Or spend the $100 bucks and use the right oil. When people take short cuts, things tend to blow -up. And that will cost you, a fk load more. Im sure trannies diffs and engines use different oil for a reason. Your building a SC engine, your going to use more petrol, wear out ya tyres and clutch prob quicker. If money is so tight dont SC it and you'll save on wear and tear and of coarse petrol.... toyota SC12 from memory used 180cc and AMR500 was around 130cc. prob better to ring up for exact specs.