16v bigport v 20v? Carbs v itb's?

[greendog]

[lolwat]

i dont think there is anything cooler then a Bullshit tuff 16v, as i personally dont like 20v's(jsut dont) but the numbers are there, so why not, save your self alot more coin in the end

[JDM-086]

I could be wrong so anyone feel free to correct me here.
In standard to mild form the 20v will outshine a 16v in performance and bang for buck without question.
Once you go past that and start including some decent high end mods, on upwards of 180HP+ (pistons, cams, ITBs, ecu, head and block work, balanced engine parts etc etc) they are very much the same or debate-ably the 16v comes out slightly better (smallport block with bigport head is the suggested winning combination at this level)

Don't take my word as gospel however. I myself are asking similar questions as I'm looking to build a 16v in the future and have a shitload to learn, simply sharing what my research thus far has led me to believe.

The first questions you want to ask before any of this is..
What do you want from the engine?
What do you want to achieve?
Budget?
You'll find quite a few of your decisions will come down purely to individual preference rather than which is outright better than the other.

[Matt]

My 2c..

FROM Factory
* 20v has the higher compression ratio blacktop being the highest...
* 20v blacktop head is the best flowing
* 16v smallport and 20v silvertop heads flow about the same
* 16v can accept larger cams but these really come into it up in the 8-10k range and revving the car that high costs $$$.

The 4age loves a bump in compression in all forms. I've always seen engines with the same amount of $$$ spent on them, the 20v is always 10-15% in front of the 16v.

I guess the reason allot of people stick with 16v is the ease to install in a RWD car, plus the initial cost to obtain the 20v.

[lolwat]

Where's gunner, his Blocktop, that made BULLShit power that when stripped down, valve train was standard, standard cams, bullshit amount of port work

[Gunner]

Magic mans engine you mean micheal, i cant lay claim to that engine. That said, I pulled it down, and it was standard. Cant remember the story, but it made a proven 120kw+ without the flowbenched headers. Having said that, it wouldnt last long, simply due to oil starvation. Not rods bending. Cams had started to chew out the guides in the front, bearings were "so so" and the pistons amd bores were wearing pretty well lol.

There is a video of it at wakefield, destroys eerything down the back straight.

They make the power, NA or boosted, i have never seen a 16v out perform a 20v of the same calibre.

[Gunner]

And yeah yoou can get a 16v to flow a fuckload, but not at the same velocity as a bt.

[JDM-086]

Correct me if I'm wrong but at a certain point doesn't 5 valves become a disadvantage over 4 valves in regards to 4age 16v vs 20v? I'm not sure on the technicalities of it but i do remember reading something of that nature here.

[Sam-Q]

yes getting technical the 20V design in general is inferior for anything that's not a tiny engine and doesn't have boost. However on the 4AGE the 20V engine has a much superior inlet port design and intake system plus the VVT so it makes up for it.

For most people here the 20V is good bang for buck.

[Gunner]

I dont actually believe that, if you look past the design and what you want to happen within the cylinder as it fills, a 20v provides a much better front. In most modern multivalve engines, you want the intake charge to tumble into the cylinder (think of it as a cloud growing as it moves accross the sky) 3 valves evenly spread accross the chamber will provide a better front for this action imo. Sure if it was an old thong slapper v8 were you want the charge.to spiral into the cylinder to fill it, the theory of valves "shrouding" other valves becomes plausible. But not in a 4A.