Potential engine mod? Otto to Atkinson conversion

[RH77]

OK, STOP and take a breath. This has become a shouting match.

I haven't been around much lately due to time issues, but I've noticed a trend whenever I do check in.

This is directed to christ. Saying "You seem to lack knowledge of the real world" is in poor taste and is not an EcoModder.com tenet.

To both wwest40 and christ: this Site has a firm foundation of stating sources of obscure or complex nature. Simply, Scientific methods of reporting is all we ask. MechEngVT was nice enough to intervene and mediate, but you both still continue.

I suggest that before this discussion continues, specific sources be stated (and preferably hyperlinked for quick/easy access).

-Rick / Moderator

[Christ]

/thread

For me anyway. I stated that clearly and concisely more than once.

[Mpower]

For the first time, Mazda launches an Atkinson version of their 1.3 liter in the Mazda2 resulting in a 20% FE improvemnt. No turbo, no SC, and no DI.

Mazda develops new NA 1.3L Miller-cycle engine for Mazda2/Demio

[Electric Frenzy]

Originally Posted by AndrewJ

So, there may be problems....


Can't seem to find any difinitive word on the HF's particular cycle (Atkinson/Otto)

sounds identical to the "miller cycle" engines used on the older Mazda Millenia S with superchargers. Smaller displacement with boost and funky timing/cam settings.

[theunchosen]

I'm not entirely certain this is a good move for Mazda. I mean everyone else is dropping off "new" GDIs that allow for substantial timing advance and much better compression and much better FE when they want to be without sacrificing HP. Costs more but the ability to run lean 45:1 is definitely worth it in my book.

[Mpower]

Originally Posted by theunchosen

I'm not entirely certain this is a good move for Mazda. I mean everyone else is dropping off "new" GDIs that allow for substantial timing advance and much better compression and much better FE when they want to be without sacrificing HP. Costs more but the ability to run lean 45:1 is definitely worth it in my book.

I see your point, but for a cheap 'n cheerful small car like the B-segment Mazda-2, turboDI or GDI may end up being too expensive. I guess Atkinson cycle NA is just a cam and calibration change which works out more cost effective. I just hope it sells so that the technology can live on.

[theunchosen]

Originally Posted by Mpower

I see your point, but for a cheap 'n cheerful small car .

The problem is the demio costs 10,000 #s. so 20K USD. Thats in the exact same price range as the GDIs. Like the Chevy Cobalt SS comes standard with with GDI and turbocharged at I believe base price is 22K. IF you bought a programmable ECU(or bought the software to reprogram the in car ECU) and ripped the throttle body off and then popped the cat and emissions off and made sure you maintained more than 30:1 you could stomp the Mazda 2.

<edit> I changed the price of the cobalt I typoed and said 2K. . .obviously not true lol</edit>

[evolutionmovement]

The Miller Cycle is a 4-stroke Atkinson cycle (technically, the type of Atkinson being discussed) with a supercharger added to make up for the power loss of Atkinson vs. Otto.

[theunchosen]

Yeah, which leaves me wondering why Mazda called it that. . .its neither turbo or super boosted. . .

[evolutionmovement]

There was an optional supercharged Miller-cycle engine (Millenia S, IIRC) they offered, but they weren't all Miller cycle.