Re: Tire Pressure

Posted by su8overdrive On 2013/3/26 14:55:12

Amen, Bishop O'Toole. I carried the 32 psi maximum cold pressure in my '40 120's 6.50/16 Denman bias plies. When i sold the car after putting a total 10,800 miles on it since rebuilding it bumper to bumper, the tires still retained ALL their tread. There was NO wear. None.

Tom McCahill spoke the truth. Other than Click 'n' Clack, mainstream America'll never again enjoy such an upbeat, entertaining, accurate a straight shooter.

A little off topic, but i doublechecked my gas mileage in that overdrive car using a calculator, and got 22.5 mpg, everything stock according to East Grand Avenue, timing either 6 degrees BTDC, no more than a degree or so more. The sole deviation was i had the 4.09:1 rear axle per non-overdrive models in lieu of the 4.36.

However, the 7.00/15 Denmans i ran on my '47 Super Clipper quickly wore down by 9 or 10,000 miles, despite proper front end alignment, etc. But remember, the cars of 1941-47 were heavier than '40 models industry-wide, and the 7.00/15 introduced for '41 solely to lower cars' profiles, despite having a slightly higher load rating than 6.50/16, still left and leave you with less payload margin.

I now run bias ply-sized 7.00/15 Bridgestone LT R230 radials on my '47 Super. Yokohama offers a similar tire of identical specifications, and until the early aughts, so did Michelin. So i've the best of all worlds: historically correct bias ply-sized blackwalls with all the advantages of radials. What amazed me was the first time i put on the brakes coming off the freeway in town traffic,
the car stopped faster with radials, too.

These LT radials will take pressures up to 60 or more lbs.
depending on vehicle weight, but most of us running such sneakers on '40s Packards and Cadillacs have found 42 psi a good figure. I run 44, but that's just me. Right smooth,
velvety ride, the single best thing you can do for an old car after overdrive and a prelube device for full oil pressure after the car's been sitting.

In fairness, few of us here gathered really remember the very best quality bias plies in the day. I'm told these were vastly better than the crappy old car hobby bias plies people in third world nations wouldn't buy but old car cuckoos, as the late Jean Shepherd called us and himself, will gladly cough up obscene amounts of money for so long as they're plastered with wide whitewalls, which most people considered tacky on high end road cars originally.

As with batteries, i'm interested strictly in the car, what Packard built, and giving it every edge possible while keeping it stock--- just well-tuned, maintained, if tweaked, only per an obscure Packard Service Counselor issued to dealers.

Regardless of tires or pressure, the hard truth is that most old cars today are cosmetically restored worn out bombs with rebuilt engines, because everyone likes rebuilding engines, while overlooking all the other grueling, arcane but vital bits.

The proceeding are but my personal experience, and i bow as always to Drs. Cole and t'others, who work and have worked on myriad old cars, Packards among them, over the decades.