Hopefully you guys don't mind my babbling.. if some aren't familiar of the aspects of short runner vs long, and plenum sizes, I'll share a bit of my work experience.
There is a pulse when the valves slam shut, this pulse returns towards the plenum and returns back to the combustion chamber and charges the combustion chamber with even more air / fuel mixture force in addition to a single path flow from the plenum to the combustion chamber.
It's a phenomenon of science of how the runner length and the size of the plenum is tuned to a specific rate for torque / hp at a specific rpm for those who aren't aware. If the runner is short, the time for this force to travel to / from the combustion chamber is shorter = higher frequency. If the runner is longer, the time to travel is longer = lower frequency. The plenum itself, can absorb time / volume, the larger the plenum, the more it soaks up time.
Therfore, a short runner and small plenum will provide a return force at a high frequency, which will be available for return force charge / performance at a high rpm = high frequency. A long runner with a large plenum will provide a return induction force at a low rpm = low frequency.
Vipers have a long runner, which provides a return induction force at low rpm, it's why the Viper engine has quite a bit of low end torque. Shorten the runner, and the max induction return force result will be at a higher rpm, which may not be ideal for a 8.0 L V10, which is not a high revving engine. High revving engines need power at a high frequency, such as short runners or a small plenum.
The problem today is that not many manufacturers have designed a feasible runner / plenum design to be dynamic, such as a runner which can change length or a plenum which can change the size of the volume. Volvo has designed a variable sized plenum, but it's quite unusual.
If this doesn't make any sense, feel free to comment. In the end, I don't feel the 8.0L is an ideal candidate for a short runner. I've designed OEM intake manifolds for several years and I just wated to share my opinion, or any knowledge if it helps for what it's worth.
Just wondered if anyone has made a short runner intake work. Fat Albert here in Phoenix tells me you could spin his stock sized 488 ci motors to 7,000+ rpm if you could find an intake/head package to feed them (I believe his peak power is still right around 6,000 rpm with a reworked stock manifold.
