B16B engine upgrade questions.

Rob wakelin

New Member
Dec 8, 2017
Ek9 race car
Ok so I race a EK9, after the last race the headgasket blew so I’m stripping and rebuilding the engine for next years season. I have a few questions. The block needs boring as it has a slight mark so I will need new pistons. Which are the best ones to go for and what compression ratio?
I can find loads of b16a high comp ones but I know these produce a lower compression ratio in the b16b.
I’ll be using the standard crank and rods but they are being fully dynamically balanced along with the flywheel front pulley and clutch cover.
Next is cams and valve train, are the std valves springs and retainers up to the job and what cams are ok to use with them? Or do I go for uprated components? As will the higher comp ration dictate what cams we can use.



Mar 31, 2009
Looks like you've got lots going on. You'll need to consider things as a total package (I.e. how well they're going to work together) and not just individual components. Everything is fine in standard trim, but once you start upgrading one component you then have a flow-on effect of needing to upgrade others to stop them being a weak link. That said, my $0.02...

- With a 0.5mm overbore something like a CP SC7116X should be what you're looking for.
- If you can squeeze new rods into the budget at the same time, I'd recommend it. Stronger, and less rotating mass.
- Cams, depends what you're looking to do with the car, and the characteristics you're after.
- Valvetrain... do recommend upgrading if you're upgrading cams. I'd generally look to get springs as recommended by the manufacturer of the cams (typically their own). Also upgrade valves and valve stems, retainers.

If you put the right package together, you don't need sky-high compression ratios to get some good power gains. Looks like you've got a fun project underway... good luck!


Ek9+Turbo+Nurburgring= Heaven
Staff member
Oct 16, 2012
as far as im aware B16b and B16a crank stroke is the same....so shouldnt effect your compression ratio.
Put the same pistons in a B18c however and the compression will shoot up.

Do you need to stick with a 1600cc to meet regulations? an over bore will put you over that is all...
If not perhaps think about stroking it to 1800cc.