December 1971, Hot Rod magazine Look at what AMC’s up to...again Shirley and N.L. Shahan trade in their successful SS/D AMX for a team of all-AMC small-block Pro Stocks By Steve Kelly * One of Shirley Shahan’s brighter qualities is that when she steps out of her race car, onlookers are often set to wondering how such a pretty, pert and fetching young lady is able to be at least as good as her male competitors. One of the reasons is that her car is well-maintained by her husband, H.L. Shahan. H.L. is the only moniker most racers know him by, and the initials certainly don’t stand for "Hard Luck". Back in 1965, Shirley took the H.L.-prepared Super Stock Plymouth to a Winternationals eliminator title. When the pair switched over to American Motors products in 1969, it wasn’t long before Shirley established new D/Super Stock records; and when they were broken, Mrs. Shahan set new marks for the same class in 1970. While Shirley is able to effectively get grease under her fingernails, she has found it best to leave the super- wrench work to H.L. And now, with a Gremlin and two Hornets running as a promotional effort for AMC dealers, H.L.’s work has been aided by the talents of Paul Phelps and Louie Wlosinsky, both employees of Landrith Corporation, a small race car prep shop near Detroit. Dave Lan+ith, former manager of Hurst Performance, just happens to be one of the organizers behind the promotional program for the AMC dealers. The AMC-dealership-backed drag team is meant to be a means of impressing potential customers in,each of the 21 American Motors sales zones. Naturally, a good amount of help was rendered by the AMC engineering department to make sure the cars perform as well as possible. The eA'orts have been rewarding. Best time-so far-on a Hornet is a 9.89-second e.t. and a speed of 139.52 mph. The Gremlin can’t get close to .the Hornets, its best performance being a 10.01-second e.t., with a top speed of 137.20 mph. One of the advantages the Hornet body has is its longer wheelbase and greater rear overhang, which help to get the car off the line quicker, due to more and better weight transfer to the rear. Ironically, when the cars are run "below weight" (i.e., below NHRA Pro Stock minimum), neither car runs equal to the times turned in at their legal Pro weight. The Gremlin can run with a weight of 2220 pounds, and the Hornets, owing to a lot of "metal thinning", come in at ten pounds less. Legal NHRA weight for the 360-cubic-inch- displacement American Motors cars is 2520 pounds. The Gremlin is used most often as a match racer for special outings, and the Hornets are put to work as showcase match racers and as entrants in national events. Except for wheelbase and body configuration, the Shahan cars are identical. The chassis work is quite refined. Front suspension is coil-spring-type, with each spring specially wound from .238-inch-diameter wire in a three-inch-wide coil. The left rear spring has five leaves, while the right has six. Each rear spring is 1% inches longer than stock, and they’re moved inward, for an increase in car height and also for tire clearance. The leaves now are shackled to the sub-frame rails, rather than bolted to their sides. Rear spring rate, at the wheel, is 145 pounds per inch on the right, 135 pounds per inch on the left. No traction bars are employed, and the rear axle housings are super-tough Danas with 9%- inch-diameter ring gears. The housings are narrowed 6% inches. Rear gears are 5.12:1, axles are from Henry’s Machine and Detroit Lockers are used. The only change made to the front end, besides the new coils, is shortened upper A-arms so that each car rides with 7%-degree positive caster, meaning that only the outside edge of each front tire is pushed against the track. Shocks are Hurst/Gabriel, the rear ones located aft of the axle housing. Steering units are from a ’65 Corvair (aluminum box), and there are lots of wheel turns from lock to lock to negate chance of driving a crooked "straight" line by accident. Air- heart disc brakes are fitted all the way around, front rotor diameter being 9~/y inches and rear 11% inches. Each car has a Line-Loc, but this is used mostly to warm up the rear tires in the staging area. The brakes are one of Airheart’s "Pro Stock Kits", and the saving in weight is 16 pounds. A stock six-cylinder model drive shaft has performed with no sign of twisting and no breakage. Transmissions are Borg-Warner Super T-10s, modified by Doug Nash and equipped with Hurst changers. Between each engine and gearbox is a 10'/y-inch Schiefer clutch (Borg & Beck style) and a 40pound steel Schiefer flywheel. Rellhousings are Lakewood hydroformed steel safety units. The chassis have been highly detailed for the cars’ ten-second workouts, and the engines have been well-built by H.L., working closely with the AMC engine wizards in figuring out a few new techniques. For instance, only the concave surfaces of the intake ports were polished. The convex surfaces were left in stock finish. Factory tests showed a drop in horsepower when the entire port was mirror-polished. Even though the engines measure 860 cubic inches, they don’t share bore-and-stroke specs with stock AM .360 V8s. The bore now is 4.187 inches, an increase of .107-inch, and the stroke is reduced by .18-inch to 3.260 inches. The crankshafts are by Moldex, made from 401 AMC VS forgings, and have been TuBtrided. The journals have been cross-drilled for better oiling, and Federal- Mogul F77 bearings are used. Bottom ends are reinforced with Milodon 892 Chrysler four-bolt-style main bearing girdles adapted to fit. (Reportedly, the switchover is fairly easy.) Compression is close to 13.7:1, and a new-design dome Venolia piston is now in use. Rod length, center to center, is 6.190 inches (stock is 5.875 inches), but this is not a Chevy rod despite its same length. Twelve-point, 7/16-inch rod bolts are used on the shot-peened and polished, forged-steel Carillo rods that use bearings "adapted" from a 302 Chevy V8. Crane roller lifters run on cams of the same make, lifting .628-inch at the valve. Opening duration is 324º. Offset valve guides are used in order to use larger-diameter valves. This is a tricky maneuver, but worth the time and labor. Intake valves are 2.165 inches across; exhausts measure 1.860 inches, come from TRW and are suspended by dual (inner damper) springs by Crane. The 1.6:1 ratio rockers are Crane-made, forged-aluminum and needle-bearing- bushed. The relatively high compression dictated 0-ringing the heads. The likeable Mrs. Shahan hasn’t been spending much time at home, nor has she been taking very long to traverse the 1820. No doubt a large number of her drag racing foes would prefer that she stay home with the laundry and cleaning, but chances of her trading a gear-shift handle for a vacuum cleaner are remote. ------------------------- Rear weight bias for both Hornet and Gremlin should be about 54% to the rear for cars to run equal with same weight. BELOW-Interior is free of nonessentials. It’s furnished with a blonde and S-W gauges. ABOVE-Intake manifold is individual-runner type, specially fabricated by AMC. Two types of Holley carbs have been used: 4500 I-R and 4700 series double-pumpers. The 750-cfm-size double-pumpers work best at present time. LEFT-Arrow indicates frame rework so that springs could be moved in for tire clearance and chassis lifting. Note the gusseted housing and Airheart discs. BELOW-Shirley does her own wheel-lifting thing with 9.89 Hornet. photography: Mike Brenner