1NZ port & polish

[ChinoCharles]

Originally Posted by Moose

OK, I can't read the Scion thread at work because it's blocked, so here's my experience with porting and polishing a head.

And Chino Charles, you are correct in that a P&P is, typically, one of the final steps, and is usually done to compliment your bolt-on power adders- but I'll help you out.

Standing alone, a P&P will gain very little- 15hp is realistic on our little engine- and that's with a very good, thorough job done on a flow bench including valve angles and fuel atomizing dimples.

Now, here is where it gets fun- adding very little to that, we can see much bigger gains- with just I/H/E, cams w/adjustable sprockets (springs and retainers, as well, by default), a fuel pump and injectors (a better fuel pump and AFR wouldn't hurt, either), and a piggyback. With these add-ons, and a dyno-tuner that knows what he is doing, you can make some really great horsepower and torque.

Cliffs?

You can P&P your heart out, but it all comes down to what else you have, and tuning, tuning, TUNING.

Heyyyy, someone that didn't try and convince me to swap my engine! Thanks Moose!

15?! That is pretty damn good, even if that is with a tune. It sounds like the optimistic side of the argument compared to Ashley's "its another cold air intake," so I'm anxious to see who is right. Honestly, everything I've been told so far backs you up Ashley... gains will be tiny, but once I have all this stuff done and I slap the piggyback on there and hand my car to Kevin, I'm expecting something crazy... for a Yaris. We shall see.

You may see a P&P 1NZ head next week.