Block castings

[Morris R.]

Would anyone know what these markings stand for on a 66 corvette 327/350hp block casting number 3858174

they are H4
852
174
that's how they are layed out on the block i hope someone knows what they are i can't find it anywhere. Thank you

p,s, Happy Mother's Day for all your mother's out there.

[David L.]

Re: Block castings

Morris,

This is my educated guess at what these castings mean.

"H4" might mean August 1964
I believe that the 3858174 block was first introduced in August 1964 as Colvin's 1965-69 "Chevrolet by the Numbers" book (pg. 61) makes this statement about the 3858174 block: "Chevrolet documentation shows this block being used as early as the 1964 model years in 300+ horsepower applications and commercial trucks". However, I have only seen theses blocks on 1966 models.

"852" probably is short for casting # "3849852", a 283 block used in 1964 and 1965 Chevrolet Pass. and Chevelle models. My engine block notes indicate an "early" 1964 Chev. 283 "Flint" engine in a junk yard in Lancaster, MA ("3849852", "K193", "F1123D"). There may be similar casting mold parts used on "852" and "174" blocks.

"174" probably is short for casting # "3858174".

When I get a chance I will check out my "3858180" block (1966 Chev. Pass. 327) and my "3970014" block (1970 Camaro SS350). I did have a "3858175" Corvette block ("J125", "6103443", "F1013HE") but sold it a few years ago. I had purchased the block from someone that lived in Latrobe, Pennsylvania, back in October 1980 and I sold to a person that lives in Pennsylvania.

Dave

[Kenneth B.]

Re: Block castings

Where on the block are the #'S?

[John H.]

Re: Block castings

Would anyone know what these markings stand for on a 66 corvette 327/350hp block casting number 3858174

they are H4
852
174
that's how they are layed out on the block i hope someone knows what they are i can't find it anywhere. Thank you

Morris -

Those are foundry core pattern numbers - that particular pattern was common to both the 852 and 174 blocks at the time. Photo below shows the refractory sand cores produced from the patterns; the cores were destroyed after the block was poured and subsequently hit the "shake-out" table to get rid of all the interior sand from the cores, and exterior sand from the cope (top half of the mold) and drag (bottom half of the mold).


BlockCores (2).jpg

[Wayne M.]

Re: Block castings

Would anyone know what these markings stand for on a 66 corvette 327/350hp block casting number 3858174

they are H4
852
174 ......

Morris --- Are they by any chance like this; ie. under the timing cover ? This is from a July '65 cast "174" block.

[David L.]

Re: Block castings

The "721" must be short for casting "3790721", According to Colvin's book the 3790721 block (327 c.i.) was used in 1965 and early 1966 Chevy II models.

Wayne,

Could the "G26" represent July 26? What is the casting date on your July 1965 "174" block?

Dave

[Wayne M.]

Re: Block castings

.... Could the "G26" represent July 26? What is the casting date on your July 1965 "174" block? ...

Dave, the block cast date is G_23_5; pad (engine) assy date F0726 ...

[Kenneth B.]

Re: Block castings

Morris -

Those are foundry core pattern numbers - that particular pattern was common to both the 852 and 174 blocks at the time. Photo below shows the refractory sand cores produced from the patterns; the cores were destroyed after the block was poured and subsequently hit the "shake-out" table to get rid of all the interior sand from the cores, and exterior sand from the cope (top half of the mold) and drag (bottom half of the mold).


[ATTACH=CONFIG]39623[/ATTACH]

You are right John. That is why I ask him where the #'s were. Most of the casting was made from the core assembly & very little from the green sand mold so a lot of the cores would work for more than one block,

[David L.]

Re: Block castings

Dave, the block cast date is G_23_5; pad (engine) assy date F0726 ...

I guess the "G26" is not a date code of any kind.