mtrevino

Okay, this is a thread for non-rotary Mazda engines.

For the technical/engineering/Mazda people out there. What goes into developing a Mazda piston engine, or even just a regular piston engine?

For instance, the 2.3 engine has been around for a few years now. They’ve spent the last year and a half putting it in higher speed vehicle with a turbo. When they introduce a new engine, is based off the previous engine? Do they just increase the liter displacement, or mess around with terms like bore and stroke?

I guess to make the question more general… when they introduce a new 4 cylinder, is it with all new technology and build… or is it simply, making the older engine better?

Supplement questions-

michael

8at18

I'm not trying to be an idiot but they can't change the displacment of the 2.3 liter engine that they put in like all of their vehicles and still call it a 2.3 liter. 2.3 liters is the displacement if they changed it, it would be like a 2.5 or 3.0 or anything that is how many cubic liters of volume can be held in all of the pistons at once

Renesis_8

They do design it with/without force induction in mind, just like the new Ford 3.5L V6 . And i think decisions like performance, mileage depends on the consumer, the trend, oil prices, etc etc. Right now I think more turbos will be put on engines to increase performance and still get okay mileage compared to a big engine with same power output.

The current version of 2.3L MZR(DISI) will be around for quite a while to come, at least the CX-7 will be around for a while!

p.s. when u mess with bore and stroke, the displacement will change, it wont be a 2.3L if u lets say shorten the stroke.
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White Widow Seeds

mtrevino

Yeah, I should say that I don't know much about engines except the general theory... and I can identify parts and pieces fine too.

Okay... if they make a change to modify the displacement, everything else would still be the same then? The materials and technology of the engine would be untouched otherwise?

So, just to steer the thread some, I'm asking the questions for completely redesigning and building a new engine then- Is it in Mazda's best interest to design/build/produce a new engine every 7-8 years or so? Or is it better to keep tweaking the 2.3 (or what they have) until nothing more can come out of it?

michael

rotarygod

They break out the checkbook, pay AER to build an engine, and then stamp their name on it!


Actually when it comes to new piston engine design, the greatest technology is in the head. A block is a block as it does a certain job. Yes there are things they worry about there to though. A crankshaft, connecting rod, piston, are all basically the same things. It's how the engine breathes that matters and how it mixes with fuel. A piston might have it's face specially shaped but this is to coincide with what is going on in the head. Certain materials are used and tried for the main engine parts to see what will hold up to the expected power levels and yet still be light enough to work. Stroke and bore are calculated to be at a certain size but this is all still what any piston engine goes through.

The head shape is where the valves are, the camshafts are, the spark plugs are, and now the fuel injectors. They work on the shape of the intake and exhaust runners for maximum flow and swirl in the combustion chamber. Do the intake and exhaust runners want to be taller, shorter, wider, narrower, for best power? Look at an LS1. It's got tall narrow intake runners compared to the old Chevy V8's which had short rectangular intake runners. This was done for flow. You also have to consider where the spark plug is in the chamber. There has been much variation on this simple piece within such a small space. Now with direct injection, they have to figure out how to get an injector pointed in the proper direction in there as well. Are there benefits from changing the piston face shape to help with uniform air and fuel distribution?

I'm actually greatly simplifying a very complex deisng problem. Typically a new engine will start with parts from an old engine and they'll install a new head on it to try things to see what works. Then they'll go and change other things to see what they can improve. While certain concepts may start out on an old engine, by the time they are done, it may be an entirely different engine altogether. Sometimes someone will just design a new engine from the ground up. You never know.

mtrevino

Thought I would resurrect my old thread about engines to add this link to Autoblog on some videos they found about blocks and a re-build(?) of a 4G63. Videos like this help me understand engines more... and hopefully for some other members too.

http://www.autoblog.com/2007/02/10/v...d-in-under-10/

The first one is about the block and is pretty informative, who know that sand was an integral component?

The second one is irritating on some level, but kind of cool to watch. In the end, the engine, all dressed up, is frickin huge!

laters,
michael

Rasputin

Some new engine programs are based on previous engine hardware with some modifications. Some other engine programs, like the new Mazda I-4s (1.8, 2.0 and 2.3) are brand new. It all depends whether the older hardware can meet the new programs requirement without too much changes. These requirements can be technical (performance, fuel economy, refinement, emissions...) or financial (cost of manufacturing).

It seems that engine life cycles are reduced now due to the rapid changes in emission regulations and other factors. They seem to last for about 5 years now, whereas they lasted for 8-10 years befors with an update at mid-life. But it fluctuates a lot depending on the engine type and car manufacturer.

Yes, car manufacturers program offices gives a set of targets to the engine developpers. There is a lot of work done upstream as the program office also defines what hardware and technology will be used to actually achive the targets. Usually, they tray to develop a family of engine, using common hardware or technology but developping a range of performance, either by offering different capacities (like the Ford Zetec-E 1.6, 1.8 and 2.0), using perf-improving technology like VVT (like Ford Sigma 1.6 VCT compared to the regular 1.6), DI (Ford Lynx 1.8 TDCi based on older indirect injection harware) and/or force induction (like Saab I-4s).


The use of some technology for an engine family can be defined from the start, or come later for a new vehicle application.


I don't understand your question about ethanol and diesel.


For the specific 2.3 DISI Turbo engine, it seems they decided to use the existing 2.3 to create a high technology high performance engine derivative. But it does not mean it was all planned since the beginning of this family of engine.



Fabrice