thanks for letting me join your group
i have a 1999 range rover p38 and I'm in the proses of rebuilding the 4.6 lump that was in it as head gasket went on it so stiped down and was venting exhaust gases into atmosphere as the head was off fined out it has a top hat liner engine. so the big job had started so thought as I'm in there I would swop out the 4.6 pistons for the 4.0 and swap the camshaft for a Kent camshaft H180
in doing the swap with the pistons I find out that the 4.0l pistons are 20grams les than the 4.6l so less mass to move witch should be better for the mass of the bottom end. so I started to clean the ports to give good air flow thru the engine (wished I hadn't started) but work on them so I can feel the benefit later so no pain no gain.
I have spent a lot of time cleaning the engine as it had a fair bit of oil all over it it was looked after very well by the first owner but the next two did it no favours as it must of had head gasket done but must have been done by a monkey as head boults were so tight had to use breaker bar and an extension bar all in all a bar three feet long bar on some boults and some were lose they had managed to brake some of the rockers as not given the right gap settings so its been a bit of a challenge to make it right but so far the bottom end is back together and sorting the heads out