Engine life when cars were first built

[Bingster]

The odometer on my '47 Desoto says 60,000. The engine did fire up when I bought the car. Do you think these are the original miles?

[Big_John]

As has been said, it was common practice for used car dealers to roll back the odometers. I remember looking at cars on lots back in the early sixties where the odometers had been rolled back to zero!

Even owners got into the act, taking 20 or 30 thousand miles off before trading in.

My top mileage though was our Chevy shop van. I traded it at 250k miles and it was still going strong. That was 220k from our driver making deliveries and 30k from my use. I would have gotten another year out of it, but a deal came along that I couldn't pass up.

[michael.warshaw]

every old mopar i have see nahs had about 50 to 80k on the clock i would say that is the norm for these cars.

[Niel Hoback]

My Dad bought a '48 Plymouth Special DeLuxe in '50 with low miles. At 82,000 and it was just about done. I remember going to Florida in it as a kid. After that,he bought a 53 Cambridge Club Sedan from a tiny little school teacher. It had practically no miles on it. Again, at 82,000 it was passed down to us kids and it was just about completely worn out. My Dad was a very gentile driver, but didn't do much if any maintenance.

At the time a car with 100,000 miles on it was something of a miracle.

[Tim Keith]

My Geo Metro with 1.0 liter three has 291,000 miles. I got it

3 years ago with 180,000 miles. I got a spare 1.0 motor from

the Pick-n-Pull for $65 and took it to a machinist and he told me

I'd be wasting money on his services as the motor showed no

wear except that oil changes were not as frequenty as ought

to have been and the rings were gummed up. He said put

new rings in the PNP motor and run it for another 200,000

miles. I'm still running the motor that came in the car.

I believe that a rebuilt flathead could probably go

200,000 miles. The thing which is a concern for me is

the 4 ring pistons and fat rings which I think would wear

the bores. If modern pistons with the thin low tension

rings were used I'd bet longevity would increase significantly.

If a 230 Dodge crank were used with 7 15/16" 218 rods the

compression height of the pistons could 1/8 inch less. There

could be modern pistons which could be used with some minor

mods. I saw some "maybe" pistons with 8 inch DeSoto 236 rods

with the 265 crank, but nothing perfect out of the box. I think

the 265 rods are 1/4" shorter, so the 265 crank with the 236

rods would enable 1/4 less compression height. The OEM

flathead pistons have a large compression height. Maybe

I'd order custom pistons. I'd bet that a flathead could be

significantly improved with lighter modern piston designs.

But its a reasonably cost to just rebuild them stock after

80,000 miles.

Edited July 27, 2010 by Tim Keith

[Mustang6147]

The internal combustion engine has come along way from then till now. Trying to figure out how long an engine with 60 year old technology will last based on hear say is almost crazy. Factor in the refined oil and additives in unleaded fuel??? Its any bodys guess. Lead helped lube the guides, oil was horrible, did the lead make up for the oils short comings?? Did I forget to mention a PCV sytem that the engine is lacking??? I battle this very topic. My engine is a 230 out of a dodge truck, and it was bought from Jasper. By saying 49 dodge truck, that is what the block serial #s match. I am no better off then having an old engine, cuz I dont know what jasper did. I would assume I have hardened guides, but did they balance it???

These flat heads have a certain charm to them though. At car shows many people admire the flatheads. I wish HP and more speed parts were readily available, and affordable. I also wish someone would mfg A/C brackets for them, they just as prevalant as the Ford flathead 8. The mopar 6 was way ahead of its time, just like the suspensions on the mopars of the 40's

[mrspeedyt]

the grey '41 desoto is at about 92000 and the blue one shows about 07000... (add a one in front of 07000) both don't show any signs of major work or replacement. my '99 toyota has 221000 miles and now has its first problem...a burnt valve.

[Flatie46]

You know anthor factor one might consider in all of this is the newer cars are getting mostley hwy miles on good roads. There is alot less wear on a car that has hwy miles than one that stop and go alot. You figure in all the dry starts and more wear in the steering and brakes. So 50,000 miles of stop and go dry starts with poor quality oil would seem like alot more miles.

Hopefully I let you know how a new[rebuilt] flathead will last using todays oils and with lots of hwy miles.

[Tim Keith]

I have an automotive technology book published in 1947. A regular procedure was to de-carbonize a cylinder head. A mechanic removed the cylinder head and scraped away the carbon. I think that was because the gasoline was poor. But every 10,000 miles ? You would also add kerosene to the oil in the winter in colder climates.

The book also said that automobile engineers agreed that motors had far more horsepower than was needed to adequately motivate the vehicles of the day.

[desoto1939]

I have a 39 Desoto that had a engine rebuild at 78k. This was in 1985. The car now has 94K onthe odometer. The second owner had the engine rebuilt I do not know if this was the first rebuild or a second.

Still has great oil pressure runs at 40 LB and has a good idle pressure. I run 10W40 oil with the bypass filter. It origanilly had the thowaway canister but converted to the dropin style filter. I change the oil about every other year becase of the low mileage that I put onthe car. It has the normal leaks but since it is a driver I keep it maintained.

So I am looking to go over the 100k mark and then it willhave approx another 25k left in the engine. I also use an additive in the oil for zinc and phosporus.

I drive the car around 50-55 mph.

Rich Hartung

Desoto1939@aol.com