Look up the ACL catalogue for more piston info and sizes
you can use l18 crank 85mm (1mm oversize) ca20e piston
with your L13 conrods for 1.895 RSR and high comp.
I think you have to mill the Ca pistons .5mm

Thanks for the combo calculator...some of the combo's to consider

1.L13 block rebore to 85mm / L18 crank / L18 rod / L18 piston
2.L13 block rebore to 86mm / L18 crank / L18 rod / L28(late) piston
3.L13 block rebore to 85mm / L18 crank / L14 rod / Z20E piston

and the results....

1.Displacement=1.770 RSR=1.669 Deck=0.55mm (piston= -4.3cc)
2.Displacement=1.812 RSR=1.669 Deck=0.55mm (would give better compression ratio due to 0cc dish)
3.Displacement=1.770 RSR=1.751 Deck=0.50mm (piston= -13cc)

The combo with L14 rods and Z20E pistons might give the perfect RSR, but we'll be loosing some compression here due to -13cc pistons.I would go for combo 2 due to higher compression and larger displacement. Any other suggestions?

**appreciate all your help for this....

It nothing complicated at all
L18 crank,
Bolt on L14 rods
stock Z20E pistons (85mm)
easy 2mm overbore

Better RSRatio, lighter pistons in one go even L20b has better RSR than L18!
Malaysia Nissan or wreckers should have the L14 rods available?.

L18 deck is -0.550 mm this one can be let alone at -.500mm

I would keep the L13 rods and use 85mm 29.1mm comp height
ca20 pistons for 1.8 rod stroke ratio and even smoother rpm.
If you are not using the L13 rods Ill be happy to swap for
some L18 rods instead.

In 93 loved my 180b SSS coupes & 1 powered by a fresh high comp L18 was noticeably better than my stock low Km 1. However did a HG coming back from Warnambool & kept overheating stopping refilling all the way for 200+ kms. I had put in an L20b w/ same induction another SSS head I had rebuilt headers etc & wow!
While I had the L18 rebuilt I was wet behind the ears & Gordon Dobey suggested I use L18 crank w/ L14 rods, Z20e pistons etc. The L18SSS head was checked rebuilt & I loved that L18 combo, flogged it without dramas for years. I had no idea "1.75" was the sweet ketchup for street engines.

+1 why do all that?

If you use the L18 crank and L18 pistons, you'll have the 1.8 liters. It's just a 2mm overbore (fairly large overbore) compared to the L13.

The stock L18 has a reputation as a "revver" so you don't necessarily need lighter pistons. She'll do 6,000 RPM all day with stock L18 pistons.

Why not just l18 crank rods and pistons if blocks same height?

Or l18 crank rods and l16 or 240k pistons?
Or just l16 crank rods and pistons?

Why all the mix and match.

Try this calc for better combos
http://www.ozdat.com/ozdatonline/enginedesign/

Pls dont use L series pistons they are heavy and too tall
for fast and high revving like modern engines use now.
You best get the L18 crank, L14 rods and use z20e pistons
and you have .5mm left over from deck height providing your
block has never been decked or for a better seating surface
you decide to deck it you will be close to 0.
Rod stroke ratio will be 1.751 or in Auto terms "the perfect ratio"

**went thru the previous threads, but was unable to find the info i require, so need some advice from you guys...

Well, i plan to rebuild my L13 to 1.8L. Yea, i know the best option is to do a L18 swap, but i plan to stick with my L13 block since its the same as L18 (wanted to avoid issues with the authority since we have a strict engine cc upgrade ruling here).

I've checked on several sites and managed to get these info's

Connecting rods
Center to center length, all use the same 21mm diameter piston wristpin.
L18, L28, L26--------------130.2mm
L16, L24---------------------133.0mm
L13----------------------------139.9mm

Pistons
Piston pin heights (center of pin to top of piston) / piston dish volume/ stock bore
L13, L24-------------38.1mm / 0.0cc dish / 83mm bore
L16, L26------------ 38.1mm / 7.01cc dish / 83mm bore
L18------------------- 38.1mm / 4.36cc dish / 85mm bore
L20B------------------38.1mm / 11.36cc dish / 85mm bore
L28 (early)---------- 38.1mm /10.90cc dish in 280Z, early ZX.('75-'80)/ 86mm bore
L28 (late)------------ 38.1mm /0.0cc Flatop in '81-'83 ZX / 86mm bore


So, my question would be - If i rebore my L13 block to 86mm to accept L28 pistons, and if i use L18 rods, and of course with L18 crank, would i be getting a 1.8L engine? Is there anything that i've overlooked or missed out?
Many thanks