You are correct on both accounts,
I have never adjusted the clearances (or checked them for that matter, 1 follower has always had a slight "tick to it), I lose motivation with shim under bucket, even though I know it's not hard - it's just annoying/painful haha.
And, as you mentioned, it can make a big difference to performance if the are out by a fair degree.
To be completely honest, the reason I haven't bothered, is the performance has been so good so far, I feel it hasn't warranted it (and a % of can't be bothered). On the flat I can wind it out so that it reaches the governor in 5 gear, with a slight/moderate downgrade it reaches the governor pretty damned quick to be honest, so much so that, overtaking trucks, particularly B-Doubles and triples is no longer a white knuckle, arse clenching "will we make it experience" . But, pure fun and exhilaration (relative for a 79 cruiser ute).
A couple of other features that I didn't mention, I fitted an inline spin-on oil filter (cheap and simple) as catch can between the PCB outlet and inlet side of the compressor, to filter out the increased oil mist generated due to the higher negative pressure created by the turbo, and to act as a sort of, restrictor in the line. Even after 30k, I can spin the filter off and turn it upside down and no oil runs out. However, it is is black and oily when you look in it, so just how well it is working could be up for speculation ????
Sitting @100k/hr on the open road, boost sits between 6 - 8 psi. It runs extremely clean with almost zero smoke, so I have found that the oil in noticeably cleaner at oil change intervals, which would correspond to the increased/cleaner combustion (for a simple old school mechanical injected diesel).
1 thing I do hear people ask a lot is, where can they find a 1HDT block and crank, to my knowledge the 1HZ and 1HDT block and crank are identical (from all the cross referencing part numbers and checking casting numbers and dimensions I have done), the only difference being the heavier rods for the 1HDT and that the 1HDT block is drilled and tapped to accept the oil drain back from the factory, where as the 1HZ block has the casting there in the block. However, it is just not drilled and tapped, the heads and injector pump are different although they share the same stud/bolt pattern and coolant/oil galleries (someone correct me if I am wrong).
I would say that it is also very possible and viable to drill and tap it rather than removing the sump the way most do (me included) when installing a aftermarket turbo on a 1HZ, having said that, it is in a pretty tight area though, when the engine is in situ?
Thanks for your comment.
