[lo bux racer]

Chrome cylinders have been around for a long time. They're called Nikasil, because they take a cylinder (usually made of aluminum) and vacuum deposit a nickel chromium coating on the cylinder wall with a high voltage process. The resulting cylinders are very light and extremely wear resistant. A number of European manufacturers have used this technology in road cars and motorcycles.

If you really want to get into the specifics of making power in an NA engine, there are a lot of things you can do. They all involve optimizing what the factory gave you in combination with changing the way the engine produces power to focus on a specific rpm range (usually higher than stock).

Many of these things are not inexpensive because the people who do them are proud of their work and present a bill commensurate with their skills and knowledge. I don't port heads for free. I don't know anyone with any talent who does. I don't build engines for free. Again, I don't know anyone with any talent who does. I do share information, and I will certainly tell you what I think will work, but even that is hard to find for free.

 

[lo bux racer]

Major headings are:

Weight reduction (especially rotating mass)

Thermal control coatings

Optimization of component parts (blueprinting)

Changing fundamental operating parameters (cams, fuel, engine management)

Which topics would you like to discuss?

 

[lo bux racer]

Dual plugs are a crutch for a poor combustion chamber design. Our cylinders are too small anyway, you really won't see much of an advantage, and you'll suffer a huge penalty for sucking up all that real estate with a plug instead of valve area.

Let's go topic by topic, and cover the whole thing. Where do you want to start?

 

[lo bux racer]

No, the counterbalance can typically be removed without any significant losses, but you will have increased vibration, and the service life of the engine mounts will suffer.

 

[lo bux racer]

Originally posted by striptyler@Apr 9 2005, 04:14 PM
earlier you were talking about a closed deck, would that help for an na engine? and i would like to think BP is a good place to start. at least see what im working with.

Also... you always seem to have lots of links to post... got a liberary of those somewhere?

honestly, im always thinking up little ideas, turns out, 99% are dumb... but having some material that was legit to read could help me not make an a$$ of myself online so much

No, a closed deck is more intended for boosted applications. The stock open deck is good to just about any NA hp you will be able to make.

I don't have a library of links, I generally do searches to find links to things I already know. HOWEVER, there is one link to a pretty good, and also pretty controversial site here. There is a LOT of information in this archive, and the results Endyne achieves are similar to what I have found in my own experiments. Spend some time reading through this archive. It's not all gospel, but a tremendous amount of the info is really good and helps you understand the WHY much better.

If you have an idea, do some research on it. If you can't find anything after using a search engine, ask here. If we still come up empty handed, it might be something no one has tried (although that's pretty rare these days). It's better to ask a question than to assume the idea is bad or foolish before even doing some discovery.

More very useful links:

Check the myths and misconceptions found on this site, and all the engine tech found here. This guy also knows what he is talking about from practical experience, not just what his buddies have told him.

 

[lo bux racer]

Bump...see myths and misconceptions link above...

 

[lo bux racer]

I missed this post. You still around Strip?

 

[lo bux racer]

Yeah, I'm pretty familiar with cryo and many different coatings. Neither of them will add power, but both will enhance reliability and allow you to make bigger tuning mistakes without damaging anything.

I was ready to talk more about cylinder heads if Strip is still around and interested.

 

[lo bux racer]

Raising compression always gives gains, but it has a cost associated with it: you will be forced to run higher octane fuel. Milling the deck is something you do to get the squish right if it isn't right from the factory. Most of the time it is not, but modern machining is making things better. The factory wants to err on the side of too tall because the engine will run too tall, but will not run too short. Decks are usually spec'd at some number + a tolerance. There is no - in the tolerance. If you get a block that is decked correctly from the factory, you are one very lucky mug. I suspect zoltiz has one of these engines because his fuel economy is so good. Deck height and squish are called artificial octane because when you get them right, the engine is far less sensitive to fuel quality.

Milling the head is a common way of boosting compression, but the 2AZ uses angled squish pads, so milling the head could be very problematic with the stock pistons. Most manufacturers leave at least 0.010" on the head to allow a light resurfacing in case of a headgasket failure, so it's certainly possible there is something there to work with. Still, I'd want to be sure I've done all the homework to make sure I have the exact clearance I want (somewhere between 0.5 and 1.0mm squish height). Too tight means the pistons will hit the head. Also, because this is an aluminum block, you need to take thermal resizing into account and set up your clearances to be correct at operating temperature. Expect the block to grow significantly from cold to full temperature.

Removing the balance shafts and lightening the crank would be excellent for improving power delivery. Neither of them will "create" horsepower, but both will liberate power currently diverted to some other function. It would not suprise me if there is 10 pounds of excess mass in the 2AZ crank. Removing it and the balancers would do wonders for throttle response. The big HOWEVER is removing the balancers will make the engine a lot more buzzy. Big fours are inherently not well balanced, and even a full precision balancing will not eliminate the tendency for the engine to shake. Expect more vibration in the car, and shorter engine mount life if you choose this path. I wouldn't do it to my daily driver, but it would be one of the first things I'd do to a racer.

I don't need to say any more about a lightened flywheel. I have one installed. It's a major improvement IMHO.

Anything that takes the engine's mechanical spec away from what Toyco intended will result in changed tuning. Reflashing the ECM or piggybacks will be necessary for anything other than blueprinting to OEM specs. So far, I haven't seen anyone successfully reflashing their ECM, although Scionspeed made veiled claims about this a while back. They don't seem to be doing very well from a business perspective these days; there are a lot of pissed off preorder turbo kit buyers out there who would say they really suck, but I have no personal experience to say one way or the other. Their parent company, Jamasco, has done some very interesting stuff, and they appear to be quite technically competent, but their business skills seem to be coming up short these days.

It would be great to have a junkyard engine to build. I can think of lots of things I'd like to check out, especially the port configuration in the head to see how it would respond to port work and ceramic coatings. That will have to wait until I get a head sitting on the bench in front of me.

 

[lo bux racer]

Bump...

No comments or questions?

 

[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.

 

[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.

 

[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!

 

[lo bux racer]

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

 

[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.

 

[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.