What Does This Stamping On The Head Mean?

There has to be an explanation. They didn't just stamp it for nothing. I also posted on the 2a site (What is this stamping on the head) and one post had the same stamp. Same age range as ours.

 

Could it be a part number for the type of head? Mine shows 807084. 807 is cast as part of the head with the 084 stamped. Plus it has 7.4 stamped in the back on the passenger's side. Which means the engine has 7.4 to 1 compression for use at altitudes above 5,000 feet. Follow the link for a picture:

20180406_181339.jpg

 

My (not very good) book shows part number 805730 for all F-134 heads.

 

OK, I just pulled a head out off the shelf. Mine reads the same as 55_willys_cj5's. Just adjacent and in line with the raised pad, I have "807" cast in the head, and the pad is stamped "084" the other smaller pad (as in ojgsoi's photo) has "JEC". My head of unknown history and is off one of the Naples swamp buggy race engines. Other parts of this Jeep were from a late '60 s F134 CJ5 with the backup light switch on the T90.
-Donny

 

PeteL, The part number you posted is for the head bolts, 14 of them. Head part numbers follow;
911689, head 6.48:1 ratio-export only
937454, head 6.9:1 ratio
649172, head 7.4:1 ratio
937450, head 7.8:1 ratio
-Donny

 

That makes sense. Mine is stamped 67 nearest the firewall which would match the compression ratio for late F134 - 6.7 to 1.

 

My back corner by the firewall is blank on mine.

 

You are correct, my error. Head is #649172 in my book.

 

Okay, the 1952 M38A1 I have is stamped "005" by the carb, and "69" at the rear corner, passneger side.
Not sure right now but I think the MD serial number may have been milled off the block.

My '56 CJ5 is… wait for it… "086".

I have a couple others I'll check after the snow melts and I can get to them.

 

The stamping on right rear corner is the CR.
6.9 CR is std. for F-134

 

So was the only difference for the high altitude a slightly shaved head for the little bit of compression gain?

I also have a 55 wagon which has the high altitude L226 flat head 6 Super Hurricane. What my research found on it was that the high altitude version had the same type stamp on a flat area indicating the higher compression. In that case 73 for 7.3 AND the first couple years included a 2 bbl instead of single. But in later years (57?) went to single even on the high alatitude. Otherwise everything in the engine the same. Wonder it that's the same on the F134 so you could make yours high altitude by just shaving the head.

 

Not sure how much to come off but I'm sure someone smarter than me could figure it out. Oh, and the high altitude 226 was painted red instead of black. The place it is stamped on the 226 is in the front by the thermostat.

Not sure if this is accurate, but found this (Jeep Engine: Hurricane F-Head 134 I4). Note the pic shows the red paint too.

 

I mentioned the head I checked was from a race Jeep (post#25). My head has been shaved at least 3/32", and the block decked a little more. I have a little more than 3/16" total between both surfaces. The pistons crowns are well above deck height with the tops milled, creating a raised section the shape of the combustion chamber. The engine was supposed to be around 10:1 compression with a thick gasket. This engine has a custom ground cam that needs that kind of compression, at least before it pulled the rod out of the bottom of the piston!
-Donny

 

While it would be nice, I guess, if the engine was the high altitude since it's going to go to the Colorado mountains and live at 7,500. It spent its entire life on a ranch in central Texas so there really was no reason then. When having it rebuilt recently, I asked the rebuilder (who has done a number of these over the past 30 years) and he said it's really not worth the time and trouble to shave it for the performance gain, saying "you probably wouldn't notice the difference and they were both rated the same HP". So I didn't do it. On my wagon it spent its original life in the mountains of eastern NM (Red River) so I'm guessing the original owner decided to get that option. I'm kind of glad he did now that it too is headed to Colorado for our 'retirement'. But it brings up a point of why did they even offer it if they were rated the same?

 

Where exactly do I find the head casting number? I don't see one that looks like the ones mentioned above.

 

Embossed numbers as observed on castings are part numbers.
But they only identify a part prior to any machining.
Often times the various castings can be machined in several ways.
A basic casting therefore frequently has the ability to become two or more different parts having different part numbers.
The actual part number may or may not be stamped into the finnished casting.
To my knowledge F-134 heads never received any distinct stamping to identify the final part number.