naviguesser

I have an older saito 120 with a newer carburetor. It's installed in a 90" Dynaflite Decathlon (approx 17lbs). Currently using an apc 15x6 prop but takes most of the runway to get off the ground. At full power with this prop tacks out at 9100 on the ground.
Thinking of using a 15x8 or 16x6. Any suggestions?

Gray Beard

My Feedback: (-1)

You mean Chuck hasn't told you yet????????? There is a prop chart sticky in the beginners forum you can look at. 17 pounds is a bit heavy for a 1.20 so the plane is going to eat up a lot of runway to get the ground speed up. I was flying my 16 pound Bipe there with an OS 1.20 and it didn't need a lot of runway for take off using a 16X6 APC. It wasn't a ball of fire but it flew.

Edwin

My Feedback: (2)

I think grey beard has it right. I run my newer saito 120s with a 16x8. The heaviest plane was 14lbs and did alright with that one.
Edwin

yellerchamp

My Feedback: (42)

16x6 apc on saito 120, rpm is 10300 run it a little rich tachs at 9850 on a gp stearman with the engine mounted upside down, plane is well over 15 lbs

AmishWarlord

My Feedback: (5)

Hey just put this prop on that 1.20 and your plane will take off like a rocket with 18 pounds of thrust. Down side is you will only be able to fly at 42 MPH.

http://www3.towerhobbies.com/cgi-bin...P?I=LXESL5&P=8