Very Interesting Engine Design

[ke70dave]

A mate of mine sent me this link today, he is looking at buying a first generation honda. Thought i would share it here.

 

The honda CVCC engine, certainly no power house, debut in 1975, and using quite an interesting way of reducing emissions. have a good read of this, veerry interesting.

 

http://www.1stgencivic.com/world/c1zr/m1/forum/viewtopic.php?t=12770

 

There is a concept around known as the "homogeneous charge combustion igntion" (HCCI), which is basically a cross between a compression ignition engine (diesel) and a spark ignition engine (petrol). in which the fuel air mixture is pre mixed (like a petrol), but then is ignited via compression (like a diesel)

 

works ok in theory, not so good in practice (without adding complex support systems, but an interesting idea as well.

 

http://en.wikipedia.org/wiki/Homogeneous_charge_compression_ignition

 

both concepts aiming to burn a very lean mixture, and keeping temperatures down to reduce the N0x's. in an attempt to reduce over all emissiosn.

 

although the HCCI engine is still in development, it seems that this honda engine was quite a good attempt at this, and quite ahead of its time with the CVCC in terms of emissions!

 

it would be interesting to compare this engine, with the emissions of popular engines of today, ie ~36yrs later.

 

discuss....

[altezzaclub]

Very Honda... like everything about them..

 

Clever idea, beautiful, complex engineering, probably delicate and prone to rust! :laff:

 

You can see that fuel injection was the deathknell of carbs, an idea like this would be easier with an injector in the small chamber. Unfortunately injection has moved the problems from mechanical ones to electronic ones!

 

The latest ones put out cleaner air than they take in AND do it at 4.5L/100km!

[towe001]

Very Honda... like everything about them..

 

Clever idea, beautiful, complex engineering, probably delicate and prone to rust! :laff:

Honda S800. Roller bearings on the crank, chain drive to the IRS :P

 

Another interesting design that seams to be coming in favour with the hybrids

Atkinson cycle engine

Based on the typical otto cycle engine (aka 4 stroke engine) but the strokes are different

[clubby2084]

Quite interesting Honda did this 36 years ago.

Sounds like what Mazda are now doing with their "SkyG" petrol and "SkyD" diesel engines.

Huge compression on the petrol engine (around 14 or 15:1), and it's an NA engine too.

From what I've read it's similar principle. Big benifits in fuel consumption and emmissions.

Their achiving fuel comsumption numbers similar to hybrids and the (new trend) tiny turbo 4's.

 

No kidding, their working on a way to adapt this tech to the rotary engine to keep it viable. Including adapting it to run on diesel (true).

[ke70dave]

The latest ones put out cleaner air than they take in AND do it at 4.5L/100km!

 

I'm not sure i buy this...

 

maybe the the midst of a massive traffic jam they put out "cleaner" air than they take it, but its still air filled with chemicals, just chemicals considered not as harmful as other chemicals.

 

but i refuse to believe that a car traveling through the country side isn't degrading the air it pumps through its engine!

 

its almost like manufacture are going a bit backwards with the engine/car design. so the latest cars are able to get around on 4L/100, according the wiki, that civic is achieving ~5.9L/100....back in 1975. so they made the cars twice as heavy, and make the engines twice as economical, you are back to where you started in terms of economy:P

[carbonboy]

No kidding, their working on a way to adapt this tech to the rotary engine to keep it viable. Including adapting it to run on diesel (true).

 

I liked their hydrogen powered concept, pity that extracting pure hydrogen takes a lot of energy in the first place. :( Diesel rotary, I can hear the Wankel purists groaning already :lol:

 

its almost like manufacture are going a bit backwards with the engine/car design. so the latest cars are able to get around on 4L/100, according the wiki, that civic is achieving ~5.9L/100....back in 1975. so they made the cars twice as heavy, and make the engines twice as economical, you are back to where you started in terms of economy:P

 

I'm glad someone other than just me thought this... :yes: With additions of features like safety cells/impact absorption zones (nevermind GPS, Bluetooth, climate control, 26 airbags & electric everything), cars are of course going to increase in size &/or weight, but surely manufacturers realise that there's other gains to be had other than just increasing the efficiency of the engine.

