OS FT-300
07-26-2004, 02:04 PM
#1
Member
Thread Starter
OS FT-300
I bought this engine used IE no manual. I am putting it on the GP Pitts. This has a 24oz tank. How long of a flight at full throttle can I get? Next question, is a 20X10 zinger pro prop. a good choice for this combo? Should I make a pressure tap for the fuel tank or just run without it? Lastly when you run this engine little oil comes out of the crank case breather. When you shut it down the oil then just runs out of it and leaves a big puddle. Is this normal?
Thanks for you help.
Thanks for you help.
07-27-2004, 09:50 AM
#2
My Feedback: (11)
RE: OS FT-300
You can download an instruction manual from the O.S. web site.
At full throttle, a 24 ounce tank will last 12 -15 minutes or so. The FT-300 IS a big engine!
On the test stand, we normally use an APC 18 x 10 and see middle 6,000's. A 20 x 10 would be too much prop. We'd want to prop the engine to turn in the mid- to high- 6,000's
It's normal for oil to come out of the crankcase breather. A bit of tubing to direct it can be put onto the drain port.
There's no provision on the engine to add pressure to the fuel tank. You can't use crankcase pressure...there is none. The engine needs the case to be open through the breather. If you make a muffler, you can then tap it for pressure, but it's not needed if you mount the engine and tank correctly.
At full throttle, a 24 ounce tank will last 12 -15 minutes or so. The FT-300 IS a big engine!
On the test stand, we normally use an APC 18 x 10 and see middle 6,000's. A 20 x 10 would be too much prop. We'd want to prop the engine to turn in the mid- to high- 6,000's
It's normal for oil to come out of the crankcase breather. A bit of tubing to direct it can be put onto the drain port.
There's no provision on the engine to add pressure to the fuel tank. You can't use crankcase pressure...there is none. The engine needs the case to be open through the breather. If you make a muffler, you can then tap it for pressure, but it's not needed if you mount the engine and tank correctly.
07-27-2004, 05:39 PM
#3
Member
Thread Starter
RE: OS FT-300
I put an apc 18X10 prop on it. It turns it at 8700 rpm. I richen it up to 8100 rpm. Is this too much rpm? Also the needle valve is turned 4 turn out. Is this normal? It turned the zinger pro 20X10 prop at 5200 rpm. Should I try a zinger pro 20X8?
Thanks
Thanks
07-28-2004, 10:02 AM
#4
My Feedback: (11)
RE: OS FT-300
Sorry, when I looked up the engine in our charts, I accidentally read the wrong line. With an APC 18 x 12 prop, we see 7,300, so your RPM with the 18 x 10 would be about right. Sorry for the error. With so many different engines, we have to use a chart that shows all of the various engines with the RPM levels we've derived from testing over the years. Sometimes I just read the wrong line.
Re-checking shows that we normally try for around 7.000 RPM. Peak horsepower is at 7,000 RPM, so propping it for around that would be best.
Sorry for the mistake.
Re-checking shows that we normally try for around 7.000 RPM. Peak horsepower is at 7,000 RPM, so propping it for around that would be best.
Sorry for the mistake.
