Engine offset on GP Super Stearman?
 

I am working on finishing my Super Stearman ARF and when I got to mounting the engine (G26) I noticed that the reference marks and engine mounting holes on the firewall are 1/4" offset to the left side of the plane. I am not using their mounting holes but I am curious if this is correct? I see no valid reason for the offset.

Thanks

RE: Engine offset on GP Super Stearman?
 

It's actually there for the right thrust that is built into the firewall. The left offset helps center the engine in the cowl while keeping the thrust angle correct. It looks weird now but will make sense when you mount the cowl

RE: Engine offset on GP Super Stearman?
 

OK, that makes perfect sense now. I will use the reference marks to center my crankshaft. Thanks for the quick reply!

John

RE: Engine offset on GP Super Stearman?
 

No problem John,

I just finished mine a few days ago and got about 5 flights on her now. She's a beauty in the air and on the ground, but you will need rudder. On mine the adverse yaw from the ailerons is pretty noticable if you forget the rudder, it's not bad but really easy to see. Her she is right before her maiden with no spinner since I needed to cut it out for the prop and had not done it yet

RE: Engine offset on GP Super Stearman?
 

Thanks again Bill. I will remember to be ready with the rudder when I get mine ready to fly. Nice looking plane you have. I really like the matching prop!

John

RE: Engine offset on GP Super Stearman?
 

Thanks John,

Pics do not do it justice. This is a bird you must see up close as you already know.

The prop is a Biela 18X6 on a RCIgnitions Converted G26 Zenoah. Needed no extra weight and it has yet to see anything above half throttle. Smoke system is ready for install. This bird just screams for smoke :D

The prop is available from here. It's a wide blade prop. I usually use a Mejzlik 18X6 on that engine but I wanted "the look" and this prop dropped rpm by 400 but it really did not take away from flying the plane.

http://www.aircraftinternational.com/

Keep us up on the build,,,

RE: Engine offset on GP Super Stearman?
 

I went to Aircraft International website. That is a really nice prop. I think after I get everything built/tested I will add smoke and one of the Biela props as well. I watched the video there about prop balancing and learned how to balance the hub. Thanks I will post again after I get closer to flight testing.

RE: Engine offset on GP Super Stearman?
 

Bill,

I mounted my engine (G26) yesterday and found that the prop nut adapter included with the stock GP spinner would not fit. Can you tell me what size prop nut adapter will work and where I could order one?

Thanks again for all your help

John

RE: Engine offset on GP Super Stearman?
 

Go to the tru-turn web site and act like you are going to buy a the same spinner. Once you choose the spinner then you get the option to pick a prop nut adapter...

http://www.tru-turn.com/

Once you get the size you can go to towers web site and get it much cheaper.

I honestly cannot tell you the size you need. The RCIgnition converted G26's have a prop bolt drilled for a 10-32 bolt so I did not need an adapter.

Also I just remembered. If you got to Horizon Hobbies web site and look under Zenoah, You will see the G26 listed there and I am pretty sure under optional accessories it lists the prop adapter and size required

RE: Engine offset on GP Super Stearman?
 

OK, thanks I will start with Tru-Turn and see if I can get it there. You have been very helpful!