Why do Flathead V8 Blocks Crack?

[JAKEFORD]

I have owned many flathead engines over the years. Some were perfect with no cracks and some had cracks. Sometimes the cracks caused problems and other times not and didn't even know about them until rebuild time came around.

The cracking I remember was mostly in the area of the valves. Seat to seat and seat to cylinder bore. Sometimes the cracking was due to coolant freezing but this should be expected if you don't keep proper strength anti-freeze in the engine.

I was under the impression that the non freezing cracks were due to some casting flaws or temperature overheating and cooling but I was never sure. I know I threw more than one block away due to excessive non repairable cracks.


Can anyone provide a better explanation?

[Ralph Moore]

Well, the cracks from the center head studs to the water jacket actually were part of the design process. They were put in to relieve stress between the cylinder walls.
The other cracks, I'm sure, were a result of the way these engines were treated, back in the day. Too many overheat cycles, and or freezing in the winter contributed to most.

[TomT/Williamsburg]

Other cracks probably came about from overheating issues. The earlier blocks had plenty of sand left in them once they left the factory, resulting in some overheating. The treatment or inadequate treatment of the overheating issues were probably more cause for cracking than anything else. If you ever talk to H&H flathead they will tell you they have never come across a cracked flathead block they could not fix. I certainly would not pay for their rebuilt engine prices knowing that but I am sure there are many who have and had no issues.

In my limited experience I have dug out a gallon pail or more of sand out of several 59ab blocks. These blicjsca a were relatively crack free and have severed me well since their rebuilds.

I guess, in the end, it's a bit if luck, acquired knowledge about overheating, and how you drive and build them that really determined whether you have a really good block or not that will not overheat. Sorry to have rambled a bit ...

[Tinker]

Well if you take a perfect block of cast metal and you heat and cool it for 80 yrs, let's say at least 200 times a yr. that's 16,000 heat cycles. Well you have a used flathead. Kind of amazing they hold up as well as they do.

[40 Deluxe]

Originally Posted by Ralph Moore

Well, the cracks from the center head studs to the water jacket actually were part of the design process. They were put in to relieve stress between the cylinder walls.
The other cracks, I'm sure, were a result of the way these engines were treated, back in the day. Too many overheat cycles, and or freezing in the winter contributed to most.

Come on Ralph, you're not serious, are you?! I have heard this comment made many times as a joke, because this type of crack is so common-such as "Ford assigned a part number to these cracks", etc. I seriously doubt, though, that they "were part of the design process"!!!

[flatheadmurre]

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I have thought about the idea of heat threating a block to releave the stress and then throwing it in the dark hiding to sit and age....
Thats what you do with a new cast iron piece but should it add something to an old block and how much ?
Have any of you guys some of the valvepocket sleeves left ?
I still have the kit but im not shure if i have any sleeves.

[scooder]

Don't know why, but in my experience the later (8BA) type blocks seem to more likely crack from valve to bore than the prewar blocks. Anybody else found this? Or am I lucky on the prewar blocks?
Martin.

[deuce_roadster]

All the exhaust created by the engine gets routed to the outside of the block through the water jackets. The center exhaust port handles 2 cylinders and concentrates more heat there. I believe this fact contributes more to the non freeze cracks then anything else.

[Kahuna]

Overheat is the only thing that I believe causes the cracks, Not heat cycles

[Ralph Moore]

Originally Posted by 40 Deluxe

Come on Ralph, you're not serious, are you?! I have heard this comment made many times as a joke, because this type of crack is so common-such as "Ford assigned a part number to these cracks", etc. I seriously doubt, though, that they "were part of the design process"!!!

I was joking, of course , but I have rarely seen a block that didn't have those cracks.

[Brian]

Scooder, I'm with you on that...the prewar blocks had better [in my opinion] metallurgy than the stuff cast post war. Definitely different composition of iron. [Less nickel?]

[petehoovie]

Originally Posted by scooder

Don't know why, but in my experience the later (8BA) type blocks seem to more likely crack from valve to bore than the prewar blocks. Anybody else found this? Or am I lucky on the prewar blocks?
Martin.

