[Mgs] Temp sender

[Barney Gaylord]

At 12:59 PM 11/17/2008 -0800, Max Heim wrote:
>Well, I just went out to take a look at it again, and there is no 
>sign of a water choke block-off (and no air injector holes for that 
>matter), so we are looking at an early style head.

Not necessarily early.  Later European spec heads and some later 
replacement heads had no air injection ports.  Sometimes the ports 
were not drilled even though the casting was configured for air 
injection.  Ditto for the late model heads with a water port on top at back.

>....
>.... markings on top surface of the head are (from rear):
>
>PAT NO
>585384
>(cast)
>
>16N9 (maybe "H")
>5 (very large)
>(cast)
>
>12H4736
>(stamped; the 6 is very out of alignment)
>....

This casting looks like a 1975-1980 Euro spec or replacement 
head.  It should have the casting bosses for air enjection and top 
water port, but the holes may not be drilled.

Engine year/   OEM Part/   Features
Engine type   Casting no.
75-80 North American spec
18V797/18V798   BHM1062/  Air injection ports
18V801/18V802   CAM1106   Single valve springs
18V883/18V884             43cc chamber volume
                           1.5625" inlet, 1.343" exh.
                           Type "B" valve hardware
                           Single valve springs
                           Water port, top at rear
                           Rear pedestal oil hole offset

75-80 Replacement  ---/
                  12H4736  Similar to CAM1106 except:
                           Air injection ports (usually drilled).
                           Dual valve springs in most cases.
                           Patent number relocated inside.
                           Water choke outlet hole drilled or not.
                           43cc chamber volume
                           1.5625" inlet, 1.343" exh.
                           Type "B" valve hardware
                           "18" on top at back

Barney Gaylord
1958 MGA with an attitudehttp://MGAguru.com