Still trying to determine my engine

[Hemikiller]

The dot/no dot controversy is well documented. Much of it stems from incorrect information published on DIY Ford, by George Reid. Apparently, in his years of experience, he never ran across a set of 71 M-code heads.



4 no dot are D0AE heads, which are all closed chamber, or *extremely* early D1AE-GA closed chamber heads.

4 dot started at the beginning of the 71 model year with the D1AE-GA closed chamber heads, continued with the D1ZE 351CJ head, and was used to the end of 351C production in 1974 on the D3ZE open chamber heads. The *vast* majority of "4 dot" heads are open chamber, as they were in production for 3 years, plus a small amount made in 71.

While date codes are the best way to determine what a 4* head is when the intake is installed, t's still not a foolproof method. Ford made batches of service replacement closed chamber heads until at least 1974. The heads on my current 351C build are service Boss 351 heads made in 1973.

 

[Stanglover]

The dot/no dot controversy is well documented. Much of it stems from incorrect information published on DIY Ford, by George Reid. Apparently, in his years of experience, he never ran across a set of 71 M-code heads.

View attachment 62836

4 no dot are D0AE heads, which are all closed chamber, or *extremely* early D1AE-GA closed chamber heads.

4 dot started at the beginning of the 71 model year with the D1AE-GA closed chamber heads, continued with the D1ZE 351CJ head, and was used to the end of 351C production in 1974 on the D3ZE open chamber heads. The *vast* majority of "4 dot" heads are open chamber, as they were in production for 3 years, plus a small amount made in 71.

While date codes are the best way to determine what a 4* head is when the intake is installed, t's still not a foolproof method. Ford made batches of service replacement closed chamber heads until at least 1974. The heads on my current 351C build are service Boss 351 heads made in 1973.

View attachment 62838

Very interesting reply Hemikiller. Especially the bit from the so-called expert with "years of experience".

 

[DAverkamp]

Very interesting reply Hemikiller. Especially the bit from the so-called expert with "years of experience".

I have that book as well and saw that as his false fact. I've seen the Clevo King from down under say one sized dot is always CC and the other size is OC, can't recall which was which but that is fake news as well.
I would still like to know more theories on the castings with #4 and #5 exhaust port (with or without) dots and are they all ID'd that way? After that I'm good with moving on!

 

[DAverkamp]

I have that book as well and saw that as his false fact. I've seen the Clevo King from down under say one sized dot is always CC and the other size is OC, can't recall which was which but that is fake news as well.
I would still like to know more theories on the castings with #4 and #5 exhaust port (with or without) dots and are they all ID'd that way? After that I'm good with moving on!

hemikiller and Don C seem to be at the subject matter expert level on here but I thought I saw a post some months ago where another guy on here got lucky and found out his girlfriend had worked in Fomoco engineering back with these babies were conceived and born?

 

[Stanglover]

I would still like to know more theories on the castings with #4 and #5 exhaust port (with or without) dots and are they all ID'd that way? After that I'm good with moving on!

Sorry, I can't help on that one. I don't remember seeing anything like that on my heads, not to say not there, I just never noticed. It would be interesting to find out.

 

[jpaz]

The heads have no specific side to be on. They are Not side specific!

 

[jpaz]

I have a 72 Q code original block and heads. Rebuilt the engine with 71 m code heads. Both have the 4 and a dot in each corner. They are marked like that so they can be installed on either side.

 

[DAverkamp]

I have a 72 Q code original block and heads. Rebuilt the engine with 71 m code heads. Both have the 4 and a dot in each corner. They are marked like that so they can be installed on either side.

Roger that, they are interchangeable and can be mounted as "bare" heads before setting up valve train, but my question is are all heads cast like mine? Zoom in and look at #4 & #5 exhaust ports on my CC #4 "small dot" heads. Are all 4V like this?
Yes, they could have been mounted with the # 5 (with dot) exhaust port on top of the #4 cylinder, and #4 (with dot) exhaust port over the #5 cylinder. My pulled out and stored original #'s matching 2V engine is the only other 351C engine I have touched so that is what I am asking about the lineage of our heads. If I saw them mounted the opposite way and observed the ports ID'd over the "wrong cylinders" I would raise an eyebrow. Or did I luck into a set of unicorn heads?

 

[71ProjectJunk]

I just looked at a bunch of 4 V heads that are for sale on eBay and it seems that those numbers over the exhaust go from at least 1 to 5 (saw 1,2,4 and5). I saw some 2V heads that had an 8 in there, so there may go that high. It seems, by the photos that I saw that there is no rhyme or reason for those numbers. Who knows what they stood for.

 

[Stanglover]

I just looked at a bunch of 4 V heads that are for sale on eBay and it seems that those numbers over the exhaust go from at least 1 to 5 (saw 1,2,4 and5). I saw some 2V heads that had an 8 in there, so there may go that high. It seems, by the photos that I saw that there is no rhyme or reason for those numbers. Who knows what they stood for.

Looking at the pics, I see what you mean. I don't think they are of any relevance to ID the heads, but to ID the patterns used in casting. I could be wrong of course, but that is the only thing that makes sense to me. As mentioned before, there would be many casting patterns in use and some sort of ID would be used for sure in case of a problem. If you ever took a look at something made of plastic, there are often numbers molded in that have no apparent relevance, but they are to the manufacturer. They indicate the core, cavity or the mold used especially when multiple molds are in use.
I wouldn't worry about those numbers too much.

