Flathead mileage?

Fibber Mcgee

Fibber Mcgee

Well-known member
I was just thinking,How many miles could you get out of a flathead back in the day?Was it anywhere close to a modern engine,I know the oil wasn't as good and the technology wasn't there but what about the lower revs and compression,and the tendancy to overbuild things in the past....
 
I've heard 50K batted around and I think that makes sense given the quality of the lubrication back then.
 
If anybody got close to 100K it was front page news. 50 - 70K was probably the norm.

On the other hand, gearing was high and there weren't many high speed roads (60mph). It took longer to get anywhere, with the result that most cars/trucks didn't see 10K per year.
 
It would be hard to say how many miles are on our old Fords ---it would be rare to see a car on a used car lot with more than 60,000 miles ---no matter how many miles on the car.

My first road car was a 46 tudor, it was from the original family, I was told the engine was rebuilt at about 80k, it showed 32 when
I got it , I overhauled it for burned valves, worn rings, it was .060 over.

I have read several storys of model As in police, mail service going over 100k with a tightening up about 60k (tighten rods,rings,valve job)

My father bought a 39 that had a documented 32k (60hp), it was tired, burned valves,broke rings.

Even into the 60s a lot of cars had their engines apart before 100k

If you put 100k on in 5 years you had a better chance than if you put 50k on in 10 years ---long trips kept the oil cleaner, short trips have more wear (most engine wear occurs in the first 5 min after a cold start).

The modern emission controls have regulated the mixture so there is ideal combustion most of the time, the oil is better, and stays cleaner, operating temp is quicker, I have taken apart engines with 250k (for gasket leaks) that have less wear than the old engines had at 50k
 
What difference do you think modern oils would make?If you had a "new" flathead with modern oils do you think that would make a significant difference.
 
I wish they would sell a hypereutectic piston in a size less the .125" oversize on 3 3/16" bore. If you could run 3-ring pistons for less friction and modify the oiling system for full filtration by any means, you would see an increase in longevity. It should as least as good as the more modern engines of the 1960s.

Oil was at its best with the API rating of SJ. With the new ratings it's starting to take a step back due to the loss of ZDDP. It's still probably better that the 20W20 oil that was available in the 50s.

Kerby
 
I bought a 51 merc engine form an original owner. Car was in exelent shape and had been taken care of with regular oil changes, ETC. The engine had 83K on it and I instaled it into my truck, including the auto trans and rear end. Unfortunately the rods were a little loose so I installed a new set of rod bearings and put on another 10K. By this time the rings wer shot and a few cyls had realy low compression.

I agree that the oil is better in some ways. I just bought a new set of Egge pistons and the came with Volvo truck rigs. This engine is going into my grand sons truck. Not sure what oil to use maybe a synthetic? with a Lead additive. But I won't live long enough to see if this works.
 
My '48 was bought new by my Father...export car originally delivered in China.
It picked up virtually no mileage in China, as Mao was camped right outside of Nanking running the presidential campaign of '48-9.
It was shipped back to the USA, where the shipping company filled it with water and left it out in freezing weather...new engine cracked and dead, replaced with complete new 59A.
Engine ran up to 180,000 kilometers, a little over 100,000 miles. My father was very careful about auto expenses and gave me the thick wad of paper with all the car's significant repairs. Engine had a valve job somewhere in the '50's, and that was only repair within engine, verified by Father's memory. He sure as hell would have remembered ANYTHING pricier than an oil change, too.
When I got it as my college transport in about '66 it had some blowby but minimal smoke and would run forever well over the speed limit, which was unfortunately well documented by several State Police organizations, and had decent acceleration...it was never an obstacle to traffic and would out accelerate minor vehicles of the day like furrin cars and Falcons. The only reliability problems came from my horrible learning curve in electrical wiring.
It eventually locked up, no water in cylinders and not the starter, and I replaced it with a dismal failure of a Genuine Ford rebuild from the dealer.
Years later, I went to move it across the garage and when I grabbed the flywheel the engine was free and turned easily...rebuilt it a few years later and never did find any reason for it having been completely unturnable.
Anyway, that one went over 100,000 and though certainly not fresh worked just fine as my transportation. I don't remember for sure but I think it went past 100,000 when it was still the only family car, around town and on trips. It got very little use between that time and my use.
 
