I ordered a plenum from Sam James that arrived the other day.  It basically takes the place of the standard baffling.  Apparently, it maximizes cooling, while reducing drag.  Pretty cool.  I think it’ll take some fitting, but I’m imagining that it won’t be any bigger of a deal than doing the baffling.  It also takes some of the air pressure off the inside of the cowl because it only pressurizes the plenum, not the entirety of the cowl.  They say that something like 50 percent of the cooling air is lost with the standard baffling, so we’ll see.  I feel two ways about it, because I like having the drag reduction,  but I don’t really like the fact that it covers much of the top of the engine, so during preflight you can’t really get a good look at the whole engine.  I’m not sure how much of it you’d be able to see through the oil door anyway, but it’ll be less with the plenum.  We’ll see.  It comes with pretty detailed instructions about the rest of the baffling that you make out of aluminum, complete with templates that you cut out and match.  Exciting!  I’d heard that there were some fitment issues with the plenum inlets not matching up  with the James cowl inlets, but mine seem pretty close.  it’s within 1/8 to 1/4 of an inch for sure.  I think.  Hopefully... More to come.

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