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MG MGA - Cylinder head

I have a cylinder head which was removed from a B. BUT it's not a B head.
The marking are the usual Patent number on the front, 565394. No date mark I can see, a 1 with A7 K7 underneath and 12H but the number has been ground off!! Some underhand dealing there I suspect!!! Inlets are 1.57 but there was pronounced "beak" between the valves. No 15,16 or 18 at the back of the head. Peter Burgess though maybe a Morris head. Any way, it is now stage 2, but would be nice to know from whence it came if anyone can tell without the 12H number!!
Allan Reeling

Missed this one, there is also a cast in number 155 under the thermostat housing.
Allan Reeling

Hi Allan, strange that someone would grind off the 12H number. It might now be difficult to identify your head. Have you tried these sites?

R A Evans

Sharp point on the Weslake promontory implies that it is a "15" or "16" head from MGA (or similar vintage engine of other application). I believe the "16" head was exclusive to MGA 1600-MK-II (1622cc) engine. The "15" head was very common, used on lots of other engine applications, including the 1622cc engine in applications other than MGA. A lot of the "15" type heads were blank, being "generic" heads with no number at that location. The valves and porting could vary considerably for different applications, so you don't know what you have until you measure everything.

A cut back blunt point on the Weslake promontory implies later production, as in the MGB. There is also a difference in chamber volume, 38cc for the "15" head, or 43cc for the "16" and "18" head.

The "L" head used on 1972-1974 MGB (and maybe later European MGB) had a larger intake valve and smaller chamber for higher compression ratio (about 38cc I think). This was accomplished by reducing thickness of the head, similar to shaving the bottom side of the "18" head. Most heads are originally 3.187 inches thick. The "L" head is thinner, about 3.140" I think. Any other head being thinner then 3.187" implies that it has been shaved in a past life.
Barney Gaylord

Thanks Barney excellent info. Looks like 1500 which was my suspicion, thanks again.
Allan Reeling

This thread was discussed between 06/12/2012 and 10/12/2012

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