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Kirk Harrell

N22YR (800 x 600: 152 KB) Hi-Res (2608 x 1952: 2.5 MB)

At Oshkosh 2007 (More photos below the text)

On July 21,2002 MII N22YR had the flap fail on the air diverter in the plenum box and the flap closed off the injector servo, effectively choking the engine. In the ensuing off airport landing the Hartzell prop was destroyed. Airframe damage was limited to a slightly sprung right gear leg and a small ding in the left wing leading edge.

Since the Lycoming IO360-B1E had 1,500 hrs, it was majored. All reciprocating parts were static balanced, and piston and valve faces were ceramic coated.

The engine mount was rebuilt to reposition the engine, and a new MT MTV-15 aluminum propeller with 4" extension on the hub replaced the damaged Hartzell. These changes necessitated a new cowl.

A new stainless 4 into 1 exhaust system was fabricated using the EAA Cafe Foundation EPG data as a guideline for optimum primary and collector tube diameter and length. The system also incorporated anti-reversion cones as outlined in Kent Paser's book "Speed with Economy". After fabrication was completed the system was ceramic coated inside and outside to keep heat in the exhaust gas and out of the engine compartment.

The offending air plenum flap was replaced with a double wall 4130 replacement flap, and the velocity stack was modified to port match with the intake servo opening. A NACA scoop was incorporated into the cowl that is sized for open throttle 2,700 rpm @ 230 mph, with an opening of about 3.5 sq. inches, but works well even on takeoff at full throttle 2,700 rpm and 105 knot Vy.

The MT prop is very smooth, and quiet. It does not have RPM restrictions like the Hartzell.

The cooling system was upgraded to include a separate plenum for the engine, which allows better control of diffusing inlet air. The system is still undergoing some adjustments to get cylinder temps up to 380 - 390F in cruise. The annular inlet ring is fixed to the plenum with a silicone baffle seal ring, and nests in the cowl opening. This aides in getting a perect seal while allowing engine movement, and also allows modifications to the inlet opening size without messing up the cowl.

While N22YR was down, the instrument panel was upgraded to include PM1000 intercom and an artificial horizon. Servo driven spring bias aileron trim was installed. New upholstery was installed. The canopy clamping mechanism was modified and beefed up to hold the canopy tightly closed in all phases of flight, and has proven to be one of the best mods during the cold winter months!

As of February 18, 2008 N22YR has logged 35.5 hrs since mods were completed. The GPS odometer totals 5,802.1 nautical miles travelled (which includes all taxiing as well as flight miles). Except for approach and ground time, all flight has been performed at breakin power settings of 24 - 25 inches manifold pressure and 2,400 to 2,500 RPM.

N22YR is an absolute delight to fly, and now with aileron trim and balanced engine, is smooth and nearly a hands free bird, even without autopilot.

Interior	Seat	Finished Cowling	Intake Plenum	Intake Plenum
Intake Plenum Installed	Anti-Reversion Cones	Exhaust	Exhaust Complete	Cowl Layup
Cowl Layup	Lower Cowl	Cowling	Cowling	Cowling
Cowling Nose	Cowl Front	Cowling	Cooling Plenum	Cooling Plenum
Cooling Plenum	Inlet Ring	NACA Duct	NACA Duct	NACA Duct

NACA Duct

Cowling

Some more links to photos of Kirk's airplane:   S-N-F 2002 and here

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