 

As Top Gear proved with the Prius & the M3, the fuel economy figures are best-case scenario marketing numbers. If you drive a normally fuel efficient car like a Group B rally car, don't expect the fuel consumption figures to match up. :wink:

Edited August 15, 2011 by carbonboy

[irokin]

its almost like manufacture are going a bit backwards with the engine/car design. so the latest cars are able to get around on 4L/100, according the wiki, that civic is achieving ~5.9L/100....back in 1975. so they made the cars twice as heavy, and make the engines twice as economical, you are back to where you started in terms of economy:P

 

I don't think you can blame the manufacturers for the extra weight though. Its all mandated by the government, I believe you can't even sell a new car in Victoria anymore without active stability control. We're travelling down the route of "well we can't be bothered teaching people to drive properly so we'll make bubble wrap cars that drive themselves".

 

Also the patent system is probably f@$king up progress in the car world just as bad as it is in IT. Every vague thing that can be patented is being patented so you can't build anything anymore. I know its supposed to drive innovation but it just doesn't, the systems broken.

[ke70dave]

I don't think you can blame the manufacturers for the extra weight though. Its all mandated by the government, I believe you can't even sell a new car in Victoria anymore without active stability control. We're travelling down the route of "well we can't be bothered teaching people to drive properly so we'll make bubble wrap cars that drive themselves".

 

yeah i guess that was what i was sort of referring too, the rules and regs of the powers at be, dictating designs.

[Hiro Protagonist]

I'm not sure i buy this...

 

maybe the the midst of a massive traffic jam they put out "cleaner" air than they take it, but its still air filled with chemicals, just chemicals considered not as harmful as other chemicals.

 

but i refuse to believe that a car traveling through the country side isn't degrading the air it pumps through its engine!

 

 

I think it's a oft-thrown around misinterpreted statement - they don't actually CLEAN the air, but I believe it comes from the fact that if you feed clean air in, the output fron the tailpipe is still cleaner than the average air quality around an industrial town (which is believeable).

 

Clarkson and Top Gear haven't helped by saying it any chance they can get though (remember this is the same guy that says "horsepowers" and "torques')

[irokin]

'torques'

 

That annoys the hell out of me... he says it like there's some universally accepted measurement of torque. Most of the time I doubt its even the SI unit.

[Hiro Protagonist]

That annoys the hell out of me... he says it like there's some universally accepted measurement of torque. Most of the time I doubt its even the SI unit.

 

 

Considering how much they switch between HP/kW, km/miles, lbft/Nm (almost on an episode-by-episode basis), who knows what it actually is....

[Timofee]

agreee with the dude up top

would be

 

prone to rust n shit wouldn't it?

[clubby2084]

I liked their hydrogen powered concept, pity that extracting pure hydrogen takes a lot of energy in the first place. :( Diesel rotary, I can hear the Wankel purists groaning already :lol:

 

With incresing emission laws (particularly Europe, and Aust blindly following) diesels are on the way out. How Mazda are going to clean up a rotary to run on diesel is a bit of a head scratcher. Considering how dirty they are on regular fuel. But, they are persisting with the rotary because it is a very flexable engine regarding what fuel it will run on.

[irokin]

very flexable engine regarding what fuel it will run on.

 

Thoroughly pistol whipped by the gas turbine, even more so in the reliability stakes. They'll run on pretty much anything that can burn and be introduced to the combustor continuously. They've been run on diesel, alcohol, vegetable oil, hydrogen and even coal! I'm surprised that no ones really had a proper go (that I'm aware of) at developing a modern production car powered by one. The Chrysler turbine car was built in the 60's, material technologies have come a long way since then.

[Redwarf]

Here you are Ben. Here's one i prepared earlier.

 

I'm trying to fit it in a kesev, but I don't want to cut the firewall, and do you think I can still use the K50?