But then again all the surfaces that matter are machined to the same tollerances.

^Yup.

40hp difference due to the engine's being "handbuilt" is just bs.

Now it would make more sense if Nissan "accidentally" put the V-Spec engine in the 'Ring car due to some highly unlikely, but inevitable error. ;-)

Does blueprinting an engine give you more hp or just more revs. Thats sort of handbuilding, polishing the intake?

I understand the balancing of all the reciprocating components during the blueprinting process will allow all around better behaviour - smoother quicker revving, slight power improvement etc.

Most tolerances today are good enough from the factory that you can't do a huge amount with it. Check out how little Car and Driver were able to eak out of their Nissan 350Z's 3.5 litre.

http://www.caranddriver.com/reviews/...ng+page-2.html

Balancing helps revs, reduces stress on the crank a bit, and helps efficiency a bit. For instance, my car's pistons and connecting rods all have identical bob weights (to the nearest gram I think.)

Also, this gets a more significant result from larger engines . . . the gain from a 6.6 litre is quite a bit larger (but given all other things equal, not proportionally larger due diminishing returns due to scaling) than what one would get from 3.8. I don't know how much the turbo could take advantage of the better tolerances and balance though. Building revs more quickly would be beneficial but that wouldn't make for a much larger peak.

^^

If Car & Drivers engine building skills are anything as pathetic as their driving skills then would not pay too much attention to any results they got ;)

well, they did hire other people to do the work and they did lunch one engine despite that.

If they and their sponsor would have had any financial sense they'd have bought an FR500C that was class competitive out of the box.