Six stroke water injection internal combustion engine?

[mrtwisty]

Hi all, had a quick (Google) search for this but can't see a thread on PH for it:

http://www.damninteresting.com/the-six-stroke-engi...

So.... What's the catch? Could it be developed successfully for mass production? Interesting 'man in a shed' roots anyway :-)

[Pistom]

Didn't Rover build a 6 stroke engine using the same principal? They never fitted it to a vehicle as they had various practical issues and it got ditched but with enough development, converting waste heat to motive power must be a good thing.

[aarondbs]

Certainly sounds interesting though I'm no automotive expert and hope there's no wind up involved

[TinyCappo]

Truly an amazing Idea! It would have to use some kind of direct injection system though. Amazing in principal especially if you can remove the coolant system but im guessing you would still need some kind of oil radiator.

[mrtwisty]

Where's Max Torque when you need him.....?

[anonymous-user]

Unfortunately, like most of these ideas, it's the application of these kinds of "energy efficiency" ideas that is the hard bit.

Now, on his bench, that 6 stroke engine probably works, but lets go into a virtual meeting with an OEM and see what happens:

OEM: so, what are the effiency gains:
Inventor: oh, at least 30%.
OEM sounds good.
Inventor: you do need to carry several hundred litres of water however
OEM: er, ok, what about the exhaust emissions, does it meet EU6?
Inventor: er, no, the cold exhaust means conventional exhaust catalysts don't work with it
OEM: ah, oh, ok, what about oil life?
Inventor: I don't know, i've never tested it,but the sump does get a bit "gunged up" after an hr or so
OEM: I see. So will it work between -30 and 50degC?
Inventor: Er, no, the water freezes below zero.
OEM: right, and what about exhaust line component corrosion?
Inventor: Not sure really, i guess everything would need to be made out of stainless steel perhaps?
OEM: And does it work with turbochargers?
Inventor: No, not enough exhaust heat energy, ah, and you need a seperate cabin heater too by the way.
OEM: Um, right, i see.......


So, to leverage that extra efficiency, the OEM has to completely redesign, and redevelop there existing vehicle platforms. Never going to happen, sorry......

[Steffan]

Max_Torque said:

Unfortunately, like most of these ideas, it's the application of these kinds of "energy efficiency" ideas that is the hard bit.

Now, on his bench, that 6 stroke engine probably works, but lets go into a virtual meeting with an OEM and see what happens:

OEM: so, what are the effiency gains:
Inventor: oh, at least 30%.
OEM sounds good.
Inventor: you do need to carry several hundred litres of water however
OEM: er, ok, what about the exhaust emissions, does it meet EU6?
Inventor: er, no, the cold exhaust means conventional exhaust catalysts don't work with it
OEM: ah, oh, ok, what about oil life?
Inventor: I don't know, i've never tested it,but the sump does get a bit "gunged up" after an hr or so
OEM: I see. So will it work between -30 and 50degC?
Inventor: Er, no, the water freezes below zero.
OEM: right, and what about exhaust line component corrosion?
Inventor: Not sure really, i guess everything would need to be made out of stainless steel perhaps?
OEM: And does it work with turbochargers?
Inventor: No, not enough exhaust heat energy, ah, and you need a seperate cabin heater too by the way.
OEM: Um, right, i see.......


So, to leverage that extra efficiency, the OEM has to completely redesign, and redevelop there existing vehicle platforms. Never going to happen, sorry......

Very informative reply. And pretty comprehensive.

Without wishing to hijack the thread the Hydrogen engine has been variously proffered as the future power source. From what I can see it suffers from equally unsolvable cost and development needs. Is that dead duck also? Please. Apologies to the OP.

[mrtwisty]

Haha, thanks MT, informative as always.

[Pistom]

Max_Torque said:

Unfortunately, like most of these ideas, it's the application of these kinds of "energy efficiency" ideas that is the hard bit.

Now, on his bench, that 6 stroke engine probably works, but lets go into a virtual meeting with an OEM and see what happens:

OEM: so, what are the effiency gains:
Inventor: oh, at least 30%.
OEM sounds good.
Inventor: you do need to carry several hundred litres of water however
OEM: er, ok, what about the exhaust emissions, does it meet EU6?
Inventor: er, no, the cold exhaust means conventional exhaust catalysts don't work with it
OEM: ah, oh, ok, what about oil life?
Inventor: I don't know, i've never tested it,but the sump does get a bit "gunged up" after an hr or so
OEM: I see. So will it work between -30 and 50degC?
Inventor: Er, no, the water freezes below zero.
OEM: right, and what about exhaust line component corrosion?
Inventor: Not sure really, i guess everything would need to be made out of stainless steel perhaps?
OEM: And does it work with turbochargers?
Inventor: No, not enough exhaust heat energy, ah, and you need a seperate cabin heater too by the way.
OEM: Um, right, i see.......


So, to leverage that extra efficiency, the OEM has to completely redesign, and redevelop there existing vehicle platforms. Never going to happen, sorry......

Pretty much what Rover found before they went on to play with jet engines. Neither took off.

[BULLITT Rich]

Pistom said:

Pretty much what Rover found before they went on to play with jet engines. Neither took off.

Pun?

[AJB]

I'm probably very wrong, but I seem to remember that the Carnot cycle is more efficient at higher temperatures? I thought that's why there's a benefit in manufacturers coming up with complex designs to allow hotter thermostats. If so, wouldn't that efficiency all be lost in a design which drops the Carnot cycle temperature? I guess it'd be less of a loss than the gain from using waste heat productively though.

[Pistom]

Max Torque summed up the challenges very well. All could be overcome but is someone going to fund the development costs for 30% efficiency in theory?

I believe it was a Hungarian by the name of Birner Tibor who first played with 6 stroke ideas in the early 1900s and it did get as far as a running engine that was used to power farm equipment.