I feel kind of dumb asking another question so soon. Im in the process of building a big bore 2.3L.
Big Bore 2.3L
KA24 pistons into a bored Z20/Z22/L20B block. The small 2.8cc dish area of the KA24 pistons helps to preserve compression ratio even with the low piston deck height. Compression ratio with a open chambered U67 head is 9.9:1 or use dished Z24 pistons and peanut chambered head for 8.9:1 compression ratio.
Parts: Z22 crank, KA24 pistons, Z22S/ L20B rods in a +2mm bored Z22 block or +4mm Z20/L20B block.
s/2+r+p= 92/2+145.9+34.0= 225.9 mm
piston deck height: -1.55mm below deck
Here is are my questions. with the KA24 piston I believe a KA24E piston was used for the math. in the 240sx world if you want to bump up the compression of your ka24de you put ka24e pistons. when you look at ka24 aftermarket forged pistons they will have 2 cr listed. ka24de 9:1 ka24e 8:1.
I purchased a z22s engine so I can use the block crank and rods. I want to use this with my A87 peanut head (currently on my l18).
so my math puts using a ka24de piston 9:1cr 22cc dish gives a 8:1cr. with a ka24de 10.5cr piston with a 9cc dish giving a 9.3cr.
These numbers are based on a z24 headgasket assuming its 1.5mm compressed. I dont know if this is right ill probably end up buying the nismo L series big bore headgasket.
1. If anyone can confirm what ka24 piston was used
2. what the compressed z24 headgasket measures at (im looking at the apex headgaset on rockauto, it states that it is mls I dont know if thats correct)
3. if my math checks out.
I dont want to end up ordering the wrong pistons and end up with a compression ratio that is "unusable"
Thank you in advance