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Engine Installation
Parts Required:
Cowl Assembly
•
Fuselage Parts Bag
•
Engine
•
Tools Required:
Electric Drill
•
Drill Bit various
•
Square
•
Steel rule(s)
•
Level
•
Masking tape
•
Marking pen
•
The engine installation requires that the cowl assembly be fitted first.
In order to obtain correct engine to cowl alignment, you will need to
get some reference marks that can only be obtained when the cowl is
complete and fitted. The engine dome has right thrust already built
into it, so all you need to do is find the centre of the spinner and transpose the information to the firewall, you will not
need to calculate the engine offset. First up you need to attach the cowl assembly, and transpose the spinners centre
from the cowl to the fuselage firewall. It s not really that difficult, but you may want another set of hands available to
assist you.
It s much easier to just use the bottom portion of the cowl, while this makes the process look a little simpler, the cowl
can change it s over all shape when both halves are joined, resulting in an incorrect spinner to cowl alignment. So, if
you can manage, try and get the required marks with the cowl full assembled, but if you find it too difficult, just use the
bottom half, but double check your marks with the cowl fully assembled.
First up you need to mask off the ply firewall on the fuselage, then fit the cowl securely. Next, we are aiming to image
the spinner centre from the cowl onto the firewall. To do this we will need a square and a rule. Place the rule across
the front of the cowl (use double sided tape to hold in place). The front of the cowl is 270mm, 135mm is centre. Using
your square set flat against the firewall, bring it to 135mm as indicated by the rule, and make a mark. You have now
found the horizontal line for the engine.
To find the vertical line place the square horizontally flat against the fire wall, and move into the spinner centre posi-
tion, mark this position on the firewall. Now that you have a vertical and horizontal mark, you can now use these
marks to draw out the position of the engine. Remove the cowl and get ready to mark out the engine placement. Use
the seam line of the fuselage as reference, but you can also place a small level on the wing tube socket in the fuselage
make sure everything is level.
Sukhoi SU 31—2.75m/2.6m
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