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11-Second "FAST" 1970 Cyclone Spoiler 429 SCJ 4-Speed: Is this the Ultimate Mercury Muscle Car?

Posted By: Evan J. Smith
1970 Cyclone Spoiler 429 SCJ 4-Speed: Is this the Ultimate Mercury Muscle Car? 
By Evan J. Smith
When Mike Roberts lets the clutch out on his Performance Blue 1970 Mercury, big things happen. The tires howl, the engine revs and the beautiful Merc lunges forward with the nose high. As his Super Cobra Jet engine swallows copious amounts of air and gas, the rpm climbs to 7,000 and Mike rips the Top Loader 4-speed through the gears. If he’s done a good job, the Cyclone whisks across the finish line in about 10.3 seconds at 127 mph. That’s moving for a street-legal, stock-lookin’, 3,950-lb. all-steel machine.
Mike runs in the National Parts Depot F.A.S.T Factory Stock presented by Cor-A-Vent. F.A.S.T. (Factory Appearing Stock Tire) category is where drivers must present a factory-original looking, very correct Muscle Car for competition. The rules of the class require a stock body and interior along with a stock appearing engine, right down to the air cleaner. Racers must use the correct carburetor, intake, heads, block and exhaust manifolds, making it quite a challenge. The catch is that everyone must race on what amounts to 8 inches “stock” bias-ply rubber, because well, it’s mandatory in the category.
They run so hard because just about anything goes internally, so Mike is running a 581-inch displacement SCJ, thanks to an overbore and stroker crank. He’s also milled and ported the heads to the limit and there’s good rods and forged pistons in there. The Holley 780 has been tweaked and the exhaust manifolds have been hogged out, too. Still, they are a major restriction as headers would be worth an easy 50 hp—but they aren’t allowed.
“I’ve always enjoyed having something that surprises people,” Mike said. “I’ve always enjoyed sneaking up on people with something that maybe looked a little milder than it was, so F.A.S.T. is right up may alley.”
Compression is upwards of 14:1 and there’s a monster camshaft of undisclosed specifications tucked in the 385-Series block. All-in, Mike says the 429-come-571-inch Super Cobra Jet makes roughly 750 horsepower and based on the 128-mph trap speed and near two-ton weight, we’d say he’s spot on.
The big unit is backed by a McLeod Soft-Lok clutch and a Ford Top Loader that has been face-plated and Mike can shift the transmission wide-open with a good grip of the Hurst T-handle and just a small kick of the clutch. As you’d expect, there’s a Ford 9-inch out back and it houses 3.91 gears.
While traction is not really an issue in 99-percent of today’s drag racing classes, the catch in F.A.S.T. is the tire rule. Getting off the line is the most difficult part of this operation and the Mercury runs on Goodyear Polyglas GT G60-15 tires aired down in the back and pumped up in the front. He’s also loosened the front suspension and shocks and stiffened the rear leaf springs and shocks.
Still, each launch is a fight. Mike generally does a short burnout, stages shallow, revs to about 3,500 rpm and cuts it loose. “I’m battling traction issues but getting faster and enjoying running F.A.S.T. and NMCA,” Mike said.  His best elapsed time has been an 11.36 at 127 mph and with more finesse’, Mike thinks he can sneak a 10.99 out of it. After watching the Cyclone Spoiler rip at the Whipple Superchargers NMRA/NMCA Power Festival presented by Paul’s High Performance last month, we think he’ll achieve his goal.

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