I was told that the 8BA blocks for the 1953 model year did not have hardened valve seats - that the block itself was used as the valve seat and that rotary valves were used to compensate for wear. Could this be the cause of "valve to bore" cracks in 8BA blocks?

[scooder]

The 8BA ones I've seen with cracks from the valves, did have the hardened seats.
Martin.

[Johnnydidd]

Flathead design has caused the cracking, very poor design. If you have flathead you will have the problem sooner or later. Block repair is a good answer, I had one repaired few years ago no problem(cracked from no 2 cylinder to valve seat). My recommendation keep as cool as possible, I am always looking for ways to keep engine cooler. I have a Model A that has been overheated to where it would hardly run no cracking, but look how the exhaust valve is next to the manifold.

[JSeery]

There is a big difference between overheating and running an engine to cool! All engines need to run at as high a temperature as is practical.

[Mike51Merc]

The problem with overheating (to the point of boiling over) is the steam pockets that form from the loss of coolant. The pockets can allow superheating conditions to occur and the hottest spots in a flathead block are the Siamese exhaust passages. This is why a lot of flatheads have cracks in the middle cylinder exhaust ports up to the valve seats.

The moral of the story is to never allow your flathead to boil over. It's one thing to get hot, it's entirely another when it gets so hot that it blows out the coolant like a geyser.

[40 Deluxe]

Originally Posted by Ralph Moore

I was joking, of course , but I have rarely seen a block that didn't have those cracks.

Pardon me, Ralph! I did take you seriously. Sorry about that!

[Ralph Moore]

I figured it sounded more technical than the Ford assigned part number. One of these days I may get lucky and get to see a NOS V8 block!

[bobH]

Originally Posted by scooder

Don't know why, but in my experience the later (8BA) type blocks seem to more likely crack from valve to bore than the prewar blocks. Anybody else found this? Or am I lucky on the prewar blocks?
Martin.

This is something that I have also wondered about. I'm thinking back to the 50's, when I worked in a small independent garage. We saw mostly 'abused' cars, usually not ones that looked well cared for. I'm pretty sure I can't recall an 8BA that didn't have a crack. I saw 59 & earlier with cracks, too, but it seemed a lot less frequent. Coincidence? Imagination?
I'm sure guys like Pete, Ron, John, and other builders that see lots of engines, would have a better 'take' on this.

[40 Deluxe]

It's easy to look back and say poor design, but look at the times: V engines up until then were multi-piece castings with much room for tolerance stack-up and leak points. The crankcase was cast and machined, the cylinder blocks were cast and machined top and bottom with lots of bolt holes to drill and tap, and the heads had to be cast and machined, plus other bits adding to the complexity and cost. Ford's engineers decided to put the complexity into a one-piece block/crankcase assembly so once they had the design down and the molds figured out, they began saving money by doing far less machining. Plus, money was scarce-depression years.

[Henry Floored]

Originally Posted by Johnnydidd

Flathead design has caused the cracking, very poor design. If you have flathead you will have the problem sooner or later. Block repair is a good answer, I had one repaired few years ago no problem(cracked from no 2 cylinder to valve seat). My recommendation keep as cool as possible, I am always looking for ways to keep engine cooler. I have a Model A that has been overheated to where it would hardly run no cracking, but look how the exhaust valve is next to the manifold.

Any cast part is subject to cracking. That is from any manufacturer. Even the much vaunted small block Chevy can acquire cracks.

The Flathead Ford can get cracked in one of three ways usually. One by freezing. Two by over tightening of the too large diameter head bolts. (the Flathead Ford would be better off with 7/16" "torque to yield" stretch bolts, there is simply too much ability to distort and yes crack the deck with the factory fasteners). Third is probably steam pockets as one other gentleman has mentioned, though that is an educated guess on my part. The Flathead block is a complicated casting and as such is quite a technical triumph to be as good as it is. It would be a strong challenge even for today's pattern makers and foundry men to try to duplicate it today.

When you comment that the Flathead is a "very poor design" I have to take issue a little bit sir. I think you might be referring to the internal exhaust porting. While yes that is unique to the Ford Flathead they do not constitute poor design. On the contrary, the exhaust porting was a no compromise solution to the problem of packaging and plumbing.

