CVH Oil Grade

[baz-r]

top tip from an engine reconditioner was
anything with hyd lifters is to run as light an oil as possible as over thick oils effect the operation causing top end tapping, worn cams streched cam chains and oil pressure build up from cold where most ware is created.
always try to run the best oil grade for climate your in (its not hot enough for high grades in the uk). its realy importent to use the right grades of oil just by making it thicker does not mean it lubricates better it causes stress on some engine parts and is not able to form the correct film thickness

as the old cvh's where not great on crankcase ventalion either so a good quality oil should be used of around a 10-40w as long as its not already worn out.
if its worn and burning oil thicker stuff is not going to fix the problem just makes it build more deposits in the cyl etc. if you realy feel the need raise the later number as this is the "hot grade"
horrid old 20-50w is for old engine designs only! pre 80s

lighter oils are a must for zetecs of all ages 5-30w,10-30w as the clearences are loads tighter
exaust cats also need lower soot thiner oils