flathead engine life before overhaul?

[DLK]

I have driven several P-15's and Chrysler Windsors in the past month that have 50-65K on the engine apparently without a rebuild. A couple of these still had what I consider good oil pressure (15-20 at idle and 40-45 at higher rpm) and no smoke or other signs of a tired engine. I guess my fear is that the engines must be pushing the limits for needing an overhaul. Can one expect a well serviced and unabused 217, 230 or 251 engine to go more than 75,000 miles? My guess is generally no.

[greg g]

Usta be 50 to 60K was considered about normal mileage for a rebuild, overhaul or engine swap. But that was on dirt roads with leaded gas and basic engine oil. So while an engien might have been on the edge of it envelope, it probably has picked up some additional life with improved fuels and lubricants. Seems that if they have good care and have good vital signs, drive em. The compression test and a check with a vacuum gauge will give you another set of things to look at to judge condition.

[randroid]

Specialdeluxe47,

Welcome to the forum. How did the PO drive the car? Was the engine allowed to get a little warm before being driven in your cold climate, and when was the choke opened fully? Any engine can be trashed very quickly, and a well-cared engine will last a long time.

I never heard of the expected life of an engine being less than 100,000 miles, but I'm still in my early 60's and don't know how things were 'back in the day'. (Sorry Greg; I couldn't resist.) Perform the tests Greg mentioned and if everything else is equal pick the one that 'speaks' to you or is the color you like best. You're buying a pig in a poke, so buy it rather than fret over it and you should have a bit of time with it to sort out what needs to be done next.

-Randy

[greg g]

Randy, back in high school back inthe dark days on 1964, 5, and 6, I worked part time at the Dodge dealership in town. There were still a lot of 40's and 50's cars running around. The dealership had 2 employees who worked in a liscensed rebuild shop. they always had 5 or 6 flathead engines, some slant 6's and a couple v8's on a rack in a small shop. The would offer the customer in need of major engine work the option of an exchange engine. there's would be pulled, a new rebuitl installed, ad the car in and out in a day. I worked i the pars dept, and say bills where the customer got a core credit for their engine aainst the sale and installation of the replacement. Their engine would then be stripped down and evaluated. If machine work was needed it was subbed out and when it returned the two fellows would build it back up, and put it on the shelf for the next customer. That portion of the business went away in about 68, when the dealership changed hands.

So I guess if you compare our graduations dates, our back inthe day might be similar, however, different areas of the country probably handled this situation in a lot of different ways.

[randroid]

Greg,

Open mouth, insert foot. I graduated in '64 and was driving ships when you were still driving on land, so I didn't pay much attention to what you land-lubbers were doing at the time, and you got hands-on experience 'during the day' to things I've only learned after my service. I learned things in the Navy I still apply today but I might never learn the details you may have forgotten. I said what I said in jest and if any offense was taken please accept my most sincere and humble apology.

-Randy

[55 Fargo]

My 218 long block flattie which was pulled from a smashed 1951 Plymouth, and miles unknown, or whether the engine was rebuilt.

But the compression test revealed, about 100 to 105 across the board for compression, cyl #5 had about 96.

The oil pressure is great 40 at an idle, 55 at highway speeds, it never drops below 30 to 35 at an idle when running good and hot.

This is with 15w 40 oil, or 20 w 50 oil, and even with 10 w 40 oil.

So I have no idea how miles I have on this engine either, or whether it was rebuilt or had a ring or valve job.

I had to clean out the crud in the water jackets, pull water tube though. The valve chambers were clean no sludge, the oil pan still needs to be pulled, I can fell a little sludge in it with my finger.

My engine give s little piff.piff, puff,puff sound when warm and idling, is this a burnt valve, or may be a leaking valve, but it still runs great, I am running a single Smithy muffler, not sure it would give this sound at an idle or not......Fred

[Young Ed]

[quote name=randroid;145594I never heard of the expected life of an engine being less than 100' date='000 miles, but I'm still in my early 60's and don't know how things were 'back in the day'.

-Randy[/quote]

My p15 was in the junkyard at 76K miles. Still ran when I got it but as soon as the oil got warm the pressure left and it started knocking.

[Plymouthy Adams]

there is a lot to be said for todays modern engine...metallurgy, design, clean proper fuel ratio injected engines at all operation speeds, higher operational temp, faster warm up periods..filtration and oil itself has put the average engine well above the 100,000 mile mark..many out there do not even call for a tune up till that point in time..only thing I do not care for in todays engines is the interferrance fit engine..these babies are so overpowered small engines in a race to compete with HP output that the actual survivability of the engine is sacraficed..when buying a modern car..I highly recommend that you verify type before buying..I can break a timing belt at 6200 rpm (just below redline) and do no damage and this engine is also double dual overhead cam with dual induction, hp and cubes are squared..again..Mopar looks out for the customer..most import cars are handgrenade engines..

