I don't know where you are getting those numbers. By my calculations, using PCT pistons in an otherwise stock B18A/B will net you around 11.55:1.Originally Posted by 99jdmLs
there were some .25 over pct pistons being sold in the for sale thread few days ago, came with OEM rings to. 175 bucks.... BNIB (a deal)
you can buy them for 169 shipped off some sites and oem rings are around 120...
http://www.zealautowerks.com/bseries.html
this is the calculator that i used, change it between p30 and the pct pistons. it goes from 11.6 to 13.1 perdy nasty!
3 different types of b16 pistons:
(all calculations are b18/b20 with a oem 3 layer head gasket)
p3-usdm b16 11.39:1 comp
p30-jdm b16a 11.61:1 comp
pct-jdm b16b 13.14:1 comp
if you want to go ls/vtec with a gsr head kiss pump gas goodbye- 14.31:1
PR3- 10.92:1
P30- 11.16:1
There's no way it's making 13:1 using a LS head. Those heads have larger combustion chambers than VTEC heads. Larger combustion chamber = lower compression ratio. Maybe you didn't use the correct piston to deck height.
Even with a B18C5 block/head and PCT pistons you are only right at 12.0:1 using a stock head gasket.
1badgvr4, are you going to be using stock sized or 0.25mm oversized pistons?
stock sized PCT pistons are good for 11.55:1.
0.25 over PCT pistons are good for 11.61:1.
The only way I know of to get 13.0:1 using stock honda parts is using a B18A/B block, GSR head, .25 over PCT pistons, and a single layer head gasket, which is good for around 13.1:1.
Most of those online calculators do not take into account the piston to deck height, and differences between head gasket types. Also, most give the wrong thickness for oem honda head gaskets.
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