New problem to solve: UK annual MOT emissions testing.
The fact that my van is a personal import into the UK (with no identical UK model) means that it should be somewhat easier to pass the annual emissions test, but it will still have to pass one. The way they do it here appears to be that the vehicle needs to meet the emissions limits applicable to the chassis (2013), rather than to the engine (2001-2006 for 3UZFE), and if there was not a UK-spec model of the vehicle, the "Basic Emissions Test" applies, which has CO limits of 0.3 at idle and 0.2 at fast idle, and an HC limit of 200ppm. I'm not sure if a catalytic converter is required even if the test can be passed without it.
Looking at the emissions table for all Lexus V8 engines sold in the UK I see that most of the 3UZ engines, were certified to meet CO limits of 0.5 and 0.3 (HC is the same). Only the later GS430 3UZs (i.e., the 6-speed auto trans versions) seem to have been certified at the lower limits--but not those used in the LS430 or the SC430, either 5-speed or 6-speed. Most of the engines I see here are from LS430s, and I think I also need the rear sump from an [EDIT: non-SC430], so this is not good news.
It may be that all of the 3UZ engines will actually meet the BET emissions limits, but I don't have any proof--and waiting until my van's first MOT would be a very bad time to find out that it didn't...
More recent engines have lower emissions, of course, but I've never heard of anyone using a 1UR-FSE engine in an H200 Hiace, which would put me much more on my own than I already am with the 3UZ conversion, and they are still very expensive second-hand.
Right now, I think I'm going to have to somehow find one of those late GS430 engines with a 6-speed trans, and then find an [EDIT: non-SC430] rear sump or buy an aftermarket one. Are there any better solutions?
Cheers,
JZH
[EDITED: SC430s have front sumps.]