Mazda have announced a motor with the old principle of compression ignition and more efficient.
Max.
https://ca.yahoo.com/finance/news/m...-longer-term-strategy-044456888--finance.html

 

Rather a cross between a Diesel and the Otto cycle.
It would seem the big trick is avoiding pre-ignition at high power outputs.

 

How is this any different than just a diesel engine running on gasoline? I'm not minimizing the work it probably took, but is it really that big a deal?

 

How is this any different than just a diesel engine running on gasoline? I'm not minimizing the work it probably took, but is it really that big a deal?

Well if it increases efficiency as they say, up to 30%, then that is a good deal.
Max.

 

Well if it increases efficiency as they say, up to 30%, then that is a good deal.
Max.

Well, compared to what exactly? A typical ICE on the road today might be at 25% thermal efficiency while there are commercial engines approaching 50% and beyond (see Toyota 1GD-FTV - 2,8 liter Diesel). Claims of 30-50% increases in ICE efficiency hit the press every week or so. Few make it to market. So a claim of 30% improvement over existing 25% thermal efficiency is a big yawner.

 

Mazda have announced a motor with the old principle of compression ignition and more efficient.
Max.
https://ca.yahoo.com/finance/news/m...-longer-term-strategy-044456888--finance.html

A mechanical engineer friend explained to me why this is indeed a big deal if they’ve really done it. In short, it directs more of the explosion energy into pushing the pistons. Better than diesel or traditional ICE.

 

All the RC Aero motors were compression ignition in my youth, glo-plug were rare.
Max.

 

So a claim of 30% improvement over existing 25% thermal efficiency is a big yawner.

Ype. I've gained that approximate average many times on vehicles just by eliminating their emissions systems and retuning for efficiency. Granted late 70's to mid 90's emission compliance defining left a huge amount of performance to be hadn on a lot of engines compared to today but still it was not hard to pick up some pretty good gains on most everything.

 

One advantage of the homogeneous charge compression ignition (HCCI) engine is that it does not have a high temperature flame-front like an injected Diesel or spark ignition engine, as it ignites more or less simultaneously in the whole volume of fuel-air once ignition temperature is reached.
Since the high temperature front is what produces much of the nitrogen oxides, the HCCI engine produces less nitrogen oxides (which Diesels have a particular problem with, and is where VW cheated with their "Clean Diesel" by trying to avoid the addition of the common urea nitrogen oxide reduction system for Diesels).
But since the HCCI engine has a compression ratio comparable to a Diesel and burns the fuel faster, it gets comparable or better fuel economy.

 

Ype. I've gained that approximate average many times on vehicles just by eliminating their emissions systems and retuning for efficiency. Granted late 70's to mid 90's emission compliance defining left a huge amount of performance to be hadn on a lot of engines compared to today but still it was not hard to pick up some pretty good gains on most everything.

As long as you aren't concerned about breaking the law or how how dirty you make the engine.

 

As long as you aren't concerned about breaking the law or how how dirty you make the engine.

In my state emissions compliance is not enforced at the public level being my state government does not believe in it's supposed value and necessity. Once you own a vehicle or piece of machinery you can do whatever you want to it to make it better.

 

Mazda have announced a motor with the old principle of compression ignition and more efficient.
Max.
https://ca.yahoo.com/finance/news/m...-longer-term-strategy-044456888--finance.html

The day they're able to use this technology on a Wankel engine I'll be the very first to buy one... Wikipedia has added an HCCI section to its article about the Wankel engine.

 

The day they're able to use this technology on a Wankel engine I'll be the very first to buy one... Wikipedia has added an HCCI section to its article about the Wankel engine.

Didn't realize they were still alive!
I remember seeing the first outboard with that motor at the London Boat show, must have been the 50's!
Max.