Small Block General Data & Specifications
 
   
    The Ford small-block V-8 was first introduced during the 1962 model year in the all-new
Fairlane. Known as the “Fairlane V-8” for its original application, the small-block began
modestly at 221 cubic-inches with a 3.50-inch bore and 2.87-inch stroke. What made the all-
new small-block Ford revolutionary was its lightweight, grey iron, thin wall design which made V-
8 power achievable in intermediate and compact sized vehicles. The small-block Ford was an
“oversquare” design, meaning the cylinder bore was larger than the length of stroke. This
allowed for larger valves, reduced piston speed and shorter connecting rods which permitted
high revs. More iron in the main bearing webs allowed for the deletion of the block skirt found
on the earlier “Y” blocks introduced during the 1950s. The small-block Ford was a quantum
leap in lightweight engine technology for Ford Motor Company.

221
The 145 horsepower 221ci V-8 was a very low displacement small-block which would have little
in common with the 260, 260, 289 and 302ci engines to follow in terms of interchangeability.
The 221’s heads employed very small ports and closed 43.5cc combustion chambers—
decidedly undesirable for performance applications and certainly specific to the 221. The 221
was available only with a Autolite 2100 two-barrel carburetor with automatic choke. It was a
short-lived powerplant—produced through the end of the 1963 model year.
 
     
     
   
    260
Introduced at the same time as the 221 was the 164 horsepower 260ci small-block sporting a
larger 3.80-inch bore and the same 2.87-inch stroke. The 260 cylinder head had larger 53cc
closed combustion chambers with the same 1.59-inch intake and 1.39-inch exhaust valves also
found in the 221. Valve stem size was also 0.310-inch—identical to the 221. Aside from
combustion chamber size, the 260 head was virtually identical to the 221 head. Like the 221,
the 260 was only available with two-barrel Autolite 2100 series carburetion. Ford’s compact
and peppy 260 witnessed production through the end of the 1964 model year. Both the 221
and 260 engines had 8.7:1 compression for reliable use with regular leaded fuels of the era.

289
For 1963, Ford increased the small-block’s bore size to 4.00-inches, with the same 2.87-inch
stroke to achieve the venerable 289ci engine. The 289 was one of Ford’s greatest success
stories because it produced plenty of power for a variety of performance applications,
including victories around the globe at LeMans, Indianapolis and a host of other legendary
motorsports venues. The 289 block was different than the 221 and 260 in that it was a heavier,
thicker casting to accommodate the larger bores. This means that you cannot bore a 221 or
260 block to a 4.00-inch bore because you will likely run into the water jacket.
 
    Your performance efforts should begin with a 289 block. All 289 heads (including High
Performance) are dimensionally the same through 1967 with .342-inch valve stems, 1.67-inch
intake valves and 1.44-inch exhaust valves. Contrary to what you may have been told, the 289
High Performance head did not have larger ports until the release of the 1967 service head.
Port size with the service head was marginally larger.

For 1963, there were two 289ci engines. The base engine yielded two-barrel Autolite 2100
carburetion, higher 9.0:1 compression (regular fuel) and hydraulic lifters. Optional was the 289
High Performance V-8 (also known as the Hi-Po) with mechanical tappets, 9.0:1 compression,
and improved cylinder heads with screw-in rocker arm studs, valve spring pockets, cast iron
headers, and Autolite 4100 four-barrel carburetion.
 
     
 
 
  The 289 engine line-up for 1964 was much the same as it was for 1963, with the exception
being an optional 289 four-barrel, low compression (9.0:1)
V-8, available only in the Mustang introduced mid-year. The only difference between the 289
two- and four-barrel engines of 1964 was the intake manifold and carburetor. Cylinder heads
were exactly the same between the 289 2V and 4V engines. The 289 four-barrel engine was
topped with an Autolite 4100 series carburetor, just like the 289 High Performance. The only
difference between the two carburetors was slightly larger venturis and the use of a manual
choke on the 289 High Performance engine.


Combustion chamber sizes in 1963-64 ranged from 52.6cc to 55.6cc for all 289 engines.
Chamber size depended upon the casting. Valve sizes were 1.67-inches intake and
1.44-inches exhaust for all 289 types. All 1963-64 289 engines had five-bolt bellhousing blocks.
 

 
  Important upgrades in the 289 occurred beginning with the 1965 model year. The most
obvious was a six-bolt bellhousing pattern, which improved the rigidity of the powertrain and
reduced noise, vibration and harshness levels. Aside from the six-bolt pattern, the base 289
two-barrel engine remained the same with its 52.6cc to 55.6cc chambers and dished pistons.
The 289 four-barrel engine for 1965 received a compression boost to 10.0:1 through the use
of flat-top pistons. All pistons, dished and flat-top, had valve reliefs. The 289 High Performance
V-8 continued for 1965 relatively unchanged.

The 1966 model year witnessed several changes in the Ford small-block. Effective May 2,
1966 in production, 289 two- and four-barrel engines went to rail-style rocker arms that didn’t
require a push rod guide cast in the cylinder head. With this change came new, pent-roof steel
valve covers that were used through the 1967 model year. One subtle change for 1966 was
the use of a finned timing cover that was also used through 1967. Aside from pent-roof,
chrome valve covers, the 289 High Performance engine continued through 1967 virtually
unchanged internally from 1963-66. One of our 302 engines will swap from a 289 very easily.

www.fordcobraengines.com



302/5.0L
When Chevrolet pushed its reliable and snappy 283ci small-block to 307 cubic-inches, Ford
stroked the 289 just .019-inch to achieve the 302. The 302 block is a different block than the
289, though both are interchangeable. The 302 block is clearly marked as a “302” in the lifter
valley. What makes the 302 block distinctive is the use of a slightly longer cylinder skirt to
accommodate the modest increase in stroke. This feature afforded the 302’s piston skirts
increased stability at the lower end of the bore, which made for quieter operation (less piston
noise).
 

  Though the 302 has a .019-inch longer stroke, it actually has a shorter connecting rod (5.090-
inches center-to-center) which is not interchangeable with the 221, 260, 289 or Boss 302. The
221, 260, and 289 rod is longer at 5.155-inches from center-to-center. The 302’s shorter rod,
when combined with the longer crankshaft throw exclusive to the 302, gives this engine a
longer stroke. Aside from the differences just mentioned, the 302 is virtually the same as the
221, 260 and 289 engines. During the 302’s first model year, 1968, those pent-roof steel valve
covers were embossed with the words “Power By Ford,” which was standard until the mid-
1970s when the Ford oval took its place.

The 302 has evolved considerably since its introduction in 1968. Beginning in 1978, Ford
began calling the venerable 302 the “5.0 Liter” V-8. It was equipped with a cast aluminum
intake manifold and spun-aluminum air cleaner housing. The 5.0L has grown to become one of
the most respected V-8 engines of our time. Beginning in 1982, Ford fitted the 5.0L with a high-
performance 351W marine camshaft to conceive the 5.0L High Output engine with two-barrel
Motorcraft 2150 carburetion. Just one year later, the 5.0L was fitted with a cast aluminum four-
barrel intake manifold and Holley four-barrel carburetion. These valiant steps led to more
powerful 5.0L engines to come. In 1985, Ford revised the 5.0L block to accept roller tappets,
which improved performance and reliability dramatically. One year later, the 5.0L V-8 was fitted
with “fast-burn” cylinder heads borrowed from the F-series trucks and Sequential Electronic
Fuel Injection (SEFI). The 5.0L engine has remained virtually the same ever since.
 
 
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