Saturday, November 25, 2017

Chapter 23 Engine Installation - prop, extension, cowl

Catto 68" diameter 78" pitch prop with nickel leading edges and erosion tape.  

Freeflight Composites cowl.   Did multiple test fits and the line that was marked looked like it was going to be pretty close so I trimmed outside of that line.   To match the plans, the cowl needs a lip along the front edge, so I trimmed off where the CF meets the lip at the turtle back and similarly, trimmed the bottom cowl.    Then used hot glue and pop sickle sticks to hold the trimmed section on as a form for the inside lip.

The blocks had to be moved in order to apply the BID that lays up in front of the cosmetic piece.  This particular area of the cowl lips were a little proud and met the wrath of the belt sander.
Pop sickle sticks and hot glue worked pretty well and was easier to remove than Bondo.
To install the Camlocs, drill 1/2" hole where the cleco holes are.   Then drill 1/8" holes for the rivets to hold the receptacle.   The bottom hole here has a Camloc receptacle riveted in.   I used a small drill bit to bevel the holes for the rivets so the heads are flush.  I made a simple jig to locate and drill the holes for the receptacles.
3 BID curing while the trailing edge is shimmed up to help correct a tendency to sag.
A layer of duct tape is on the bottom of the turtle back/spar lip.  Flox was applied and peel ply over that.  Nut plates were installed on the cowl and screws are holding the cowl in place for the flox to harden.   While the flox is still green, it's sliced with a box cutter along the seam.  Then after the flox cures a little more, the screws are removed and light pops with my hand broke the flox loose along the cut seam.

Chapter 23 Engine Installation - Aero Sport Power Build School - Superior XP-382 Wildcat

Parts painted and neatly laid out.  A 360 is on a cart in the queue behind mine.  Contact points were masked off and left unpainted where the case bolts tighten.  Heads are ported and polished.   I kind of wish I'd had the heads finished like the ones behind with black barrels and unpainted heads.

When I saw this I initially gasped, but you'll notice those are soft aluminum jaws in the vice and did not mark up the crank.  A plastic bag was put over the flange, greased up and then we heated the seal and slipped it over the flange and it popped right on.  This is a counter balanced crank.  The weights only go in one way.  

We installed the rod bearings.

The case accommodates roller lifters.  Also, the holes where the through bolts pass are machined to accommodate O-rings.   The case is also machined for the longer stroke.

Holes are drilled to accommodate oil flow back into the sump for inverted flight.  Nice to have if I swap the engine to something else some day.
The two additional drill holes are visible.

  Nozzles aka "squirters" will be installed that sprays oil into the bottom of the piston.

The crank, bearings, seals, silk thread, cam, roller lifters were installed.  Then some cardboard inserts held the upright rods in place when the other case half was put in place.    There are bolts installed and wired that keep the rollers in place.

The push rods are checked for straightness.

Sump and oil pump is installed.  Push rods, tubes, rockers are installed and valve lash is checked.  Only one push rod was one step to long (valve lash was under minimum clearance).   The shop has plenty of push rods in stock of various lengths.

Hall effect sensors installed.  Accessory case, oil pump, sump, coil mounts, various oil galley plugs and fittings are installed.  Install the alternator bracket before installing the Hall effect mount.

The SDS dual fuel pump assembly.

Ready to go onto the test stand after installing the injectors, fuel block, pipes.  The coils were strapped to the engine mount to avoid damage and make it easier to spot leaks.  They used their oil adapter instead of my 90 degree adapter.  The SDS system has a cold temp sensor in one of the cylinder intake ports.

"That's a lot of wires" was a common comment from the mechanics familiar with the traditional mags and Bendix systems.  It took a bit longer to connect everything but next time will go faster since they'll re-use some of the SDS harness.  Fuel pressure regulator was set to 40 .lbs with engine not running.   Post shut down has fewer steps than a bendix/mag system.  Don't have to re-check the mag timing, balance nozzles.

After getting the master ECU selected and electronic mixture set it started fine.  Pulp mill stack is in the background.

Test panel gauges.   The control box for my SDS system is setting on top of the panel.

Initially, WOT was around 2750 and after running for awhile consistently came up to 2800 RPM.  About 50-100 more RPM than the 200 HP engines with the same prop.

Temporary mount for the ECU.  A fuel pump is below it.
Cranked up after tweaking the electronic mixture knob a little richer.

Engine running at 2800 RPM and bypass fuel is visible going back into the fuel tank.  Fuel pressure was set to 40 .lbs without the engine running.