happypappy

My Feedback: (10)

Am assembling a Kadet Sr. and it seems like there is way too much down thrust built into the firewall and subsequently the mount/engine.
I have measured, with a digital angle finder, 6.2 deg down, when compared to the flat surface of the wing saddle. Can anyone out there measure theirs and compare it for me? This angle really came to light when trying to mount the cowl. Engine is a Saito 72 and the mount is dead center around the original holes. Crank is dead center also. Have posted at another site also to get some help as fast as possible. Thanks!

drone pilot

You can take some of the down thrust out with wedges or washers, but Sig doesn't usually make mistakes with their ARF's / kit's. If that is the way it is built, I'd go with it.. I haven't met anybody yet that has found a problem with putting it together the way it is.. Have three among people I fly with......You might want to try flying without cowl and see how it flys. If you don't like the way it flys, shim out some down thrust then deal with fitting cowl.....

Sport_Pilot

The firewalls down thrust is about right for a .40 sized engine. You will need more for a .46 and still more for a .60. This is a light plane with a high lift wing, it needs plenty of down thrust.

jonnyolson

hmmm. So as you increase engine size, you need to increase the down angle of the engine(negative thrust angle or negative engine incidence). Is this to somehow offset the negative pitching moment of the wing,because of increased thrust vectoring? Point the lift vector forward thus giving a postive pitching moment to offset the weight or??????????????????? I have allways been interested in this. What happens if you don't point the engine down after adding a larger engine? Any help or input appreciated.