Thursday, November 24, 2011

History of the Ford Small Block V-8

This Windsor, Ontario built 90° V8 was introduced in 1962 as a 221 cubic inch engine. It was Ford's first modern lightweight small-block replacing the old Y-block. In 1963 the small block displacement was bumped up to 260 and 289. The change was increase cylinder bores on early 221's from 3.5" to 3.8" on the 260 and the later standardization to 4" bores on later engines. The 289 was also fitted with larger valves than found in the earlier small blocks. The photo to the left shows a 1966 289-4V sitting smartly in the engine bay of the same year Mustang. 

Through the years, not all small-block Windsor's were produced solely at the Ontario plant, but the name stuck with the engine. The photo next right, shows the Windsor, Ontario engine plant during production. In 1962-63 the gross horsepower rating of the 221 was only 145HP. With the introduction of 289 in 1963, horsepower jumped to 195HP with a 2-barrel carburetor and 225HP with the 4-barrel. The 289HP pushed horsepower ratings to 271HP in 1965 which required the engine to be fitted with many heavy-duty factory parts. The 289HP has different cylinder heads from those of the standard 289. The 289HP heads have bigger valves and smaller combustion chambers.

Carol Shelby used the 289HP as the base for his GT350. The Shelby's were rated at 306 HP by using a larger carburetor, high-rise intake and less restrictive exhaust. In 1966, High-Performance Models of the Mustang were also fitted with 289HP engines as an option.
In 1968 the stroke was increased by using shorter connecting rods increasing displacement to 302 cubic inches (5.0 liters). This engine was used in Ford products through 1995. In 1968 , 2 and 4 barrel version of the 302 were also available. 302's found there way into Shelby GT350 in 1968.
With the introduction of the 351 Windsor in 1969, 4 barrel versions of the 302 were dropped.By 1971 emissions regulations began robbing horsepower from the once might small block. With reduced compression ratios and the addition of mechanical smog devices, the 302 manage to only pony-up 140 HP in 1975. In the mid to late 70's, small block performance stagnated amongst factory built 302's.
Ford introduced the "High Output" 302 in 1982, sparking new interest in Ford small block racing. Throttle Body Fuel Injection came in 1984 and Sequential Electronic Fuel Injection in 1986. As computers started taking-over control of emissions and fuel injection systems in the early 1980's, horsepower gains would become regular feature of the 302 for it's remaining years.
As mentioned earlier, 1969 introduced the 351W engine rated at 250 HP with a 2 barrel and 290 HP with the 4 barrel. The 351W has a taller deck height to increase the stroke. While al 289, 302 and 351 Windsor's share a 4" bore, the 351W engine has many changes that set it apart from other Windsor engines. The intake, heads, pushrods, block height, and firing order are just a few of the more notable differences between the 351W and other 4" bore Windsor engines.
Another variant of the small block Windsor is the Boss 302. These engines where built as Ford's entrance into Trans-Am road racing. SCCA racing rules required that at least 1,000 production vehicles were to be fitted with the Boss 302 in order to qualify for the event. Boss 302's used a standard 302 Windsor engine block, but are fitted with cylinder heads from the 351 Cleveland. This and other improvements set it apart from the standard 302.
Even though the Windsor engines no longer adorn today's Ford production vehicles, the aftermarket market bristles with excitement. Enthusiast have a long list of specialty parts to choose from, which are all made especially for the 5.0 liters of yesterday. Thus, keep the a legend alive for many year to come.

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