07-22-2013, 06:26 AM
The 351 Cleveland engine is one of the engines in the 335 FORD series of engines. Other engines in this series are the 351Cleveland Boss, 351 Cleveland HO, 351 M and the 400 series.
The C behind the engine denotes the place of manufacture - Cleveland, Ohio. As opposed to a 351 W where the "W" stands for Windsor, Canada its birthplace. Now to clarify the "M" located behind some of the 400 series engines. It does not stand for 'Modified" or "Michigan" as most people think. It is simply a suffix added to denote a different engine from the Cleveland and Windsor.
Some suffixes found on this engine family stand for performance options such as H.O. stands for High Output and CJ for Cobra jet. As a matter of fact, these engines were the result of Ford's quest for a bullet proof medium displacement high performance engine for use in the production vehicles. Alas the timing was poor as the gas prices rose and the fickle public went on to grossly underpowered vehicles that moved at a pace between slow and slower.
The 351 Cleveland engines used "canted" valves and large intake and huge exhaust valves for maximum breath ability. A canted valve is set in the heads at an angle, not vertically. Canted valves increase performance by allowing the heads to flow a higher ratio of gas and exhaust in and out of the heads than normal valve design. As a result, power is increased and fuel efficiency is also increased. Because of these characteristics, 351 C engines are very well known in both the NASCAR and Pro Stock Drag car circles. When driven in everyday traffic, they can be fuel efficient operating as an engine would if it in the 300 CID size.
The 335 series engines use a dry manifold configuration. In other words, no coolant flows through the manifold. At the front of the block, there is an integral timing chain cover, at the top left hand side, coolant enters the block through the thermostat and then part of it goes through the radiator and part of it goes through the water pump. At this point below the thermostat on 351 C engines is a brass diverter valve. This diverter looks small and unimportant but it is critical. Made of brass it looks like a brass freeze plug with a hole in it and is driven into a seat below the thermostat. If you have an engine you are going to hot tank, REMOVE THE DIVERTER VALVE. Hot tanking will eat the brass and no one makes these that I can find. Your engine will overheat without this valve. To remove the piece, you can generally pry it up from a small hole located below it. Or you can sometimes drill a small 1/8 inch hole off to one side and remove it with a slide hammer puller. Do not destroy this piece. If you feel lucky go to your Ford dealer and ask for part # D0AZ - 8K517-A.
351 C 4 bbl engines produced through 1971 and all 351 C 2 bbl engines use 2 bolt mains. All HO, Boss, CJ and 1972 - 73 engines use four bolt mains. However, all blocks are cast to accept 4 bolt mains and if you have a set of 4 bolt main caps, you just need to also have enough money to pay to have a machine shop drill out the block and tap it.
The Boss 351 had some differences from the other engines there are: it was fitted with a dual point vacuum advance distributor, it had a rev limiter that was almost immediately removed by the consumer because they did not want to be limited to the 6,050 - 6,150 RPMs that Ford set the device at. The engine was also the only one to receive solid and adjustable lifters. In 1971, the engine was fitted with an aluminum intake manifold. All other 351 engines got a cast iron version.
The 351 4 barrel engine was designed to breath, and breath it did. The intake ports are so big that the engine does not run efficiently until it gets to at very high RPM. In contrast, the 2 bbl engine had undersized ports and did not breath well at all. It had low end torque, but petered out at higher RPMs. I you are very lucky, there is an Australian version of the manifold that has intake ports that are not quite as large as the 4 bbl version but bigger than the 2 bbl version. I have never seen these heads, but have read about them in the past.
Ford 351 Cleveland V8 Engine
The 351 Cleveland was introduced in 1969 as Ford's new performance car engine and was built through the end of the 1974 model year. It incorporated elements learned on the 385 big-block series and the Boss 302, particularly the poly-angle combustion chambers with canted valves and the thin-wall casting technology.
