Speaking of cars left off the list, by coincidence, on the subway this morning I was reading Ro McGonegal's "Back in the Day" column in the current (June '06) issue of Popular Hot Rodding. One subject is his eye-witness account of a magazine drag test performed on a '69 Yenko
427/425 COPO Camaro for the July '69 issue of Super Stock & Drag Illustrated. Here are some excerpts:
"Save for its intake manifold, the L72 engine was an all-iron big-block that was factory rated at 425 hp. It included an 800-cfm Holley carburetor and dual-point ignition, maintained a compression ratio of
11.0:1, and was commanded by a solid lifter flat tappet camshaft with
316 degrees duration and a 0.520-inch lift. A forged rotating assembly underwrote the purpose. . . . [The L72 Camaro package] came through with clunky cast-iron manifolds and tiny exhaust pipes routed for convenience sake through that stubborn POS cross-flow muffler. When I got on the gas hard, the thing hissed funky like a berserk vacuum cleaner. [This is a description of Ro's own L72 '69 Camaro.] . . .
"According to the Yenko propaganda, their car had not been salved to perform its best. The changes included clips on the front half of the leaf springs to staunch windup when slicks were biting, and Doug Thorley's exhaust panacea. . . . The engine in our gold/white-striped test car had been subjected to the Minimal Diddle: the spark plugs were the ones driven in; it had 16 degrees at the crank and 24 in the distributor, but the carburetor, cylinder heads, and cam timing were supposedly unmolested. . . . [Ro adds that Yenko prohibited flat shifting for this test.]
"[O]n a dreary, moist day in April [a] raw breeze blew down the track toward the starting line, but the light rain had ceased. Ambient was in the 50s. [Yenko-supplied SS/E race driver Ed] Hedrick staged on the line and made an exploratory pass: 14.02/102.50. You could almost see the drool. Getting serious, [Yenko employee Dick] Williams pumped the F70x15 Wide Ovals (not Polyglas) to 28 psi. Hedrick burned them in, staged, drove the car out about 50 feet and then stood on it. Each time he changed up, the tires squealed long and healthy. The L72 ran
12.80/108.56.
"For try three, [Williams removed the air cleaner and left the baseplate that sealed to the hood, but kept the headers capped. Hedrick changed his style, coming out at 1,500 rpm. The big motor liked this and responded with a 12.59/108.17. Patience for the street tires had worn as thin as their tread. We . . . screwed on the 8-inch wide
7.80-8.00x15 M&H slicks (at 9.5 psi). Williams stuck on [some 6"] collector extensions. . . . Open headers and slick tires markedly improved the Camaro's performance: 12.15/114.14. . . .
"We bumped the timing 2 degrees. Ed changed gears at 6,500 rpm and ran a 12.10/114/60. And for that old (draft-dodger) college try, Hedrick did the burnout ritual, staged, and everything clicked right for an
11.94 at 114.50. . . ."
OK, so an L72 Camaro was not common (between 500 and 1000 for '69).*** And slicks and open headers (or dual points for that matter) were not factory equipment. Still, an 11.94 at 114.50 for a production line car with open headers, an 8" slick, and a timing bump, are some awesome numbers.
Here are some more specs on the L72, from
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: RPO L-72 427/425 engine, which includes a four bolt main block, 11:1 forged aluminum pistons, mechanical camshaft (.520in, 316 degree duration intake, 302 degree exhaust) and forged steel crank. Big Valve Heads 2.19in intake and 1.72 exhaust), A Holley 780 vacuum secondary carburetor, an aluminum intake (163), chrome valve covers, and single point aluminum distributor (499) were also included.
(I don't know what the "(163)" or "(400)" numbers mean.)
*** The L72 was a regular production order ("RPO") on the '66 Corvette and the '66-'69 Impala, and a central office production order ("COPO") on '68-'69 Camaros and about 50 '69 Chevelles.
Well I'm rambling here. Time to hit the "send" button.
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