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We had a lot of choices to make when it came time to fill out the engine compartment for this year's sweepstakes airplane. Although the Cessna Cardinal doesn't have as many supplemental type certificates (STCs) available to it as, say, the 172, there's still a lot going on up front, and ways to tweak performance and make the airplane easier to use and maintain for the winner.

The fire up front
Lycoming had agreed early on to provide the project with a factory-overhauled engine. But we had a choice to make. The 1977 177B Cardinal was originally delivered with a Lycoming O-360-A1F6D engine, with D4LN-3000 "dual" Bendix magnetos. The Bendix dual (or double) mags have two independent distributors but share a single rotating magnet and a common drive gear — a single drive to the engine — and are contained in one housing.

The commonly identified drawback to this mag setup is that single drive; the initial iteration of these mags, the 2000 series, had a slew of airworthiness directives issued on them shortly after their debut. The 3000 series improved greatly on its predecessors, but the stigma wore on. The Bendix mags require special attention during routine maintenance in order to keep them happy; if properly cared for they have proven to be durable mags. But we chose to move to a pair of standard "single" Unison Slick mags to make maintenance a little less involved. With the engine change, we also installed a new Champion ignition harness.

When we sent in the propeller to American Propeller for overhaul and its special paint process, the company determined that the prop couldn't be overhauled. We were surprised, because the prop had just been overhauled two years prior, but American Propeller found rust in the hub, as well as the fact that the blades were past serviceable limits. So they provided a new two-blade McCauley prop at their cost, along with the overhauled McCauley governor. American Propeller customizes the prop by applying its proprietary Designer*Prop paint and leading edge to match the striking paint scheme on the Cardinal.

Accessories to the fact
Although the engine plays a major role, the engine's accessories are more than mere bit players. We added two accessories to the lineup that would save us some weight up front. Though not as nose-heavy as larger Cessna singles, the Cardinal still benefits from a bit of weight shaving. To this end, we selected the Plane-Power lightweight alternator and Sky-Tec lightweight, high-torque starter.

The Plane-Power AL12-60 replaces the 60-amp Ford alternator delivered with the Cardinal. The alternator can deliver up to 70 amps if used with the proper wiring, and it weighs 9.8 pounds (about 2.5 pounds lighter than the alternator it replaces). It delivers more amps at a lower rpm and runs cooler than other alternators on the market.

The Sky-Tec Flyweight high-torque inline starter weighs about 9.4 pounds, according to the manufacturer, which is just a hair more than half the weight of the Prestolite starter it replaces (18 pounds) — and it delivers more power sooner than stock starters. It also features a Kickback Protection System (KPS) shear pin to minimize damage to the ring gear and starter in the event of a premature ignition misfire event (otherwise known as "kickback"). Both Sky-Tec and Plane-Power have PMA (parts manufacturing approval) for the alternator and starter, so only the standard logbook entry is required on these swaps.

We exchanged the serviceable but worn vacuum pump for a new pump from Rapco, so that the winner gets to start fresh. Although the life expectancy of vacuum pumps varies, new Rapco pumps will utilize an update to the Smart Stick wear indicator using a new caliper-style device to help determine whether the pump needs replacement. Mark Gaulke from Rapco expects owners and technicians to get even more use from the caliper device than just vacuum-pump inspection. To back up the vacuum pump, we installed The Vac Source's SVS-5 standby vacuum system, which supplies back-up vacuum pressure based on the differential between ambient and engine manifold pressure.

Proving that even seemingly small components can make a difference, I was thrilled to get a call from Scott Peterson at the Donaldson Company, with an offer for a new engine intake air filter. Like the air filter in your car, this component needs regular replacement, and ours was definitely due, so we were glad to take him up on the upgrade from the stock filter. This Donaldson filter is an improved version of the old-style, paper-type induction filters, and it's not affected by the 500-hour replacement AD that affects Donaldson's original paper filters.

More power?
Some aircraft have a wide variety of STCs available for various engine choices for those owners who want — no, need! — more horsepower. This isn't really the case for the fixed-gear Cardinal. Though there are a small handful of STCs for engine upgrades and tweaks, most commonly (though it's still uncommon) is the exchange from the carbureted O-360 to an injected IO-360 found in the retractable-gear models, which ups the horsepower from 180 to 200. However, this exchange isn't the easy drop-in that it sounds like, since the replacement requires significant changes in baffling, with some cooling and other penalties. So we looked elsewhere for more power.

I'd performed several flight tests on aircraft equipped with Power Flow Systems' tuned exhausts over the years (see "Pilot Products," February 2002 Pilot and March 2006 Pilot) and was familiar with the system they had developed for the fixed-gear Cardinal. These systems replace the stock exhaust headers, collector, and muffler with new corrosion-resistant stainless-steel parts. By scavenging the cylinder's exhaust pulse with the suction created by the previous pulse, the tuned exhaust fosters the smooth flow of exhaust gas and reduces the pressure in the muffler system that can cause the exhaust from one cylinder to back up into another cylinder. Thus, the cycle runs more efficiently and fuel burn decreases (or power output is increased for the same fuel burn, depending on the setup).

Taking one look at the stock exhaust on the Cardinal, we knew we needed at least a cosmetic replacement. And if the system performs anywhere near as well as it does on the Mooney M20J and the Piper Cherokee 140 I tested, we're in for about a 150-fpm gain in climb performance, a several-knots increase in cruise speed, lower fuel flow, and lower, more consistent cylinder head temperatures to boot. Stay tuned (ha!) for more after I've been flying the airplane for a few hours.

The Power Flow System also utilizes a special cowl exhaust fairing, which was provided to us, along with other aircraft speed modifications, by Maple Leaf Aviation. The fairing enhances the look of the cowl while driving down drag from the exhaust pipe. Maple Leaf also loaned us a set of wing pins that we welcomed during the reassembly process — these specially made pins helped ease the reattachment of the wings, providing support while our technicians set the real wing bolts. Thanks to our friends up in Brandon, Manitoba!

Putting the engine to bed
The name "Tanis" has been synonymous with installed engine preheaters for many years, and the company graciously offered to send us a preheating system for the Cardinal, in the event our winner lives in a state where winters involve less-than-freezing temperatures. (Some of our members in Minnesota, North Dakota, and the Upper Peninsula of Michigan would note that summer nights could get pretty chilly too.) In addition, Tanis Aircraft also provided the engine and propeller blankets that protected the airplane's powerplant during Sun 'n Fun. These will go on to the winner as well.

We'll talk about the overhaul of the baffling, new baffle seals, and other get-ready engine tasks in next week's update.

E-mail the author at julie.boatman@aopa.org.

Fast-forward to the present day, and Lycoming (now a global operating division of Textron's Avco subsidiary) specializes in piston aircraft engines for both certified and experimental applications. The O-360 engine powering the 1977 Cessna Cardinal comes with Lycoming's roller-tappet technology, which debuted in 2005. One hundred years of innovation and reliability stand behind this year's AOPA sweepstakes airplane. Visit Lycoming's Web site or call 570/323-6181 for more information.