XiOus271

ok, im running an F23a5 cause thats all we could afford when we bought my accord, but i am wondering... what gives the F23a1/4 extra hp and torque? im sure after reading through my manual that its the compression ratios and maybe some other things, since i think my a5 is 8.6 or 8:1 or around there while the a1 is 9.3:1. does anyone know what honda did to achieve this and if it would be possible for me to raise my f23a5 to that ratio? i know its kinda stupid, but id rather ask and maybe learn something. thanks in advance.

philadd

The f23a5 is the non-VTEC motor, rated at 135hp. The f23a1/4 is essentially the same motor, but with VTEC, and rated at 150hp. The f23a5 uses pistons with a slightly different dish shape (-18cc's vs -13.x cc's on f23a1/4). This will cause the difference in compression ratio (although I don't know the compression ratio of the f23a5).

Changing out the pistons would give you the about the same compression as the f23a1/4, but let's think about this for a moment. You'd still be missing VTEC, which is causes most of the power difference. For now, let's put the VTEC issue aside and talk about just the pistons. With all that money/effort spent, you'll have a slight bump in power, but then you'd need to worry about about if your ecu can handle the change. After all, it wasn't programmed for 9.3:1 compression...

notoriousB

f23a1 = 9.3:1 compression - vtec
f23a5 = 8.8:1 compression - no vtec

could you bump your compression up? sure. is it worth the effort/cost? not really. might as well bump it up to 11:1 and actually get a few ponies if you want to go through the effort. can you build your own motor? if not, it's going to cost a few bucks to have the motor work done.

XiOus271

given the time and the money, im sure i could. as long as i know what im doing and what to do, im good to go. so far most of the stuff doesnt look that difficult, so heck it might be worth a shot!

Mauro Gelbert

Do F23A1 pistons fit in F23A5 engine?

GhostAccord

Yes!