[lo bux racer]

Bump...

No comments or questions?

 

[striptyler]

Sorry.. i caved and got a new toy, which has kept me busy just about all summer, something about bikes is just great if you ask me

anyways, i have done a few things to date, but nothing significant...

I still want to attempt to put a clutch on my power steering pump, and i want to get the head ported/cleaned or otherwise. I pulled it out to look at it, and saw a few things i would like to try to change. Velocity stacks - i know they are widely debated, but when i put them on my bike i swear i felt a little sharper response on the throttle. But in lookin at that, i noticed that the intake valve angle is very sharp in our cars. as i recall, high velocity gas doesn't like to take sharp turns. Is there any way to change the intake angle without destroying flow patterns? and its there anything better than a flow bench for checking how well stuff is working that you are doing to it?


and by any chance do you know of anybody hear on the east coast who has done reputable work? (and might let a guy like me kick around and try my hand at it)



edit: One of my students owns a salvage shop... so i may see if i can get a head of an older car to play with for a free lesson or something

 

[lo bux racer]

Getting a scrap head to learn on is a great idea. I'm not quite sure what you mean about the intake angle. If you are referring to the valve itself, then no you really don't want to change that angle. Millions of man-hours of research have been put into optimum angles for valves, and you would be hard pressed to improve on a 45 degree base angle. There are LOTS of arguments about pull away angles, like how many, and what specific angles work best, and does a full radius seat actually deliver better performance over a seat with distinct breaks in the angles, etc.

Serdi's seat cutters let you do pretty much anything you want in terms of angles. They are also the most consistent from seat to seat, and far better than stones for consistency. Don't get me wrong, I've cut thousands of valve seats with stones, and they do work well, but not as consistently and accurately as using the Serdi system with its carbide blade. This also applies to four stroke motorcycle engines. That's where I learned most of what I know about NA engines.

 

[striptyler]

What i mean, i guess... is that the air tract through the head takes a sharp cut. On the motorcycle, its a much more straight flow. I wish i could sketch on this... like a simple windows paint... oh well.


rather than shaving the deck, is there a way that may be as simple as say... pistons? or would that mess with the combustion chamber too much?


good to be back

 

[lo bux racer]

No, pistons don't solve the problem. Manufacturers do a pretty good job of getting the top of the piston fairly close to specification above the wrist pin. All the height dimensions are indexed to the wrist pin center. You really have to get the block decked to the right height. It makes all the difference in the world when its good compared to when its bad.

Cylinder heads on bikes are light years ahead of cars (except real racing engines). They have very straight, very downdraft ports with fairly narrow included angles between the valves to minimize surface area in the combustion chamber. There are lots and lots of reasons for why bike heads are better...

Car engines have to fit under the hood, so its just about impossible to get a decent port design. They almost always end up being too flat (centerline too parallel to the piston top), and needs lots of help if you really want high flow from them.

That's a lot of why I did the NA 2JZ head. The intakes are really a LOT nicer than the turbo head, and the exhausts are nothing but stellar compared to the turbo head. In fact, the turbo head is a perfect example of function following form. The two turbos had to be configured for sequential operation, so they had to be pretty close together. The only way they could do this was to aim the exhaust ports on 1 and 6 at the very middle of the head. So the exhaust ports for 1 and 6 are very long and aimed toward the engine's center. 2, 3, 4 and 5 all have very short ports, and even then, 3 and 4 are slightly aimed toward center. There is only one reason to have all this screwy crap going on: to fit the turbos in the space provided by the body designers. If the engine designers had their way, the ports would all have been equal length and straight as an arrow. They certainly are on the GE head.

I've seen some diagrams of the ports in the 2AZ. They are pretty normal except Toyco played some games with roof height on the intakes to provide swirl generation just before the air goes through the valves. I've played with that before and you can make some interesting things happen, but it requires a lot of time and testing to get it right. There are a few things I think might be interesting to investigate with this head, but again, you need one to work with, and you need a flowbench, and a LOT of time.

 

[striptyler]

Ok, so i called rudy, my student to see if he had anything on the lot.

He said he had an 05 TC that got wreked pretty good. Car met back of 18wheeler at 40+ mph. He hasn't even taken a look at it yet, but im gonna go down this afternoon and see if there is anything usable on it.

