My New Engine—Tearing Down the Corvair

My new Corvair engine. This crankcase and the heads (actually, just one) will be
powering my Super Baby Great Lakes.

Bell housing off. A fifth bearing will be replacing this.

The crankshaft on top and camshaft on the bottom. The propeller will bolt onto the top shaft.

One of the two carburetors. My airplane engine will have only one carburetor and will be mounted below and to the rear of the engine, similar to a Continental or Lycoming.

Removing the engine oil apparatus (I don't know what it's called).

The alternator. My engine will use a John Deere alternator.

oil filler, etc.

Mike, holding the fan shroud. Check out the giant mice nest!

Magnesium fan and mice nest. I'm about to discover that mouse urine does major damage to aluminum.

Removing the harmonic balancer with a flywheel puller, $13 at Harbor Freight.

Again, the oil pump case (or something along those lines) on the rear of the crankcase.

The alternator. I'll send this in as a core and get a rebuilt one with points and electronic redundancy.

Having fun with my plane.

Pressure washing things. It didn't really help all that much.

After removing the fan and oil case cover. You can see the pistons, rods, and crankshaft in there. Cool stuff!

I convinced my wife to try out the impact wrench. She was nervous on the first one...

...but then thought it was cool. She did all the nuts on that cylinder head. I later learned that you're not supposed to use an impact wrench for this. Use penetrating oil and a hand tool so you don't apply too much torque and damage the case studs.

All twelve nuts off the case studs.

Push rods, rocker arms, and baffles.

Removing the cylinder head.

One of the baffling clips off and looking at the push rod tubes.

Head coming off.

Head off, push rod tubes coming out, cylinders awaiting removal. They slide right off.

The head and its combustion chambers. Each cylinder has a gasket right where Mike's finger is pointing, not a single gasket like most car engines.

Bottom of the engine with the oil pan removed.

This is the bottom of the half of the engine where the mice had their giant, cushy home. Notice all the corrosion?

I couldn't get this head off. I thought maybe the push rod tubes were stuck and so I cut them all in half.
That didn't help.

Tapping on the head wouldn't get it off, so I went ahead and undid all the rod caps and cracked the case. That left me with just the side of the case with the stuck head.

The camshaft.

The crankshaft, hydraulic lifters, and remaining case half, cylinders, and head.

This head was stuck big time. I ended up banging on the rod ends to try and use the pistons to drive the head off. One of my swings was off a bit and ended up hitting the crank case with the hammer. See next photo.

My damage to the case. I'm hoping this can be repaired.

Massive corrosion, clogging of the fins, and damaged fins. Damn mice. I'm sure this head is a write off. Hopefully I can just pay a core and get a rebuilt head without sending one in.

The culprit. This is why the head wouldn't come off. One of the case studs is essentially welded to the cylinder head. Another adjacent one is similar but not this bad.

To get the head off, I ended up cutting two case studs with a cutoff wheel on my angle grinder. Apparently, removing these from the case is a tricky job best left to a professional, or you risk damaging the case. I need to send my case halves to have them machined for three-liter pistons and fifth bearing anyway, so I have no motivation to mess with these.

First Wing Done!

Truth is I have a tiny bit of sanding left to do, but that shouldn't take more than a few minutes. I'm going to post a video summarizing some highlights about building this wing and a possible major piece of rework that I'll decide about after building the other three wings. I'll be starting on the upper left wing pronto. I'll be documenting that build with video, so there probably won't be any posts here for a while.

(By the way, the wing weighs about 21 pounds.)

Wing—Odds and Ends

There are lots of ways to skin a cat. After getting the leading edge wing tip pieces on, I discovered it needed a good bit of fairing. I wasn't sure how to proceed, so thought I would try an epoxy mix. I had oodles of the epoxy left from O'Reilly, so I mixed some West System colloidal silica filler into some of that. The back of the carton says that it's toward the strong/hard-to-sand end of the spectrum (there's only one more that's more difficult-to-sand/stronger). Well, turns out they weren't kidding. My arm almost fell off sanding that stuff.

So, I bought the 410 (last one on the right of the spectrum—easiest to sand). However, I didn't try that. I might try that one later. I ended up using something else I bought at the same time (from West Marine). It's in a caulking tube and is made for fairing. It's by Pettit Paints and is called EZ-Fair. I like it quite well. It's pretty easy to use and much easier to sand.

Some people also use Bondo and other people recommend Super Fil or Evercoat Quantum Filler. So, there are lots of choices. I'll probably try some of the others on the other three wingtips.

By the way, my fiberglass work is awful! I'm sure I'll get better at it the more I do it, though. Thankfully, you can slop more goo on it, do some more sanding, and cover up the first attempt.

This stuff was really hard to sand.

This carton contains the 410. It should be much easier to sand. I'll try it another time.

This stuff worked pretty well. Unfortunately, it's really expensive. Seems like all epoxies are quite expensive.

One end of the tube that will help to form the cutout in the center of the upper wing.

The other end of the tube that forms the center cutout of the upper wing.