1975 8KCAB engine alignment

D

dvermeer1

New member
Hi everyone

I have a 75 Decathlon that I recently purchased. When the prebuy annual
was done it was discovered that the wrong engine mounts were used. They
were replace with the Lord aerobatic mounts (I verified the part number). After
about 10 hrs I discovered the front right exhaust manifold had been rubbing against
the cowl. I attempted to adjust the cowl and that's when I noticed that when sighting
down the upper cowl from the spinner, the engine appears to be sitting approximately
1/4 to 1/2 inch to the left when looking from the front of the aircraft. I know a lot
of these motors were canted that way from the factory but I am not sure if Bellanca
did this or not. I don't think these mounts are adjustable. Has anyone ever seen this before?
It seems to have all started after the new mounts were installed.

Thanks in advance
Dana
 
I have a 1975 Decathlon, the engine is mounted straight. I would check the Lord mount installation and torque, I would torque them while the engine weight is being lifted by a hoist.
If that doesn't help I'd look at the engine mount tubes very carefully.
 
How does it fly? Is the ball centered with no rudder? It is not that uncommon to need to trim the hole in the cowling for additional exhausted pipe clearance.
 
Thanks for the info. My exhaust is not rubbing where it extends out of the
bottom of the cowling. It is rubbing where the exhaust on the front right
manifold makes its first bend. Just to the right of the landing light. I am going to
undo the mounts and remount and retorque everything and see if I can straighten
the engine out.

Dana
 
Lord Mounts are offset.
Does your mount have the properly located roll pin holes to align the lord mounts?
 
Just to update those that are interested. We pretty much
figured out that when the aircraft was rebuilt they did a less
than desirable job on fitting the cowl. The engine is aligned properly
with the aerobatic mounts and pins now (ACA sent me a jig for the the proper
hole alignment), although I still had the problem. Our eventual final fix was
to shorten the 4 exhaust manifolds by 5/8 of an inch. This worked perfect and
I now have plenty of clearance. It raised the muffler assemble up slightly but
there were no clearance issues anywhere. The only modification I had
to make was to slightly enlarge the hole in the bottom of the cowl where the exhaust
passes through.

Cheers
Dana
 
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