Ford 335 engine

As newer automobile engines began incorporating aluminum blocks, Ford closed the casting plant in May 2012.

[1] All 335 series engines shared the same 4.38 in (111 mm) bore spacing and cylinder head bolt pattern as the Small Block V8 family.

[4] The 335 series use a dry intake manifold with the radiator hose connecting vertically to the cylinder block above the cam timing chain cover.

[6] The result was an oil system very similar to the 385 series V8s, adequate for street engines but falling short in high-revolution race use without modification.

[1][7] In addition the oil system not prioritizing the main bearings, the 335 engines have excessive clearances in the lifter bores.

[8] The closed combustion chamber promotes better swirling of incoming air fuel mixture, giving it a low-rpm torque advantage, and requires less machining to obtain high compression ratios.

[8] However, the open chamber heads valves are less shrouded, which improves low lift airflow,[4] and they exhibit better emissions characteristics.

[1][8] Most 335 series engines used stamped rocker arms with cast fulcrums that made for a non-adjustable valve train.

[4] However, the Boss 351 and 351 HO had an adjustable valve train, using rocker arms mounted on screw-in studs and guide plates.

Sales and marketing forecasts for the 1969 model year called for a second line, which was organized at Ford's Cleveland, Ohio, engine works.

This led to elimination of coolant flowing through a 'dry' intake manifold, a potential source of leaks and minimized unnecessary heat transfer.

It used the small port 2V cylinder heads with open combustion chambers to produce a more economical passenger car engine that was tuned more for low-rpm torque.

[5] These engines also included cast-aluminum flat-top pistons, stiffer valve springs, a high-performance hydraulic camshaft, and a squarebore Autolite 4300-A carburetor.

Rated at 330 bhp (246 kW), it was fitted with a four-barrel Autolite model 4300-D spreadbore carburetor, an aluminum intake manifold, solid lifters, dual-point distributor, a six-quart oil pan, and cast-aluminum valve covers.

[16] The January 2010 issue of Hot Rod reported a project in which a Boss 351 was assembled to the exact internal specifications of an original motor, but fitted with open, long tube, 1-3/4-inch Hooker headers (vs. the stock cast-iron manifolds), a facility water pump, a 750 Holley Street HP-series carburetor (vs. the stock 715 CFM Autolite unit), and minus the factory air filter assembly, engine accessories, or factory exhaust system.

[17] A measurement of SAE net horsepower would be significantly lower, and represents a more realistic as-installed configuration with all engine accessories, air cleaner assembly, and automobile exhaust system.

[5] This resulted in a compression ratio decreased to 9.2:1 while the cleaner-burning open-chamber heads helped meet the new emissions regulations.

[1] The "351 CJ" high-performance engine included a different intake manifold, high-lift, long-duration camshaft with hydraulic valve lifters, higher rate valve springs with dampers, a 715-CFM spread-bore 4300-D Motorcraft carburetor and a dual-point distributor (only with four-speed manual transmissions - not sold in California).

[5] This engine was different from the 1970-71 M-code 351C having a more aggressive camshaft, a spread-bore carburetor, a four-bolt block[15] and the lower compression allowed regular fuel to be used.

All 400s were low performance engines that ran on regular fuel and all used a 2-barrel carburetor, a cast-iron intake manifold, and small port 2V cylinder heads.

Weighing just 80% of a similar big-block,[22] it was originally available in Ford's Custom, Galaxie and LTD lines, and in Mercury Monterey, Marquis, and Brougham for the 1971 model year.

[citation needed] The development of the 400 V8 led to a significant design flaw that remained with the engine throughout its production life.

For 1975, Ford dealt with this problem by decreasing the compression ratio further with a larger 15cc piston dish and reducing ignition timing.

When the 351 Cleveland was discontinued after the 1974 model year, Ford needed another engine in that size range, since production of the 351 Windsor was not sufficient.

The 351M was the last pushrod V8 block designed by Ford[26] until the introduction of the 7.3-liter "Godzilla" engine for the Super Duty trucks in model year 2020.

[citation needed] Likewise, Ford's use of the 400 block in the creation of the 351M engine has resulted in the 400 mistakenly being referred to as the "400M" or "400 Modified."

Reduced demand for larger engines due to tightening CAFE regulations led to the abandonment of the 351M/400 and the Cleveland production line.

Initially, the cylinder blocks were imported from the US, while the remaining parts were manufactured in Australia at the Geelong Ford Foundry.

Australian-built 351 engines were also used by De Tomaso in Italy for the Pantera, Longchamp, and Deauville cars after American supplies had come to an end.

The 302C had used the "quench" closed combustion chamber with a volume of 56.4–59.4 cc, the smallest of any 335 series engine cylinder head.

1973 H-code 2V 351 Cleveland
An Australian factory-forged 302 Cleveland crankshaft in-situ. The number "302" confirms its intended displacement.