Which oil for a FOrd Crate 351 / 385HP

[Ant]

I think there is too much accent on this forum towards thin oil, I ran 500,000k in a 1300cc Mazda with Castrol 15w 40 (no engine primer) and have since sold it and its still going.

If you are living in below zero conditions which we do in winter, with Ford 351 I would consider a 10w 40 semi synthetic and throw some ZDDP in if flat tappet camshaft, or run a race designed oil like Joe Gibbs XP7 10w-40 and change it out before 3000miles, don't do short run driving. Joe Gibbs oil would definitely be available in the UK, as it is here in NZ.

With cars that may not be used for weeks/months at a time I wouldn't use a full synthetic, unless needed for racing and started regularly. Some car museums don't store cars for longer periods with full synthetic oil, as apparently it runs off parts like pistons, camshafts and you end up with a dry start.

I will be running an oil like J Gibbs semi synthetic 20w50 and turning on oil tank heaters prior to start up, my engine builder recommended this as my engine is more of a race engine with larger clearances, and this oil would stand up better in a hot race situation that the engine was designed for.