Picked this up at Hershey without paying enough attention, only to discover the hole in the top of the mushroom cap. I ran across a comment that this is for a 914-6, so just wanted to confirm.

Thanks.

Click to view attachment

I believe you're correct. Since the -6s blow more air through the heat exchangers, it is probably to allow more heated air to ex cape when the flapper valves are closed.

Thanks for the confirmation, George. Guess I'll be posting a FS ad.

It should still work for a -4 as well, just bleeds off more air if the heat isn't being used in the cabin.

Yep, I would think so. But my guess is that the mushroom cap, pointed inboard, is intended to shunt the hot air back to outboard. Having the hole just allows hot air inboard. (But then wouldn't that be an issue for the -6's??) I'm new to the 914 world so what do I know. I'm just speculating.

Yep, it is for a -6.

Here's a couple of picture of the HEs on a 914-6 with a view of the heater "flapper box"

Click to view attachment

Click to view attachment

Thanks all. I believe this is an original part, not one of the recent repros. I'd be interested in suggestions for a fair price. It should go to a good -6 home.