What should i look for? i mean will an impact like that damage the engine? or will it be ok so long as nothing actually impacted the engine?


and how much does stuff like this normaly cost? i doubt im gonna pay for it... buti want to know how expensive the bottle of alcohol i give him should be

 

[lo bux racer]

A head alone usually goes for about a grand new and somewhere between $500 and $600 used if it is in good usable condition. If it is broken in anyway, it sells for scrap metal prices. However, even if it is damaged, it can be used as a development mule for the flow bench.

I wish I had someone in CA who had a wrecked engine they would give me. I'm jealous!

 

[striptyler]

Well... my job is to teach rich people to fly, flight instructors normaly become well connected if they work hard...


Anyways, the car is a mess, total loss.

it looks like the motor just about tore itself from the engine mounts, the top was impacted my something (metal bumper on 18 wheeler maybe?) anyways, the whole thing is jacked up. the inside is all rusted from the battery acid and everything is sticky, i assume from the radiator.


on a side note, the crumple zones on a TC... They crumple pretty good.

 

[striptyler]

I pulled it, well parts of it this weekend. Left the tranny, but got the top end to play with.

I see that lance also has a head to play with now, so hopefully he can post something of good use to me

i would have pulled more, but A, was free, B was such a mess i didn't wan't to bother.


i also got 1 right light unit. (right side, no idea how it's not destroyed) and the p/s pump, and AC unit... ( gonna finaly try to put that a/c clutch on the PS system so i can selectivly turn of power steering. who needs it at highway speed anyways.)

i Guess all in all, your either gonna call me strip, or tyler... but Ty's the name.

Lance, if you do find stuff, try to post pics so i can try to follow along. i got a shop to work on, but somewhat limited tools, im also east coast so it would be hard to come visit.

 

[lo bux racer]

If you ever find a 5 speed Camry gearbox, that would be VERY worth taking.

 

[striptyler]

is it geared diffrent than the scion?

Have you recieved your head yet?, i am looking forward to diving in

Does the 2az have regular cams? and if so, is there anyway to get them shaved for a more agressive profile? I won't need them for a little while, so why not?

Also, working at the airport, we have these things called Gami Jectors, which are fuel injectors tailored for each individual cyl. (diffrent oriface sizes) This is supposed to help with thermal eff., as well as increase engine life ( maintains a more even thermal profile) especially in the boosted engines.

Some A/C engines are boosted as far as 56 in MAP... which i believe is almost 28 psi... on an Unmodified engine.

Also learned that airplanes run about 65-75% max BHP.. while cars run normaly about 12%... and i thought a/c engines were old/poor design. Typicaly car engines put into A/C last less than 1000 hours at that output, while the typical A/C engine will go nearly 4000 hours.

and i thought Toyco overbuilt (j/k)

 

[buderic]

I was reading this and was really interested if you guys ever came to any conclusions about this stuff? Maybe it is in a different topic? Just really curious about what you guys found out.

Major bump, I know.

-Eric

 

[alas]

Major double bump. Very interesting and Boy I think I can get some heads pretty easy.

 

[magnus213]

Reading this thread is more difficult than my entire week of (high) school. Extremely interesting, though, I've bookmarked the two sites and I'll start reading up.

Lo bux, how did you learn all of this? Honestly? Because right now, at 17, I am totally in the dark about what you're talking about and it makes me sad.

 

[striptyler]

Wow.. diggin in the grave yard here

Yeah, i got head work done to the spare, and tossed it on the car. i went the econ route. Sad to say, but a port n polish won't net you much here. The VVt-i system does a pretty decent job of working the head for what it's worth i figure.

I don't really know of anybody who's had head work done, where they really did the reasearch, and flow testing required to do a good job. That would be $$$

I am looking for an entire motor now. I want to tear it down, build it up Print it, and see what i can get from it... NA. but thats all pipe dreams now i think. WHen i started this thread i was a flight instructor, now i am an airline pilot, and the situation has changed.

 

[PhamKL]

Well that's going to be a huge loss to this community. I just got through perusing the Scionlife forums and the title of this thread is definitely justified. It's just people doing what others have done and what everyone does. I want power. Get a turbo. Done. Honestly, grabbing a high temperature thermostat? I think that's brilliant. The idea is simple and the solution stares at you everytime you open the hood but no one thinks about it! Of course, less room for a tuning error, but assuming Toyota reliability and otherwise normal operation, it's great.

