Mrs. Billet

Ok, I found one 15" double white wall tire. It's a vintage bias ply.
I have no experience with bias ply aside from removing them from old cars.
Should bias ply be driven across the states? Or fast? Or nothing wrong with them?
Here is the 15" tire from Coker tires, it's a bf goodrich L78-15.
Can someone fill me in on what the difference between H and L is?
BF Goodrich Bias Ply | Dual Narrow Whitewall
 
Here we have a goodyear custom super cushion tire but no double white wall.
Go down about half way.
Goodyear Bias-Ply Antique Tires | Discount Prices

On this page it states that the custom super cushion was made between 57-64. Does that mean that this custom super cushion is not the original spare for this car?
 
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FIRST, there were numbers to denote the tire's section width and rim diameter. No mention of load ratings. As 8.00x14
Second, came the lower-wider tires of about 1966, as in 8.25x14 (repl the prior 8.00x14).
Third, then came the AlphaNumeric sizes in about 1969 or so. The letter indicated "Load Rating", but not with respect to the number of plies in the carcass of the tire. As in H78x14 ("H" = load rating, "78" = Aspect ratio, "14" = rim diameter).

The load rating numbers went from "A" to "L", with the aspect ratios varying from "78" down to "50" at that time. The combination of load rating and aspect ratio determined the diameter of the tire (i.e., "Revs per mile"). The largest tire Chrysler used OEM was L84x15, but others just used L78x15, but with "Extra Load" capabilities (i.e., 6-ply rated and inflation pressures to 36psi rather than 32psi).

Fourth, came the P=Metric sizing. Part of the seemingly up=coming "metric age"? 1 inch = 25.4 millimeters. Normal inflation pressures went to 35psi rather than the prior 32psi for alleged better fuel economy. As some others were rated to 45psi with no increase in load capacity, by observation. As in P225/75R-15.
"P" = P-metric sizing "225" = section width in millimeters "75" = Aspect Ratio "R" = radial, but "D" meant "bias ply/diagonal" "15" = rim diameter

The double-stripe (equal widths) white sidewalls seemed to be specific to 1970 and 1971 C-body cars. The H78x15 spare that was in my '70 Monaco Brougham was a H78x15 Firestone Belted tire. It had some wear on it, so was probably the best one of the orig tires when the new tires were purchased.

Chrysler products ususually had Goodyear tires on them. The pictured Goodyear Custom Power Cushion Belted was the OEM-level tire of that time and is what our 1972 Chrysler Newport Royal came with (a factory a/c car), but a single whitewall of about .75" wide.

Chrysler and others used the double or triple-stripe whitewalls for several years in the later 1960s to early 1970s as "something special" to do, but these special sidewall treatments gave way to the normal approx .75" wide whitewalls of the later 1970s. By that time, the nostalgia deals were operative and some Chrysler top-level cars had whitewalls that were a bit wider, like 1.0" wide for an extra-luxury look. Over time, those went away, too, leaving only the "normal" .75" whitewalls for replacement.

When the P-metric "fuel economy" tires came online, they were also lighter weight. Comparing a prior H78x15 tire to a P225/75R-15 tire, the later one is several pounds lighter than the H78x15 tire. From about 30-32lbs of tire weight down to about 27 pounds of tire weight in EACH tire. The only real place they could remove the weight was in the tire sidewall area, although the tread area is probably a bit thinner, too. It should also be mentioned that many of the newer 20" tires have about 8/32" of total tread depth, down from 11 or 12/32" for "old design" tires. But with the same mileage ratings for the newer tires! Which means a modern, low-rolling resistance rubber in them, BUT that thinner tread CAN result in some wet weather traction issues on the Interstate, alomg with some plus and minus side issues, too. Which can be where the "tire spec" charts at www.TireRack.com can come in handy!

When all we had were "bias ply" tires, nobody worried about how good they were at high speed uses. Just that the faster you were going to run them, or how much weight the car/pickup truck had in it, the more air you put in them, up to the recommended 32psi for a 4-ply rated tire. Nobody worried about "tire age" back then as the tires would normally last about 35K miles at best. Maybe up to 45K if you took really good care of them and drove easy?

In the later 1960s, "bias-belted" tires came out as a transition between bias ply and radial tires. A hybrid of sorts. The benefits of a more stable tread without the added cost or ride harshness (at lower speeds) of the true radials (as in Michelin X). BFG and UniRoyal had USA radials which were either aftermarket or OEM, starting in about 1967-1968 on some GM cars, with Ford having optional Michelins on some 1969 models.

Keeping up with the new tire technologies and models was almost as time-consuming as keeping up with the new cars each year, back then! A really fun time to be a car person!

