November 11, 2009
First Flight With 'New' Engine
Progress on the restoration of the Win A Six in '06 Sweepstakes airplane just took a giant leap forward. Last week, Ultimate Engines of Mena, Arkansas, finished its overhaul of the Six's 260-horsepower Lycoming O-540. On Friday, March 3, I flew in to Little Rock via airlines, and Ultimate's Ken Schreiber was waiting. He's Ultimate's test pilot, and he'd just finished flying a five-hour shakedown period with our/your revivified engine. Now he was going to ride shotgun as I flew the "new" engine back to Mena.
Our 99.5-nm flight from Little Rock to Mena took about 45 minutes, and in that time there were some vivid impressions. The first one came right after startup. Where the original engine was rough at idle power, the overhauled incarnation was noticeably smoother. Of course, that's what you'd expect from an engine that had had its crankshaft, connecting rods, and pistons balanced within a couple grams. The Lasar ignition system let the engine start with just two blades of rotation from the newly installed Hartzell three-blade propeller. So it was like push-button starting, with a near-instantaneous lightoff.
And the propeller! American Propeller's paint job made this prop stand out on the ramp like you wouldn't believe. It has the power to draw a circle of admiring gawkers from the deepest recesses of even the quietest FBOs.
The next improvement showed up during the takeoff from Little Rock. The takeoff run was sprightlier than I remembered, and during the climbout I saw 1,000 fpm. Of course, with partial fuel and just two passengers, we were light. But the airplane was light when I first flew it (with just me aboard), and back then the best I could eke out was an 800-fpm initial climb.
In cruise, I saw 130 mph indicated airspeed, but this by itself meant little because the atmospheric conditions were different than those that I obtained during my pre-overhaul flights. The next day, I'd have time to work the numbers in detail.
Nightfall came during that return flight, and while Schreiber and I had dinner, one of Ultimate's mechanics removed the oil filter and inspected it for signs of metal contamination. The results? So far, so good.
The next day dawned with essentially clear skies from Mena to my destination - Florida's Vero Beach Municipal Airport. That's where LoPresti Speed Merchants is located, and that's where the Win A Six will get its airframe cleanup and speed mods.
Good weather for the duration of a seven-hour, 900-nm trip is rare, and that was fortuitous. The Win A Six is very much a VFR-only airplane at this stage of its refurbishment, so flying in clouds was a no-no. Also, at takeoff the newly overhauled engine (with new oil filter) had logged a mere seven hours of flight time. At this tender age, it's always best to fly in good weather, during the daytime, and as close to suitable airports along the route of flight as possible. Just in case. Ultimate had done a great job overhauling the engine, but prudence dictates conservative flying during the engine's break-in period.
Mena to Vero Beach - 141 knots true!
It would be a long flying day. I planned a route that went from Mena to the Pine Bluff (PBF) VOR, then on to the Greenville (GLH) and Meridian (MEI) VORs. From there, it was on to the first stop at the Dothan, Alabama, airport. I used the airplane's Garmin 430 as the primary navigation tool. For cross-fixes I relied on the aging but serviceable Bendix/King KNS 80 RNAV. If by chance every box on the panel died, I carried my trusty old Garmin III Pilot as a battery-powered backup avionics "suite."
During engine break-in, I was told to use full power for takeoff, of course, but for the rest of the initial climb, the drill is to dial propeller rpm back to 2,600 rpm while leaving the manifold pressure floored. Once in cruise flight, I was told to bring the power back to 75 percent. At my cruise altitude of 5,500 feet msl, that meant 22.5 inches of manifold pressure and 2,400 rpm. To lean the mixture, I used the ship's EDM-700. Schreiber said that with the EGT (exhaust gas temperature) of the hottest cylinder (No. 4) at 1,200 degrees Fahrenheit, the mixture would end up being in the best-power area. The EDM 700 makes it easy to determine peak EGTs: Just watch for the temperatures to rise, then fall. Then enrichen the mixture until you see temperatures 50 degrees richer (i.e., cooler) than peak.
