[2.2 Straight six]

At work we use Petrol (gasoline) and diesel as degreasers. sit the parts in a tub of petrol and leave them for a couple days. cuts thorugh it pretty well.

petrol and a scrubbing brush is very effective. you'll want an inhalator thingy. the fumes smell nice at first, but screw with your head after a while. and get some washing up gloves. petroleum products are carcinogenic. (cancer-causing)