The Ford Barn

Easy · 04-08-2023, 06:42 AM

What is the recommended pressure to run in the 19 inch American Classic radials?

nkaminar · 04-08-2023, 07:04 AM

The tires have 35 psi printed on them. I found this to be too low. I run 50 in the rear and 45 in front with my heavy Fordor. Go for a drive of about 10 miles then touch the sidewalls. It they are hot to the touch then the pressure is too low. The sidewalls should be warm, but not hot. Disclaimer: Since the tires have 35 psi printed on them, you are on your own when increasing the pressure. Modern tires that are not damaged, for instance by running on them when they are flat, can withstand 200 psi. But I am telling you what I do and not recommending that you do the same.

old31 · 04-08-2023, 08:06 AM

Coker told me to run 35 psi on my 19" ww radials.

Y-Blockhead · 04-08-2023, 09:54 AM

I tried 40psi in my 4.50-500x19 American Classic radials and found the ride a little on the harsh side. Drop down to 35psi and the ride is much more to my liking.

I suggest you try different pressures on your car and find what you like.

alexiskai · 04-08-2023, 10:07 AM

I’m guessing the different answers have a lot to do with the different weights of these cars. Neil’s car is pretty heavy as I recall.

Y-Blockhead · 04-08-2023, 10:19 AM

Sponsored Links (Register now to hide all advertisements)

Quote:

Originally Posted by alexiskai

I’m guessing the different answers have a lot to do with the different weights of these cars. Neil’s car is pretty heavy as I recall.

I can't imagine his car being that much heavier than my '30 Town Sedan.

Big hammer · 04-08-2023, 12:07 PM

IMHO by over inflating your radial tires, you’ve turned them into bias ply tires

CarlG · 04-08-2023, 02:07 PM

My Coker 19" radials say on the sidewalls: Max 44 psi. I run mine at 40 psi, works for me.

alexiskai · 04-08-2023, 02:57 PM

If you run the car’s weight and the tire load rating through tire pressure calculators, usually you come out with 25-35 psi as the recommended pressure, depending on the body type and expected passenger weight. I did this for the American Classic 21” radials.

jadatis · 04-08-2023, 05:02 PM

Tirepressure is all about load on tire, and maximum speed used.
All not to overheat any prt of tire-material, when driving the speed constantely.
So if you give tire specifications, this "pigheaded Dutch selfdeclared tirepressure specialist" will make a pressure/axleloadcapacity list, with build in reserve.

Then you only need to determine the axleloads acurately and s3arch them back in my list, the most tricky part, and your responcibility.

Need next.
1. Maximum load or loadindex.
2. Kind of tire to determine the maxloadpressure.
3. Speedcode, less important.

nkaminar · 04-08-2023, 07:07 PM

My Fordor has a heavy metal trunk in the back loaded down with heavy tools and parts. Another heavy tool box in front with oil, coolant, and more parts. Plus all the added body insulation and tools under the seats. Did I mention there are lots of tools. With the tire pressure I run the radials still perform like radials.

Again, it comes down to heat. High temperatures can limit the life of a tire and ruin the inner tube. Too much flexing leads to too much heat.

Model A Ron · 04-09-2023, 09:50 PM

Quote:

Originally Posted by nkaminar

My Fordor has a heavy metal trunk in the back loaded down with heavy tools and parts. Another heavy tool box in front with oil, coolant, and more parts. Plus all the added body insulation and tools under the seats. Did I mention there are lots of tools. With the tire pressure I run the radials still perform like radials.

Again, it comes down to heat. High temperatures can limit the life of a tire and ruin the inner tube. Too much flexing leads to too much heat.

I just got a set on this weekend and filled them to 35. I have not went for a test drive yet but the tires look underinflated at 35. I will see if they get hot after a 10 mile ride and I have a feeling they will......next will be increase to 45. I tend to run my modern cars at max psi.....tires last longer and better MPG. You do get a harder ride but I will take that for more tire life.

TerryO · 04-10-2023, 08:13 AM

I run 35 lbs and they drive very well...

TOB

goldie · 04-10-2023, 11:16 AM

If you remember back in the olden day when radial tires first came to use in the USA they all bulged. They appeared to be low on air pressure but were not. My new American Classic radials set at the max of 35 psi also have that bulging look where the rubber meets the pavement. Have to believe modern radials have stiffer sidewalls, but not the American Classics.

04-08-2023, 06:42 AM	#1
Easy Junior Member Join Date: Mar 2014 Posts: 12	Radial tire pressure What is the recommended pressure to run in the 19 inch American Classic radials?