Both a 4V (4-barrel carburetor) performance version and a 2V (2-barrel carburetor) basic version were built, both with 2 valves per cylinder. The latter had a different cylinder head with smaller valves, smaller ports, and open combustion chambers to suit its intended applications.
Only the Q-code 351 "Cobra Jet" (1971-1974), R-code "Boss" 351 (1971), and R-code 351 "HO" (1972) versions have 4-bolt mains although all 335 series engines (351C/351M/400) have space for them even in 2-bolt main form. The main difference between 351C/351M/400 engines is connecting rod length and main bearing size. The 351M/400 engines have the largest bearing size and the tallest deck height while sharing the 429/460 bell housing pattern. The 351C engine has a medium main bearing size and shorter connecting rods than the 351W and the 351M/400 while retaining the SBF engine mount locations and bell housing pattern. The 400 engine has the longest stroke of any SBF or 335 series engine.
All of the 351C and 351M/400 engines differ from the 302/351W by having an integrated timing cover casting in the front of the block to which the radiator hose connects.
H-code
The majority of 351 Cleveland engines are H-code 2V (2-venturi carburetor) versions with low compression. They were produced from 1970 through 1974 and were used on a variety of Ford models, from ponycar to fullsize.
M-code
The M-code version was produced from 1970 through 1971. Both years offered quench heads but 1970 offered a slightly higher (advertised) 11.0:1 compression ratio whereas in 1971 the chamber was opened up slightly reducing the advertised compression to 10.7:1. The 1970 4V head is identified with the proper date code casting and a "4" cast on the upper corner of the head. The 1971 4V head is identified with a "4*" (four-dot) casting at the same location. Hydraulic lifters were also specified, with the M-code producing about 300 hp (224 kW). 2-bolt main caps were used along with a cheaper cast iron intake manifold.
1971 R-code (Boss 351)
The 1971 R-code "Boss 351" used higher compression (11.7:1) with the quench head 4V heads, solid lifters, an aluminum intake manifold, and 4-bolt main caps. so It produced about 330 hp (246 kW).
1972 R-code
The R-code 351 Cleveland for 1972 was considerably different. It had reduced compression for emissions compliance and used open-chamber heads. It had a solid lifter camshaft, however a four barrel carburetor was retained. It produced 275 hp (205 kW) using the new SAE net system.
Q-code (Cobra-Jet)
The Q-code "351 Cobra Jet" version was produced from May 1971 through the 1974 model year. It was a low-compression design that included open-chamber "4V" heads, a special intake manifold, special hi-lift long duration hydraulic camshaft, special valve springs and dampers, a 750 CFM 4300-D Motorcraft Carburetor, dual-point distributor, and 4-bolt main bearing caps. It was rated at 266 hp (198 kW) (SAE net) for 1972 when installed in the Mustang and 248 hp in the Ford Torino and Mercury Montego. The horsepower rating dropped in 1973 to 246 hp for the 4-barrel for the intermediate Fords, and still retained the higher 266 hp rating in the Mustang. The 351 CJ (now referred to simply as the "351 4V") was rated at 255 hp in 1974 and was only installed in the Ford Torino, Mercury Montego and the Mercury Cougar.
Ford 8 Cylinder Engines
Ford introduced the Flathead V8 in their affordable 1932 Model B, becoming a performance leader for decades. In the 1950s, Ford introduced a three-tier approach to engines, with small, mid-sized, and big block engines aimed at different markets. All of Ford's mainstream V8 engines were replaced by the overhead cam Modular family in the 1990s, however the company is expected to introduce a new larger family, the Boss/Hurricane, by the end of the decade.
