As most of you know, I have almost the full Sam James system...cowl and plenum (Van's wheel pants however). I was very happy with the finish on the cowl and have no regrets with that purchase...the alum inlet rings are just cool looking, as is the entire cowl design.
The plenum is a different story altogether. It hasn't fit well from day one and here I am still messing with it at this late stage. Off the shelf fiberglass parts shouldn't need major surgery to work well in my humble opinion. But hey, on the bright side, I am getting to be a fiberglass expert!
So, Sam James expects you to mold your plenum in the front to the engine case. And that's what most guys do...put some mold release on the engine and do your layups in place. They then seal that gap with high temp RTV. To me, that's crap...there is no way I want that shoddy look on my plane (no offense if that's what you did/do), along with the fact, to remove the plenum you need to peel it off the engine. It wont come off often...but I don't want that scenario to deal with. So, how else to secure the front of the plenum??
Whatever I do, it leaves me with more work...ugh! It never ends, I feel like crying uncle sometimes. Finally, I decided I wanted to design a front mounting box for the plenum. Here are my first steps in going down this road...its still in progress as we speak. How I tie it all together is still being decided...and no, I don't always have it all figured out before I start, otherwise I might not ever start. Sometimes in life, we just need to jump and build our wings on the way down. ;)
I was very happy how my sheet metal box came out, matching the contour of the plenum...I find it fun doing things from scratch, although its so time consuming.
It took some doing but I designed and fabricated this engine attach bracket out of 0.060" alum sheet. Came out real nice. It was then riveted to the box structure, see below.
Here you can see how it all is coming together.
You'll see in my pics later, but I am fiberglassing the gaps now...this gives you an idea where I started from. This plenum work is one of my last major tasks...so I'll be happy to have this behind me.
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