 

[basstrix]

I have a variety of c heads....I'll take a look at this. Agree, this has nothing to do with L vs R. Mfg's try NOT to do L/R parts unless necessary. Part numbers cost money to manage, stock, maintain, design, etc...

 

[DAverkamp]

I just looked at a bunch of 4 V heads that are for sale on eBay and it seems that those numbers over the exhaust go from at least 1 to 5 (saw 1,2,4 and5). I saw some 2V heads that had an 8 in there, so there may go that high. It seems, by the photos that I saw that there is no rhyme or reason for those numbers. Who knows what they stood for.

I have a variety of c heads....I'll take a look at this. Agree, this has nothing to do with L vs R. Mfg's try NOT to do L/R parts unless necessary. Part numbers cost money to manage, stock, maintain, design, etc...

Cool cool. As I was asking way in the beginning of this thread, I pulled out my orginal H code 2V/FMX/2.75 open RE to store for the future value of her after I searched for and bought a 4V 4B short block to rebuild for 450 ponies max in the ragtop because... its a ragtop.

When I got it and disassembled to pre-clean, chase threads, etc. to save shop costs before I sent it to the builder, I took for granted the head exhaust port markings (# 4* over 4th hole and # 5* over the 5th hole) I did assume (we all should know that ref) that those ID castings were the norm because it made sense to me that those markings mated to the cylinder they were covering. When I got my engine back after dyno the L/R bank heads were mounted the same way I removed them so again, I thought that's all normal.

My curiosity has expanded as the countless variables of block/head coding differences from so many are being brought up here, and yes I understand it doesn't matter, however, there must be a reason somewhere... back in a microfiche file...

 

[71ProjectJunk]

Cool cool. As I was asking way in the beginning of this thread, I pulled out my orginal H code 2V/FMX/2.75 open RE to store for the future value of her after I searched for and bought a 4V 4B short block to rebuild for 450 ponies max in the ragtop because... its a ragtop.

When I got it and disassembled to pre-clean, chase threads, etc. to save shop costs before I sent it to the builder, I took for granted the head exhaust port markings (# 4* over 4th hole and # 5* over the 5th hole) I did assume (we all should know that ref) that those ID castings were the norm because it made sense to me that those markings mated to the cylinder they were covering. When I got my engine back after dyno the L/R bank heads were mounted the same way I removed them so again, I thought that's all normal.

My curiosity has expanded as the countless variables of block/head coding differences from so many are being brought up here, and yes I understand it doesn't matter, however, there must be a reason somewhere... back in a microfiche file...

I am sure that those numbers meant something at the casting foundry, but what if anything they had to do with the actual product that came out the other end is hard to say. Those numbers could be tied to what shift in the day they were made, or to what specific head casting station area they came from, or to the specific mold that was used, who knows. Unless we find someone that worked wherever they were casting these heads, we probably will never know. There are a lot of casting numbers like that on parts that today it is hard to tell what they meant. If I were to take a guess I would imagine that those numbers will separate the heads based on some specific casting station or time frame. I know the heads have a casting date code, so if they found a casting problem on a head first thing to do is to find the date and pull all those heads from that date, but those numbers could be a substation or something of the sort, so they would know that they need to pull all heads from this date on forward with a 4 on the exhaust port which meant the 4th casting station or something like that. That way they would not have to pull every head made on that date, just the ones cast on that specific mold... Just a wild guess.

 

[basstrix]

Those marking could be something as simple as how many times that particular batch of sand had been used. Pure speculation.

 

[Stanglover]

All of the above back to post #50.
They are not the numbers I would take much notice of if I were looking for or buying a set of heads. That said, it is a curiosity for sure.

 

[midlife]

To answer your question as to determining your engine, the answer is pretty clear to me: it's a V8!

Only took 56 replies to get to the right answer...

 

[DAverkamp]

To answer your question as to determining your engine, the answer is pretty clear to me: it's a V8!

Only took 56 replies to get to the right answer...

Rite? You must be in the "secret squirrel squad" madirishguy was referring to. I still like your work as my lady hasn't caught on fire from your wire.
Since there seems to be no meaning (to date on here) regarding exhaust port markings I will let my son know for the day after I croak and he puts her up for sale he may get more $ if he includes:
*RARE* #'s matching 4 & 5 cylinder exhaust port "unicorn" 4V CC (* doesn't matter 4 dot or not) heads,... to the rest of her description.

 

[tpj71mach]

Pardon my ignorance, (I have just came over to Mustang after restoring a few Camaro's and Chevelles) but are these heads open chamber or closed chamber?

 

[tpj71mach]

What is the better head to have for a Cleveland, the open chamber or closed chamber? The stamping number on my head is D1AE-GA and the dates codes are 0F17 and 0G24. My heads have the 4 on the corners but no dot on one side and doses have dot on the other side?



The engine and heads are still at the machine shop but these are pics I took as I was disassembling it.

 

[tpj71mach]

Also, as long as I am asking, the engine stamping number is D2AE-CA but I don't have the date code can you determine what engine this is? Thanks