Front baffle standoff?

[455 Bravo Uniform]

IO-470 in a 182P (atypical combo).

Are there typically brackets, standoffs, or cushions that prevent air from pushing this front baffle against the cooing fins of the #6 cylinder?

Looked at a neighbor’s O-470 in a 182Q and see not much difference other than one inboard-most fin eating into the baffle.

Common or am I missing a part?

 

[Dan Thomas]

The parts manual shows nothing there. I have seen rubber U-channel glued to that edge. And I have seen a strip of RTV along the backside top edge of the baffle, but the baffle needs to come off, be cleaned, a strip of RTV applied and be allowed to set, then reinstalled.

And I have seen RTV squirted in there and it gets into the fins and blocks the airflow; not what you want at all.

The wear I see there is mostly due to the clearance between the baffle and fins. The wind has the baffle vibrating against the fins. That baffle should be formed so that it fits snugly against the fins, and it needs to come off to get that right.

 

[MauleSkinner]

The wear I see there is mostly due to the clearance between the baffle and fins. The wind has the baffle vibrating against the fins. That baffle should be formed so that it fits snugly against the fins, and it needs to come off to get that right.

So just to clarify this in my mind, the manufacturer’s intent is to be snug against the fins with no standoff of any kind?

 

[kyleb]

So just to clarify this in my mind, the manufacturer’s intent is to be snug against the fins with no standoff of any kind?

The intent is almost certainly for the baffle to be tight against the cylinder so you get the maximum amount of benefit from each molecule of cooling air.

 

[Stewartb]

Covering #6 is to reduce cooling at that cylinder head. I’ve never seen a blocking baffle that covers a cylinder barrel. I doubt it does much if anything.

 

[Steamflyer]

Looks pretty typical. Barrel is steel baffle is aluminum. Not much contest. Please no RTV.

 

[Dan Thomas]

So just to clarify this in my mind, the manufacturer’s intent is to be snug against the fins with no standoff of any kind?

Yes

 

[Dan Thomas]

Covering #6 is to reduce cooling at that cylinder head. I’ve never seen a blocking baffle that covers a cylinder barrel. I doubt it does much if anything.

That baffle isn't blocking the cylinder barrel. It is making sure that air flows in a controlled manner from the high pressure above the engine through all the fins to the low-pressure at the bottom. Without that baffle one can get a cold spot there and hot spots everywhere else on that cylinder, especially on the bottom, causing thermal distortion of the cylinder.

When I was a kid, my first car was a VW Beetle. The crank was broken in the engine, so I bought another engine for $50 and put it in. There was all this sheet metal stuff that had been installed all around that engine, aside from the fan housing, and I left it off, figuring that the engine would cool better without it. I was wrong, really wrong. That engine got really hot. My uncle told me that manufacturers don't install stuff that costs money unless the engineers demand it, and all that sheet metal was there for good engineering reasons. I installed it all and the engine was fine after that. That baffling was there to prevent hot air off the engine from coming back up into the engine compartment and getting recycled via the fan.

I have dealt with engines missing parts of their baffling. Sometimes it's not pretty. Obvious heat damage in places.

 

[Dan Thomas]

Looks pretty typical. Barrel is steel baffle is aluminum. Not much contest. Please no RTV.

No RTV? Why not? It's not being applied to an oil or fuel system. It's being used to cushion the baffle against the cylinder fins, and I have seen it used that way many times and have used it myself. Believe it or not, that aluminum can wear notches in the fins. Any dust can embed in the aluminum and do that. In the first picture in this thread you can see the beginnings of that.

 

[Stewartb]

I’ve done a lot of temperature balancing on my engines. I’ll stand by what I said. That baffle isn’t doing much if anything.

Here’s my 180’s #6. The head baffle was originally the 1” part visible under the new one I added. My CHTs are very close to equal across all 6. You can see the bottom is sealed. There’s no need to block a barrel.

 

[Gary Ward]

A 0-320 has these baffle springs to keep the baffles tight up against the cooling fins of the cylinders.