Twiddler

How hard is it to remove the cylinder head on the 1NZ-FE? I think I read on another thread that you can do it with the engine in the car. I was wondering if anyone has tried porting and polishing the head for more power? Is there enough meat on the head to shave it down and go from 10.5:1 up closer to 11:1? Anyone try this yet? I'm new to fuel injection so I don't know how this effects the fuel curve. Are there any aftermarket intake manifolds out yet?

Seems like a lot of people are looking for power with turbo and blower options, but there might be 10-20HP hiding in head flow, manifold, and compression.

thanks for your time

Andy

Derk-xB

Nobody that I've seen

Are you talking about shaving the deck?
I'm sure on an econobox's head there's plenty of flash/crap in the ports, but I haven't seen any pics of our heads.

None that I've seen.



Heads seem like a resonable place to pick up some hp. Our intake manifolds are short and seem pretty unrestrictive (though I've never seen the insides...) I'm sure some P&P of the ports would yield some decent gains w/o much sacrifice and w/o changing the power curves.

jct

i'm not sure you wanna do this...

if you do you would have to run a higher fuel octane

Twiddler

Are our manifolds ceramic by the way? I guess like on the new vettes. I imagine that leaves a fairly clean port.

You might have to. I've seen as high as 12.5:1 in some race competitions with 92 octane. I think most modern aluminum heads can push 11:1 on 91 as long as you check the timing. You can also ceramic coat the chamber, valves and ports as a measure of protection to cool the charge a little more.

If you did port the head or add compression, would any computer changes be needed? When you add an aftermarket blower...do any new calibrations have to be made?

thanks again


Andy
http://www.piratesofhorsepower.com
http://www.cobralads.com

Ashe_WCM

If you shave anything off you will decrease the compression by increasing the area the F/A mix gets compressed into, Unless of course you get higher compression Pistons.

Twiddler

I think there might be some confusion...when I said to shave the head, I meant to flat mill the base of the entire head which effectively reduces the chamber volume. When you decrease the combustion chamber's cc, you increase compression. If you port and polish the chamber itself, then yes you would be enlarging the chamber area, reducing compression.

Here is an example of what I meant from a head manufacturer's site. These are mustang heads.
http://www.airflowresearch.com/pages/225sbf_rh.htm

At the bottom they say Angle Mill (6cc Maximum Mill) .008” per cc and Flat Mill (3cc maximum Mill) .006” per cc Every .006" you shave off this head drops the chamber volume by 1cc. This same procedure can be done on any head.


Andy
http://www.piratesofhorsepower.com
http://www.cobralads.com

Derk-xB

I would assume they're aluminum heads...I couldn't find anything in the Scion brochure.


Needed? I dunno. But, if I went through the trouble of decking the heads, I'd want to know my A/F was ok at the very least, and probably be curious if I was getting any timing retardation (due to the ECU sensing knock/ping and pulling the timing).

hotbox05

port and polish along with a cran cams regrind ( 95 per cam ) would probably net you a decent amoung of power , along with a good valve job. i'd guess about 15 or 20. and milling the head would most def require higher octane , i'd assume theres plenty o meat to be ground down seeing as how other toyot heads i've seen are.

onto another thing yes it can be done with motor in car but is not the easiest task , the valvetrain will be the least fun.

fredrick_brown

i say go for it ive did a 100. on a crx si ran strong until the belt sliped on 91octane and what is deal with the crane cam have they been dynoed yet anybody