By the end of 1962, GM was out of NASCAR and their streak of dominance abruptly ended.

Ford had already initiated the march to victory and Chrysler wasn’t going to let them eat the pie alone. Both manufacturers started an aggressive development of performance parts to satisfy the needs of NASCAR.

So, where do you start creating a winning race car? Of course, with the largest, most powerful, and obscene engine you can create.

NASCAR executives quickly realized that without hard limits, factory development would quickly go out of control and ruin the sport. So, in 1963, NASCAR introduced the 428 rule. Engines would be limited to 428 cubic inches of displacement to prevent excessive development and retain reusability of parts and components for less fortunate teams.

Big block power

But even so, seven liters is still a huge displacement and there’s lots of power to be made, provided you throw enough engineers at the problem. Many worthy engines lived, performed, and died in the search of the ultimate NASCAR engine.

Chrysler developed the legendary 426 Hemi V8 – the most revered engine in Mopar history, worshiped by old and young alike.

Ford emerged with its own mythical power plant – the mighty Boss 429 – an engine for when losing is not an option.

The technology developed to win at NASCAR also trickled down to the street in some form or the other, powering some of the rarest and coolest muscle cars ever built.

1963 was a great season for Ford who won 23 races, with Mercury adding one for the team. The newly introduced FE 427 side oiler proved a worthy race engine. Supposedly, the NASCAR prepped engine was good for 450 – 550 horsepower, which is a lot even by today’s standards.

The 1963 Daytona 500 was an absolute slaughter.

Driving the Wood Brothers No. 21 Ford Galaxie, replacement driver Tiny Lund achieved victory thanks to a clever pit stop gamble. Lund led four other Ford drivers for a 1-2-3-4-5 finish – absolutely crushing the competition in the most popular race of the Grand National series.

Chrysler’s 426 Max Wedge engine (awesome name) was also very good. Plymouth won 19 races in 1963, 14 of which won by Richard Petty.

Joe Weatherly won the 1963 NASCAR Grand National season with only 3 wins.

426 Hemi V8 – the birth of a legend

In 1964, Chrysler introduced their legendary 426 ci Hemi V8 engine – a marvel of automotive engineering.

Based on the Max Wedge engine, Chrysler engineers returned to the hemispherical combustion chamber design which was very successful in the late 1950s and offered improved thermal and volumetric efficiency.

The engine was heavy, sitting around 720 lbs. However, the special thick-wall iron block and new heads could contain a 12.5:1 compression ratio. Hemi blocks used an oversquare design with a 4.25-inch bore and a 3.75-inch stroke. A canted valve design allowed the engineers to fit bigger valves inside the combustion chamber – 2.25-inch intake and 1.94-inch exhaust.

The combination of this block and head made the Hemi rev-happy with plenty of airflow at high RPM to sustain big power. Breathing through a Holley four-barrel carburetor and a dual-plane, high-rise intake manifold, the Hemi developed around 550 – 600 horsepower.

Grinding at the ports and valves and tuning the engine could supposedly get you beyond 750 horsepower, though with questionable reliability – even for NASCAR standards.

Either way, the engine squeezed enough juice to allow Paul Goldsmith to run his Plymouth Belvedere to run at a record 174.91 miles per hour at the qualifier for the 1964 Daytona 500, with Richard Petty just below at 174.42 mph.

Petty recorded an average of 154.334 mph during the race and won the 1964 Daytona. Four Hemi-powered cars finished in the top 5 with a brave Marvin Panch driving his Ford into the 4th position.

Petty ultimately became the 1964 NASCAR Championship.

The Hemi was brilliant but expensive and complicated to produce. Chrysler did not manage to put 1,000 engines on the road – a revised NASCAR requirement.

Further pressured by Ford, NASCAR banned the 426 Hemi for the 1965 Grand National series. MOPAR engineers worked around the clock to develop the Hemi and relied on the engine to win. Chrysler boycotted the race for most of the year, focusing on drag racing instead.

The 1965 NASCAR Grand National series went almost entirely to Ford.

FE 427 Cammer V8 – a worthy competitor

Meanwhile, Ford’s NASCAR-prepped FE 427 side oiler V8 engine was really good, but it couldn’t compete with the Hemi on the track.

