When Mike Roberts lets the clutch out on his rare 1970 Mercury Cyclone Spoiler, big things happen. The tires howl, the engine revs and the beautiful Merc lunges forward with the nose high.

As his 429 Super Cobra Jet engine swallows copious volumes of air and gas, the rpm
climbs to 7,000 and Mike rips the Top Loader four-speed through the gears. If he’s done a good job, the Cyclone Spoiler whisks across the finish line in about 11.1 seconds at 131 mph. That’s moving for a street-legal, stock-lookin’, 3,950-lb., all-steel machine.

Running an 11.15 at 131 on stock bias-ply tires is a Herculean feat, but this Mercury does it. (Photo by Evan J. Smith)

Mike runs his mighty (and mighty rare) Mercury in the F.A.S.T. (Factory Appearing Stock Tire) category, where drivers must present a factory-original looking, very correct muscle car for competition, but lots of internal engine modifications are allowed. It is one of only 341 Drag Pak/Super Cobra Jet Spoilers sold in ’70.

(There is also a category for less modified cars called Factory Stock. We recommend going to the sanctioning body’s website for complete information and all class breakdowns.) There’s also the Pure Stock Muscle Car Drags, and we’ve featured two machines recently from that group, Bruno Beltrame’s L78 Camaro and David Povio’s Chevelle SS454 LS6.

Rules Of Engagement

The basic rules of the F.A.S.T. 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 real catch is that everyone must race on what amounts to 8 inches of stock-style bias-ply rubber.

“It’s 1970 Cyclone Spoiler in Competition blue,” said Roberts. “The engine is a 429 Super Cobra Jet with a factory four-speed and 3.91 gears. I’ve modified it quite a bit to run in the FAST class. It has to look stock, but internally it’s got a lot of things done to it. I’ve been having fun, although I’m battling traction. It’s getting faster as I learn more about what it likes,” he added.

These cars run so hard because just about anything goes internally in the engine.
Roberts 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, Roberts says the 429-come-571-inch Super Cobra Jet makes roughly 750 horsepower. That estimate is based on the 131-mph trap speed and near two-ton weight.

The big unit is backed by a McLeod Soft-Lok clutch and a Ford Top Loader that has been face-plated and Roberts 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.

“I’ve owned it for about 10 years, but I never raced it in stock condition,” said Roberts. “It hasn’t been in stock condition for quite a while so all the racing I’ve done has been in FAST. I just really enjoy the aspect of it looking stock, but you have to be innovative to run well. You’re always coming up with new ideas, and that’s the part I really enjoy about it is the innovation, always trying to think of little tricks that you can do to make them faster.”

While traction is not really an issue in 99-percent of today’s drag racing classes, the catch in FAST is the tire rule. Getting off the line is the most difficult part of this operation. 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 stiffened the rear leaf springs and shocks.

Still, each launch is a fight. Roberts does a short Second-gear burnout, stages shallow, revs to about 3,500 rpm and cuts it loose. Roberts’ best elapsed time to date has been an 11.15 at 131 mph and with more finesse, there’s no doubt he can sneak a 10.99 out of it.

“That’s my goal, to run in the 10s,” said Roberts. “The mph is enough to go solidly in the 10s, but, you know, this car has leaf springs and 8-inch tires. They’re not wide and not tall.”

Under The Hood

His 429 4-barrel was rated around 370 horsepower from the factory (and shared its factory cam with the Boss 429), but to go hundred 131 miles an hour, it’s now likely developing over 700 hp.

“I haven’t had it dyno’d yet, but I think to pull what it does, at the weight, it’s got to be around 750,” Roberts believes. “I’ve had these cylinder heads for probably 30 years, and I’ve ported them like five times, so they’re maxed out. It’s got a large roller cam in it and high compression. It’s about 14:1 compression. I’ve done a lot of work on the intake to make the plenum work better, and a lot of porting on the heads and on the exhaust manifolds. You can’t run headers, so the exhaust manifolds are the real challenge on these engines.

While they’re better than a stock exhaust manifolds, they’re still restrictive, so you really have to work on them to make these engines work. The 429 Super Cobra Jets came with a factory smog pump, and the factory carb is a 780 Holley
that’s been just highly modified.

“I’ve got the rev limiter set at 7,200, and I’ve hit it, so that’s about as high as I like to take
it. If I didn’t mention it, the clutch is a McLeod Soft Lok with an aluminum flywheel,
adjustable pressure plate and sintered-iron disk,” Roberts said. “I’m still working with the adjustments on it. I haven’t quite mastered that yet. But, yeah, you can do a lot of adjustment with counterweights and with pressure adjustments.

“As for the suspension, it’s limited. You can’t run traction bars, and you can’t really run
any kind of traction devices. The main thing that I did on it that helps is on the rear leaf
springs, just adding extra leaves. The way that you assemble the leaves is really critical.
On the front end, you just loosen things up. And really good shocks are important, but
not anything too overly trick. A lot of it’s just trial and error.”

Furthermore, there’s no lightweight wheels — you have to use their steel wheels, but he
does have aftermarket disc brakes front and rear. Stopping is important.

“Pure stock is a lot more restrictive,” Roberts stated.

On the exterior, the Cyclone Spoiler maintains the factory appearance, with 429 badging, deckled spoiler, and stripes. Only the front air dam is absent.

“Yeah, these cars are super rare, and trying to find any parts for them is difficult,
because they don’t really reproduce anything,” Roberts said. “I’ve searched for years to
find individual pieces of chrome and different things like that.”

One of the most unique features on a Cyclone is the grille, the so-called “Bunkie Beak,” named after Ford’s president at the time, Semon E. “Bunkie” Knudsen, who was a big proponent of the protruding nose. Cyclones got the gunsight grille, unlike the standard Montegos.

“They’re kind of an acquired taste. Some people love them, some hate them. I’ve taken the car racing before, and I’ve been sitting there and hear somebody say, ‘that is ugly. I hate the grille on that.’ But I have a love for the car and I plan to keep racing it for a long time to come.”

We think the Cyclone Spoiler looks amazing, especially when it flies through the traps at 131 mph on stock bias-ply tires!