoted 6800 rpm is max which means RED LINE,all rotax up to 582 should have a max of 6300 rpm in climb out and ground run should be 6100-6200..some will say 6500 on climb out but according to Rotax (Austria) it all about the torque range,,anyway all seem to be within range,I max at 6200 on climb out and 6000 om ground running a 447 - b type 2:24 with a power fin ground adjust 56" x 10deg ..

l always climb out at 6800 most off the guys l fly with do the same ,and cruise at 5200.

 

 

[Guest nunans]

l always climb out at 6800 most off the guys l fly with do the same ,and cruise at 5200.

Just out of interest, if wide open throttle on climb gives you 6800 then what would it rev to in level flight if you didn't pull the throttle back?

Also what speed does it climb at when revving 6800 and what speed does 5200 give you in level flight?

 

What diameter and how many blades is your prop?

 

 

[skyfox1]

Just out of interest, if wide open throttle on climb gives you 6800 then what would it rev to in level flight if you didn't pull the throttle back?Also what speed does it climb at when revving 6800 and what speed does 5200 give you in level flight?

What diameter and how many blades is your prop?

Hi full throttle is 6800 so climb out at full throttle climbs at 50 knts at 5200 cruises at 55knts also depends on conditions.

l run a 60 inch three blade ivo prop with a c type gear box with 2.62 ratio on a rotax 503 on a Maxair Drifter.

 

cheers Geoff..

 

 

[Guest nunans]

Ok then, that's pretty good being able to knock 1600 rpm off your engine speed and pick up five knots at the same time! Must be alot of slip during the climb out...

 

 

[skyfox1]

Ok then, that's pretty good being able to knock 1600 rpm off your engine speed and pick up five knots at the same time! Must be alot of slip during the climb out...

No slid slip best rate off climb is 39knts at straight and level 6800 it will do 75knts .

Because of my short runway we take off a 50knts to clear the obstacles.