At no time during the flight did any cylinder head temperature (CHT) go higher than 360° F. The coolest cylinder was No. 1, which is at the front of the engine. There, EGTs ran at around 1,089 degrees, and CHTs were a low 280 degrees. This indicates either a bad EGT or CHT probe or a baffling issue that allows too much cooling ram air to hit that front-most cylinder. This issue will be resolved at LoPresti Speed Merchants, where their new "Wow Cowl" will more evenly distribute the incoming ram air.
Some 70 nm west of PBF, I took down the first data. At 5,500 feet pressure altitude and 53°F (14°Celsius), with an altimeter setting of 30.38 inches Hg and a 75-percent power setting of 22.5 inches Hg and 2,400 rpm, I saw 130 KIAS and a true airspeed of 141 kt. Not bad at all. On the delivery flight to Mena with the "old" engine, the best I saw in cruise was 122 KIAS and 135 KTAS. That was with an OAT of 20°C/64°F - also at 5,500 feet - and power set at 24 inches and 2,400 rpm. So it seems that the overhaul added at least 5 kt. I'll run more data after the engine has finished the break-in and LoPresti's mods have been installed.
Soon, I crossed the Mississippi River, flew over the familiar catfish ponds and flatlands of Mississippi, then pressed on toward MEI. Every 40 minutes or so I'd switch tanks. This early model Cherokee Six has four separate fuel tanks, so you have to keep good track of your fuel state and switch fairly frequently. The main tanks carry 25 gallons each; the auxiliary, outboard tanks carry 17 gallons each. This setup was an option back in 1967; standard fuel capacity was 50 gallons in the main tanks only.
The landing at Dothan was a graceless affair. Seems I haven't quite made peace with the Six's landing behavior. A crosswind tried to blow me sideways after a too-firm touchdown. Worst of all, I made a three-point landing. Hope no one was looking.
I made it my business to check the engine after the tanks were topped off. With the stock cowl, you can remove the entire top half, which gives you a fantastic view of the engine compartment. I saw no oil leaks or other signs of trouble and noted that the oil quantity had remained steady at 10 quarts. Fantastic. Maybe the engine is already broken in, I thought. (Break-in is considered complete when oil consumption has stabilized, or a certain number of hours has passed - say, 25 hours).
Then a crowd formed. As soon as I took the cowl off, a force field was energized. It drew about a dozen pilots from the ramp - all of them eager to take a peek at that glorious engine and the propeller's paint job (done by American Propeller Service). There were ooohs and aaahs, and I spent 20 minutes or so talking about the new powerplant.
From Dothan, it was a 2.8-hour trip to Vero Beach (VRB) via the Seminole (SZW), Cross City (CTY), and Ocala (OCF) VOR fixes. Then it was radar vectors for a 110-degree heading around the busy Orlando airspace, followed by direct VRB.
I landed at Vero around 6 p.m., and this time my landing performance was much better. I'd rank it as an 8 or a "B." Approach was at 90 mph and full flaps, touchdown was mains-first at stall speed, and ground roll was astonishingly short.
Curt LoPresti came out to meet the Six and I, and he proceeded to show me another Cherokee Six-260 that LoPresti Speed Merchants was working on. The new cowling was installed on this airplane, as well as the new, aerodynamically clean wheelpants.
The cowl had the LoPresti-signature circular ram-air cooling inlets, plus a single large cowl flap (stock Sixes are cowl-flap-free) and a LoPresti "Boom Beam" xenon landing light. The sides of the cowling had hinged access panels.
We'll talk more about the LoPresti mods and their installation in a future update. We'll continue to post the latest photography on AOPA Online, as well as short videos documenting the upgrade process.
Of course, you'll also want to keep looking in AOPA Pilot magazine for even more reports on the Sweepstakes project.
Stay tuned! Soon, we'll be able to report on the speed gains that LoPresti Speed Merchants predicts for our/your Win A Six. Will it be the 12-mph speed boost that Curt said he saw on the last Cherokee Six-260 to get LoPresti mods?
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