Greetings,
I recently purchased some parts for my E-Type from a gentleman who threw in what I assume to be an XJ Series lll engine head. The code next to #6 spark plug port appears to be GZ72. Any clues as to what model would match this head based on the code and attached photos? It appears the head was removed and had #6 intake and exhaust valves replaced and never reinstalled. #6 valves are in new condition.
Thanks,
Kevin
Kevin, if the inlet valves are larger than the E’s it’s from the series three XJ cars. You can look up the diameters online. Obviously a 4.2 of course and no air injection holes I guess.
David
Thanks David,
Based on the intake / exhaust valve size (1 3/4 X 1 5/8) and that it has no air injection ports, I am concluding it must be from a 4.2 Series ll E-type or a 4.2 Series l or ll XJ6. Would there be any distinguishing features that would narrow it to one or the other?
Late S1 XJ heads had the injection ports, as did S2. I can’t think of a difference between early XJ and E 4.2 heads.
But only for the emissions engines. Rest of world heads such as my fuel injection 4.2 don’t have air injection, but if the head is from i.e. the states that narrows it down to the E type with some possibility.
I don’t know about the numbers but maybe you find something on the web or via xkedata.com saloondata.com or xj6data.com that helps. The Mark X might also have had such a head, and the Daimler limousine? But I‘m guessing and don’t know anything further. The 72 of course might be the year, all in all the head must be interchangeable in any case.
Edit; it is not. A series two 4.2 E Type head has GW694 stamped in so it is not a giveaway. But it has bolts in the casting holes where the sparking plugs are whereas at least my SIII head has simple frost plugs. You might find a few pictures on the web pages above to narrow it down, good luck.
Fact is from the waterways this head looks very nice!
David
At the back of the head there are 2 extra water ways , I think they was added on the XJ6 !
So would need work to fit some blocks with just 2 holes .
GZ72 is not a year, it is what we are calling (for lack of any better term) a head production sequence number. Each type of XK head had these numbers, initially in the middle and later at the back. They started with A1 through A999, then B1 through B999 and so on, eventually getting to Z and then two letters. For example my XK120 has the number E5, and I have an XK140 head with the number BC444. Not many people pay much attention to them. We are attempting to coordinate them with approximate production dates, but still need a lot of data.
Try posting your question on the XK-Engine forum.