1. Lengthened connecting rods
2. "ladder frame" crankshaft main bearing box/girdle
3. Increased crankshaft stiffness (which raises friction)
4. Asymmetric piston skirt

http://www.nissan-global.com/EN/DOCUM ... w/VQ_E_070802_X-1a-02.pdf

These changes were made to the High Rev version of VQ35DE, allowing it to go to 7500 RPM.

The first two items confirm what D is always saying.

The good old A-series doesn't need any of these mods to turn 7500 RPM and more. Though I suppose it might be smoother with them, but A-series is already pretty smooth.

ahh, rod stroke ratio. countless discussion about this on the net.

It makes a measurable difference, but not much of a difference. Enough for manufacturer to chase a fraction of an MPG/fraction of one hp.

they do bring differences.

http://planetminis.com/forums/perform ... atio-fully-explained.html

yes, they do bring differences. they are very small differences in terms of HP.

The very thin rings these days with modern ways of finer graded honing reduces break in times while improving sealing and bearing durability but having less metal floating around with first oil. The use of the A12 crank into an A14 block with extra block height needs forged quality or prepped 140 to 142 mm long conrods depending if using 29 or 28mm comp height piston. That would take the rod stroke ratio to 2:1.
Good oiling and pan design is a must and head would need need some investment.

good vid on honing, clocking rings etc
http://www.youtube.com/watch?v=1Doa-0M2flg