Re: 356 CI Compression Ratio

Posted by su8overdrive On 2023/12/31 17:03:00

Scott, your and TxG's, Wat's mpg all sound familiar. I long ago had a 3.9 axled '51 288 (later that year the factory revised to 3.54 like the 327 300/400), got about what the above posters report. However, my '40 120 with 4.09 (instead of 4.36) axle and overdrive, razor tuned, 32 psi cold Denman bias plies, once returned 22.5 mpg.
Yes, really. And much of that was 60-65 mph.

My '47 Super Clipper despite a 3.92 rear axle in lieu of usual 4.09 with overdrive and aforementioned 7.5:1 327 head, running 41 psi cold bias- s i z e d 7.00/15 Bridgestone LT radials gets half that. 356 Packards, like an old friend said of his '41 Cad conv. (346-ci L-head) when he left the Navy after War II, would "pass everything but a gas station."

However, a 4,300-lb. curb weight, flathead (L-head), 336.7-ci, factory compression 7:1 '51 Lincoln with 3.31 rear end and overdrive for a 2.39 final drive, won that year's Mobil Economy Run Sweepstakes with 25.488 mpg (ton mpg figure of 66.484). Motor Trend's editor Griff Borgeson, who wrote accurately and deeply about many cars both sides of the Atlantic, Channel, observed 24.448 mpg in this same car, which had been torn down and inspected to confirm being entirely stock after impounded when Chrysler complained.

Remember weight. For some reason, few old domestic car blokes care about weight. When Bentley coaxed their 278.7-ci F-head six, 3,750-lb.. 3.08:1 axled '52 Continental to 118.75 mph, they did so by greatly increasing tire pressure, removing the spare tire and back seat. Some of us are more interested in absolute speed than acceleration because the higher the former, the more relaxed ambling. The Bentley Continental's 0-60 was 13 seconds, same as a well-tuned 1940-50 356 Packard, tho' the lightweight '40 160 business coupe might manage just over 12 seconds. This aside because long ago, i fawned over Packard Darrins and Continentals. But honest Darrin owners admit that lovely as the 1938-40 editions are, factory cars are better. (1941-42 Darrins shared more factory parts but are to some of us overbearing, blowsy looking.)
Continentals have that cartoony rear overhang, and R-R/Bentleys have added, pointless complexity, as well as a nut-for-bolt copy of Packard's Saf-T-Flex i.f.s, abandoned in the '56-on Clouds and S-Types for the same reason Packard also used a conventional GM-type i.f.s. in the 1941-47 Clipers; the lowered floor pan left no room for Saf-T-Flex's long torque arms, and cost cutting at both Packard and in Crewe, England.

In short, don't go overboard on compression. A little boost, okay. More important: Look to the "compleat car." And lose weight. Bill Lear said, "I'd sell my grandmother to lose another pound from a Lear Jet." Packards were nonpareil road cars in the '30s and '40s, so don't fathom why most of the preceding may as well be in Latin.

According to a Chevron engineer, himself owning an old muscle car, any brand gasoline will last a year so long as not exposed to temperatures much above 80. But Stabil's not a bad idea, the regular not marine type. Keep it simple. Don't reinvent the wheel. Factory standard. Packard knew what they were doing.

Nothing you do will make them drive as well as a new Camry. Ferrari friends laughed that a stick Honda Civic of the '90s would outperform their '58 Berlinetta, '59 Pinanfarina coupe, even '63 Lusso; out accelerate, out brake, out corner the fabled Prancing Horses. A late friend owning a parade of high-end '30s, '40s stuff, Delahayes, Hispano K6 and J12, Delage D8, Bugatti Types 57 & 101, '39 Lagonda V-12 Rapide, supercharged '36 Auburn 852 speedster, Marmon 16, said his little Geo Metro "drove better than all that old crap," and his cars, everyone, first ran as intended, t h e n and only then went to the shows.
My Super Clipper has lower piston speed than the aforementioned Bentley Continental, which used an engine tracing to the 1922 R-R Model 20, itself cribbed from the '20 Buick Six, though in the words of the respected Laurence Pomeroy, "not so good." Again, R-R was disassembling a new Limited annually in the years just before War II to glean the latest Detroit production tips. My '47 Super is a Buick Roadmaster according to Packard, not a bad thing. If you fancy the '30s fire trucks and realize Duesenbergs overrated, overpriced (then and now), overhyped, taking nine years and several iterations to find homes for only 480 editions, then 385-ci Chrysler Imperial/Packard/Pierce-Arrow eights are the way to go. If you really want the overkill of a V-12, a Pierce over a Packard, tho' both obviously good cars.

Pardon the verbiage, but what i am t r y i n g to impart is perspective. Without that, and appreciation for the real thing, what's left of the old car hobby drifts more and more to retrorods, Frankencars. We've seen '30s Packard Super Eights and Twelves with big block Chevy crate motors.

Enjoy the ride.

Hope springs eternal, sports fans. Happy New Year.