August 2009 Issue

(Editor's note: We think this first person account nicely illustrates one of the mantras of our hobby, that of realizing dreams by building the cars that dominate our childhood memories. We're confident that you will glean some useful information here from Allen's experience of building his dream.)

story & photos by Allen Nicholas 

A little history; As a kid growing up near Mid-Ohio Sports Car Course in Mansfield, Ohio during the 1960s, I developed an early passion, though my mom called it "the disease," for racing and the many different types of sportscars that came to town each summer. The United States Road Racing Championships (USRRC) stopped at Mid-Ohio as it toured tracks throughout North America from 1963 through 1968 offering close, competitive racing in two separate categories--the Driver's Championship featuring big-bore sports-racing prototypes, plus a separate Manufacturer's Championship consisting of professional and amateur entrants, racing "production" GT Porsches, Alfas, Corvettes, Ferraris and my favorites, the all-conquering 289 Shelby Cobras. During this period, road racing in North America was growing rapidly in popularity and the USRRC eventually morphed into the CanAm and TransAm series.

Fast forward some 40 plus years and it was finally time to build my own 289 USRRC replica for the street and track days. Friends of mine were shocked that I would choose a small-block car over a 427. Don't get me wrong, the big-block SC is still the undisputed "production" brute of all time, but having watched Ken Miles, Dave McDonald, Bob Holbert, Tom Payne and Bob Johnson slide those 289 cars around the tracks for 200 miles in the '60s, my mind was made up.

I started with a visit to Kirkham Motorsports in Provo, Utah where I discovered that their aluminum-bodied 289 FIA Hybrid (no, not that kind of hybrid) offered exactly what I was looking for, the classic FIA/USRRC body on an updated chassis with a fully adjustable coilover suspension. I was the consummate kid-in-a-candy-store when David and Thomas Kirkham sat down with me for an afternoon to go over the options that would help me replicate this historic car. I planned to do it right, which meant it had to include FIA-style wheels, fl ared fenders, under-frame side exhaust, forward-braced rollbar, front brake scoops, etc. I did vary from the original FIA dash layout. The racecars had the speedometer on the far right side of the dash, directly in front of the passenger (to more easily scare the hell out of them, I believe). To me, the large 427 twin dial layout seemed more practical for quickly knowing exactly how far over the speed limit I'm going, without having to focus on a three-inch dial, mounted three feet away.

The original racecars all had 48mm downdraft Weber carburetors. I knew all of the little quirks associated with driving a street car equipped with multiple Webers, but I wanted the performance and the look of a USRRC car so I was prepared to just deal with it. Then, in mid 2005 I discovered modern day computer technology made it possible to assemble your own electronic eight-stack fuel injection system using "off the shelf" aftermarket components. After researching various engine builders and component manufacturers I settled on a Keith Craft 351 Windsor engine, stroked to 408 ci topped with a TWM throttle-body fuel injection system controlled by a Comp Cams F.A.S.T. XFI engine control unit (ECU) and Aeromotive high-pressure fuel pump and filters. It looked like I could achieve a 289 USRRC Weber look and performance without the hassles -- no adjusting the choke when it's cold, or re-jetting, just turn the key and drive it.

With the help of these companies and the Kirkham family, I planned the necessary modifications needed for this type of fuel delivery system and shipped the fuel injection components, Tilton carbon clutch and flywheel assembly, along with an Aviad eight-quart aluminum oil pan to Keith Craft for engine balancing, assembly and dyno tuning. At the time I stressed to Keith that this wasn't to be a hand grenade requiring 100-octane fuel that would overheat in traffic or need freshening up every few thousand miles.

While waiting for the engine to be completed, I busied myself by prepping the chassis, installing Second Skin Audio's heat insulation to both sides of the footboxes, plumbing and mounting the fuel pump, filters, oil cooler and remote filter, installing a Kirkey vintage racing seat, dead pedal and finishing the interior.

After a few weeks of anxiety, I finally got a call from Tony Loy at Keith Craft saying, "Your engine pulls 584 horsepower at 6,250 rpm on the dyno. Do you want us to try and get more out of her?" (expletive deleted!) Let's see, 584 hp at the crank in a 2,200lb. car on 12-inch tires! No, I believe that will do. It's important to note here that with 10:1 compression and a medium-grind hydraulic roller cam, this engine is happy on what they call gasoline here in California (91 octane) and it runs between 170 and 190 degrees F in hot weather, so I got exactly what I was looking for, reliable horsepower.

For a period-correct look, I mounted the F.A.S.T. ECU and MSD spark box out of sight under the dash, routing the wiring harness through the firewall for connections to the various engine systems and I have to say, it really was a plug-and-play system as all plug connections come prelabeled. F.A.S.T. provides a software program on CD and when downloaded onto a laptop computer and connected to the ECU via a USB cable, you can tune the engine on the fl y by adjusting the values for air-fuel ratio, rpm, and timing advance, all while sitting in the passenger's seat.

To achieve maximum horsepower, Keith dyno-tuned the engine at wide-open throttle with no air intake filters or back pressure in the exhaust. Great for horsepower bragging rights, but for driving in traffic on the street, not so much. Here's where modern EFI has it all over Weber carburetion. When using the laptop to change the engine mapping, you can build and store multiple programs in the ECU to match the engine performance to your driving needs, whether its the, street, strip, or on a road course. After installing the engine in the car, I took the necessary measurements and ordered 4-into-1 custom headers from Wilson Headers of Roswell, NM along with baffled side pipes from Tubular Automotive in Rockland, MA. Once the car was on the ground and the engine running, we went to work on the laptop, leaning out the mixture and changing the timing advance for the proper idle speed, while compensating for back pressure from the muffl ers in the side pipes. At times this process was frustrating and consumed a considerable amount of time. Even after a day on Westech's chassis dyno, it still took a number of runs on the street, working with the laptop before it was finally comfortable in stop-and-go traffic. However, now that it's dialed in, the engine pulls strong through the entire rpm range with a nice lumpy cam at 950 rpm idle.

Installation of this system is a relatively simple, bolt-on process offering a retro racing look with modern day street performance. TWM and F.A.S.T. offer kits for small- or big-block Fords, Chevys and Mopars. Do it yourself, or have your engine builder take care of it for you.

Mission Accomplished -- I've accumulated many photos along with over two dozen books documenting the Cobra era of the 1960s, all of which proved extremely valuable in the planning and building of this replica. My goal of assembling a USRRC Cobra with as high a degree of authenticity, performance and reliability as my wallet would allow, was achieved with a combination of readily available parts and the assistance of some very knowledgeable and helpful people. I still have an itch, but now I can scratch it, with a short walk to the garage and the turn of a key.

Article as published in the August 2009 issue of Kit Car Builder Magazine - www.kitcarclub.com