And I'm totally going to ride this question on the tail of that post: does our engine run a Miller cycle at any point? The Prius's Miller cycle seemed easy enough to induce so maybe with a cam controller we could add a fifth stroke too? Or maybe one could induce deacceleration fuel cut off? Doc I showed that DFC doesn't exist in a useful range but using a partial throttle controller with MAP feedback (assuming a MAP reading at idle is unique and constant) could one get the injectors to effectively not inject fuel?

This thread is sorta becoming like an open forum for idle engineering....

 

[lo bux racer]

There's no MAP on this engine configuration. The ECM has no idea what manifold pressure is. It infers what it might be based on airflow, but it only needs to calculate load, and you don't absolutely have to have manifold pressure to do that.

No way Miller cycle. Cam duration isn't anywhere near long enough to make that happen. It's also not the panacea for economy. It was originally developed for engines running in a very narrow rpm range like a stationary generator set because it can be tuned to be over 50% thermally efficient. The guys buying fuel thought that was a great idea. While it's true Mazda got it to work in the Millenia, no one else has adopted the technology for a car because the wide range of engine speeds just doesn't lend itself well to this kind of operation.

It's unfortunate that the engine didn't respond well to a street port, but I can't say I'm surprised. Toyco does a pretty good job from the factory, and you'll typically only get a few percentage points improvement. It's not like the old days when you could see 25 or 35 percent improvements with just a simple clean up and blend with a decent three angle valve job. It takes a lot more these days because they've figured out how to get a LOT from the basic casting without doing a lot of meticulous machine work.

The other thing you are fighting is no one really knows where the biggest restriction in the intake is. It might be the manifold, it might be the airbox (although I doubt it), it might be the fundamental port shape. Hard to say without putting the whole shooting match on the flow bench and figuring it all out. Of course, once you've done that you'll know exactly what and where to make changes for the biggest impact. Still, it's time and money.

Anyway, building a 2AZ all motor will not be a big hp affair. There are some gains, but fundamental geometry is against you. The stroke is really long, so you're only going to be able to maximize efficiency in a relatively narrow rpm range (assuming you want to cover more than a quarter mile at a time) and hope for the best. This is why forced induction offers the best opportunity to make power. You'll never spin this engine like a Honda for high rpm hp, so you've just got to make the best with what you have.

 

[PhamKL]

I know the engine uses an MAF but I was talking about the MAP adapter for an engine management device but I guess there's no way to fool the ECM into cutting out fuel with a piggyback.

Anyways, Toyota also uses a Miller stroke! I don't know if it's actually implemented into anything in production but I found this article:
http://www.sae.org/automag/toptech/1298t06.htm

Specifically:
QUOTE

Further, the gasoline engine is specific to the hybrid application. It is a dual-overhead camshaft, 16-valve, 1.5-L inline four-cylinder unit with aluminum cylinder head and block. It is a long stroke engine with a unique bore pitch (distance between the bore centers) for the sake of compactness. The engine operates in a relatively narrow band, its upper limit being 4000 rpm, with emphasis on fuel economy, and its components are optimized in size (e.g., its thinner forged crankshaft, and smaller journal and pin diameters). The engine employs the Atkinson/Miller high-expansion principle by means of late intake-valve closing. While the engine's mechanical compression ratio is about 9:1, its virtual compression ratio (expansion ratio) is as high as 14:1, without inducing harmful detonation. The Atkinson/Miller cycle's known quality is a marked reduction in pumping losses.[/b]

so it takes more than just retarding the valve timing?

 

[lo bux racer]

Yes, it takes a complete set of design principles. Notice what they're doing with it - narrow rpm range, generator set. This is where the whole thing started. There are a LOT of optimisations you can do when you limit the rpm range the engine will see. It's these broad flat torque curve engines that are hard to build.

 

[striptyler]

The days of simple power adders is pretty much done up i think. The engines are being brought under so much control, soon you will have to be smarter than the manufacturer if you want to make the motor do anything else. I think I and others have pretty much come to the conclusion, it's not worth trying to make a slow car fast in the long run. Yea it's fun to do, but you don't get the gratification like you did back in the day when a carb swap meant good power, and cars had cool names, like Hemi Cuda.


Or you can turbo.. but that is not cheap, nor is it proven on a TC yet. When my TC dies, Then i may try to do something to it. Till then, I'M doing pintless stuff... I'm thinking about rewinding my window motors to try to make them faster. Maybe take 15% of the turns out.