Hi all.

Is there a simple formula or a chart that would give you the flight time or fuel burn for a particular engine?

For example, I wanted to know how much fuel a Super Tigre G75 consumed at Wide Open Throttle for 1 minute. Or even better, 10OZ tank with a G75 will provide approximately ____ minutes of run time.

I've looked at the specs for OS engines and the Super Tigre but fuel consumption seems to be left out.

Most folks I've talked to say to run it on a stand at WOT and time it or fly it until it starts sputtering. The last approach seems risky - especially after a touch and go while climbing out.

Thanks in advance.

r/hank

The dead give away for a tank emptying , is 1 the plane becomes lighter and 2 the engine leans out enough to be heard in the air signaling it's almost time to land. Other than that I use the timer on my radio. I have it set for 15 minutes and have never expired that on any plane I have flown.

the most accurate method is to just run the engine on the ground and time it! then set ur timer a few minutes less to account for fuel used when starting, taxing, waiting etc.

There are far too many variables to say how long an engine will run on a particular size tank. Even two identical engines can be quite different. If you're worried about dead sticks on first flights then the safest way is to run it on the ground for maybe 5 minutes at full throttle (worst case scenario) then see how much of the tank was used. If it used half a tank then you can say you've got 10 minutes of full throttle flying before it stops so give yourself room for error and land at maybe 8 minutes. But you won't be flying full throttle so check the amount used after that 8 minutes and get a better idea of how much is used in normal flying. Always leave a safety margin.

Here's what I do for this problem. After the motor is broken in, I will run the engine on the ground and run it at full throttle and I will time it takes for the engine to die. I will run 3-4 tanks through it so I can get a good idea of how long I can fly before the engine will die. I will then subtract a minute or so off of that figure. I will then set my timer for the time I came up with. I've never ran out of fuel doing this, and I've always have plenty of time to get the plane down after the timer goes off.

Hope this helps

Ken

60's burn about one ounce per minute wide open. Ten ounces, ten minutes. Your 75 will burn slightly more. Count on 8 1/2 minutes wide open. You can stretch that a bit with power management. Often by several minutes. Touch and goes give great mileage. The smallest tank I use with a 60 is 12 ounces. I would suggest at least 12 or 14 ounces for a 75.

I get decent flight time with a 10 oz tank and a GMS 76, about 11-12 mins.

What RCKen said... This is the same procedure that I use and has not failed me yet... Well 1, and only 1 time I forgot to refuel (BSn with someone) gets your attention when the engine quits BEFORE the timer goes off.
-Tom

Thanks all.
I'll run it on the ground at WOT and time it and substract a few minutes.

Think I need a larger tank G75 + 10 oz tank does not appear to be enough.

regards,
hank

the WOT method for me doesn't even come close, I fly lots of 3d stuff so a fair amount of my time isn't at full throttle. pulling out of a hover is about the only time, other then that it is half or less. learn to hear your lean engine, I can usually pick that up on most of my planes with a minute or so of above idle throttle left, enough to get a nice landing in.

I've found that the times can vary with fuels also. I've only been doing this a year but higher nitro fuel seems to demand a richer mix and thus burns more fuel than lower nitro.

What I do is count turns on my hand fuel pump to fill the tank. I then set my time for about four minutes and fly pretty close to wide open throttle for that time, then land. I then refuel and count the turns to top off. From there I just extrapolate how much longer I could have flown before running out of fuel and try to give myself a minute of margin.

I've also learned that the left stick actually has positions between idle and WOT. I've learned to enjoy flying at half-throttle and using power when I need it. That approach usually gives me more of a margin on flight time.

Mark