It doesn't irritate me - I've got shares in Castrol, but it does amuse me a little

Back to the subject;

Unless you're running leaded race fuel (or Avgas) A747 is the wrong oil, X77 is Castrol's top 2t race oil for unleaded fuel.

And both are castor based and have a higher shear strength than synthetic oil but they (and A747 especially) are a pain to mix, don't like being kept in the cold, don't store well, are expensive and will gum your rings up.
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Please do not PM me technical questions, if you can't find it on the Forum start a thread