Some observations . . . when the P-Metric radials came out, there were some internal tweaks which took out some of the 45mph ride harshness that some cars were sensitive to. Chryslers ususally a bit more than others, due to their UniBody construction rather than "body on frame" (i.e., most Ford and GM cars). This also seemed to take out a bit of the "radial feel" of the earlier Michelin X tires, too. The earlier cut-away illustrations showed the carcass plies running at a 90 degree angle to the rim, with the "belt plies" running at a 90 degree angle to the carcass plies. More recent P-metric cut-aways show a slight angle between the belt plies with then no always being parallel to each other, but with maybe a 10 degree angle, for better impact harshness reduction, I suspect. Not unlike the belts in the bias-belted tires, by observation. Interestingly, many brands now use "a cap" on top of their normal radial belt plies, for added high-speed durability. This cap generally run parallel with the wheel rim's bead.

In modern/current times, I don't know that anything other than an OEM-brand radial would be good for a long trip, as we used to take 2-week family vaciations back then. It seems to me that repro tires might not be of the same exact weight and contruction as they were when new. Which means use a readily-available tire for daily use and leave the expensive repro tires for shows and those who can afford almost $1k/set in tires that look correct for their vehicle. Which is one reason the whitewall Hankook Kinergy tires were so good to see!

For the progression of tire sizes on Chrysler products in the later 1960s to earlier 1970s, check out the dealer order guides for standard and optional tires at www.hamtramck-historical.com.

Enjoy!
CBODY67
 
A few before and after pictures.
This is the first round of cleaning and it is not complete. Only the top so far. Will get to the bottom of the car later.
Very dirty car. No one had ever detailed the engine bay in my opinion.
There are so many paint dobs and factory doodles that I am surprised.
Guess I'm used to hooptie's that have been touched by a jack *** far too many times. This car is a time capsule.

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Here are a few doodles and paint dobs just to show some of them.
I don't think anything has ever come out of this engine bay.
Drivers valve cover has a circle, a 120 or 125 and behind the circle there is a line going straight down to the valve cover bolt.

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A few before and after pictures.
This is the first round of cleaning and it is not complete. Only the top so far. Will get to the bottom of the car later.
Very dirty car. No one had ever detailed the engine bay in my opinion.
There are so many paint dobs and factory doodles that I am surprised.
Guess I'm used to hooptie's that have been touched by a jack *** far too many times. This car is a time capsule.

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Oh damn, that cleaned up real nice!
 
Well, sitting in a garage since 84 in Kansas puts a ton of dirt on top of anything that has oil on it.
I used a purple power soak that I applied twice.
Power washed.
Then I applied a double coat of simple green. Yellow kind.
Then power washed specific areas.
Very simple to start.

Next I will detail everything with lacquer thinner to make sure there is no dirt on anything.
Then I usually use a rubber protectant of some sorts and apply it by hand to all rubber in engine bay, then I take a cloth and buff the protectant off of the rubber pieces so it is not shiney or oily.
 
Anyone have any information about the 125 and 389 on the valve covers?
The circle and line obviously had something to do with the bolt, gasket or seal in that area.
 
I apply degreaser's with a spray bottle that foams the products. Seems to work better than a windex style sprayer.

This time I used a george foreman concentrate grill cleaner. It foams the product for the grills that it is used for. Works great.
 
Gotta be careful with the power washer though. It does erase some markings. I lost a few hose numbers when I wasn't paying enough attention.
It will also blow off black paint from fittings and black brackets.
I lost a little green off of some of one of the carburetor brackets. Didn't lose the green on the springs as I tried my best not to lose that green color.
 
Next I will detail everything with lacquer thinner to make sure there is no dirt on anything.

Be careful with that stuff....it will remove paint and is not a good degreaser anyway (too volatile). I recommend mineral spirits or wd-40 for final spot cleaning grease.

The other methods used with the purple degreaser, grill gleaner, and power washer are very harsh and I would not use them if hoping to preserve any original finishes. However, your engine is very clean and prepped if you plan on repainting everything. It looks nice.
 
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Here are a few reference pictures of the trunk. Not cleaned yet. It appears the factory put seam sealer on each little dip in the middle of the trunk.
This is an untouched trunk. No work has ever been done to it as I can tell.
I still have to clean it up as it is very dirty.
And there are oil spots on the wheel wells for some reason. Dirt on all the seam sealer. Not a spec of rust.

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Looking at the pictures I now realize the oil on the wheel wells is from the grease on the trunk hinges. Must have gotten hot and ran down the supports onto the wheel wells.
It will be cleaned.
 
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