Quote:
Originally Posted by spool twice
is a stroker kit + higher rpm build possible? Keep in mind that piston speeds are greater per given RPM with a longer-stroked displacement.
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The possibilities will be defined by the specifics of the pieces. I don't know the answer.
But in general what matters in the bottom end with respect to rpm is not piston speed, although that is a short-hand people on the internet seem to use, but the acceleration of the pistons and con rods as they move up and down. They are accelerated by a force and this force is what causes stress and strain on the components. If the mass is reduced, then the forces applied are also reduced (at a given rpm), and in a linear way. This can allow for more engine rpm and/or a longer stroke. So, for example, this is why the Corvette Z06 and the 911 GT3 and the 458 all use titanium connecting rods.
Also, it's worth noting that BMW built its own S65 stroker with the 4.4 liter GTS. And didn't they keep the same redline?
As for the top end, building a 9000 rpm engine would need to consider the valvetrain, what springs to use, whether lighter valves were needed, etc, etc.
Finally, you'd need to make sure the intake and exhaust didn't prevent the needed breathing at 9000 rpm and you'd need different cam timing to move the torque curve higher in the rpm range.
I completely admit I'm an internet/arm-chair engine designer but, nonetheless, I don't think this engine is out of the realm of possibility.