1920–1932 Lincoln 60 Degree Fork & Blade V8 — (357.8 & 384.8 cid)
1932–1953 Flathead V8
1952–1957 Lincoln Y-block — mid-sized (317/341/368), HD truck (279/302/317/332)
1954–1964 Y-block V8 — small-block Ford/Mercury/Edsel (239/256/272/292/312)
1958–1968 MEL V8 — big-block Mercury/Edsel/Lincoln (383/410/430/462)
1958–1976 FE V8 — big-block
1958–1971 Generation I (332/352/360/361/390)
1962–1973 Generation II (406/410/427/428)
1965–1968 Ford 427 side oiler
1958–1981 Super Duty truck engine — big-block (401/477/534)
1962–2000 Windsor V8 — small-block (221/255/260/289/289HP/302/351W/Boss 302)
1968–1997 385 V8 — big-block (370/429/460/514)
1970–1982 335/Cleveland V8 — mid-sized (351 Cleveland/400/351M/Boss 351)
1983–present Ford/Navistar Diesel V8
1983–1987 — 6.9 L IDI (indirect injection)
1988–1993 — 7.3 L IDI
1993–1994 — 7.3 L IDI with Turbo
1994–2003.5 — 7.3 L DI (direct injection) "Power Stroke"
2003.5–present — 6.0 L DI "Power Stroke" (Only E series vehicles currently)
2008–present — 6.4 L DI "Power Stroke" (Only F series vehicles currently)
1991–present Modular V8 —OHC 4.6/5.4 L V8
1997–present Triton V8 — truck versions of the Ford Modular V8
1996–present Jaguar AJ-V8 — small displacement DOHC V8 engine family also used by Lincoln LS and Ford Thunderbird
1996–1999 Ford Yamaha V8 — 3.4 L DOHC 60° V8 designed and produced with Yamaha Motor
Corporation The 3.4L was used in the taurus SHO V-8.
2005–present Volvo V8 — 4.4 L DOHC 60° V8 produced by Yamaha Motor Company in Japan in connection with Volvo Skvode Engine plant Sweden.
Cosworth DFV — DOHC 3.0 liter racing engine
2006–present AJD-V8 — DOHC 3.6 L twin-turbo Diesel
2010– Ford 4.4 Turbo Diesel — DOHC 4.4 L twin-turbo Diesel
2010– Boss/Hurricane — OHC 6.2 L V8
The C behind the engine denotes the place of manufacture - Cleveland, Ohio. As opposed to a 351 W where the "W" stands for Windsor, Canada its birthplace. Now to clarify the "M" located behind some of the 400 series engines. It does not stand for 'Modified" or "Michigan" as most people think. It is simply a suffix added to denote a different engine from the Cleveland and Windsor.
Some suffixes found on this engine family stand for performance options such as H.O. stands for High Output and CJ for Cobra jet. As a matter of fact, these engines were the result of Ford's quest for a bullet proof medium displacement high performance engine for use in the production vehicles. Alas the timing was poor as the gas prices rose and the fickle public went on to grossly underpowered vehicles that moved at a pace between slow and slower.
The 351 Cleveland engines used "canted" valves and large intake and huge exhaust valves for maximum breath ability. A canted valve is set in the heads at an angle, not vertically. Canted valves increase performance by allowing the heads to flow a higher ratio of gas and exhaust in and out of the heads than normal valve design. As a result, power is increased and fuel efficiency is also increased. Because of these characteristics, 351 C engines are very well known in both the NASCAR and Pro Stock Drag car circles. When driven in everyday traffic, they can be fuel efficient operating as an engine would if it in the 300 CID size.
The 335 series engines use a dry manifold configuration. In other words, no coolant flows through the manifold. At the front of the block, there is an integral timing chain cover, at the top left hand side, coolant enters the block through the thermostat and then part of it goes through the radiator and part of it goes through the water pump. At this point below the thermostat on 351 C engines is a brass diverter valve. This diverter looks small and unimportant but it is critical. Made of brass it looks like a brass freeze plug with a hole in it and is driven into a seat below the thermostat. If you have an engine you are going to hot tank, REMOVE THE DIVERTER VALVE. Hot tanking will eat the brass and no one makes these that I can find. Your engine will overheat without this valve. To remove the piece, you can generally pry it up from a small hole located below it. Or you can sometimes drill a small 1/8 inch hole off to one side and remove it with a slide hammer puller. Do not destroy this piece. If you feel lucky go to your Ford dealer and ask for part # D0AZ - 8K517-A.