The Caddys and LaSalles ran exhaust out the top and it's very "busy" on the top of the engine. Intake and exhaust manifolds fighting for the same space.

Pick your poison I guess but the Ford solution is not a poor design in my humble opinion.

[Johnnydidd]

Henry Floored: How would design the engine if it was up to you? Did Caddy crack as much as Ford? I don't believe so.

[Henry Floored]

Originally Posted by Johnnydidd

Henry Floored: How would design the engine if it was up to you? Did Caddy crack as much as Ford? I don't believe so.

I would design a Flathead exactly like the Lincoln 337, except for a lighter rotating assembly and possibly 5 main bearings. Other than that the Lincoln 337 is the "zenith" of side valve V8 technology to date.

[Mike51Merc]

Originally Posted by Johnnydidd

Henry Floored: How would design the engine if it was up to you? Did Caddy crack as much as Ford? I don't believe so.

The thing is that a Cadillac's price was multiple Ford's, and so was a Lincoln. Ford's secret to success was providing an eight cylinder engine to the masses for the same price as the competitor's six.

[alchemy]

I HAVE SEEN a flathead Ford with no cracks. It is an NOS block, but it has no cracks.

I can't remember seeing any others without cracks though.

[40 Deluxe]

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Originally Posted by Johnnydidd

Henry Floored: How would design the engine if it was up to you? Did Caddy crack as much as Ford? I don't believe so.

Caddy also had a good eight years of watching and learning from Ford.

[Allan Wylie]

Originally Posted by scooder

Don't know why, but in my experience the later (8BA) type blocks seem to more likely crack from valve to bore than the prewar blocks. Anybody else found this? Or am I lucky on the prewar blocks?
Martin.

It's the first time I've read about this but for what it's worth, the Canadian 8BA blocks we have here in New Zealand seem much more prone to cracked valve seats than earlier Canadian blocks. C59A and C69A blocks usually have the "Ford part #" cracks but rarely any others.
If I had my druthers I wouldn't use an 8BA in a performance application but I read about others who do, apparently successfully, so I wonder; are some 8BAs more prone to cracking than others?

[oldbugger]

when I rebuilt my 53 merc engine the machine shop said it was the first flathead they had seen with no cracks. my lucky day. Paul

[flatheadmurre]

Im not sure how well the formula of the material was kept uniform during the years and between different foundrys.
If one was to cast a new block without counting dimes adding a higher nickel content and some other tricks would do wonders.
The flathead is an amazingly good compromise between weight/size/performance/cost.
Starting to add separate exhaust you get a bigger/heavier engine.

[Henry Floored]

If Ford somehow could resurrect a new Flathead block with a few improvements it would be tremendous. Compared to some of the money spent on other things a Flathead block would be a drop in the bucket.

[Henry Floored]

Since I was challenged earlier on how "I" would build a Flathead I'll go ahead and explain that.

I would put a carefully shaped intake port in it with a great "short side" radius in it.

In the exhaust ports I would fill in the dam at the end exhaust ports. That would be a smooth ramp to help the exhaust out.

The center exhaust port would be split by a separating wall. All the exhaust valve pockets would be more like an upside down OHV valve pocket.

No more removable guides!

Camshaft would rube in 5 bearings and be larger in diameter.

For a "shoot for the moon" option I'd put 5 mains in her with a light rotating assembly and as big a bore I could fit in there.

[flatheadmurre]

If youre redesigning for better performance why not go with a new crank to solve the firing order...taking care of the shared exhaust port.
Problem is your flathead wont sound or be the same anymore...

[Mike51Merc]

Originally Posted by flatheadmurre

If youre redesigning for better performance why not go with a new crank to solve the firing order...taking care of the shared exhaust port.
Problem is your flathead wont sound or be the same anymore...

The shared ports don't suffer from a firing order problem. They suffer from a shared port problem.

[flatheadmurre]

Originally Posted by Mike51Merc

The shared ports don't suffer from a firing order problem. They suffer from a shared port problem.

And whats the problem with sharing a port ??

