I took the engine, a Lycoming O-320-D2A, to a local engine shop to have the oil filter adapter and governor adapter added and the engine changed from fixed-pitch to constant speed, and a few other things. The engine hasn't been run since Lycoming pickled it on 2002. That's Joe Folchert of Aircraft Engines & Cylinders in Greeley, CO. (If the Tinypic.com image doesn't show up, please click here.)
The RV-3B plans don't show a firewall recess and I know one will be needed, but until I have the built-up engine, I don't know where to locate it.
You might be asking, hey, what happened to the wings? Are they done? Well, no. But the bottom skins should get riveted on soon and I've been working on other things, waiting for that.
One of them is that to locate that firewall recess, the engine mount needs to be on the engine. The engine mount came unpainted. I cleaned the gray off it and was getting ready to shoot the rattle-can high-temp paint (the snow on the paint bench melted and it's operable again - in fact, I used it today) when I realized that the paint needs a three-step cure up to 600 degrees. I didn't have an oven big enough and was reluctant to take it that high anyway since I'm not a metallurgist. I did spray a couple of samples and cure them to 400 F, to see how that affected the paint and found that this cure slightly increased the susceptibility to abrasion and greatly increased its resistance to chipping. The abrasion test was to drag a 100 grit piece of sandpaper over the paint, weighted down with a bucking bar, one pass each sample (also here)
The cured sample is on the right in one photo above and on the bottom in the lower photo.
The chip test was to drop a metal chisel on it from 12.0" above, 3 drops per sample. (also here):
The paint was Rustoleum's 2000 degree spray paint. I sprayed a primer coat, a white coat and a clear coat and waited a few days before curing and again before testing.
I went out and bought a paint that doesn't have the high temperature resistance of Rustoleum's but doesn't need a baking cure, either. Haven't painted it yet.