nsxracer

Will it benefit me to increase cylinder size and get bigger pistons to make it a 2.2 vs 2.0? I have a loud knock when I start the car and it gets louder with throtle. I figure I have bearing problem at the least. What would you guys do if you were rebuilding? I might go FI in the future.

dhayner

You can't just bore it oversize (much). The FRM (Fiber Reinforced Metal) cylinder lining is very thin, about .02 I think. You could sleeve it out some significant amount - I don't know exactly how much.

The AP2 gets its 2.2 liters by stroking, not boring. That's why the rev limit gets lowered to 8000 rpm.

nsxracer

ah so stroking is different. Damn I am stuck now.

driftintherain

if i were in your situation... i think i'll just port and polish the head...

nsxracer

but its the bottom end thats went bad...

Antonov

i think ultimately it depends on whether or not you want to go FI. Porting and polishing wont do a thing if you're planning on staying NA, in fact you have to add material to the exhaust ports in order to see gains from head work. An overbore via sleeves might not be worth the effort/money if you plan to stay NA. If you go FI than you might have to sleeve the block anyway, but you will get more gains from an FI standpoint by increasing the stroke rather than the bore.

Soul Coughing

does the knock sound like this?

http://www.youtube.com/watch?v=dyBllnMZaLE

If it does, you scored a bore. If it is your bearing, stop driving it now, and you might be able to salvage your crank etc...

You can't re-finish the block if your scoured a bore, you will need to re-sleeve, or get a new bottom end!