Falling in love is pretty common in the back of a car; though rarely does it take place on a parcel shelf. Less often it occurs in a brief moment of weightless bliss, as it did for Keith Tisherman while he was flung back and forth across his uncle's then-new 1971 Datsun 240Z while threading the needle through West Los Angles traffic.
As luck would have it, Keith became the third owner of the same Z he'd fallen for when he purchased it very used from his brother in 1999. Having dreamt of this opportunity for a good portion of his life, no time was wasted in forming a plan and a budget to return the car to its original glory-and maybe a bit more.
Being a hands-on guy, Keith skewered the Z on a rotisserie, spinning and stripping it down to a bare chassis in his garage. Paint, underbody coating and Bondo were all blasted away, denying corrosion any place to hide. The unibody, doors, hood and hatch were delivered to Doug's Custom Paint in Chatsworth, California, for a fresh coat of Mercedes S-class silver all-around.
Top-End Performance (TEP) of North Hollywood, California, was contracted to build a mild, twin side-draft L28 faithful to the Z's early 70s vintage. As the phone hit the receiver though, it was clear to Keith that he and his wallet had tumbled headlong into the world of project creep.
A heavy-duty L28 turbo block is the foundation for the big, naturally aspirated powerplant. Three liters of displacement come from boring the cylinders out to 90.5mm, rather than through the more conventional use of an LD28 stroker crank. The stock crank retains its 79mm stroke, though it has been balanced, straightened and polished. The rods are also blueprinted factory parts. Combined with lightweight 10.75:1 compression JE pistons and a set of Total-Seal rings, it's clear the under-square motor is designed to spin. An N42 aluminum head, which received a port, polish, and a three-angle valve-job, sits atop a Nissan Comp 1.0mm metal head gasket. Both the intake and exhaust valves are oversized and swirl polished stainless pieces, 44mm and 38mm, respectively. Valve motion is orchestrated by TEP's .510-inch lift, 307-degree duration cam and dual valvesprings. The rockers, retainers, and all fasteners were replaced with new factory parts, with the exception of the important hardware, which was substituted for ARP bits. The Nissan high-capacity 280Z turbo oil pump was tuned with dual pressure relief springs to raise the systems regulated pressure to a level sufficient to ensure lubrication at high rpm. A 7.5-quart, fully baffled Datsun Competition oil pan keeps the pick-up submerged.
Electronic control of fueling and ignition timing is pretty much mandatory when using such a high compression ratio and California gas. Boasting a simple programming interface and integrated direct-fire ignition, the Electromotive TECII was selected as a suitable system for this straightforward application. TWM Induction's sweet individual-runner throttle bodies, sized at 45mm, are used to meter air to the cylinders. Where most would either forego an air filter, or use filters mounted to the end of the intake trumpets, Keith made the smart choice and plumbed cold air in from the front grill through a K&N cone filter. RC 390cc/min injectors are fed by a Bosch racing pump and controlled by a TWM adjustable fuel pressure regulator. Exhaust passes unfiltered through a ceramic-coated Nissan Comp 6-2-1 header, then through a 2.5-inch Borla exhaust and XR1 muffler. Though Keith has yet to dyno the car, such engine combinations are said to make between 240- and 260-wheel hp at around 7500rpm.