Ford 351C 4-V Marketing Manual

[Mach 1 Club]

                                                                                                   

[Rare Pony]

Great find! Wish I had a 351

[djjsc]

Possibly one of the best items of automotive factory literature ever printed. VERY well written; all the facts are there in an understated tone. I have that manual, along w/ a '70 Sportsroof Deluxe M-code.

Let me comment on the Cleveland engine based on the factory literature I have.

1970: VIN H; 351 2V, 2 bolt mains, flat top pistons, 9.5:1 compression using 76.2cc (averaged) open chamber heads, small ports, 2.04 intake/1.65 exhaust valves, 250 gross HP @4600 rpm, 355 ft lbs gross torque @2600 rpm.

1970: VIN M; 351 4V, 2 bolt mains, flat top pistons, forged steel connecting rods, 11:1 compression using 62.8cc (averaged) closed chamber (quench) heads, large ports, 2.19 intake/1.71 exhaust valves, slightly better cam & valve train, 300 gross HP @5400 rpm, 380 ft lbs gross torque @ 3400 rpm.

1971: VIN M; 351 4V, 2 bolt mains, flat top pistons, 10.7:1 compression using 66.1cc (averaged) closed chamber (quench) heads, large ports, 2.19 intake/1.71 exhaust valves, slightly better cam & valve train, 285 gross HP @5400 rpm, 370 ft lbs gross torque @ 3400 rpm.

1971: VIN Q; 351 4V, 2 or 4 bolt mains, flat top pistons, 9:1 compression using 75.4cc (averaged) open chamber heads, large ports, 2.19 intake/1.71 exhaust valves, Cobra Jet cam, spread bore carburetor, 280 gross HP @5800 rpm, 345 ft lbs gross torque @3800 rpm.

1971: VIN R; 351 4V BOSS, hi nodular iron block w/ 4 bolt mains selected for hardness, selected hi nodular iron crankshaft, forged pop-up pistons, forged steel conrods shot peened & magnafluxed w/ 180,000 PSI bolts, 11.3:1 compression using 66.1cc (averaged) closed chamber (quench) heads, large ports, 2.19 intake/1.71 exhaust valves, solid lifter cam & valve train, spread bore carb on hi-rise aluminum intake, 330 gross HP @5400 rpm, 370 ft lbs gross torque @4000 rpm.

1972: VIN M & Q; same as ’71 Q except for camshaft retarded 4 degrees, 266 net HP @5400 rpm, 301 ft lbs net torque @3600 rpm.

1972: VIN R; 351 4V HO, same as ’71 R w/ the following changes; forged flat top pistons, 9.2:1 compression using 75.4cc (averaged) open chamber heads, solid lifter cam (retarded 4 degrees) & valve train, 275 net HP @6000 rpm, 286 ft lbs net torque @3800 rpm.

1973-74: VIN Q; 351 4V, 2 or 4 bolt mains, dished pistons, 8.2:1 compression using 78.4cc (averaged) open chamber heads, large ports/small valves, 2.04 intake/1.65 exhaust valves, Cobra Jet camshaft retarded 4 degrees, spread bore carburetor, 248 net HP @unknown rpm, unknown ft lbs net torque @unknown rpm.

I mention the VIN H 351C 2V only once (1970) as a base reference. It was avail in other yrs w/ only slight changes fr ’72 on. Note that VIN H in these yrs can also mean a 351W (Windsor) engine; a completely different block & design. VIN H in any Ford/Mercury can be either Windsor or Cleveland during the ’70 thru ’74 model yrs.

Note that Ford never made the same 4V Cleveland 2 yrs in a row; save for ’73-’74. Every yr there were small differences even using same VIN codes as previous yr. Also, I am certain that compression dropped on the '72 Q engines compared to their '71 versions but can find no documentation of that in the Ford literature I have.

In the preceding narrative I highlighted the changes, no matter how small, that were made fr yr to yr. To compare; just refer to a previous/later yr.

I also want to state something about HP. I believe Ford, for the most part, used very conservative gross ratings. In some cases HP did not lose much when Ford switched to SAE net ratings (compare '71 to '72 Q code). But it is misleading to think that similar engines between different yrs would be as close in performance as published factory ratings seem to indicate. Many automotive journalists of the time agreed that the BOSS 351 was very close to, if not in excess of, 400 gross HP. Yet Ford rated it at 330HP. Anyone who drove these cars (GM & Mopar incl) during the yrs that compression dropped & camshafts were retarded to meet emissions specs knows that the newer engines were pale imitations of the former. In some cases they weren’t even close; unless you chose to be blinded by factory ratings.

[Kit Sullivan]

Totally agree. The BOSS 351 was a screamer, and anyone who has driven one knows that.
I had a 71 m-code convertible that would flat smoke a 73 Q-code Mach 1 a friend of mine had.
The '73 versions of the Cleveland were vastly underpowered.

[Mustangmike]

I enjoyed reading the marketing brochure for the 351C. The testing techniques were most likely state of the art in 1970 but I wonder how they compare to todays? Thank you for sharing!

[djjsc]

I enjoyed reading the marketing brochure for the 351C. The testing techniques were most likely state of the art in 1970 but I wonder how they compare to todays? Thank you for sharing!

I read somewhere Ford started development of a new engine family in 1966; goal being a strong, compact, lightweight engine design capable of high horsepower & torque while escaping lofty insurance premiums on big inch motors. The heads were ready (1969) before the block; one reason why the BOSS 302 appeared mid '69 model yr after the disappointing record of the '68 "Tunnel Port" in SCCA Trans Am. New manufacturing & testing methods began right alongside the completely new design. State of the art in 1970. Strong, compact, lightweight, high HP/TQ & lower premiums; all the goals were met. Smoking chebbyo'le at Trans Am (1970) & the dragstrip (351C Pintos) was just icing on the cake. Blame emissions standards not forseen in 1966 for the 351Cs short North American lifespan ('70 thru '74).

[Steven Harris]

Good stuff.

Oh what would have been and still could be if we still had representation rather than condescension.

[Mustangmike]

I enjoyed reading the marketing brochure for the 351C. The testing techniques were most likely state of the art in 1970 but I wonder how they compare to todays? Thank you for sharing!

I read somewhere Ford started development of a new engine family in 1966; goal being a strong, compact, lightweight engine design capable of high horsepower & torque while escaping lofty insurance premiums on big inch motors. The heads were ready (1969) before the block; one reason why the BOSS 302 appeared mid '69 model yr after the disappointing record of the '68 "Tunnel Port" in SCCA Trans Am. New manufacturing & testing methods began right alongside the completely new design. State of the art in 1970. Strong, compact, lightweight, high HP/TQ & lower premiums; all the goals were met. Smoking chebbyo'le at Trans Am (1970) & the dragstrip (351C Pintos) was just icing on the cake. Blame emissions standards not forseen in 1966 for the 351Cs short North American lifespan ('70 thru '74).

Very interesting to know thank you!