I know its been done 9million times...

But

I was wondering what oil I should use, its pretty tappety, I reckon need to change cam n tappets (got spare new cam an tappets jus need to change em) but what oil should I use meanwhile, I think the oil ive got in it is too thin once it warms up, cant remember what viscocity but its fully synth castrol stuff iirc

I was told 15-50 mobil 1? dont need anything too fancy tho.