Cleaned my 4.6 RV8 heads in thinners, then petrol, took off casting marks and cleaned up the ports with carbide burrs, soda blasted them, ground the valves in, washed in petrol again, then in the bath with industrial degreaser and very hot water and jet spray shower head, when dry I spotted a bit of crap down one hole, went at all the tapped holes with cotton buds and thinners here is the result ! that's over a 100 cotton buds in the pic and they are still not clean! I had already run a tap down all the holes before I started, with the cotton buds the worst was the rocker bolt holes, full of oil.
