Building on the remarkable racing achievements of the 550 Spyder, Porsche’s 718 RSK model refined its predecessor’s design and engineering even further, evolving to stay competitive and keep pace with changing race regulations While improving on the setup of the Spyder by being lower and lighter and having better handling, it used the same mid-mounted engine, the 142hp 1.5-liter Type 547/3 quad-cam engine introduced with the 550A Spyder.
Although the RSK’s debut at the 1957 24 Hours of Le Mans was marred by an accident, in the following year it went on to win both First-in-Class and Third overall. The RSK also took the European Hill Climb Championship in both ‘58 and ‘59 and won the Targa Florio in 1959. During this time period, there was a suspension switch from swing axles to wishbone control arms. Also, a center-seat configuration was developed that could be quickly converted to a two-seat, left-hand drive setup, depending on the race venue.
Changes in the FIA racing rules in 1960 prompted some other modifications in the RSK. These included a larger cockpit and windscreen, along with a new double-wishbone rear suspension. Powered by a bigger version of the Type 547/3 quad-cam engine, the 1.6-liter engine delivered 160hp. Now referred to as the RS 60, this lightened, more powerful racer took home victories in 1960 at both the 12 Hours of Sebring and the Targa Florio. For the third year in a row, it successfully defended its winning streak at the European Hill Climb Championship. Yet again in 1961, Porsche owned the European Hill Climb Championship, but this time as the RS 61 model (though it was essentially unchanged from the RS 60). That same year, another variant, the W-RS model, was variously powered by two new air-cooled engines, a two-liter version of the quad-cam, and a flat-8 engine from the Porsche 804 Formula One car.
While this new setup didn’t quite achieve the same success at Le Mans (finishing 8th in 1963), the W-RS continued Porsche’s stellar achievements in the European Hill Climb Championship, winning every year from 1963 until 1982, an astonishing 42 titles in all.
Clearly, such an impressive race car, one that dominated sports car racing in a decisive manner, merits a modern-day tribute. That’s exactly what Rock West Racing had in mind with its RW RSK model. Just as the original race car was derived from its predecessor, so too the RW RSK draws on the proven design engineering of the RW Spyder—but with some slight enhancements to accommodate the different body shape and for driving on the street as well. These changes begin with relocating a pair of cross members, and lowering the engine mounts slightly to fit under the RSK body.
Otherwise, the foundation has the same three-inch, mandrel-bent, round-tube frame. At the front is a reconditioned and upgraded VW beam axle with new ball joints, ride height adjusters and modified torsion leaf packs. In addition, the rear suspension features a custom torque tube along with lengthened, adjustable spring plates to suit a mid-engine application. This stronger chassis can handle a wide variety of powertrain options, ranging from an air-cooled VW Type I or Type IV to a Porsche 356 or 911 six cylinder (using a longer chassis with De Dion suspension), or even a water-cooled Subaru boxer engine.
The basic body form of the RW RSK, molded from a specific, authentic race car, employs laminations of fiberglass cloth, mat and Coremat®, saturated with resin and laid up by hand. Once the body is cured, the chassis is fitted to the body while it’s inside the mold. The body and chassis are assembled together using resin and fiberglass, structural adhesive and mechanical fasteners.
The RW RSK is offered in several original-style configurations for both the cockpit and rear deck. These layouts consist of either left-hand-drive with dual seats, or a center-steer, single-seat setup, and headrest fairings behind either the driver or driver and passenger seats, depending on the corresponding cockpit setup. Other options include a 911-style fan shroud, rollbar(s), leather cockpit upholstery, and right-hand drive.
Given the exclusivity of this period-correct racing reproduction, which requires specialized parts such as a custom windshield, fuel tank and light assemblies, the RW RSK commands a somewhat higher price tag than its sibling, the RW Spyder. A well-equipped deluxe package is priced at $25K, and rollers start $35K. While the standard color is silver, custom-tailored paint schemes with racing livery (such as stripes, number balls, and fender spears) can be applied as well to represent different eras of competition and even individual race cars.
Whatever the configuration of the body, engine setup and level of customization, the RW RSK achieves a high level of sophistication and historical accuracy for the discriminating collector and performance enthusiast.