[Rumble1960]

It's not always miles that determines the need of a rebuild, in my case my engine needed a rebuild because it sat unused for many years. I had some pitting on the cylinder walls and had to have it bored .030 to clean the cylinders up, it still ran good but I feel better now that its gone.

[Young Ed]

To answer the original question if they run good now and are taken care of going forward they should last a long time. Dad has a 50 plymouth that I highly doubt has ever been touched internally. Its at about 90K miles and has just now started to burn a little oil. My 51 ply has 202K on it with 1 rebuild at about 110K. So that first build lasted quite a long time.

[DLK]

The oil pressure is great 40 at an idle, 55 at highway speeds, it never drops below 30 to 35 at an idle when running good and hot.

This is with 15w 40 oil, or 20 w 50 oil, and even with 10 w 40 oil.

So I have no idea how miles I have on this engine either, or whether it was rebuilt or had a ring or valve job.

......Fred

You must have done a great rebuilding job (or whoever did it). I must say I have yet to drive a flathead rebuilt or otherwise that never got below 30 pounds of pressure. My 53 Desoto had a recent rebuild when I bought it and still only put out about 20-25 at idle with 10W40 in it. My 47 Plymouth that had 65,000 and definitely was in need of a rebuild was down to 10 at idle when warm.

[Oldguy48]

If my faded memory serves me well enough, many years ago, if your vehicle reached the "magic number" of 100,000 miles, you were indeed a fortunate owner. And a rebuild or engine swap was in the immediate future. I speak through experience because when I was a teen, our family car was a P15. It had two engine swaps before it was finally put out to pasture. Of course, fuel and oil quality has improved greatly since those days, and I'm sure that had a lot to do with it's demise.

[55 Fargo]

I can't speak for the United States, but I know in Canada, especially rural people, they didn't put on the miles per year we do now.

People didn't go for long commues and road trips as they have done in the last 40 years or so.....Fred ps is my thinking correct on this one?

[PatrickG]

doesnt george asche have something like 400,000 thousand miles on a flattie with the original bearings?

i'm almost sure I read this on someone's blog about their visit to his shop....

[Don Coatney]

doesnt george asche have something like 400,000

thousand miles on a flattie with the original bearings?

i'm almost sure I read this on someone's blog about their visit to his shop....

Why does your posting smell like garlic:D

I am not sure how many hundreds of thousands of miles he has on his

Plymouth engine but he has done what is not recommended and shimmed

the bearings. On my last visit he gave me a ride in this car. He started it

cold and floored it as soon as he hit the road with no warm up time. It ran

great and held good oil pressure.

[PatrickG]

Why does your posting smell like garlic:D

I am not sure how many hundreds of thousands of miles he has on his

Plymouth engine but he has done what is not recommended and shimmed

the bearings. On my last visit he gave me a ride in this car. He started it

cold and floored it as soon as he hit the road with no warm up time. It ran

great and held good oil pressure.

haha well it is Garlic Festival Weekend...

and i think yours may be the story i was thinking of.

[P-12 Tommy]

If my faded memory serves me well enough, many years ago, if your vehicle reached the "magic number" of 100,000 miles, you were indeed a fortunate owner. And a rebuild or engine swap was in the immediate future. I speak through experience because when I was a teen, our family car was a P15. It had two engine swaps before it was finally put out to pasture. Of course, fuel and oil quality has improved greatly since those days, and I'm sure that had a lot to do with it's demise.

I agree. When I was a kid, by 100,000 miles they were junked.

[DLK]

I agree. When I was a kid, by 100,000 miles they were junked.

I guess that is why so many of these cars have been brought back from years in the field or barn with only 60-70,000 miles - at that point they were considered junk back in the 50's and early 60's. It has to be true that modern lubricants have something to do with greater longevity of the engines now.

[rlovette]

My P-11 has just over 23-thousand original miles--so as you might guess, it's done a lot of sitting. Like has been stated, that posts its own set of problems.

My dad had a '52 Desoto Hemi station wagon--and it was on the road until the late 70's. It still ran fairly well--but in his words, "it was addicted to STP." It probably needed a re-build at 97-thousand miles.

[Lou Earle]

Well my 2cents worth

When George Asche was at my house he had just turned 250000 miles

He bought that car used and has never put a wrench on the engine.

He uses synthetic oil and changes oil about every 4 or 5 thousand miles.

believer the following to be true

Oil bath filters are OK IF KEPT PROPERLY MAINTAINED.However many times oils not replaced or the hair is not cleaned and I think the hair wears out and cannot hold the oil in suspension so they become ineffective and of little value.

Next we now have excellent fuel filters that stop a lot of crud into the engine.

