Wednesday, June 4, 2014

Vans Aircraft RV-12 Airplane Build, Section 48: Exhaust System (part 2)

Reference for this entry: page 48-04, 48-05, 48-06, 48-07; 2.0 hours

This entry will finish the installation of the exhaust system on the RV-12 airplane. I should note to torque down the exhaust stud nuts I needed a 12 mm crowfoot.

Reference: Page 48-04

Step 1: Apply a light coating of Loctite Heavy Duty Anti-Seize compound (or equivalent non-copper paste) to the inside surface of the four ball-joint receptacles on the Muffler Assembly.

Builder's note: OK, I put it on the outside of the exhaust pipes.

Step 2: Attach the Muffler Assembly to the exhaust pipes using the supplied springs. Make sure the springs are oriented so there is no contact between the coils of the spring and the exhaust pipe.

Step 3: Tighten the exhaust nuts on each of the pipes enough to seat the exhuast pipes in the ports on the engine but don't fully tighten yet.

Step 4: Grasp the muffler portion of the Muffler Assembly and apply force fore and aft while moving the muffler side to side approximately one inch each side of center. This will allow the exhaust system to settle into the "least stress" position.

Position the so that it is centered on the engine and tighten the stub nuts to 106- 177 in-lbs.

This completes page 48-04.

Reference: Page 48-06

Step 1: Install the bottom cowl. Check for clearance between the pipe and the opening in the bottom of the cowl. Adjust the side to side position as needed. Then enlarge the opening to allow at least a 1/4 inch clearance between the exhaust pipe and the cowl opening. Then shorten and deburr the exhaust pipe so it does not extend less that 4 inches beyond the cowl.

Step 2: Remove the exhaust springs one at a time and fill them with RTV, the reinstall them and RTV the hook ends of the springs to the muffler loops.

This completes page 48-06.

Reference: age 48-07.

Step 1 & 2: Install the EGT probe onto the #3 and #4 exhaust pipe. Route the wires back the the firewall and connect to the appropriate wiring harness.

This completes this installation of the exhaust system and muffler onto the RV-12. Next will start the Cooling system.