Somethin' Extra's engine req's
 

Taken from Towerhobbies.com .....

Engine: .40-.46 (6.5-7.5cc)(2-stroke)
OR .56-.65 (9.2-10.6cc)(4-stroke)


Do you think a Saito .72 or an OS .70 is too much power for a Sig Somethin' Extra? I am currently running a Thunder Tiger .46 Pro on it with an 11 x 3 prop.

RE: Somethin' Extra's engine req's
 

The Saito 72 or OS 70 4 strokes will be fine. You will be at the upper end of the power requirements. You will find that the 4 stroke engines of that size MAY be a little over powered for the plane (depending on the weight). You will be running a larger prop, so make sure you have adequate ground clearance (you should be ok on that). You will most likely be running a 13x6 prop on those engines vs an 11x6 you are presently using.

My Saito 72 provides power ABOUT equal to a good running/hot 53 to an average/semi tired 60.

You fuel consumption will be a lot less - figure an additional 25%+ flying time compared to the 46.

Don't forget to rebalance the plane :D

Good luck. I think you will enjoy the sound of the 4 stroke much more than the 2 stroke. Remember, if the engine is not putting out smoke, you are most likely running it too lean.

Hope this helps.

RE: Somethin' Extra's engine req's
 

I have a Saito 56 on mine and love the combination. I think the OS may be a bit heavy for this airframe. The trade off of power may not be worth it. The Saito 72 would be a better choice if you need 3D power. Prop clearance may be an issue.

Difficult to believe you can get that TT .46 to perform very well with a 11X3 prop though. Have you tried a bigger pitch like a 11X5? Or 12.25X3.75?

RE: Somethin' Extra's engine req's
 

I did a test yesterday at the field. I put on about 6 different props, ranging from 10x5's up to 11x6, and I liked the 11x3 the best. I am not a speed demon, but do like the vertical pulls from the 11x3 the best.

RE: Somethin' Extra's engine req's
 

Rich, the saito .72 is my favorite engine for .40 size planes. They are lighter than most .46's and a heck of a lot more torque. The saito .72 would be perfect for your SE. I have a sig se with an irvine 53 on it. I am running a 12" prop and have only about 1" of prop clearance with the stock landing gear. If I was going to put the saito .72 on this bird, I would check out a new landing gear to give you the required clearance for the 13"-14" props. A good place to get one of these gear is: www.tntlandinggear.com, part number LG-177

RE: Somethin' Extra's engine req's
 

Already have the dubro fiberglass gear under it. Same gear that I used for my LT-40 taildragger conversion, but painted it gloss black.

Clearance isnt an issue anymore :)

RE: Somethin' Extra's engine req's
 

Go for it. The Saito would be just peachy in that plane. You'll love it.

Mark Shuman

RE: Somethin' Extra's engine req's
 

I think I will start saving up for a Saito 72. Might go with the FA-72 Golden Knight since it does match the colors of my plane.