Two of a Kind

Also from Issue 201

  • Driven: 2013 Boxster S
  • Driven: 2012 Cayenne Turbo
  • Interview: Roland Heiler
  • Road test: 2012 911 Carrera Cabriolet
  • Stirling Moss reflects on his Porsche years
  • A 1979 930 that came with some 1980 parts
  • 2012 911 GT3 RS 4.0 versus 1965 911
  • ALMS: Sebring 2012
  • Smart Buy: 2001–2005 911 Turbo
  • 1972 911T race car becomes road car again
  • Drendel Family Collection auction
  • Porsche Camp 4: Winter driving school
  • How to get streak-free, haze-free windows
  • Tech: Warm-up, pinion bearing, bucking 944
Buy Excellence-201-cover
Two of a Kind 0
Two of a Kind 1
Two of a Kind 2
Two of a Kind 3
Two of a Kind 4
Two of a Kind 5
Two of a Kind 6
Two of a Kind 7
Two of a Kind 8
Two of a Kind 9

Both Moran and Willhoit knew engine choice was the key if they were going to meet their goal of combining good looks with startling performance. Previously, Willhoit created a 1925-cc powerplant for Moran’s Speedster. With electronic fuel injection, it made a claimed 152 hp and 140 lb-ft of torque. Moran wanted more.

“I’m a very visual person and wanted (the coupe) to reflect the GT flavor of my Speedster, but I also wanted it to be a more powerful cruiser,” says Moran, who deemed a full two liters of displacement appropriate for the 150-pound-heavier coupe.

Instead of taking the usual 2.0-liter route with Mahle cylinders on a later 912 crankcase, Willhoit decided to go for 2002 cc using custom 91-mm, Nikasil-coated aluminum cylinders made by LN Engi­neering with a custom 77-mm Scat crankshaft. The latter uses Clevite two-inch rod bearings, while Carrillo connecting rods locate 91-mm JE pistons set up to yield a compression ratio of 11:1.

The camshaft offers 260° of duration at .050-inch with .390-inch of lift, and operates Willhoit’s favorite combination of 42-mm intake and 34-mm valve exhaust valves via pushrods rendered in 2025 aluminum. The valves are stainless steel and benefit from dual valve springs with Will­hoit’s own guides and retainers.

Sprouting from the cylinder heads are thinly screened 48-mm throttle bodies made by TWM. Each cylinder is fired by a pair of 10×19-mm spark plugs. The twin-plug distributor and fuel rails were developed by Willhoit and work with a magnetic crankshaft-triggered ignition system and Motec engine management, which provide batch-fire ignition and fuel delivery. An M&W dual-output CDI ignition box makes the former possible, while a Bosch 12-volt alternator allows the use of these modern systems in a normally 6-volt 356A. An aluminum crank pulley saves a little rotating mass while an ATI harmonic damper smoothes the big four out.

Air flow, from intake to cylinder head to WR sport muffler, was optimized based on Willhoit’s earlier research to maximize torque. The final numbers are 170 hp at 6900 rpm and 143 lb-ft at 5100 rpm — claims that suggest this air-cooled, eight-valve, pushrod four can rival the torque of the factory’s 2.0-liter development of the exotic, four-cam Fuhr­mann four.

To ensure all that torque gets to the ground, Scott Hendry of Scott’s Indepen­dent in Ana­heim packed a 716 transmission housing with C-B-A-B gears, a 7:31 ring-and-pinion, and a GT torque-biasing differential. This is mated to the engine with a lightweight flywheel rendered in 4340 chromoly, a Kennedy Engi­neered Products Stage I aluminum pressure plate, and a dual-friction clutch disc.

With the powertrain finalized, attention turned to the chassis. The forward spring rates are 20-percent stiffer than stock and are kept in check by Bilstein Sport dampers. The spindles have been decambered by 1.5°. A Will­hoit Restorations anti-roll bar measuring 17.5 mm was installed, as were aluminum tie rods with heim joints. In the rear, 26-mm torsion bars and Ele­phant Racing bronze spring-plate bushings with early 911 spring-plate covers stiffen things up. These are damped by Von shocks with a lower heim joint to clear the wider-than-stock wheels. 

Connect with Excellence:   Facebook Twitter