Baffling

Today I installed the aft baffles on the engine. I started by picking up some high temp RTV from AutoZone. The RTV is used to provided a cushion for the baffling where it will vibrate against the engine. I masked up the aft baffling, roughed it up with sandpaper, cleaned it, and then smeared RTV in the specified locations. This was then left to dry for a few hours.

Later in the day I installed the aft baffles, and looked to areas where it was rubbing against the case. I found a few locations, and marked them with a sharpie. Then I uninstalled it all, filed down the offending areas, and then reinstalled for (hopefully) the final time.

Tonight I test fit the aft baffling on the engine.

I found a couple of rivets that I had forgotten to set, so I went ahead and tried the aft baffling on the engine, and then took it off and set those rivets.

Trying the baffling on the engine was a little tricky. The instructions say to remove the oil return line from cylinder 3 to make it easier to install the right baffle. I can see why, it definitely gets in the way. But instead of undoing the fitting, just a gentle bend as it’s going on solves the problem. The much harder issue is the aft left baffle. It took me almost 30 minutes of trial and error to finally find a way to get it in. The trick is to insert it at about 45 degrees, getting the baffle under the engine mount bolt, then working it down into position. It also helps to angle it slightly forward.

I scratched a lot of engine paint off, and scratched the baffles, but was able to get them into position.

That’s when I realized another issue. I had installed the bracket on the wrong side of the case, and the holes were not even close to lining up.

I took it all off again… will fix it tomorrow.

Tonight I continued working on the baffling. I had to drill out a few rivets and redo them, as they had tipped over too much. I also found a mistake where I’d used the wrong nut plates, so I replaced those.

With the riveting done, I installed the fittings on the top of the engine case. These help hold the baffling in place. I had to gently bend the fuel line out of the way to ensure enough clearance from the bracket.

Today I made some more progress on baffling, deburring, dimpling, countersinking, step drilling and then riveting together parts. It’s been I while since I needed to use the compressor, but I needed to use the rivet gun in a few places. I almost always use the Main Squeeze hand-squeezer for rivets.

I decided to take a break from wiring, and start back on the engine. Cracking open the baffling section, I made some progress on the first few steps, marking and trimming the doublers, and deburring parts.