Part 2: ’68 to ’73
- 303 and 366 race engines
- 366 proposed production engine
- SD-455 production engine
While Pontiac was showing...
While Pontiac was showing off the new ’69 Trans Am to the press at Riverside International Raceway, as shown here, Pontiac’s Special Projects team was back in Pontiac, Michigan, working on homologating a 303 engine for the SCCA Trans-Am series.
In Part I, we introduced you to some of the dedicated engine engineers and scientists who worked on moving Pontiac out of the world of the Straight 6 and straight 8 and into the future of the Pontiac V-8.
For this installment, Pontiac Special Projects Engineer Herb Adams shares how he and his team developed the 303ci Trans-Am series and 366ci NASCAR Grand Am series race engines, the proposed 366ci production engine, and the SD-455 production engine.
“I was fortunate to be the team leader in the development of these engines,” Adams says. “Pontiac Assistant Chief Engineer Bill Collins assigned Special Projects the job of developing a race engine for use in the SCCA Trans-Am series. It all started after racer Jerry Titus came to Pontiac and asked us to design and deliver a Pontiac 5.0-liter engine for his race car that could compete against the 475hp Chevy small-block race engines. Since Pontiac was not allowed to directly support racing due to the 1963 corporate edict, our non-descript department, named Special Projects, allowed us to work under the radar on high-performance racing and production-engine development.”
Pontiac Special Projects Engineer...
Pontiac Special Projects Engineer Herb Adams leads H.B. Bailey and Tiny Lund through a turn on the Daytona International Speedway road course for the Citrus 250 on February 18, 1972. “We were testing the 303ci race engine,” Herb recalls.
What follows are Herb’s recollections of Special Projects teammates Tom Nell and Jeff Young, and their contributions to Pontiac’s high-performance V-8 programs.
Title: Assistant Race-Engine Engineer, Pontiac V-8 Power Development
Accomplishments: 303ci direct-drive dry-sump, SD-455 clean-block test, reverse manual-valvebody automatic transmission
Tom Nell started at Pontiac in June 1959 in chassis drafting, where he remained for three months. He then moved on to experimental engineering. There, under the direction of Pontiac’s senior project engineers, he wrote work orders to Pontiac’s repair shop and dyno lab to test experimental engine components, and then oversaw and evaluated the testing results.
I don’t recall the first time I met Tom, but I sure remember our first road trip together. I had graduated from General Motors Institute, and he and I were testing Pontiac’s factory air-conditioning systems in southern Texas. There was other Pontiac staff with us, and we all had two-way radios. I remember drivers from the end of the line radioing him and saying, “Hey, Tom, slow down.” That’s when I knew Tom was into making Pontiacs go fast.
This vintage Pontiac publicity photo shows a dressed-out tunnel-port 303. The photo was likely arranged to show SCCA officials that the Pontiac 303 was a production engine.
He was directly involved in the Super Duty program for approximately one month before the 1963 GM racing ban. He observed that the dual-quad, high-rise plenum manifold, which was shipped in the trunk of the ’63 SD cars, produced no throttle response on hard launches. He took the initiative to fix the problem. “I was getting a lot of complaints about it from the drag racers,” Tom says. Carb manufacturer Carter and Pontiac agreed that the fix was necessary, and all of the racers who received the original four-barrel carbs were sent new ones at no cost to them.
Sometime prior to February 1963, Tom procured a dead 421-SD under Pontiac’s employee-purchase program, rebuilt it, and supplied it to Cam Gagliardi and Gil Kramer, who put it in a ’53 Studebaker. In the NASCAR Modified 250-mile race (Permatex 250) on February 23, 1963, it was clocked at 163 mph, qualified on the outside pole, led 74 of 100 laps, and won the race. The next year, Tom invited me to come to Daytona to be a crewmember for him and the Pontiac-powered Studebaker team, which I did.