Hi,
One does not usually turbo a 2H, especially the early models. The later models have a oil pickup for a turbo but no return as a 12Ht has, the early models do not have this pickup at all.
I bought a late model, with a turbo already fitted, so no worries there
Rule of thumb is you do not turbo an early high milege 2H, they overheat, crack heads and damage pistons.
As you know I have been looking for a head, you send me the Ebay link, but freight was not feasable
2H compression is 20.5, a 12Ht compression ia around 18.7.
The 12Ht is designed for a turbo, the 12HT has a different crankcase, conrods, pistons and head. A 2H is sleeved where the 12HT is not, the 12Ht has oil-squirting the 2H is not.
Actually the crankcase is the same, the 12HYT has a stiffening plate though. Newer piston designs eliminates the need for oil-jets.
I would not turbo my 2H, if I did I would buy a second 2H, get a full reco kit $900 ( sleeves, pistons, bearings, gaskets etc) a 2H motor you can buy for $2,200, a turbo kit is around $1850 = nearly $5,000 and that's not including labour.
You can buy a 12Ht for $5,400.
It is impossible to find a good 12HT here, they all need a lot of work, work that has already been done on my 2H
It's not worth turboing a 2H unless you do it correctly and in that case you may as well buy a 12HT. The 2h motors finished production in 1989, whereas the 12HT were still produced in the very early 1990's
It will be done the right way, I have a Garrett turbo that will go on ebay, and I plan to use a variable turbo to get optimum boost in the entire rev-range
I plan I buying a 12Ht and a reco kit for it and keeping it in storage until my 2H reco motor dies. The problem is the resto I have done will probably last another 30 years in which case I will be dead before I get to use it.
If I could undo buying the 2H I would, but now I will stick with it and see how well I can get it to perform.
The 12Ht is a nice motor, 135HP good for 500.000klm plus, if I was out on a trail I would prefer a 12HT to a turbo'd 2H, proven motor, reliable and tuff.
Anyway that's my $0.02