[Henry Floored]

Originally Posted by flatheadmurre

If youre redesigning for better performance why not go with a new crank to solve the firing order...taking care of the shared exhaust port.
Problem is your flathead wont sound or be the same anymore...

Hence the wall between the center exhaust ports at least to a reasonable distance into a shared exhaust passage.

[flatheadmurre]

Its a hard task to solve real good without changing the outside dimensions.
A baffle to guide the flow of the exhaust is a good bit on the way.
I was more thinking crossfire or something real drastic

[Mike51Merc]

Originally Posted by flatheadmurre

And whats the problem with sharing a port ??

The only problem with sharing a port is that the shared ports see twice as many hot exhaust charges, yet they are structured and cooled the same as a non-shared port.

In my opinion, the real problem with Ford flatheads is the fact that the exhaust travels a painfully long and crooked path inside the block before it exits. Just look at all the 90 degree turns it has to make before leaving. Cadillac put the exhaust ports on top, resulting in an unorthodox looking engine that performed better.

[ford38v8]

Henry's insistence on doing things his way was always with a purpose, to solve or prevent a known problem. He routed the exhaust through the block in order to heat the cylinders as quickly as possible, knowing that cold starts are the most destructive to an engine. As is usually the case, solving one problem creates another.

[Mike51Merc]

Originally Posted by ford38v8

Henry's insistence on doing things his way was always with a purpose, to solve or prevent a known problem. He routed the exhaust through the block in order to heat the cylinders as quickly as possible, knowing that cold starts are the most destructive to an engine. As is usually the case, solving one problem creates another.

If you look at an inline flathead (Ford and all others), the intake and exhaust ports are on the same side as the intake and exhaust valves, therefore they don't have Ford's intentional cylinder-heating as you described.

The problem with joining two inline flathead fours in a "V" is that it is desireable to have the intake and exhaust in a "cross flow" configuration, but there's no practical way to have the valves on opposite sides of the same cylinder bank, so instead they just routed the exhaust out the opposite side by creating ports inside the block. Cadillac decided to put both ports on the "inboard" side.

[flatheadmurre]

Originally Posted by Mike51Merc

The only problem with sharing a port is that the shared ports see twice as many hot exhaust charges, yet they are structured and cooled the same as a non-shared port.

In my opinion, the real problem with Ford flatheads is the fact that the exhaust travels a painfully long and crooked path inside the block before it exits. Just look at all the 90 degree turns it has to make before leaving. Cadillac put the exhaust ports on top, resulting in an unorthodox looking engine that performed better.

Theres a little bit more to it then just the heat...

To get a motor perform real good you should have a skavaging effect.
And you want the cylinders sharing port to fire as far apart as possible.
And on top of all performance aspects you want a well balanced engine and not a pogo stick under your hood.

[Mike51Merc]

When it comes to exhaust pulses, 90 degree crank V8s have a syncopated rhythm. What I mean is that regarding left and right banks, there isn't a left-right balance to exhaust beats (like there is with a 180 degree crank in many European V8s). The result is a loss of scavenging, but the benefit is a smoother engine.

Looking at the flathead firing order, the middle cylinders (with the shared ports) are separated in order by a cylinder on the opposite side, which is pretty much the same as you'll find on a more modern overhead valve Ford V8.

[Tom Walker]

Its interesting that when Cadillac produced the ground breaking OHV V8, they compromised with a centre siamesed exhaust port. It works fine till you want to squeeze the last few hp out of it.

[Lawrie]

Poor design my a**,the flatheads in my 33,34 and dragster perform as good as or better than most engines of the day,my 33 tows a caravan all over Australia no drama,what other old car can do that reliably,
Lawrie

[Henry Floored]

Originally Posted by Lawrie

Poor design my a**,the flatheads in my 33,34 and dragster perform as good as or better than most engines of the day,my 33 tows a caravan all over Australia no drama,what other old car can do that reliably,
Lawrie

I agree with this. My 75 year old Ford hauls the balls! At 73 years of age I replaced the rod bearings while the engine was still in the chassis. The main bearings,oil pump, pistons, rings, valve train and valve seats are still original. She still runs like a top.

[Flat32]

While I'm certain there are various causes for various Flathead block cracks it is fairly certain stress does it.

