Hipo heads irregularity

[Boxerville's Manor]

Can someone tell me why some hipo heads had "4V" casted near the spark plug hole and other hipo heads didn't? 

[J_Speegle]

Did you look and can you share the casting dates?

[Boxerville's Manor]

5K2 date. 

[6s1640]

It is likely just a production variation.  A survey could establish the transition date code.  I'll start.

Casting Date    "4V" present?
5K2                  Yes
5K4                  Yes
6B23                Yes
6B28                Yes

I have two HiPo 289 service heads dated 1973.  I will check them as well and add to survey.

Cory

[98SVT - was 06GT]

They used several patterns at a time when making up the molds - some may not have had the 4V on them. In addition to the part and date/shift codes you'll probably find some wayward digits that don't have any explanation except to the original casters who when they found some bad castings they could could be used to trace them back to the pattern.
Took a tour of the Cleveland casting plant when I was 14. My uncle was a Ford VP and ran the place. Decided on the spot Foundry work wasn't for me.
Pretty much the same way it was done in the 1960s.
https://youtu.be/DXwAnazjphQ?t=320
Same idea but 30 years of improvement in casting tech
https://www.youtube.com/watch?v=ziVhj2oifl0

[s2ms]

Hi Cory, another one for your survey...

Casting Date    "4V" present?
6A31                  Yes

[6s1640]

Found the service heads date 3M20 for December 20, 1973.  I believe these are last produced HiPo 289 heads.  These also have the "HP" cast inside, under valve cover.

I also found some earlier heads (4L16 and 5H20) on auction No. 267573597761

Plus two more service heads (8K20) on FB

Casting Date  "4V" Present
3M20              No
4L16              No
5H20              Yes
8K20              No

I have a pair of June 1968 HiPo service heads, but they are on a car am I am unable to see if the "4V" is there or not.  Maybe I'll try some mirrors.

Cory

[Bob Gaines]

I am curious if those 73 and 68 HIPO heads have the plugged thermactor ports ?

[pbf777]

    Some more:

    "5L4" (pr.) yes "4V" 

    "3D18" & "3D24" no "4V"

    And as to Bobs' inquiry, the latter 'do not' have casting provisions for the passage or the plug/bunghole machining. 

    Scott.

   

[6s1640]

I am curious if those 73 and 68 HIPO heads have the plugged thermactor ports ?

Hi Bob, the 73 heads appeared to have a provision that are not drilled out as far as I can tell.  There appears to be a fastener in position, but it looks cast in. I've attached an image. On the 68 heads these features are absent.
Cory

[Bob Gaines]

Very interesting . I had thought that after later 67 all of the service HIPO heads had the thermactor ports . Your 68 heads seem to disprove that theory.Thanks.

[6s1640]

Starting to see a pattern.  Still more data needed.

[JD]

Cory's image lightened only to make it easier to see the "fastener in position" areas he circled - it really screws up the rest of the color of the shot but helps to se in the circled areas. - I can delete if he doesn't want it here.

[TA Coupe]

Not the best picture, but if you zoom in on the lower left, you can see that my 68 hipo heads do not have the smog port either.

    Roy

[S412gofast]

6M22 with thermactor ports
No 4V.
These may be service heads.
Is there a way to tell if they are?