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.

IMG_2334_1.JPG

IMG_2331_1.JPG

IMG_2330_1.JPG

[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.

[Abracadebra172]

I fully respect the opinions previously expressed about intercylinder baffle orientation of the asymmetrical inner baffles on the O-300. But, has anyone actually confirmed the manufacturer's answer as to whether the longer end should face forward or rearward? I have a complete new baffle
kit and just looked at the existing baffles on my engine (newly purchased 1958 airplane) and discovered they face forward on one side and rearward on the other. No CHT guage so no info available on whether temps are better on one side or the other. Thanks in advance for whatever info you may have.

[n2582d]

If your existing baffles have the longer leg on one side facing forward and rearward on the other side, then you have four identical baffles instead of two p/n 0450322-2 for the left side and two p/n 0450322-3 for the right side. The long leg of the baffles face aft. Take a look at fig. 63 of your C-172 IPC. Here's a screen shot from the Airforms catalog which confirms that:

Screen Shot 2024-11-24 at 7.38.37 PM.png

Screen Shot 2024-11-24 at 7.56.55 PM.png

[Abracadebra172]

Thank you SOOO much. I was stymied but this clearly explains it. Again, thanks.