For the particular intake port to cylinder ones I have a suspicion they are primarily caused by overheating like happens during a common boil over, but with the real stress being caused by relatively cool air coming into the port if the seriously overheated is restarted too quickly and worse if trying the restart with a wide open throttle.

I can easily see a poorly maintained cooling system car boiling over going up a steep hill and the driver continuing to the top when he should just stop.

I was taught to shut down and let the engine cool without doing anything and not to add water until I could lay my hands on the heads.

As far as the 337 engine goes I had one that I picked up in a scrap yard back in 1960 and before I took it apart my car mechanic uncle told me it will be cracked at the intake ports and most of them were in his experience. He was right. Every one was cracked.

I put that cracked engine into my father's F-8 dump truck and he ran it around his place for years with no real problem.

On Henry's Flathead design I'm intrigued by it to the point I'm making a 1/4 scale model of it and working on making 1/4 scale molds to attempt casting the block in bronze. This project has given me a very intimate appreciation of how it was done.

This is a link to my drawing file of the cores and mold as I am building it. Following what I can see in the River Rouge Tour video on Youtube.

https://www.dropbox.com/s/jdm9pf08cu...0mold.exe?dl=0

Flat32

[FrankWest]

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Interesting thread...
I know it has nothing to do with flatheads but It always amazed me the Volkswagen aircooled engines? My brother always has volkwagons and I took my driving test on a volkwagon bus in 1977. The motor always seemed to run smooth. I wonder how those blocks held up to cracking?

[19Fordy]

I have a spare, used, magnafluxed 8BA block with no cracks. Bought it in the 1980's from Doug Shull who was an advisor in the V-8 Times magazine many years ago.

[tubman]

I just sold an uncracked 8BA to a fellow up here building a hot rod. It came out of a 41,000 mile '50 Ford that a tree fell on in a storm in 1954. Someone tried to repair the damage by using a cutting torch to cut through the windshield posts and ended up setting the interior on fire. The car sat in a garage until the late eighties, when I bought it. I parted the car out and saved all of the good parts. A couple of months ago, this guy called me, hearing I had some engines. We made a deal on this one, because I had come to the conclusion that I'll never get around to using it. We pulled the heads, and there were NO "part number" or other cracks. A subsequent magnaflux and pressure test confirmed that this was a completely crack-free block.

My theory is that this was an almost new car when it was damaged and put away, and had never had a chance to overheat or be abused. This leads me to believe that the cracks are caused by abuse (overheating) when the cars become older and less valuable, and that properly maintained flatheads will probably not be cracked. This is confirmed by the fact that the engine that I pulled out of my 82,000 mile '51 Ford shows no "part number" or other cracks either. This engine came out of a "Sunday car" purchased originally by two bachelor farmer brothers to go to church in. After the last brother passed, the car was left to their elderly cleaning lady who couldn't drive. I bought it from her nephew and can assure you that that car was never abused or overheated either.

I pulled the engine from that car because it started making a funny noise I could not track down. I checked a number of things, including the fan bearing and throwout bearing and still couldn't find the noise. Although the engine ran good with excellent oil pressure, I decided to replace it before something bad happened. I replaced it with a '51 Mercury engine I had. Fords and Mercury's used different oil pans, so I removed and cleaned them so I could put the Ford pan on the Merc. In the bottom of the Ford pan I found a chunk of the thrust surface of the rear main bearing lying in the bottom of the pan. I am sure that is what it is because I had a set of new main bearings "in the box" to compare it to. In talking to my machinist we came to the conclusion that it had to be either a defective bearing or more likely an "assembly error".

I think Ford did a better job on these castings than anyone gives them credit for these days.

[RKS.PA]

I agree with you, tubman, that Ford's castings were better than we give them credit for in the breach. I remember my dad's flatheads, bought new, never had a cracking problem discovered on rebuild. And, I don't every recall vapor locking and we were using them hard on the farm in N.J. in the summer heat. As you noted above, it's what happened later in their lifetimes that causes the cracks. Of course, our gasoline didn't have any "corn" in it either!!!

[rotorwrench]

Man this is an old one. I must have missed it a few years back.

