Thrust angle for 200HP

[swinn]

I am ready to install the engine mount on the Long-EZ for our 200 HP IO-360 engine. I have been told that the thrust angle should be changed to accomadate the higher power engine to reduce the down thrust on takeoff. Does anyone know if the thrust angle needs to be changed, and if so what angle should be used?

[Jon Matcho]

Scott, I'm certainly no expert on the subject, but have lurked on all the mailing lists for the past few years. FWIW, I've never heard of changing the thrust angle.

 

I've heard of changing the thrust line an inch, but you need to be careful with that too. Why not finish to plans so that your only major variable is your big engine? High speed taxi tests will eventually give you a good feel of your takeoff roll.

 

Just a thought.

[swinn]

Jon, that sounds like the plan to me. I have gotten similar feedback from several sources now that the plans thrust angle should work fine.

[longez360]

Disagree. I adjusted the thrust angle on my 360 powered Long EZ with washers under the mount. The vertical vector component of the original O-235 was used to calculate the new thrust angle. I theoretically gained a fraction of thrust, but vibration did go down. Big surprise was elevator position. Although I never measured speed, my trim drag should be lower. Takeoff roll was essentially unchanged. Prop position changed approx 3/8" from memory.

 

Cheers

 

Wayne Blackler

IO-360 Long EZ

VH-WEZ (N360WZ)

AUSTRALIA

[Jack Morrison]

I have an E Racer with a sio540, thrust angle is the same as an E Racer with a O320 or an IO 320. Works perfect. 360 HP V 160 HP.

 

Jack

[swinn]

Wayne,

 

Thanks for the information. We may try changing the angle with washers to see if there is a change in the future.

 

--Scott