Oil grade? 1300 Marina unleaded rebuilt

[audi90]

What grade of oil is best fir a rebuilt 1300 Marina engine with an unleaded head???
I have just changed oil and put in 15/40 part synthetic

[GreenGiant57]

Hi. My 1275 Marina engine has done about 57,000 miles on Halfords 15W50 mineral oil and then latterly their 20W50 Classic mineral oil with out any problems (so far!!).

[bmcecosse]

20W 50 is the oil to use. Nothing fancy required for these engines. While the semi 15W40 would be ok in winter - it's a bit on the thin side for summer use......and far too expensive for a Marina engine!