B17a1 rebuild

IntegraDB2

New Member
i was wondering if anyone was certain on compression ratios. on my B17 i am currenlty rebuilding i want to up the compression from stock 9.7 to 1 . to atleast 11 to 1 maybe 11.5 to 1. i am looking at getting either ctr or itr pistons ( i would imagine this will put me in my desired comp. range) does anyone know the compression ratio i would get out of these.?? also what about clearence with valves (down the road skunk2 pro series stage 2 cams) will be inserted will my valves still have plenty if clearence? one last thing will either of these pistons cause me to have to get my rods shaved for clearence with the head or will they bolt of to stock crank and rods ? advice much appreciated
 

mirrorimg

Well-Known Member
That calculator tells me that I will have 11.35:1 C/R compared to the c-speed's 10.3:1. Thats quite a bit of difference, and thats not taking into consideration however much was taken off during resurfacing the head and decking the block. I think thats a overestimated.
 

tilegend

New Member
mirrorimg said:
That calculator tells me that I will have 11.35:1 C/R compared to the c-speed's 10.3:1. Thats quite a bit of difference, and thats not taking into consideration however much was taken off during resurfacing the head and decking the block. I think thats a overestimated.
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using what specs?
 


mirrorimg

Well-Known Member
B18B1head, block, crank, RS machine ITR(USDM) style piston, bored out to 82mm, OEM headgasket. Didnt change the elevation on the calculator.
 

tilegend

New Member
mirrorimg said:
B18B1head, block, crank, RS machine ITR style piston, bored out to 82mm, OEM headgasket. Didnt change the elevation on the calculator.
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piston to deck height clearances differ from the two calculators...

c-speed calculator has that the B18A/B blocks are 212.39mm in deck height...
meanwhile the zeal calculator has the B18A/B deck height as 211.84mm

a lot of people assume that all B18 blocks share the same deck height.
 

IntegraDB2

New Member
thank you that website does help it says w/ my setup the p3 pistons which i would prefer to have a two layer head gasket i would recive 11.2 to 1 that is exaclty what i want. But it is required to mill 1 mm on my rods? also do you think these p3 pistons will be okay for a daily driver setup? or maybe should i just go with jdm itr pistons? advice is appreciated thank you
 

tilegend

New Member
IntegraDB2 said:
thank you that website does help it says w/ my setup the p3 pistons which i would prefer to have a two layer head gasket i would recive 11.2 to 1 that is exaclty what i want. But it is required to mill 1 mm on my rods? also do you think these p3 pistons will be okay for a daily driver setup? or maybe should i just go with jdm itr pistons? advice is appreciated thank you
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you're confusing me on which pistons you want

your second post said CTR PR3.... but there is none...

CTR uses PCT pistons (JDM B16B)

PR3 is USDM B16A

and P30 is JDM B16A

for either the PR3 pistons or the P30 pistons you will not have to mill your rods. you only have to do that if you want CT-R, GS-R, or IT-R pistons.
 
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IntegraDB2

New Member
ok well i was confused also on the ctr pistons. ok to get it cleared up i want either pr3 or p30 pistons. you dont think ill have to have my rods shaved with these pistons?
 

mirrorimg

Well-Known Member
Pick the pistons you want. The machine shop will tell you if you need to shave anything off for clearance issues. You should not have any issues with the PR3 or P30 pistons on the LS rods.
 
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