Intercylinder Baffle Orientation

[bjoness]

Can anyone definetely confirm the proper orientation of the inboard baffles on an O-300? The baffles are assymetrical, with one side larger than the other. Parts books, both for the 170A and early model 172s, do not clearly show the orientation. I believe the larger side should be installed facing aft, but would sure like some confirmation. Also, does anyone know the reason for the orientation, whatever it is?

[blueldr]

I believe that the baffling should be installed so that the push rod tubes get the most even cooling airflow since they are sort of primary oil coolers for the engine.

[GAHorn]

Larger portion aft is what makes sense if one considers the normal airflow and how the air must be encouraged to pass downward then aft thru the fins before exiting.

[hilltop170]

Don't know if these pictures will help or not. Click on picture to enlarge.

[GAHorn]

That engine has a heck of a problem with INTAKE AIR LEAKS!
(Bet that made the assembler mad when he realizes he must remove those intakes to install the hoses.)

[lowNslow]

It is actually much easier to install the engine on the airplane with the manifolds removed.

[blueldr]

George,
If you connsct the intake manifold gaps with "duck" tape, you don't have to remove them.

[hilltop170]

There weren't any gaskets on the intake flanges, either. And those plastic cups inside the intake manifold tubes stopped any airflow. No wonder it wouldn't start!

Actually, the assembler temporarily installed the intake so I could see how it looked.

[blueldr]

Richard, --- on final assembly, --- hoses or "Duck Tape"?

[hilltop170]

Both!

Just kidding.