MegaSack DRAW - This year's winner is user - rgwb
We will be in touch
https://www.engadget.com/2017/08/08/mazdas-engine-breakthrough-promises-big-fuel-efficiency-gains/
If this is what it seems, it could be the answer to the liking for diesel engines, fuel efficiency and torque, but without the NO2 and particulates that diesel produces.
They've managed to produce a compression-ignition petrol engine, available from 2019, so this could be the best link between current I/C engines and developing extended range electric engines.
Although the Americans seem to have accidentally invented a way of producing hydrogen from water with a special alloy made from scrap aluminium, which could make hydrogen-powered cars a real possibility without needing anything more than a tank of water!
I'll try to find the link to that in a bit, but things are looking very interesting indeed.
I was reading about the Mazda in Autocar, they were suggesting it was going to be a very lean burn engine under low loads, closer to stoichiometric under full load. I had always understood lean burn and 3way cats don't get on well, so I wonder how they have got round this potential hurdle
Mazda director Kiyoshi Fujiwara, who have oversight of the firm's R&D programme, explained that this “very lean air-fuel mixture that is too lean to combust by spark ignition [alone] can combust by this method cleanly and rapidly”. He added that this enables "better thermal efficiency, improved fuel economy and lower nitrogen oxide emissions". Other benefits include higher efficiency across a wider range of revs, thus improving engine responses and performance.
https://www.autocar.co.uk/car-news/industry/groundbreaking-mazda-skyactiv-x-petrol-engines-be-‘cleaner-electric’
Its still theoretical.
I know you're emotionally committed to burning stuff cz but its just energy, doesnt really matter what makes the tin boxes move does it?
The burning stuff market is tanking(pretty good time to buy a van imo) they'll all be falling over themselves to make electric now but dont worry they'll also be advertising it so you'll feel good about wanting it, consider it asperational etc. I expect to see an electric hierarchy developing very soon.
Always wondered why they never did a compression ignition petrol engine.
Always wondered why they never did a compression ignition petrol engine.
I thought that was "detonation" and melts pistons..
Detention doesn't melt pistons, on the contrary detention is incomplete, inefficient and poor combustion. Its the shock that causes damage to engines as you've effectively got an explosion going on instead of a controlled flame that burns hotter and burns alot more of the fuel. That is that rattly noise you hear when your engine is knocking - well not so much with modern engines that have knock control systems.
These new engines vary compression ratio so use a Diesel cycle at low power levels and engine revs to maximise economy where detonation can be controlled, but if you demand more performance from the engine the compression ratio reduces and the engine reverts to spark ignition to deliver the performance.
They've been working on these for years. I first read about them about 10 years ago where Mercedes had an engine on a test bed. The challenge is not in the mechanics of it, but in the control of the whole thing. Lots of parameters to control. Mercedes were using engines with eccentric little end bearings to vary the stroke of the piston to manage compression ratio. Other manufacturers were using systems that raised and lowered the cylinder head somehow to vary compression ratio. So a whole other order of magnitude of complexity going on.