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The history of Ford’s iconic flathead engine

23 September, 2015

Ford’s flathead V8 is the forefather to the entire American V8 scene, with its bang-for-buck performance at the time of its launch unlike nothing else the world had ever seen. It was introduced in 1932, and designed for production by Carl Schmaltz, Ray Lard, and Mil Zoerlein. The design was simple, with poured babbit-style main bearings, 21-head studs, one belt for the generator and fan, and two water pumps.

The pioneering flathead V8s did have their flaws, though — cracking was common, as was oil starvation when turning the car around hard corners, leading to seized crankshaft bearings. Check out the timeline of the famed engine’s production below:

1933: Aluminum heads and higher compression give an extra seven kilowatts, while ignition and cooling improvements help reliability.
1934: New dual-downdraught Stromberg 40 carburettor and new intake manifold adds an additional seven kilowatts. Bottom end benefits from an industry-first and a cast-alloy steel crankshaft.

1935: Carburettor replaced with Stromberg 48, and the camshaft is updated. The engine design also benefited from improved crankcase-ventilation system.
1936: Carburettor changed once more, this time to Stromberg 97 on all V8-85 (85hp/63kW) engines. Cooling capacity and radiator surface area increased, to aid with cooling. LB block gains separate main bearing inserts, while babbit-bearing mains are retained on all other motors.

1937: The V8-60 enters production as a response to European displacement taxes, and British taxes based on bore size. The V8-60 is notable by its 17-head studs, instead of 21. The V8-85 gains a larger water pump and main bearing inserts, as well as new cast alloy-steel dome-top pistons.
1938: Ford switches to a Holley carburettor, from the Stromberg 97.

1939: A Ford-built dual-downdraught carburettor helps pump the V8-85’s torque output to 210Nm. Head stud count is increased from 21 to 24, and the main journal size is once more increased. Mercury used an overbored flathead, displacing 3.9 litres (239ci), which also gains a strengthened crank, rods, and other internals.
1940: The V8-60’s last production year. Ford produces ten alloy blocks for experimentation purposes.

1942: Power now rated at 67kW (90hp), despite no mechanical changes. Flat ‘crab’ distributor cap with separate ignition coil introduced.

943–1945: Ford production diverted towards World War II effort.

1946: Ford gains Mercury flathead, with unique alloy pistons, bearings, larger rod journal size, and pressurized cooling system. The ‘V’ angle between valves (between driver and passenger sides) is reduced from 101.5 degrees to 100 degrees, to reduce cracking. New one-piece distributor cap replaces old two-piece design. Fan shifted slightly upwards, to reduce water spray onto the engine in wet weather.

1948: New 5.5-litre (337ci) flathead introduced for F7 and F8 trucks.
1949: The 5.5-litre flatheads became available in the Lincoln range, with increased compression. Mercury V8 stroked, increasing power. Major mechanical revisions are also made in 1949. The bellhousing is now cast as a separate unit to the block. Oil pump and coolant systems are updated. Improvements are made to the valve guides, and intake and exhaust systems. Main bearings are upgraded, via stronger caps and improved webbing.

1950: Piston design revised to eliminate piston slap when cold, and camshaft revised to minimize tappet noise. Three-blade fan replaces old four-blade design. 
1952: Mercury 4.2-litre (255ci) flathead increases compression, taking power to 93kW/125hp. Revised cam profile takes F-series truck power rating to 79kW/106hp.
1953: Ford’s 50th anniversary also marks the final year for the flathead in the USA, replacing it with the overhead valve (OHV) style Y-block.

This article was originally featured in a previous issue of New Zealand Classic Car. Pick up a copy of the edition here: 

Lunch with… Brian Lawrence

Hearing Brian’s stories at the Levin tribute day (see Motorsport Flashback) made me realise that despite knowing him for nearly 30 years, there was much about his involvement in motor sport that I didn’t know. Since the ‘Lunch with’ series started, we’ve made a point of focusing on other contributors to the sport beyond the drivers. I’ve ‘lunched with’ journalists, a photographer, mechanics, preparation wizards, and F1 team members, but never before a promoter. In the near future we have lunches planned with more drivers, a team owner, and a sponsor, but now is the time to interview Brian David Lawrence.

NZ Classic Car, March/April 2024 issue 392, on sale now

With this issue 392, we celebrate 60 years of the Ford Mustang.
We commence with a rare Paul Fahey replica Shelby Mustang owned by another kiwi who we should celebrate, Rodger Cunninghame.
Roger has been strutting his stuff with race cars for 50 years now and it seemed appropriate to celebrate both the milestones in this edition even though Roger is retiring from racing now, the Ford Mustang lives on.
Roger is also a longtime member of The Southland Sports Car Club (SSCC) which is also celebrating a big anniversary, its 75th. It sure is celebration time!
Quinton Taylor writes “In 1956, Rodger joined his father Bruce and his mate, club president Des Kilkelly, helping with building new grandstands at Teretonga and the start of a long association with the club.
“I was just a wee kid working with Dad on that. They had been shifted here from some other local sports club and bought here, and they had to put all the seating back on them.”
Rodger always had a liking for making things go faster and it didn’t take him long to tinker with cars as we looked through a couple of very comprehensive scrapbooks recording many amusing moments on and off the racetrack.”