The Speed Holes Racing AMC Marlin took home the Organizer’s Choice award at last year’s Colorado 24 Hours of LeMons race, because A) it has a 454 yanked from a wrecked GMC truck set back about three feet from the Marlin’s normal engine location, B) it has a Jaguar XJ6 rear suspension and differential, C) it has hundreds of speed holes punched into the body and, most of all, D) it’s an AMC Marlin. The Marlin wasn’t exactly fast (the tall Jaguar gears and very tired 300,000-mile EFI small-valve engine didn’t make for great acceleration out of the turns), but the handling was surprisingly good for such a big car. For the 2011 B.F.E. GP, Speed Holes Racing decided that more power would be needed.
The LeMons Supreme Court gave Speed Holes a generous residual value after last year’s race, allowing them to dump another few hundred bucks into the car. Changing the differential gearing from 2.75:1 to 3.73:1 will help de-dog-ify the acceleration at hilly, oxygen-poor High Plains Raceway. Adding forced induction should
cause the engine to spray connecting rods in all directions alleviate the oxygen-shortage problem.
In charge of this upgrade is Speed Holes Racing team captain Cadillac Bob. Cheap junkyard superchargers are easily obtained, as long as you go for a Toyota Previa centrifugal blower or a GM 3800 V6 Roots blower. Bob went for the latter option, figuring a pair of superchargers meant for an engine of 231 cubic inches displacement apiece should be just about right for a single engine displacing 454 cubes.
The plan is to push about 5 PSI of boost down the factory throttle body, using this industrial pressure gauge to keep the driver in the know.
Bob fabricated a plenum and mounted the blowers backwards on its sides. The compressed air will come out the top, once he cuts a hole and mounts a flange for ducting.
Because the supercharger input shafts will now rotate backwards, Bob had to do some surgery to flip the internal drive gears around and keep the vanes rotating in the correct direction.
The nice part about this setup is that removal of the entire supercharger assembly should be pretty quick,
when if something goes wrong with one or both of the blowers at the track.
Meanwhile, Bob’s shop has filled up with projects. In the foreground is a LeMons-bound Jetta that needed its janky cage fixed. In the background is my ’66 A100 van, which is getting new axle kingpins.
In the rafters of the shop, an early-60s-vintage rail dragster.
Beneath the dragster, a seriously chopped Coupe DeVille.
Nearby sits an old-timey hot-rodded Model A four-cylinder engine, awaiting installation into Bob’s super-slammed Ford coupe.
What sort of car should receive this WW2 military-issue Cadillac flathead V8?
The B.F.E. GP takes place weekend after next, so there’s plenty to do between now and the green flag. Still, compared to last years’ panic-stricken thrash, this time around should be a walk in the park. I look forward to hearing those blowers screaming on the race track!
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