So Which Flathead Do I Have?

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Fortunateson

Well-known member
Just picked this up now I need info...which flathead did I get? DF752513-D378-4B12-99A7-1B82CDEFEB94.jpg

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Fortunateson said:
Just picked this up now I need info...which flathead did I get?View attachment 476510

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Fortunateson....Because you have likely heard me say this before....you seem to have either an 8BA-type Ford, or an 8CM-type Mercury. Your pictures show NO half bell, and those numbers mean NOTHING of significance that anyone still breathing can remember. Why....because Fords and Mercs SHARE a single, COMMON block! Peripheral, bolt-on parts, in addition to crankshaft used, determine Ford or Merc heritage. DD
 
In addition to what V8Coopman said, many many 8BA era flatheads these days are found with a mix-and-match selection of parts from different year cars and trucks. Pictures of the whole engine, then more specific pictures of the various parts will allow us to determine what you have.
 
V8COOPMAN said:
Fortunateson....Because you have likely heard me say this before....you seem to have either an 8BA-type Ford, or an 8CM-type Mercury. Your pictures show NO half bell, and those numbers mean NOTHING of significance that anyone still breathing can remember. Why....because Fords and Mercs SHARE a single, COMMON block! Peripheral, bolt-on parts, in addition to crankshaft used, determine Ford or Merc heritage. DD
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Yeah I know all that you STATED but the part ABOUT the numbers I posted. I JUST thought that someone would be able to decipher them. As far as peripheral parts are you referring to the cam, rods, pistons, oil pan, etc. Not peripheral just part of the package.

The heads are the ever popular Merc “instant improvement” ********. The crank is a Ford not a Merc so I know that much even though the Merc crank I was hoping to find wasn’t there. Even though I won’t be having this block Magna fluxed any time soon I did take a hard look at the decks, pan rails, and cylinders and could not see any cracks whatsoever I feel good about the purchase. It will be a backup to my backup...

Came out of a ‘51 pickup but I suspect it may have been rebuilt at some point as there is virtually no ridge at the top of th cylinders.

I suppose I should have simply titled this thread... “What Do These Numbers Mean?”
 
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Slow down dude. It's okay. Don't take anything personal.

What would you like to know? Casting peripheral engine parts numbers?


On a 1970's bmw there was a window/hole that looked down off the bellhousing to set initial timing. off the flywheel.
 
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Fortunateson said:
I JUST thought that someone would be able to decipher them.

The heads are the ever popular Merc “instant improvement” ********.

I suppose I should have simply titled this thread... “What Do These Numbers Mean?”
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As Denny ("tubman") .....a seriously-afflicted old Corvette "numbers-matching" kind of guy has stated in the past .....in the case of these old late model 8BA-types, nobody still living today that we have found, has any documentation referring to almost ALL of these cast-in number/letter references. It just so happens that I am also one of those sick-o, old Corvette numbers freaks that just knows that those markings once meant SOMETHING, but with these late flatties, it's just info likely lost to the wind for the duration.

Also, the Merc heads are the exact opposite of "instant improvement", because they are lower compression than comparable year Ford heads! DD
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I agree they mean something. Like parts numbers. Henry was too cheap to include them for the fun of it. They are part of the cast, not stamped in later. Probably like the 59a casting. Nothing to tell you what block you have from what I know.


Well if you put a blower on the lower compression heads might be okay. or mill them.
 
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Maybe you should make one. It would sell well. Well maybe not make you rich. But it would be interesting. Maybe just a pdf to be added by a few that can be printed. Printed by me but certainly not added by me.


Write it down. I'm a decent illustrator.


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That’s why I called the Merc heads “ instant improvement” ********. I presume in the old days most knew the Merc engines had more horsepower so swapping heads would give the illusion of the engine be a true Merc.
 
If you put truck 8rt heads on a merc, you wouldn't do much on a merc car motor, but make it slower. Merc's had a 4" crank. So putting merc heads on a regular 3 3/4 stroke isn't going to do much or anything.


You could do better milling some stock heads. There is no replacement for displacement.
 
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You could take two identical blocks. Same heads. One is bored 40 over. The other is 120 over. The 40 over has a 4" crank and the 120 doesn't. Which one would you take?
 
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Tinker said:
You could take two identical blocks. Same heads. One is bored 40 over. The other is 120 over. The 40 over has a 4" crank and the 120 doesn't. Which one would you take?
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Obviously, the one with the 4" crank. Ford cranks are everywhere.

Then I'd bore it .125" over.:D
 
I'd leave a little meat on the bone. As a driver. We all are not making drag records. But i get what you are putting down. With a good re-builder you could do a 4.25 scat crank too.



Guess is my thinking is leaving something and still going faster, it's been done.. Not sure it matters. Probably a lot of good blocks out there bored to sleeve without understand power. probably easier to get power with a bit of boost and a solid cylinder wall then a small bore difference.


The real power of a flathead is in the lower end of the block.


Sometimes I just want to cruise along a lake drive at 35 mph.
 
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Contrast the pics I posted pics at beginning of this thread epics of my Merc block I posted last year. Anyone know why they did away with casting the type of block it was in the post ‘49 blocks?

And I consider it a Merc block because it was bone stock, never rebuilt, had all the Merc components, and came out of a Mercury...
 
Seems we're splitting a lot of hairs here. As there are no known differences between the Ford block and the Merc in 49-53, a Ford block could be a Merc block or a Merc block a Ford block. There is no more value to a block that came out of a Merc than a block that came out of a Ford.

They're all just 8BA blocks to me and just about everybody else . . .
 
Fortunateson said:
Anyone know why they did away with casting the type of block it was in the post ‘49 blocks?

And I consider it a Merc block because it was bone stock, never rebuilt, had all the Merc components, and came out of a Mercury...
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Fortunateson ....The practice you speak of.....limiting the casting-TYPE marks on the half-bell area ..... actually had it's roots with the post-war blocks when both Fords & Mercurys began sharing the IDENTICAL "59" block which had a 3-3/16" bore, and which were BOTH rated at identical horse powers. I believe it was all pretty-much carved in stone by the time the post-'48 blocks were the current offering for '49 thru '53. The fact of the matter had become what myself and others keep trying to convince YOU of here.....Ford & Merc blocks had become IDENTICAL! That would actually be considered a pretty smart economic (and logistical) move on the Ford Motor Company's part.

Your second statement above brings THIS comparison to mind. Thousands of Jeep Cherokees, model years around the 1998 timeframe had 318 cu. in. Dodge engines in them from the factory. So, would using your logic above arbitrarily make all those Cherokee powerplants "JEEP" engines? DD

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