Some kind of forklift had these engines and just
to look at they seem tiny even to a J series
but maybe similar in weight minus a cylinder?.
SD16 stroke is 99.8mm and all use 83mm bores yet
full wet sleeve design and here in turbo!!!!
for the sd15et which is interesting and unusual.
https://secure.smsdiesel.ie/en/industr ... es-engines-83mm-bore-size

You would need a 3.45 ratio and even lover to
use these little gems but would be a unique setup.
https://secure.smsdiesel.ie/en/industr ... es-engines-83mm-bore-size

crankshaft is fully counterweight as well and maybe better
to use the sd15t engine for a bit more rpm & high boost

here is some kind of catalogue
http://www.cnrefone.com/catalog_list.asp?engine=SD15T(1.5)

video!!! of NA sd15
https://www.youtube.com/watch?v=gg-tnIRuzyM