Intresting question on Facebook about high head with no Ford USA

[Mark Gregush]

The timing was great! I was just yesterday cleaning up a high head that did not have Ford USA or the normal mold mark at the water outlet. I have read that the Ford on the side of the block was dropped around 1925/26, but what about the head? Did all Ford heads have the Ford USA on them, am I looking at an aftermarket head, or maybe a later Ford replacement? This one looks like a standard compression chamber. (Ya I should be so lucky, for it to be a high compression)I tried doing a search but came up blank.

[George Hand]

The "Encyclopedia" indicates that wording removed August 1926. George

[speedytinc]

Didnt the late heads come unmarked as you describe.(26-7)? They are of the lowest compression because of the worsening gas quality. These unmarked heads are found on vaporizer motors. I see them frequently. No reason to bother with em. Hope Im not bursting your bubble.

[John kuehn]

Yes the encyclopedia says that the Ford lettering was removed from the 26 heads. I still think I have one of those heads or maybe an aftermarket head unmarked in my parts barn.
It’s also come up before that the late blocks after 25 didn’t have Ford on them either. I may have missed that in the encyclopedia.
The replacement blocks were made up to around 1940. Those may be ones that weren’t marked. Not for sure.

[Joe Bell]

I have an unmarked High compression head, thought it was a late 26 head till I pulled the engine down and found the inside casting looks like Pruis's head inside? I did not notice at first there was no wells around the plugs, been running it for years and love it!

[speedytinc]

I have an unmarked High compression head, thought it was a late 26 head till I pulled the engine down and found the inside casting looks like Pruis's head inside? I did not notice at first there was no wells around the plugs, been running it for years and love it!

IRON HEAD?!?!?! Fantastic if so. Now I gotta turn over ever 27 looking head looking for a sleeper!

[Mark Gregush]

Thanks for the information. I didn't know about the compression being lowered again with the introduction of the vaporizer carb setup. I found a letter in Bruce's book about the vaporizer and lower grade fuel, but nothing so far re the compression drop, but will keep my eyes and ears open. It would be interesting to know the difference in ratios between the two styles of high heads.

[Adam]

Didnt the late heads come unmarked as you describe.(26-7)? They are of the lowest compression because of the worsening gas quality. These unmarked heads are found on vaporizer motors. I see them frequently. No reason to bother with em. Hope Im not bursting your bubble.

According to Bruce’s research, combustion area of Non-script high heads are the same as all the other script high heads made after 9/25/18, except for about 1 month (of script heads) in ‘26 when the compression was raised then lowered again. You have to cc a head to know for sure, but odds are fairly slim to run into one unless the production date of your car falls in that range and it still has its original head.

Here is the correct info:

[Mark Gregush]

Thanks Adam. Looks like the change only was in place for a few weeks. A very slight increase in compression, then back to same.

[speedytinc]

Interesting. 26 compression increase, then 1 month later a decrease? Confusion. Do I frantically search for this very limited head? Is it a corrected mistaken notation? Was I 1/2 right repeating a wives tale? Is this Joe's head? Why was there a need for the vaporizer without the added compression loss? Fantastic piece of documentation. Thanks for the clarification?
You, sir are a trouble maker!

[Joe Bell]

Here is a picture of the head that I have been running for years

[speedytinc]

Interesting. 26 compression increase, then 1 month later a decrease? Confusion. Do I frantically search for this very limited head? Is it a corrected mistaken notation? Was I 1/2 right repeating a wives tale? Is this Joe's head? Why was there a need for the vaporizer without the added compression loss? Fantastic piece of documentation. Thanks for the clarification?
You, sir are a trouble maker!

Sooo. I have to look for the illusive hi compression head. AND, CC every non script head virgin head I can to confirm they are the same compression.as earlier heads to disprove the myth for myself. THANKS A LOT. Another Pandora's box!
Thanks for the pix Joe. Are you sure it is an uncut virgin? This new info has rocked my religion.

[Joe Bell]

I had to mill it to clean it up and address for the bigger intake valves and 280 cam, valves touched side of head.