[Habelter]

like it says what break in oil https://mechanicguides.com/best-oil-additive/ or just use zink additive?

also what do yall use during engine assembly?

i used to use stp oil treatment on everything and then just dump in some good ol castrol 20/50 and fire it up, but i havent built any "new-fresh" engines (about 7 years) since they really started screwing with the petrol products

[JimDirt]

Welcome to the site !!

Oil is going to get you different answers , as people have different experiences and preferences as how to properly break -in a engine , I personally use a non Synthetic motorcycle specific oil for break in that fully meets the manufacturers specs , then switch to Full Synthetic usually after 2 oil changes , that gives the rings enough time to seat , and I do not use any additives as they are usually to reduce friction , and friction is what seals the rings , so I would not recommend anything that would slicken up anything , if you choose to use it after the rings have seated , that is fine , but during break in , I would stay away from any friction modifiers as they have a tendency to varnish the rings , and you will have issues getting them to seal properly , basically , when you note that it is not using oil , because after a change the level has not dropped , then you go do a ride or so and the level stays the same , then it usually means the rings have seated and you switch to whatever oil you prefer for the long term and whatever additives suit you .... , for weight I would use a 0-40 or 10-40 for break-in, I use 10-40 Full Synthetic after break-in ...................