Originally Posted by chip-3door

Things to consider for strength:

Block itself not letting the crank loose from the mains (in some cases you need to strap them or run a girdle)

Rod bolts are under ENORMOUS extra strain at the end of the exhaust stroke at very high RPM and normally are the first thing to be needed

Rods themselves may stretch

Valve springs may not be able to shut the valves quick enough

Oil pump may start to cavitate and not work properly, same for water pump, and alternator may not be able to hand it and need an underdriven pulley



Things to make it worth revving that hard, As Simon briefly mentioned, you have a shortened induction stroke timebase to work with for each cycle, so consequently you need to do things in order to maiximise the VE of the engine, such as:

Larger ports in the head / better inlet (eg ITB's)

Hotter cam with both more duration and more lift

Higher CR to actually maximise the torque from the underfilled cylinder

Larger valves to increase the breathing effiency





so basically, you are hardly going to have anything you dont have to modify at massive rpm like 9000+ on most engines.