Thanks for the help on this one gentlemen.
I've just taken the timing side covers off and I think that the engine has had an SRM conversion. It appears to have a needle main bearing and the oil supply to the crank appears to come from the pump through a tube in the inner timing side casing (with small o rings either side of the casing) to the outer and then up to an oil seal which sits in the outer and feeds oil into a tube in the end of the crank shaft. If this isn't an SRM conversion, perhaps someone can tell me, I've never seen one? If it has been done on this engine it would have been about 9 years ago (2 owners back from me) and I don't know if the SRM have altered the design of their conversion since then.
However, JOHN, I can't see where ..'the pipe is pressed in and welded over'. Can you give me more idea of where this is please? Is this the small tube which I mentioned above which goes through the inner casing?
It does seem that, for those of us with a rev counter drive taken from the oil pump which blocks off access to the nice convenient flat face at the side of the pressure relief valve area (as used by lucky Muskrat), we could either come in at 6 o'clock under the PRV, (like Nigel) or into the casing flange just below the PRV breaking into the oil hole feeding up to the PRV from the pump. I'll check on casing thickesses to decide on the optimum approach.
Alan.