- Joined
- Nov 13, 2018
- Messages
- 4,510
- Reaction score
- 4,464
- Points
- 113
- Location
- Canaan,NH
- Vehicle Year
- 1993
- Make / Model
- Ford Ranger
- Engine Type
- V8
- Engine Size
- 351
- Transmission
- Automatic
- 2WD / 4WD
- 2WD
- Total Drop
- 3"
- Tire Size
- 235/55R16
- My credo
- If you don't have time to do it right will you have time to do it over?
They switched to net hp in about 72, that wasn't the source of most of the power loss, it just lowered the ratings.Remember....hp spec changes in those years gross and net.
Compression ratios dropped. cam timing was retarded, fuel mixtures were leaned out, and exhaust was restrictive. Ignition timing advance curves were tightened- read that restricted. From 73-76 Ford raised the deck height of 302's(and I think 351's) by .023" which dropped the compression. The crank sprocket had 6 degrees of retard built into it. They decided it was cheaper to cast the thermactor passages into cylinder heads than to use external tubes and that intruded on the ports, my thumb wouldn't fit in the ports on my 302 heads. My 1977 Duraspark distributor's centrifugal advance wasn't all in until over 4500 rpms. The stock exhaust manifolds had 1 3/4" outlets, into a 1 3/4" Y pipe which went to about 2 1/4", into the cat, back out at 1 3/4" and into the resonator , then over the axle and into the muffler. A V8 Mustang II ran 17.7 at about 80 mph according to magazine tests and got 12 mpg- at least according to all the customer complaints we got. Low compression + retarded timing + lean fuel mix = a lot more throttle to do the job and that killed the gas mileage.