Ford developed a worthy Hemi competitor for 1964 – the 427 SOHC “Cammer”.

It also used hemispherical combustion chambers. Each bank featured a single overhead cam driven by an idler shaft, positioned where the in-block cam used to live. Larger stainless steel valves, sodium-filled exhaust valves, and beefier springs allowed the engine to breathe better at high RPM, increasing volumetric efficiency and power.

Crowned with two four-barrel carburetors the 427 Cammer engine could generate up to 657 horsepower at 7,500 RPM and 575 lb-ft of torque at 4,200 RPM.

The engine helped Ford and Mercury cars win 36 races in 1964 to Chrysler’s 26. They lost the title to Petty’s phenomenal performance but overall dominated the Grand National season.

NASCAR officials, however, decided that overhead-cam engines had no place in the race. The 427 Cammer and a Hemi DOHC prototype were banned from the competition.

In 1966, the 426 Hemi was allowed to participate again, after adapting it for legitimate use on the street. Street Hemis were advertised with 425 horsepower and 480 lb-ft of torque. The engines were produced between 1966 and 1971, powering numerous legendary Mopar muscle cars.

David Pearson was the 1966 NASCAR Grand National champion and James Hylton was second – both driving for Dodge.

Ford’s 427 Cammer V8, however, remained banned and it was their turn to throw a tantrum and refuse to participate in NASCAR. Ford’s hiatus was not particularly long, though. Sales were dropping in proportion to its absence at the NASCAR podium.

Ford returned in 1967 for an abysmal season. The company only saved face thanks to young Mario Andretti who won the 1967 Daytona 500 in front of a record audience of nearly 95,000 spectators.

The same year, Richard Petty achieved legendary status, becoming the 1967 NASCAR Grand National champion, winning 27 out of 48 races he entered, with a streak of 10 consecutive wins.

The Hemi V8 was walking over the competition.

Until the Boss came around…

Boss 429 V8 – losing is not an option

There was no way in hell Henry Ford II was going to lose. He didn’t lose to Ferrari and he wasn’t going to lose to Chrysler either.

The FE 427 Cammer engine was a costly mistake, however, the Total Performance program justified all racing development costs, as long as Ford won.

For 1969, Ford came up with a new engine. The Blue Oval tasked their main NASCAR partner – Holman-Moody to design a new powerplant from the 385 engine family. Holman-Moody put two competing teams to work and emerged with the Boss 429 – a pure, race-bred engine that was going to power the Fords to victory.

The block was cast iron with a thin-wall design and four-bolt main bearing caps. With its oversquare bore ratio – 4.36-inch bore / 3.59-inch stroke, it was created to produce gobs of power at high engine speeds.

But what really made the engine shine was a set of state of the art aluminum heads. The Boss featured a nearly hemispherical combustion chamber (referred to as the crescent) with 2.28-inch intake and 1.90-inch exhaust valves. The valve train used flat tappet solid lifters and a redesigned oiling system that brought oil through the head passages and rocker pedestal.

Untold hours of work went into discovering the best port shape and size for optimal airflow at high RPM. When fully tuned, the Boss 429 generated up to 620 horsepower at 7,000 RPM.

But Ford’s real advantage was in weight. The complete 429 engine was around 15% lighter than the Hemi ~ 600 lbs vs 700 lbs. That’s an absolutely huge difference for a racing engine.

And even so, you could see how engine development had reached a plateau. Despite how many cubic meters of dollars were thrown at the problem, power levels barely crept forward.

Between NASCAR’s rules and the available technology, both the Boss 429 and the Hemi 426 were about as good as they were going to get.

Even with these massively powerful engines, wind resistance is so strong at 180 miles per hour, cars just couldn’t accelerate any further. More power was no longer going to solve the problem.

Engineers had to look at it from a different perspective.

Stay tuned for new articles in the series to be published each Monday. Links will appear below as they get published.

• Part 1 – Win on Sunday, Sell on Monday – NASCAR’s Evolution in the 1960s
• Part 2 – Before the Aero Wars, There Were the Engine Wars
• Part 3 – First Shots Fired – 1968 Aerodynamics in NASCAR
• Part 4 – The First Aero Warrior – 1969 Ford Torino Talladega
• Part 5 – Blinding Speed – 1969 Mercury Cyclone Spoiler II