About the only thing I can add is that the flathead V8 was one of the most compact and simple design engines of its type ever made (just not simple to cast). I beg to differ on comments about poor design. For the price and reliability they had when properly cared for, they were one of history's better designs. It's limitations are what made it obsolete. Ford just wanted larger engines that were lighter weight and cars were not getting smaller or lighter in the mid 50s.

If a person compares the average size and weight of the cars & trucks of the 8BA era to the earlier types, a person can see why the 8BAs were wearing out a bit faster. Excessive heating and lack of proper anti freeze in freezing temperatures were the two big killers of flathead blocks. This had more to do with poor maintenance than it did with design.

[tubman]

Also, consider the thousands (actually, probably millions) of Ford V8's that passed through the re-builders in the forties thorough the sixties. I don't think they would have rebuilt an engine with a cracked block. It's only when they got to be old neglected "beaters" that got no care or consideration at all when the bad things started to happen.

[Bored&Stroked]

I saw a couple earlier comments about 8BAs seeming to be more cracked than earlier models - my observations would conclude the same thing. However, this thread also made me wonder if by the time they were using flatheads in the early 50's, maybe they were really flogging them in heavier cars, with automatic transmissions and maybe inadequate cooling systems?

Was wondering if more of them overheated due to the more extreme conditions they MIGHT have been subject too? Anybody have any comments to ponder? I've never owned a flathead powered car that was newer than 1940 - so I have no experience to work from.

Also, then there is the load-o-matic situation . . . one where in 100% stock form, it works well . . . but the minute you put dual carbs on a 49-53 engine, then the situation gets worse than the earlier front-mounted models. Without the correct/stock vacuum signal, there tends to be too little advance - which also contributes to over-heating in certain cases.

Just pondering this stuff on a Sunday . . .

[richard crow]

the simple fact is the eng. was a poor design. the big flaw was the exhaust gases going through the block. if thick head ford would have improved it with an over head design like the arden heads the eng would be made to this day.

[harleyjohn45]

I had a 1953 ford in 1953 and drove it fast, cruising at 65-70 mph. Top speed was 85 mph. It had overdrive and got 20 mpg, I drove it until 1959 and traded it in with 135,000 miles. I never had an over heating issue. I now have a 1953 8BA in a 1930 ford, and if I drive it too hard it tends to heat up. I intend to use evapo rust to clean the block and then install a fan shroud. I believe a fan shroud would eliminate a lot of over heating problems.

[Admiral]

Originally Posted by Bored&Stroked

I saw a couple earlier comments about 8BAs seeming to be more cracked than earlier models - my observations would conclude the same thing.

This has been my experience as well. The late-run blocks seem to have more cracking issues than earlier examples; casting quality also appears a little rougher, with far more flash and core wire hanging around.

[tubman]

Originally Posted by richard crow

the simple fact is the eng. was a poor design. the big flaw was the exhaust gases going through the block. if thick head ford would have improved it with an over head design like the arden heads the eng would be made to this day.

This has been bothering me for a day. It mystifies me why someone would post something like this on a board dedicated to flathead Fords.

[Henry Floored]

Originally Posted by richard crow

the simple fact is the eng. was a poor design. the big flaw was the exhaust gases going through the block. if thick head ford would have improved it with an over head design like the arden heads the eng would be made to this day.

I happen to think that the exhaust port routing is the best possible compromise in a single camshaft side valve “V” engine.

If you place the exhaust port exits in the valley you are forcing the exhaust gasses to do nearly a 180 degree turn at max velocity and expansion.

In the case of the Ford design the exhaust exits the valve pocket then gently falls downward and away. I spend a good amount of time cleaning up the exhaust port opening and exit to maximize this efficiency and minimize turbulence through the port.

If one concentrated on those areas you would realize that a Flathead Ford has high volume exhaust porting. Much higher than engines with greater displacement. This was no mistake. I think Ford engineers did it this way to remove back pressure and hence heat from the exhaust seat quickly and efficiently.

The engines that I have built here in Florida that I still have contact with consistently run 170 - 180 degrees water temperature. In the heat of the summer in stop and go traffic maybe they tickle 185 -190. The thermostat in my modern vehicle doesn’t even open till it reaches 197 degrees.

