Right and down thrust for engine?

[BC0979]

I mounted my engine today and it seems to be pointed down too much. "The manual" states 0-2 degrees down and 2 +/-1 right.

What is the reference line or plane to measure this from?

Sure would have been nice for ICP to reference it back to something like the firewall

For those of you that have been flying the S, to what thrust angles did you set yours up

BTW, I am not using a rotax but the thrust angles are important regardless of the engine brand.

Any insight would be helpful

Thank you

Bryan

 

 

[facthunter]

Reference something like the crankcase Joint and a laser would have to help. A few degrees doesn't lose much thrust. .   Nev

[IBob]

Hi Bryan, I believe ICP pre-adjust the angle on the ring mount provided, with packing washers at the silent mounts. So if you look at those washers at the 4 mounts, they are not evenly distributed.
But that will not be any help to you if you are using a different mount.

 

The aircraft with standard wheels sits with the upper rear fuselage horizontal (or parallel with the ground).
It says in the manual 'Inclination of axis of propeller to upper part of rear fuselage : 0'-2' down.' So that is your reference in that axis: the plane of the upper rear fuselage.
And the 2 plus/minus 1' right is from the centre line of the fuselage.

[Marty_d]

Hi Bryan,  I don't have a Sav, but a CH701 which is a bird of a very similar feather.  Plans called for right thrust 3 degrees (0 down).

I just used 3D CAD to locate the engine centreline 3 degrees from the fuselage centreline.  Of course the prop plate should still be in the centre line of the aircraft, which means the back end of the engine is kicked out to the left (port).  Then drew the location of the Rotax ring mount holes behind the engine and drew in a mount to fit.  This seems to have worked.

Having said all that, doing it with washers sounds easier if that's an option.

[pluessy]

Warning! Warning! If your engine turns the same way as the 912 (CW looking from behind, then the advise so far is correct.

If your engine is turning CCW, then the offset needs to be to the left.

[BC0979]

Gentleman,

Thank you again for all the helpful input.

I am mounting a Viking 130 on my Savannah.

I currently have standard tires on her.

I just needed to know what settings I should be aiming at.

Surly, test flying would be in store. Flying it without cowling.

 

[Kiwi]

11 hours ago, BC0979 said:

BTW, I am not using a rotax but the thrust angles are important regardless of the engine brand.

 

Please check that propeller rotation is the same as the Rotax 912 before you set the offset. 

[BC0979]

Rotation is the same, thanks for replying 

[facthunter]

The "normal" cowling is an important part of your engines cooling . I wouldn't recommend flying or even extended ground running without it. Nev

[BC0979]

On 20/07/2023 at 1:41 AM, IBob said:

The aircraft with standard wheels sits with the upper rear fuselage horizontal (or parallel with the ground).

It says in the manual 'Inclination of axis of propeller to upper part of rear fuselage : 0'-2' down.' So that is your reference in that axis: the plane of the upper rear fuselage.
And the 2 plus/minus 1' right is from the centre line of the fuselage.

IBOB,

Your translation of the italian-english manual was most helpful. "Upper part of the rear fuselage" that could mean a lot of things including the top surface of the rear fuselage LOL

With 3 washers I am currently at 2.8 degrees down

 

What I need now is to figure a way to measure my right thrust.

I have been looking for a digital horizontal protractor to reference from the firewall to the engine gearbox face which is perpendicular to the prop shaft