racerguy

So I was looking for some high compression pistons for a B18C I am building. I WILL BE USING THE LS RODS AND CRANK. I am familiar with using Mahle rods in my H22. Anyways they offer 12.5:1 pistons but specifies with a 42cc head. What kind of cc's does my stock head have? Mainly im just wanting to make sure I am not going to have any piston to valve clearance issues. Also, I know LS and b18c pistons are different stock, will I have any issues if these dont specify bc all they say is b18. Or if you guys have any high compression piston brand preferences please let me know. I'm planning on sending an order in tomorrow.

http://realstreetperformance.com/Pro...ower-Pack.html

racerguy

Just found these from wiseco.
Evasive Motorsports | PH: 626.336.3400 Mon-Fri, 9am-6pm PST: Wiseco B18C 81.5mm 12.5:1 Pistons

racerguy

One more thing... If it makes a difference I'm using BC cams

blackeg

are you planning on spraying or any other kind of forced induction?

if not then you just need to run the nippon or rs machines pr3 pistons.

Honda B-Series Compression Calculator by ZealAutowerks

there's the zeal calculator page, play around and see.

just slapping it together, your combo looks to be 11.5:1. a 2 layer hg and or some milling you are at 12:1. much above that isnt really needed, especially if this is a pump gas operation.

racerguy

I don't understand. How would I have 11:5 with 12.5 compression pistons? Plus I would think the longer rod raised that a little. Like 13.0 or something. Does it not work like that?

blackeg

too many other variables going on to have the manufacturer's generic compression claim be totally accurate.

zeal is arguably the best/most accurate calculator. ive used in plenty and trust it. and, gsr rods are longer but the deck height is a bit taller. the oem gsr piston has the pin at a different height placing it higher up so you can get the 10:1 with basically a flat top where as the b16 is also about 10:1 but has a dome

4drboostking

iTrader: (1)

Zeal is accurate but only if you know all the data and most people dont. Deck/head milling etc.