BSA A65 Spitfire crankshaft centre web

[teebee67]

Hi,

I have a 1967 Spitfire and when stripping the engine found the crankshaft has a much slimmer centre web. All the cranks I have seen have had a centre web about 2" wide whereas mine is about half of this all the way round. Is this normal. I am sure I have seen a reference to "slim cranks" somewhere but can't remember where or when (old age).