F23A oem piston combinations

[jdm92_accorn]

with all of the following combinations the piston will need to be turned 180º in the hole and when using the 87mm tsx pistons you will need a custom head gasket like the ones from bisimoto. i also recommend using new pistons if possible. they can be bought with ring sets for usually under $400. used pistons tend to be shaped to the engine they came from which if is excessive can cause premature ring failure in the engine you install them in. i have found that oem pistons are more than capable of the 230-250whp range naturally aspirated and due to their expansion rate are much less noisy and tend hold compression longer. this is due to minimal piston slap when the engine is cold compared to forged pistons. this all in mind, forged pistons are much stronger and when planning a higher HP goal you need to weigh your options.

this is a bone stock F23A bottom and bone stock F series sohc vtec or non vtec head.


this is a bone stock F23A bottom and milled F series sohc vtec or non vtec head( .020").


this is a F23A bottom bored to 87mm with 04-08 K24A2 TSX pistons and bone stock F series sohc vtec or non vtec head.


this is a F23A bottom bored to 87mm with 04-08 K24A2 TSX pistons and milled (.020") F series sohc vtec or non vtec head.


this is a F23A bottom bored to 87mm with 09 K24Z3 TSX pistons and bone stock F series sohc vtec or non vtec head.



this is a F23A bottom bored to 87mm with 09 K24Z3 TSX pistons and milled (.020") F series sohc vtec or non vtec head.


this is a bone stock F23A bottom with 02-04 RSX pistons and bone stock F series sohc vtec or non vtec head.

[Jarrett]

Unless your F-series build does not involve pulling the engine then I really don't see a reason not use an F23A1/4 shortblock. You can usually get them at the junkyard for $150 or so and they have less miles than the average F22A/B block. Right off the bat you're half a point higher in compression and the potential to swap in different OEM pistons for higher compression is much easier with the 86mm bore. All this is assuming that the F23A block is in decent condition.

The increase in displacement and lowered torque curve are just nice added bonuses.

[dwhacks]

Where did you get your measurements from? I've been trying to re-create this using the same site and come up with way higher compression.

For instance, you have -6.5cc dome K24A2 TSX pistons, yet the calculator says, 0cc dome for that piston. With the k24a2 pistons using the numbers from that site it says 11.69:1.

I would like to try some k20a1 pistons in a f23a block (no need for over bore) but it says i'll be over 12:1.

[Jarrett]

It's a pretty good bet that if the calculator has 0cc for a piston, that they don't have any information on it at all.

[dwhacks]

Thats an interesting point I didnt think about.

With all these boring to 87mm options, what about h23a1 or h22 pistons? has anyone tried that? at least they wouldn't need to be rotated 180 degrees.

Preferably I would like a combination that didn't require a custom head gasket.