Out of interest, how do you think the quality of oil today compares to that from 50 years ago when these engines were first cobbled together?
Quality / viscosity. Different things
Personally I do not think that the 1850/Sprint engine was 'cobbled together', I think that they were very well engineered by some very talented people. I would suggest that if you need to use a high viscosity oil to maintain pressure that you should be looking to rebuild your engine rather than mask the problem.
Yes, exactly that, cobbled together. Wasn't this the very reason the car was never called the 135 because they couldn't manage to build engines to a consistent standard?: and just like when I removed the cills, one side had red lead inside, the other was bare metal.
My engine was built by Trackerjack and has done 2000 miles, I'll let him know you're calling his abilities into question!
And btw, the engineering and design of the engine isn't being brought into question, the building, manufacture and supply of the parts is.
Triumph was run by accountants not normal people...er.... I mean Engineers.