351 C 4 bbl engines produced through 1971 and all 351 C 2 bbl engines use 2 bolt mains. All HO, Boss, CJ and 1972 - 73 engines use four bolt mains. However, all blocks are cast to accept 4 bolt mains and if you have a set of 4 bolt main caps, you just need to also have enough money to pay to have a machine shop drill out the block and tap it.
The Boss 351 had some differences from the other engines there are: it was fitted with a dual point vacuum advance distributor, it had a rev limiter that was almost immediately removed by the consumer because they did not want to be limited to the 6,050 - 6,150 RPMs that Ford set the device at. The engine was also the only one to receive solid and adjustable lifters. In 1971, the engine was fitted with an aluminum intake manifold. All other 351 engines got a cast iron version.
The 351 4 barrel engine was designed to breath, and breath it did. The intake ports are so big that the engine does not run efficiently until it gets to at very high RPM. In contrast, the 2 bbl engine had undersized ports and did not breath well at all. It had low end torque, but petered out at higher RPMs. I you are very lucky, there is an Australian version of the manifold that has intake ports that are not quite as large as the 4 bbl version but bigger than the 2 bbl version. I have never seen these heads, but have read about them in the past.
Ford 351 Cleveland V8 Engine
The 351 Cleveland was introduced in 1969 as Ford's new performance car engine and was built through the end of the 1974 model year. It incorporated elements learned on the 385 big-block series and the Boss 302, particularly the poly-angle combustion chambers with canted valves and the thin-wall casting technology.
Both a 4V (4-barrel carburetor) performance version and a 2V (2-barrel carburetor) basic version were built, both with 2 valves per cylinder. The latter had a different cylinder head with smaller valves, smaller ports, and open combustion chambers to suit its intended applications.
Only the Q-code 351 "Cobra Jet" (1971-1974), R-code "Boss" 351 (1971), and R-code 351 "HO" (1972) versions have 4-bolt mains although all 335 series engines (351C/351M/400) have space for them even in 2-bolt main form. The main difference between 351C/351M/400 engines is connecting rod length and main bearing size. The 351M/400 engines have the largest bearing size and the tallest deck height while sharing the 429/460 bell housing pattern. The 351C engine has a medium main bearing size and shorter connecting rods than the 351W and the 351M/400 while retaining the SBF engine mount locations and bell housing pattern. The 400 engine has the longest stroke of any SBF or 335 series engine.
All of the 351C and 351M/400 engines differ from the 302/351W by having an integrated timing cover casting in the front of the block to which the radiator hose connects.
H-code
The majority of 351 Cleveland engines are H-code 2V (2-venturi carburetor) versions with low compression. They were produced from 1970 through 1974 and were used on a variety of Ford models, from ponycar to fullsize.
M-code
The M-code version was produced from 1970 through 1971. Both years offered quench heads but 1970 offered a slightly higher (advertised) 11.0:1 compression ratio whereas in 1971 the chamber was opened up slightly reducing the advertised compression to 10.7:1. The 1970 4V head is identified with the proper date code casting and a "4" cast on the upper corner of the head. The 1971 4V head is identified with a "4*" (four-dot) casting at the same location. Hydraulic lifters were also specified, with the M-code producing about 300 hp (224 kW). 2-bolt main caps were used along with a cheaper cast iron intake manifold.
1971 R-code (Boss 351)
The 1971 R-code "Boss 351" used higher compression (11.7:1) with the quench head 4V heads, solid lifters, an aluminum intake manifold, and 4-bolt main caps. so It produced about 330 hp (246 kW).
