1HZ-T Question

My bad. Forgot to mention the car is an 80 series with the 1HZ

Chop, probably a tad late to ask the question if it has just been fired up..............

G'day Chop
I understand there is two sizes of inserts for the head, a 42mm and a 44mm. I presume the head fitted with the 42mm insert is for turbo. It still has a swirl chamber but it would be smaller than the flatter top piston uses for natural aspiration 1HZ. Since you mentioned quite high boost, it would seem to be to compensate for a lower than designed compression ratio. For example, a direct inj engine uses less comp ratio but that is varied by boost level / throttle using the turbo to create more air in each charge and results in higher comp than static. The figure of boost you gave seems higher than a 16:1 CRD diesel or infact higher than the 7to8 Psi of a 12ht direct inj engine. Perhaps ensure you can begin low with boost and only use what you require so no excessive cylinder pressures or temps are created. The boost compensator simply holds/slows the pump rack from opening so fuel injection amount doesn't go above what can be burnt at that moment of acceleration.
Cheers