NEPTUNE ENGINE POD
 

PUT TOGETHER A NEPTUNE SAEPLANE AND PUT A MAGNUM 70 4 STROKE ON IT. CHECKED ENGINE THRUST AND IT WAS OFF TO THE LEFT 3/8 OF AN INCH. I HAVE R.C. LAND AIRPLANES AND THEY ARE IN THE MIDDLE OR A LITTLE BIT TO THE RIGHT. ANY HELP WOULD BE WELCOME. THIS IS MY FIRST SEAPLANE AND DON'T WANT TO DESTROY IT. THANKS

RE: NEPTUNE ENGINE POD
 

Hello,
I haven't surfed seaplanes for a while and you've probably discovered the answer by now but here is mine.

Thrust angle on almost all engines in down and right to compensate for left torque and the tendency to clime under power.

Carlos

RE: NEPTUNE ENGINE POD
 

Carlos is correct,but since the thrust line is way above the airfoil,even 0* is O.K.
Just put washers between motor mnt. & firewall on one side.I'm assuming the 3/8" was measured from tip of prop to end of fuse.-Jeffo

RE: NEPTUNE ENGINE POD
 

Even more so: Since the thustline is so high, and the CG is WAY below that and so is all the drag, the thrust angle in a Flying boat is usually UP as much as 3 degrees. Otherwise when you punch power, inertial and drag forces want to cause it to pitch down. Also they give FBs T-Tails so that the downwash from the upthrust hits the elevator to help counteract the nose-over moment especially on sudden acceleration.

With up-thrust it is necessary to compensate for the misalignment of the airflow through the propeller disc, so right thrust is also dialed in 2-3 degrees.

I'd start with up three and right three degrees. If it's too much the plane will balloon a little. That's better than suddenly powerdiving into the dirt.http://www.dkimages.com/discover/pre...776/279444.JPG
Here's full-size Lake amphibian. Even tho it's a pusher you can see that there is a lot of upthrust.

RE: NEPTUNE ENGINE POD
 

Jim;Good advice!!My firest seaplane I put in the usuall down and right thrust would on a land plane!Actually it made a very nice boat could drive it at about any speed on the water and stick like glue.That was a good lesson for me,you may have saved this fellow lot of frustration!I know I sure was discusted with my Sea Dancer till I learned that lesson!

RE: NEPTUNE ENGINE POD
 

[8|THANKS FOR ALL YOUR HELP ON THE SEAPLANE FELLOWS, WE'LL GIVE IT A TRY. RAY]

RE: NEPTUNE ENGINE POD
 

Thanks everyone!! All of your info was great!