Well I have decided against an RB30DET at this time in my life, I have a girlfriend of 5 years to marry sometime (still time to back out, I haven't proposed yet!!) and an extension to the house to do, the list goes on! Sigh!
I did some maths on the parts I have and came up with this engine combo:
F54 block
LD28 crank
L24 rods
N42 head
GTR +1.00 pistons (87.00mm) (30.3 pin height)
1mm head gasket to suit overbore (used 89mm bore for calcs)
Swept cyl. capacity = (8.7^2*Pi/4*8.3) = 493.4cc
Piston to deck = 207.87-83/2-133-30.3 = 3.07mm below deck
Available compression capacity = swept capacity + 44.6cc (head) + 6.5 (HG) - 16.3 (piston dome) = 528.2cc
Compressed capacity = 44.6 + 6.5 + 18.25 (piston to deck capacity) -16.3 = 53.05cc
Gives a C/R = 528.2/53.05 = 9.9566:1 basically a bee's dick from 10:1
Dome protrusion above deck = 207.87-83/2-133-30.3-3.48 = 0.41mm above deck which *should* provide enough clearance for valve train components.
This would keep the capacity under 3000cc to keep the car in the same category and other L series zeds at sprints. I think with a matched cam and head work to allow peak breathability, it would be quite a rocket engine. Anyone have any thoughts?