Fourth generation[edit]
Truck Six Overview Production 1964 - 1996
Layout Displacement 240 cu in (3.9 L)
300 cu in (4.9 L)
Cylinder bore 4"
Piston stroke 3.18" (240)
3.98" (300)
Combustion Fuel system
Output Power output 114 hp (85 kW) - 150 hp (112 kW)
Torqueoutput 260 lb⋅ft (353 N⋅m)
Produced at the
Cleveland Engine plant in
Brook Park, Ohio from 1964 through 1996, the 240 and 300 Sixes are well known for their durability. Simple design and rugged construction continue to endear these engines to a number of Ford enthusiasts to this day. The engine has earned the monikers "bulletproof" and "indestructible" by many. Popular legend holds that are numerous claims by owners who have purposely sought to destroy a Ford straight-six through intentionally abusive use, but who were unsuccessful in doing so.
One example of the engine's sturdy design is the fact that no timing chain or timing belt (both of which can break, causing unwanted downtime or even engine damage...although this is extremely unlikely in the case of a chain) is used. This generation of Ford Six was designed with long-wearing gears for that purpose instead. Very few modern engines use timing gears; belts and chains are by far more common. This is because engine makers long ago (in the 1930s) discovered that gear-driven camshafts are more expensive to build, heavier, sap more power out of an engine from, and transmit harmful shock impulses. Belts are easily replaced at intervals, and chains will generally last as long as the engine will. Also these engines employed 7 main bearings, which is far more than is necessary at the power level.
Both the 240 and the 300, no matter the application, used a single barrel Autolite 1100/1101 (or Carter YF/A)
carburetor until the introduction of electronic
fuel injection in 1987. With proper gearing, many F-trucks and Broncos achieve 20+mpg. This fact was heavily used by Ford's advertising campaign (some television advertisements and written literature even claimed 30 mpg), since the V8 engines in these trucks rarely achieved over 14 mpg.
The fuel economy of the 300 makes the engine a popular choice among truck enthusiasts that want both power and economy. The addition of performance parts (such as
intake and
exhaust manifolds with a
four-barrel carburetor) place the engine power output near the same levels as the stock 'HO' ('High Output') version of the optional 351 V8, with little or no change in economy.