1972 R-code
The R-code 351 Cleveland for 1972 was considerably different. It had reduced compression for emissions compliance and used open-chamber heads. It had a solid lifter camshaft, however a four barrel carburetor was retained. It produced 275 hp (205 kW) using the new SAE net system.
Q-code (Cobra-Jet)
The Q-code "351 Cobra Jet" version was produced from May 1971 through the 1974 model year. It was a low-compression design that included open-chamber "4V" heads, a special intake manifold, special hi-lift long duration hydraulic camshaft, special valve springs and dampers, a 750 CFM 4300-D Motorcraft Carburetor, dual-point distributor, and 4-bolt main bearing caps. It was rated at 266 hp (198 kW) (SAE net) for 1972 when installed in the Mustang and 248 hp in the Ford Torino and Mercury Montego. The horsepower rating dropped in 1973 to 246 hp for the 4-barrel for the intermediate Fords, and still retained the higher 266 hp rating in the Mustang. The 351 CJ (now referred to simply as the "351 4V") was rated at 255 hp in 1974 and was only installed in the Ford Torino, Mercury Montego and the Mercury Cougar.
Ford 8 Cylinder Engines
Ford introduced the Flathead V8 in their affordable 1932 Model B, becoming a performance leader for decades. In the 1950s, Ford introduced a three-tier approach to engines, with small, mid-sized, and big block engines aimed at different markets. All of Ford's mainstream V8 engines were replaced by the overhead cam Modular family in the 1990s, however the company is expected to introduce a new larger family, the Boss/Hurricane, by the end of the decade.
1920–1932 Lincoln 60 Degree Fork & Blade V8 — (357.8 & 384.8 cid)
1932–1953 Flathead V8
1952–1957 Lincoln Y-block — mid-sized (317/341/368), HD truck (279/302/317/332)
1954–1964 Y-block V8 — small-block Ford/Mercury/Edsel (239/256/272/292/312)
1958–1968 MEL V8 — big-block Mercury/Edsel/Lincoln (383/410/430/462)
1958–1976 FE V8 — big-block
1958–1971 Generation I (332/352/360/361/390)
1962–1973 Generation II (406/410/427/428)
1965–1968 Ford 427 side oiler
1958–1981 Super Duty truck engine — big-block (401/477/534)
1962–2000 Windsor V8 — small-block (221/255/260/289/289HP/302/351W/Boss 302)
1968–1997 385 V8 — big-block (370/429/460/514)
1970–1982 335/Cleveland V8 — mid-sized (351 Cleveland/400/351M/Boss 351)
1983–present Ford/Navistar Diesel V8
1983–1987 — 6.9 L IDI (indirect injection)
1988–1993 — 7.3 L IDI
1993–1994 — 7.3 L IDI with Turbo
1994–2003.5 — 7.3 L DI (direct injection) "Power Stroke"
2003.5–present — 6.0 L DI "Power Stroke" (Only E series vehicles currently)
2008–present — 6.4 L DI "Power Stroke" (Only F series vehicles currently)
1991–present Modular V8 —OHC 4.6/5.4 L V8
1997–present Triton V8 — truck versions of the Ford Modular V8
1996–present Jaguar AJ-V8 — small displacement DOHC V8 engine family also used by Lincoln LS and Ford Thunderbird
1996–1999 Ford Yamaha V8 — 3.4 L DOHC 60° V8 designed and produced with Yamaha Motor
Corporation The 3.4L was used in the taurus SHO V-8.
2005–present Volvo V8 — 4.4 L DOHC 60° V8 produced by Yamaha Motor Company in Japan in connection with Volvo Skvode Engine plant Sweden.
Cosworth DFV — DOHC 3.0 liter racing engine
2006–present AJD-V8 — DOHC 3.6 L twin-turbo Diesel
2010– Ford 4.4 Turbo Diesel — DOHC 4.4 L twin-turbo Diesel
2010– Boss/Hurricane — OHC 6.2 L V8
![[-]](https://mach1club.com/images/collapse.png "[-]")
