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.

[Dragonacc]

Originally Posted by ChinoCharles

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.

If it's free does it matter if the gains are small?

If you had to pay for it on the other hand, I wouldn't recommend the expense.

[ChinoCharles]

My concern is this.

I get my head ported next week and go to the dyno. We dyno the new head and everything is whacked out. I lost 5 HP throughout and the ECU is now running a 9.5 AFR. In other words, my main concern is that the stock ECU isn't even going to know where to start.

If this is the case, so be it... the P&P just has to wait until I have a piggyback.

If not, I'll do the P&P first.

What ends up happening is I am literally loading my car like a slingshot right now. With every mod I do, I'm getting power earlier, although I'm not necessarily getting more of it. The engine is running richer and richer. The power also comes on sooner.

Then I get a piggyback and it is the proverbial launch of the slingshot. All of the sudden AFR is where it ought to be, the HP curve doesn't flatten out at 5000 RPM anymore and my car literally nets 25 HP in one day... at least I hope.

If it does, it proves my theory that there is power in this engine and that kid on Scionlife spent all the right money on all the wrong shit. If not, I'll probably be the last person to mod a 1NZ.

[Dragonacc]

Originally Posted by ChinoCharles

My concern is this.

I get my head ported next week and go to the dyno. We dyno the new head and everything is whacked out. I lost 5 HP throughout and the ECU is now running a 9.5 AFR. In other words, my main concern is that the stock ECU isn't even going to know where to start.

If this is the case, so be it... the P&P just has to wait until I have a piggyback.

If not, I'll do the P&P first.

What ends up happening is I am literally loading my car like a slingshot right now. With every mod I do, I'm getting power earlier, although I'm not necessarily getting more of it. The engine is running richer and richer. The power also comes on sooner.

Then I get a piggyback and it is the proverbial launch of the slingshot. All of the sudden AFR is where it ought to be, the HP curve doesn't flatten out at 5000 RPM anymore and my car literally nets 25 HP in one day... at least I hope.

If it does, it proves my theory that there is power in this engine and that kid on Scionlife spent all the right money on all the wrong shit. If not, I'll probably be the last person to mod a 1NZ.

Normally I'd expect an engine to lean out as more airflow mods are added, if yours isn't it makes me think the ECU is "learning" and trying to keep inside some kind of stock parameters. If that's the case the P&P will probably be more of the same.

[Moose]

Charles, wait until you have the piggyback and some better injectors, or you will run lean. On top of that, with these ECUs the knock sensor may start bitching as well because the engine will try to adjust timing to match the new amounts of air flowing through the head- this is one of the reasons I built a non-VTEC B18 in my Civic.

The goal is a nice, FLAT 12:1 air fuel ratio- and don't get mad when your MPG goes sub-30.

[ChinoCharles]

Sub-30 I can live with. I don't drive much. (Yeah right )

Wait... or I will run LEAN? I'm running rich now... is there a chance a P&P will balance it out a bit, or at least enough so that I can go with the P&P now and roll around on it for a month before its piggyback time?

[Moose]

Originally Posted by ChinoCharles

Sub-30 I can live with. I don't drive much.

Wait... or I will run LEAN? I'm running rich now... is there a chance a P&P will balance it out a bit, or at least enough so that I can go with the P&P now and roll around on it for a month before its piggyback time?

How rich are you running? 10:1? Worse?

Never mind, I just saw 9.5:1. Holy shit! Is that all across the powerband or just in one place, like a peak?

[ChinoCharles]

10.75:1 at worst, 11.5:1 66% of the powerband.

9.5 was a hypothetical.

2000-5000 RPM: about 11.5:1 AFR
5000-5800 RPM: descends to 10.75:1
5800 on: stays around 10.75:1, horsepower flattens out, torque decreases 10%.

[largeorangefont]

Originally Posted by ChinoCharles

10.75:1 at worst, 11.5:1 66% of the powerband.

9.5 was a hypothetical.

2000-5000 RPM: about 11.5:1 AFR
5000-5800 RPM: descends to 10.75:1
5800 on: stays around 10.75:1, horsepower flattens out, torque decreases 10%.

Taking AFR through through the tailpipe on a dyno through OEM cats will give you invlalid results. You need a wideband with a bung installed pre cat.

Your mileage will improve after a tune. That is if you aren't flooring it more than you were to begin with.

If you are gonna get a PnP done free by a reputable shop in your area, yes It may be worth it. If some toolbox shop does it, it will most likely do more harm than good. I wouldn't pay to have it done to this motor. The funds are better spent elsewhere, either an engine swap, or a turbo\supercharger.

I used to work at a shop porting cylinder heads for many championship race teams in various forms of racing, so I know all the processes and methodologies pretty well. Moose is correct, although I doubt you would see 15 Hp on this particular engine without cams or other component upgrades.

[jdubau55]

The 2ZZ is out of the question IMHO. There will be much easier swaps soon. I really think your best bet is to just find a Yaris thats totaled and rape the engine out of it. Make it your coffee table and then slowly build it in your living room. Build it bulletproof and slap a turbo on it. A 1.5 liter motor with a proper turbo build should have no problem making 250 WHP and be perfectly stable. Its all about the build though.

