what motor should i build

[NoDOHC]

4-port FTW! 6-ports have far too late of intake port closing when the 6-PI is active.

build yourself a good streetport on a 13b FOUR port engine. (as mentioned above)

I couldn't agree more, just be careful who's street port you use for your 4-port. Most street ports extend the intake port upward, which is equivalent to delaying the close on the intake valve. There is no benefit to be had with a late intake valve close (it decreases dynamic compression ratio). This technique does not even make as much torque as a cleaned up stock port when naturally aspirated (although it does allow more boost in turbo form).

You can extend the port upward, but make sure that the port still closes when the stock port does (don't change the port timing).



Actually I am intending to do another build using Renesis rotors and a lot of devcon, to see if I can get an earlier Intake port opening and an earlier intake port closing (which should give 10% more torque that I am making).