My workshop manual, Sunbeam 260, issue 1964, lists, in the General Data section, the valve head sizes as 1.59 inlet and 1.39 exh. Stem dia is 0.3097 to 0.31. On checking my engine (1964 casting), which I think is original, the valves measure approx 1.68 and 1.45, and 0.344 respectively.
In my Ford Engine rebuild book by Geroge Reid, the head data section shows two sizes of valves for the 260 engine, only those of 62/63 years having small valves as per my WS Manual, but changing to 1.67/1.45 for 1964. Surely all 260 Tigers had the larger valves?
I wonder if any Mk1 Tigers had early spec engines with smaller valves?
Has anyone got a later issue WSM showing updated sizes? Also is the valve stem size in my WSM a mistake?
Is there a list anywhere of any corrections to the WS Manuals which Tiger owners would be well advised to know about?
Yes, indeed the stock Tigers had the smaller valves. However, the cars were homologated with the larger valve sizes for competition which resulted in the disqualification of first place overall finisher Peter Harper in the 1965 Alpine Rally when it was discovered during scrutineering that his engine was fitted with the smaller, stock valves. Pure irony.
I have the same manual as you have with the smaller valve sizes, but I would assume there would have been a Rootes amendment somewhere. Not sure either if there was an amended manual either (I might ask around at the club). It’s a good pick up because if you wanted to order a new set purely from the manual you would have a set of valves that are useless.