I put a brand new raised deck WWII engine that was from a bunch of engines Dennis Carpenter found in India about 40 years ago. I installed the engine over 30 years ago and have put over 108,000 miles on it in my 39 Ford convertible. I put Castrol 20/50 in it before installing the engine in the car and it has had nothing but Castrol 20/50 in since. I had an oil leak at about 85,000 and pulled the pan and there was not a drop of sludge in the pan and the lower end looked good and clean. There was a spot of hard dirt about 2 1/2"s in diameter 1/16" thick in the lowest spot of the pan near the drain hole which I scraped out. I drove it to from Florida to Pa. in June and all summer in Pa. and back to Florida in October. With a 3:78 Columbia I drive at 65 to 75 for 650 miles the first day and a little over 500 the second day. It used less than a 1/2 quart of oil on the trip back and not a drop of coolant. I figured 21 MPG by the gas slips but I have to check the charge slips and make sure I didn't miss one. This engine runs perfect and still sounds like a new one. It has 45 lbs of oil pressure driving and 15 lbs at Idle. Runs at 175 to 178 at 70 MPH when it's over 90 outside. Stock fan, no thermostats, Skips pumps, 2 gallons of Prestone and 2 quarts of Purple Ice. No flex hose problems with the new gas since I switched to Bob Shewmans new "no problems" fuel flex hose. G.M.
 

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Re: Flathead mileage? Bruce

Bruce,
Regarding your comment on a "dismal failure of a Genuine Ford rebuild by the dealer". I tore down a worn out 59 A-B last Spring with a "genuine Ford rebuild tag" and the main bearings had the adhesive shims and wrapped right over the oil holes!! John
 
I think the awful air filters and the airflow thru the pan were the main killers. I have a 59A breather that is a project of mine. I have been soaking it in lacquer thinner for months and it is still completely clogged up. That cone on the fuel pump rod is supposed to circulate air thru the pan. I can just imagine the air from the dirt roads going into the pan.
The engine I am building will have full lube filter, a modern large airfilter, and a pvc system. It should be good for an easy 150k. I am going to use Rotella oil in it. My 241 Dodge loves the stuff.
 
I was a teenager in the 50's, my next door neighbor told me his Fords normally needeed a ring job about 50,000 miles. This was in Detroit where engines didn't warm up much in the winter and driving distances were short. They didn't have and expressway till the 60's. Engines tended to have a lot of sludge in them when they were torn down in those days.
My first car was a 1934 Ford 3 window coupe, as a kid I thought it was great. Till winter came with no heater or defroster! It was turned into a chopped hot rod and I bought a 1939 Ford standard 2 door with a Southwind heater for dating! :-).
Mark W. Slight
 
Oil as improved as stated up through SJ, but I think moly rings, piston engineering and pcv system that was adopted in the early 60s was a leap forward in longevity for engines. JMO
 
Leaps for durability: PCV, Large modern paper air filter at carb and breather, any modern oil. Also maybe a full flow filter drilled in, I suspect less important than PCV!
WE could use...really modern pistons designed to stay round when hot, good modern rings seem to be available in a very limited range of flathead sizes.
I think this along with very good machining is what has boosted OEM engine life from an expected 100,000 to between 2 and 300,00...
 
On my Genuine Ford rebuild, I discovered a VERY deep gouge left by a loose piston pin in one cylinder. Upon pulling out that piston, I discovered the pin to be properly locked in place. Someone had rebored a thoroughly dead cylinder and dropped in the new works without giving a damn...
I ran it that way, not much choice with no money or time, and it soon ejected a valve seat, revealing a crack. Worst flathead I ever met.
 
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