04-08-2023, 07:04 AM	#2
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,897	Re: Radial tire pressure The tires have 35 psi printed on them. I found this to be too low. I run 50 in the rear and 45 in front with my heavy Fordor. Go for a drive of about 10 miles then touch the sidewalls. It they are hot to the touch then the pressure is too low. The sidewalls should be warm, but not hot. Disclaimer: Since the tires have 35 psi printed on them, you are on your own when increasing the pressure. Modern tires that are not damaged, for instance by running on them when they are flat, can withstand 200 psi. But I am telling you what I do and not recommending that you do the same. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

04-08-2023, 08:06 AM	#3
old31 Senior Member Join Date: Jan 2016 Posts: 2,097	Re: Radial tire pressure Coker told me to run 35 psi on my 19" ww radials.

04-08-2023, 09:54 AM	#4
Y-Blockhead Senior Member Join Date: Jul 2011 Location: Redondo Beach, CA Posts: 5,849	Re: Radial tire pressure I tried 40psi in my 4.50-500x19 American Classic radials and found the ride a little on the harsh side. Drop down to 35psi and the ride is much more to my liking. I suggest you try different pressures on your car and find what you like.

04-08-2023, 10:07 AM	#5
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 2,353	Re: Radial tire pressure I’m guessing the different answers have a lot to do with the different weights of these cars. Neil’s car is pretty heavy as I recall.

04-08-2023, 12:07 PM	#7
Big hammer Senior Member Join Date: Jun 2014 Location: Land of Lincoln Posts: 3,131	Re: Radial tire pressure IMHO by over inflating your radial tires, you’ve turned them into bias ply tires __________________ Don't force it with a little hammer tap, tap, tap get a bigger hammer tap done

04-08-2023, 02:07 PM	#8
CarlG Senior Member Join Date: Nov 2010 Location: Anchorage, Alaska Posts: 9,115	Re: Radial tire pressure My Coker 19" radials say on the sidewalls: Max 44 psi. I run mine at 40 psi, works for me. __________________ Alaskan A's Antique Auto Mushers of Alaska Model A Ford Club of America Model A Restorers Club Antique Automobile Club of America Mullins Owner's Club

04-08-2023, 02:57 PM	#9
alexiskai Senior Member Join Date: Apr 2018 Location: Mebane NC Posts: 2,353	Re: Radial tire pressure If you run the car’s weight and the tire load rating through tire pressure calculators, usually you come out with 25-35 psi as the recommended pressure, depending on the body type and expected passenger weight. I did this for the American Classic 21” radials.

04-08-2023, 05:02 PM	#10
jadatis Junior Member Join Date: Apr 2011 Posts: 8	Re: Radial tire pressure Tirepressure is all about load on tire, and maximum speed used. All not to overheat any prt of tire-material, when driving the speed constantely. So if you give tire specifications, this "pigheaded Dutch selfdeclared tirepressure specialist" will make a pressure/axleloadcapacity list, with build in reserve. Then you only need to determine the axleloads acurately and s3arch them back in my list, the most tricky part, and your responcibility. Need next. 1. Maximum load or loadindex. 2. Kind of tire to determine the maxloadpressure. 3. Speedcode, less important.

04-08-2023, 07:07 PM	#11
nkaminar Senior Member Join Date: Jan 2012 Location: Western North Carolina Posts: 3,897	Re: Radial tire pressure My Fordor has a heavy metal trunk in the back loaded down with heavy tools and parts. Another heavy tool box in front with oil, coolant, and more parts. Plus all the added body insulation and tools under the seats. Did I mention there are lots of tools. With the tire pressure I run the radials still perform like radials. Again, it comes down to heat. High temperatures can limit the life of a tire and ruin the inner tube. Too much flexing leads to too much heat. __________________ A is for apple, green as the sky. Step on the gas, for tomorrow I die. Forget the brakes, they really don't work. The clutch always sticks, and starts with a jerk. My car grows red hair, and flies through the air. Driving's a blast, a blast from the past.

04-10-2023, 08:13 AM	#13
TerryO Senior Member Join Date: May 2010 Location: N. GA Posts: 531	Re: Radial tire pressure I run 35 lbs and they drive very well... TOB

04-10-2023, 11:16 AM	#14
goldie Junior Member Join Date: Jul 2022 Posts: 25	Re: Radial tire pressure If you remember back in the olden day when radial tires first came to use in the USA they all bulged. They appeared to be low on air pressure but were not. My new American Classic radials set at the max of 35 psi also have that bulging look where the rubber meets the pavement. Have to believe modern radials have stiffer sidewalls, but not the American Classics.