Mother of God, someone help me QUICK!

[racerx]

I need to know the bore size of the motor from an 86 Honda Prelude 2.0Si.

I believe that's the A20A3 motor, but I'm not sure. Help?

[racerx]

alright, i got the bore diameter. 82.7

can anyone confirm the piston diameter for me? is it 81mm?

and does anyone have the wrist pin diameter for a B20A5/3/7???

[racerx]

... thanks for all the info guys... lol

anyway, i figured out what I needed to do, so here's some potentially very useful information for future reference, for anyone who might need it:

BS/BT/A20A1/A20A3
Bore: 82.7mm
Piston length: 65.3mm
Wrist pin dia: 20mm
Wrist pin length: 62mm

Piston Ring Groove sizes:
1.5 1.5 4.0

[superaccord]

Matt, why did you need to know?

[racerx]

a guy was selling a set of pistons from another board. they were forged steel, 10:1 compression, and he had the honda part number, but he wasn't sure what it would work in.
so i called honda, and they said it was the oversize piston (by 0.3mm) for a 1985-87 Prelude 2.0Si, and I wanted to know if I could fit that into my engine.

Unfortunately, the wrist pin is a full 1 mm smaller in diameter, so they'd just bounce around... bummer... he was asking $100/shipped for 4 pistons, rings, and wrist pins.
He'd been trying to sell it for a while I guess, and no one was buying. It's sold now.

[PhydeauX]

The should have worked fine in your engine if they were really for an 86-87 prelude Si. They may have been the custom diamond pistons that has the smaller wrist pins to let you run b18a rods. I think thats how it works anyway, sean had some posts on it a while ago.

andy

[racerx]

oh, sorry this is for a B20A for a prelude. lol I should have stated that before, but since these parts were for an A20A3, I figured it was relevent enough to post here.