Slow progress on the baffles… I got the left-side baffles mostly fitted. By the way, the CB-706B spacer I made per the plans was way too short and I had to remake it from leftover material. Do yourself a favor and verify all dimensions given in the baffle plans before you start cutting!
The two rear case baffles didn't initially fit together very well with the center baffle brace:
A lot of the trouble was that they needed to be trimmed to fit better around the various bumps and bulges on the engine case… a process that took a lot of on-and-off fitting.
Closeup view of the same area after improving the fit:
On to the inlet ramp baffles… I did the usual steps of match drilling and deburring, and also drilled a one-inch hole as specified in the plans:
I had to disconnect the factory-installed prop governor oil line, which eventually ends up going through a grommet in that big hole:
Initial trial fitting of the right inlet baffle:
Closeup of the prop oil line; the yellow square is a bit of foam rubber to keep the pipe from getting all scratched up. Also note that the baffle needs to be trimmed to keep it from grinding against the ring gear.
I removed the dummy prop hub and flywheel for easier access:
Further work on left and right inlet ramps. You can just see where I ground away some of the right-side one to clear the ring gear:
The plans have you rivet "temperature risers" to the inlet ramps, which are simply a couple squares of aluminum that block some of the airflow to cylinders 1 & 2 (the front ones) so it can be used by cylinders 3 & 4 (the back ones). Problem is, the sizing of temperature risers is somewhat peculiar to each particular installation, and the plans method of attaching them requires you to remove the baffles and drill out rivets in order to modify them. Not a great idea if you ask me. Instead, I put some nutplates on the inlet ramps (screws visible in this photo) so I can experiment with differently sized temperature risers as needed.
Both inlet ramps fitted to the engine:
I was getting frustrated trying to decipher the next page in the plans, so Mary brought some refreshment down to the garage. I tell you what, the atmosphere in this place isn't so great, but the service is excellent.