[Dragonacc]

Originally Posted by jdubau55

The 2ZZ is out of the question IMHO. There will be much easier swaps soon. I really think your best bet is to just find a Yaris thats totaled and rape the engine out of it. Make it your coffee table and then slowly build it in your living room. Build it bulletproof and slap a turbo on it. A 1.5 liter motor with a proper turbo build should have no problem making 250 WHP and be perfectly stable. Its all about the build though.

You are going to spend a lot of money to get that 250hp... Why build an engine if you are only going to get 250hp? If someone is hell bent on making a lot of power in a Yaris the 1nz is not the way to do it.

[jdubau55]

As far as the PnP goes. I say do it. All it can do is help if its done right.


I am talking reliable, easy, HP. Swapping a 1NZ for a 1NZ would be straight forward. Sure you could make more HP, but the more you make the more risks you are taking.

[Moose]

Originally Posted by largeorangefont

Taking AFR through through the tailpipe on a dyno through OEM cats will give you invlalid results. You need a wideband with a bung installed pre cat.

Yeah, I was wondering what was up with your AFR.......that's not even close to what it should be! I mean, 11.5:1 is acceptable, but when you start dipping into the 10.X:1 area, that's not good. You could start having problems long term- excessive carbon buildup, detonation, premature O2 sensor failure, etc.....

[acrbill]

The thing about porting and polishing is that every head design requires different work. A lot of the time there is a long trial and error process before every bit of power is extracted.

There are basic things that every head port & polish should include.

Port match intake ports to the manifold.
have a slightly rough texture to the intake ports to help the fuel mix with the air.
open up the exhaust ports and get them as smooth as possible.
unshroud the valves if needed and polish the combustion chambers.

A bad port job can cost you power all over the place too. Keep in mind that it takes 8-12 hours to port and polish a head (for someone who does it often) so if some guy is offering it for free I would be suspect.

Porting heads traditionally offers huge gains. The problem with the Yaris is that it has a relatively low rev limit so much of the potential gains will be beyond the stock rev limiter.

If the guy is just going to clean up the ports I wouldn't bother. Once you open the motor up you are opening the proverbial can of worms.

[ChinoCharles]

Wow, a lot to respond to.

About the AFR being wacky, it was taken through the tailpipe.

The next question would be when I dyno the car with the new test pipe this Sunday, should I get an accurate AFR reading due to the fact that the cats are being removed?

And about the shop... this is a local area shop involved in racing engines and they want to break into the subcompact market. They offered me a P&P to display a sticker. They said it would take four days. I told them I am very interested, but I would like to know what they suggest on a low displacement engine like the 1NZ. If they say "nothing different from a Ford V8" I'll be weary.

[acrbill]

Man it kills me to do this to you. It seems like every thread you create I pop on and attempt you ruin your fun.

I would run away from that deal. Nothing in life is free.

Here is an example of how shops with good intentions end up screwing people in the long run. Unfortunately its far too common.

A few years back I took a side job working for a very well known person in the car community.

My job was to fabricate turbo kits from scratch. He had very good intentions up until the point he stopped paying me and he took a lot of peoples money.

One guy actually let the shop use his car in order to build the turbo kit. In return he was supposed to get a free kit.

He ended up picking up the car after over a year went by and the car was worse off than when he dropped it off.


Now if a shop says they are going to do free work, they are not going to give the car a whole ton of attention if paying customers come in.

You also have to think about all the potential problems that might come up.

Removing the head means that you will need a new headgasket, headbolts, intake and exhaust manifold gaskets at a minimum. What if they skip a few teeth on the timing belt when they install it and the valves contact the pistons? The fact that you are not paying them means you will have zero recourse if something goes wrong.

If they have no experience with a Yaris head they won't know where the water jackets are in the head. If the guy porting the head takes away too much material in the wrong spot the head will be scrap.

Are you willing to have your entire valve train removed? Toyota engineers who set the torque specs for every nut and bolt know what they are doing. The shop that is not getting paid might not take the same care.

They say it will take 4 days, I would budget 2 weeks at a minimum.
They say they will do the work for free. I would make damn sure that you buy an OEM headgasket and headbolts and bring them in with the car. Those are non reusable parts that they might try and reuse.

I would be very very careful.

[largeorangefont]

Originally Posted by ChinoCharles

Wow, a lot to respond to.

About the AFR being wacky, it was taken through the tailpipe.

The next question would be when I dyno the car with the new test pipe this Sunday, should I get an accurate AFR reading due to the fact that the cats are being removed?

And about the shop... this is a local area shop involved in racing engines and they want to break into the subcompact market. They offered me a P&P to display a sticker. They said it would take four days. I told them I am very interested, but I would like to know what they suggest on a low displacement engine like the 1NZ. If they say "nothing different from a Ford V8" I'll be weary.

Theoretically, yea the AFR should be accurate. however, I rarely have seen a dyno tailpipe sniffer that is accurate. They are dropped, stepped on, dirty, and run in the worst possible conditions (super rich, super lean) etc. Just take it for what its worth.

It sounds like they aren't going to do anything radical with the head. Probably just some cleanup and smoothing if they think it is only going to take 4 days. Keep in mind car work is like construction work. 4 days equals 4 weeks. And that is if all the new gaskets are available from your local dealer. They may even use aftermarket gaskets to replace the OEM stuff, so be aware of that.

Ashley

[ChinoCharles]

Advice noted. Thanks.

Decision shortly.