So I gotta say there is more to the Ford V8 than meets the eye. That’s why I think it was an overachiever of an engine.

[rotorwrench]

Originally Posted by richard crow

the simple fact is the eng. was a poor design. the big flaw was the exhaust gases going through the block. if thick head ford would have improved it with an over head design like the arden heads the eng would be made to this day.

By this analogy, any engine becomes a poor design when it reaches obsolescence. Ford and Cadillac both made larger engines in the valve in block design but one was a good tank engine and the other was just plain too heavy to be a long term product. The 337 only lasted four years but it did the job they wanted it to do. The Cadillac 331 was already in production when the 337 came out. But look at the size of those old Cadillac cars too. The 331 didn't last a long time either.

I can't poo-poo the Duntov brothers but they really just made a band aid to get more power from the Ford flathead V8 engine for truck applications. It made it a lot more complex and heavy. The Y-blocks only lasted a little over 10-years so what kind of design is that. A Ford 302 V8 would have more power and be a lot lighter. The Ford 289/302 was in production longer than the flathead and is a better design for functionality plus light weight but is came along almost a decade after the flathead was dead and buried plus it is only available as a crate engine now. We have more modern aluminum computer controlled V8 engines available for certain applications but whether they are a better design or not is moot. This is over 50 years after the flathead was in production. You would expect better designs with that much water under the bridge.

When you compare the flathead Ford V8 engine to other prewar engines, it was like a rocket compared to anything else and it was less expensive than most other brands. It wasn't till 1948 that the old flathead was showing its age and it still kept up with the competition fairly well.

[Art Newland]

Hey Richard Crow,

[40 Deluxe]

As I remember, by the mid to late '50's, the 8BA style engines were known for cracking. As we know, ignition timing that is retarded causes overheating, AND, Loadomatic distributors often had ruptured diaphragms. Ergo, cracked block! In addition, many people still ran plain water in the summer. Thus, mucho scale in the cooling system.

[Dobie Gillis]

Originally Posted by Admiral

This has been my experience as well. The late-run blocks seem to have more cracking issues than earlier examples; casting quality also appears a little rougher, with far more flash and core wire hanging around.

I know this thread is pretty long in the tooth but it piqued my interest (too much time on my hands?) I agree with Admiral about the late-run castings. I had a '53 block repaired and the guy said as he was drilling it for pinning he was hitting hard and soft spots in the cracked area (exh. valve seat to cylinder). This indicates to me that the alloy wasn't well homogenized before it was poured. The hard and soft spots set up stress areas due to differential expansion. Stress will relieve itself given an opportunity such as overheating. I believe the foundry did a slipshod job of mixing the alloy. Not on all of them, mind you, but on enough of them to give the late blocks a reputation.

[philipswanson]

The problem is exhaust gas is routed up and then does a u turn out the side of the block. The problem is the head functions are in the block instead of the head itself. Think about all the heads on other engines today that crack. Much more than even the flathead. That's a characteristic of combustion and the firing chamber and valves. Problem is the flathead had the valves in the block instead of in the throw away heads of today. Especially aluminum heads of overhead engines are cracking like crazy, even today. Ever take a Honda or Toiletta apart?

[big job]

Fact fiction or a myth. Back when these were the top guys class A divison, oval track racing. No body ran a late engine. All were the 239 AB's with 42 to 48 bodys. So the
race track gossip was, many engines like 49 to 53 may be from a truck who knows.
All agreed, when worked to death and thermostats opened, a rush of cold water made
these cracks, I just don't know, but does make sense, I think. Then a couple of 49 coupe shoe box'es : never did anything, just the ride for 'last'.. We, number #93 did one 1 first and constant 2&3, we were hot. Never blown an engine either. Oh yeh one
V8 General Mess of Crap, I think a 283. Now watch the Fords go by !!
What ever I sell my self to jump back to those times: the smell of hamburgs smothered with onions beer and nitro methane good times yes ole Ron...sam

Oh my eyes are a running from the nitro. Seekonk speedway, Mass & Thompson CT.