Thread: Land Rover reveals engines of the future

Originally Posted by Hay Ewe

Repair by replacement?

it surprises me still that basically IC engines are still the same, pistons, valves, large amount of head above the cylinder. All they are doing is changing the structure and technology around the center to reduce the emisions and reduce the friction losses.
If they can reduce the heat lost, that would be good as well

Orbital Valves to me seem a better alternate, less rotating mass, no springs etc but sealing them is the problem. Maybe the seals need to become a driver replaceable item? ha ha, like that is going to happen these days - or at least a 30 minute job.

Hay Ewe

Google Bishop rotary valves,designed by an Australian. Pat

Originally Posted by PAT303

Google Bishop rotary valves,designed by an Australian. Pat

I have book marked this thread to review later and follow the hyperlinks and red up
thanks

Originally Posted by Gerokent

I entirely agree. But as I stated "If there had been more reserch and development in previous years, the alternitaves MAY have come a long way further than they have"
In regards to fast re-fueling and extended range, what about hydrogen cell.
How many ideas have been brought up and shelved by the oil companies?
And are we really making less emissions from these modern engines, think about all the extra manufacturing that takes place and the NON-longevity of the engine its self. They are a throw away item.

Nope.

Simple analysis of the thermodynamic cycles of these alternative engines can be done in a few minutes and show you the limits on their efficiency

This is the first test of any proposed engine and it's enough to throw out virtually all alternatives immediately.

The remaining alternatives are usually ruled out easily with manufacturing difficulties that outweigh any benefits they may have.

Originally Posted by PAT303

You have to ask why we are still using 4 stroke engines,planes,ships,trains have all moved on from sail,steam,piston engines but vehicles are still the same as they were 100 years ago,the reason is no other type of engine can idle around a car park one minute and drive at 110 on a freeway the next without any issue's other than changing gears and putting your foot down.There is no other engine that can do what your basic 100 year old 4 stroke ICE can do. Pat

Hydrostatic drive, electric drive, (CVT transmission to some extent) vehicles have no need for engine revs to vary, so that vairable can be discounted.

For that to work the engine would need to be at top rev's all the time then,thats not really viable then is it?,and what powers the gearbox?,a 4 stroke ICE. Pat

Originally Posted by Gerokent

Hydrostatic drive, electric drive, (CVT transmission to some extent) vehicles have no need for engine revs to vary, so that vairable can be discounted.

No it can't. The most efficient gearbox on the planet is a manual gearbox.
Automatic torque converter gearboxes are slightly worse, cvt and hydrostatic are much worse in efficiency. Not to mention the weight penalty.

Introducing a big driveline inefficiency is not going to improve fuel economy.

An engine is at it's most inefficient when accelerating from low revs to high revs under load, it does this every time you change gears. When an engine is at higher revs and no load it can go to a loaded condition with not much loss of efficiency. This negates the savings (wear and tear, fuel usage), from vairing the engine revs all the time. This is the claim of the CVT.

Originally Posted by Gerokent

An engine is at it's most inefficient when accelerating from low revs to high revs under load, it does this every time you change gears. When an engine is at higher revs and no load it can go to a loaded condition with not much loss of efficiency. This negates the savings (wear and tear, fuel usage), from vairing the engine revs all the time. This is the claim of the CVT.

If your engine is using high rpm on every shift then it likely needs a better control unit.