Guys,

The problem I have is: I have an airplane (Tucano 120) to install an engine to, but there are no lines crossing that hole where the tank goes into and this plane has a cowl.

Can you teach me any technique to install the engine and have it aligned with the cowl properly? Thanks!!!

Flavio

One of the best manuals I have come accross for the instalation of the engine and cowl was the Hanger 9 Spitfire MK II. I learned some good techniques from following these directions (don't tell my wife I followed the directions). Here is a link to the manual on line:

http://www.hangar-9.com/ProdInfo/Fil..._60_Manual.pdf

You will of course have to make adjustments to fit your aplication but the techniques should be universal.

Mr67Stang,

Thanks for replying, but my problem is a little harder, because there's no relative reference relating the firewall to the center of the cowl.

Thanks anyway,

Flavio

Are you talking about mounting the engine off-set on the firewall to account for the right thrust so that the prop is centered on the cowl? If so it depends on the distance from the firewall and the prop driver and the angle of the right thrust. For example, if that distance is 6 inches and the right thrust is 2 degrees then you must mount the engine mounts at 0.21 inches to the right of the firewall center (looking at the firewall from in front of the plane). The formula is:

Offset = (Firewall to prop drive distance) X sin(angle of right thrust).

cheers

are you talking about the engine thrust line?or centering the engine.most manuals will show you where and how to mount the engine per kit unless you are going to mount the engine other than what the instructions say.there is a vert and horz thrust line.the pdf that Mr67Stang posted shows you how for that airplane but it is the same idea with most any kit.

Yes. If you mount the engine central on the firewall but you introduce some side thrust, then the prop driver won't be central as it exits the cowl. So in this case you need to mount the engine off center on the firewall. If you add down thrust, you have to mount the engine slightly high on the firewall for the same reason.

hope this helps
/colin

Crtmmac,

You really solved my problem! Thank you so much!! Quedstion now is: angle is -2 degrees... After applying the formula, I've got a negative number, which is -5xx mm. Is it to the left or to the right?

Thanks!

Flavio

Hi Flavio.

I assume that -2 degrees places you engine into right thrust. That's normal to counter the severe left torque of the engine. That means that looking from the rear of the plane, the engine will point a little to the right. That's normal. All my singles have right thrust. Now look at the firewall from the front of the plane. The engine will be pointing slightly to your left. Therefore the the rear of the engine mount must be set slightly to the right of center. (looking from the front).

If you want to apply down thrust. This counters a plane with a flat bottomed wing from climbing when power is added. The calculation is the same, but now the engine will point downwards and the rear of the engine mount must be slightly higher that the thrust line of the plane.

Good luck. I am glad I could help

/colin