Next the oil filter- the by pass works just fine however our filters are 100 times better.

The engines are high nickel content so the blocks are fine etc.

Seems to me the key really becomes the oil.Our present oils are light years ahead of the then oil- 20 cents a quart-for the good stuff!!!15 cents for the re used!!!

So it always comes down to clean gas air and oil and long running engine.

It would not surprise me at all to see a 48 or so go 300,0000 before any work is necessary.

Also remember the first go round is usually just rings and maybe bearings- an in the car job - very cheap.

and remember this at 1.50 a quart for OK oil if you burn a quart every 300 miles for $450 you can go 30 thousand miles!! or for $1500 you can go about 450 thousand miles.

Me ,I suspect these cars never wear out if cared for- In 1972 I was in NY city and saw thousands of old dodges and plyms as taxis-I asked why

the guy told me - spoke English then-they were cheap never wore out or broke down and were sought after but the pollution was going to get them.

Any way my 2 cents-

What would I do I would drive it until it drops- meanwhile looking of another engine-used and get her ready to dropin-in then next 40 years or so

Lou

[Tony Cipponeri]

It's not always miles that determines the need of a rebuild, in my case my engine needed a rebuild because it sat unused for many years. I had some pitting on the cylinder walls and had to have it bored .030 to clean the cylinders up, it still ran good but I feel better now that its gone.

I do agree with that, I bought my 50 Plymouth in Arizona, and drove it home to Riverside Ca. Three days after getting home I lost a valve seat on #2 exhaust. after tearing the motor it was apparent that it had been rebuilt not too long ago. I didn't even have to do a clean out bore on the cylinders, but my machinist told me that two other valve seats were loose. The PO I bought it from didn't know anything about the motor,and told me so when I bought the car. So I guess it sure depends upon the workmanship too. Tony C

[55 Fargo]

Well my 2cents worth

When George Asche was at my house he had just turned 250000 miles

He bought that car used and has never put a wrench on the engine.

He uses synthetic oil and changes oil about every 4 or 5 thousand miles.

believer the following to be true

Oil bath filters are OK IF KEPT PROPERLY MAINTAINED.However many times oils not replaced or the hair is not cleaned and I think the hair wears out and cannot hold the oil in suspension so they become ineffective and of little value.

Next we now have excellent fuel filters that stop a lot of crud into the engine.

Next the oil filter- the by pass works just fine however our filters are 100 times better.

The engines are high nickel content so the blocks are fine etc.

Seems to me the key really becomes the oil.Our present oils are light years ahead of the then oil- 20 cents a quart-for the good stuff!!!15 cents for the re used!!!

So it always comes down to clean gas air and oil and long running engine.

It would not surprise me at all to see a 48 or so go 300,0000 before any work is necessary.

Also remember the first go round is usually just rings and maybe bearings- an in the car job - very cheap.

and remember this at 1.50 a quart for OK oil if you burn a quart every 300 miles for $450 you can go 30 thousand miles!! or for $1500 you can go about 450 thousand miles.

Me ,I suspect these cars never wear out if cared for- In 1972 I was in NY city and saw thousands of old dodges and plyms as taxis-I asked why

the guy told me - spoke English then-they were cheap never wore out or broke down and were sought after but the pollution was going to get them.

Any way my 2 cents-

What would I do I would drive it until it drops- meanwhile looking of another engine-used and get her ready to dropin-in then next 40 years or so

Lou

Hi Lou, there were still a lot of cabs using flatties in 1972, thats amazing.

I agree with the oil, better than ever before.

My engine has some miles(unknown to be exact), but this engine has decent compression 100 to 105 average, and idle oil pressure 40 psi down to 30 to 35 when the engine is good and warm, 50 to 55 psi on the highway.

The engine runs great, but I am still nervous going over 50 mph, even with a 3.73 rear end, I am afraid to blow anything up if I drive at 60 mph sustained...............Fred

Edited July 28, 2009 by Rockwood

[Young Ed]

Fred Id go faster then that. Oil pressure is good on the highway you should be good for 55-60.

[kencombs]

Chrysler stuff was very popular with cab companies because it is/was tough!

Standard used to be, as I was told by a taxi owner/ expect 125,000 on the original, then 100k more on a rebuild. Then junk the worn out hulk. These numbers went to 175/125K on slant sixes.

[PatrickG]

Well my 2cents worth

When George Asche was at my house he had just turned 250000 miles....

....It would not surprise me at all to see a 48 or so go 300,0000 before any work is necessary...

Lou

I agree. with good oil and regular maintenance, barring any flukes of nature I wouldn't be surprised to see a flattie go just as far if not farther than any honda civic, toyotta camry or any other "super" reliable car of today.

oil quality has come so far, its really all in the up keep.