Comments by "John Burns" (@johnburns4017) on "driving 4 answers" channel.

  1. Volvo cars had a high percentage of British content. Hepolite pistons for example.
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  2. One of these engines was built and inserted into a Ford Granada in England - about 25-30 years ago. It gave far more torque, especially at the low rev range, reducing the size of the transmission, or if designed right for a particular car, and body designed for the engine, no transmission at all. The flat boxer-type arrangement also gave a lower centre of gravity. It was pretty smooth going by reports, which was encouraging.
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  3.  @toyotaprius79  And what relevance is that?
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  4.  @brianmack6285  Small size and weight in a hybrid engine is quite important for packaging in a car. The engine will by nature be a part time engine that will be rarely used, so fuel consumption when running on the ICE engine is not important at all. This is where rotaries score highly and even more added value in the smoothness.
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  5.  @brianmack6285  There is a Nissan car available that has a piston engine turning a generator only that powers an electric traction motor. It is simple and reasonably economical. High efficient electric motors improve matters.
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  6.  @advorak8529  In cars sometimes known as an electric transmission, as it replaced the gearbox. But performing like a CVT gearbox with no stepped gears - sort of.
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  7. 1) Cams and chains wear. After time engine performance deteriorates. With freevalve it does not. 2) Cams make a big impression on oil wear. With camless the oil lasts longer. That is why fully synthetic oils are superior in engines, they resist such severe compression. 3) With cams you need a more powerful oil pump which takes power from the engine. With Freevalves this is not a problem. 4) Oil lasts longer, so change intervals are longer. 5) The engine is physically smaller and lighter, a knock on for better fuel efficiency.
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  8. Any engine that has pistons that move 180 degrees is going to have problems with efficiency.
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  9.  @natural_law  Yes, very reliable.
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  10.  @jimmydesouza4375  wrote: "Battery tech hasn't improved since the 90's." Are you kidding!
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  11. Look at the disc yolk Cross engine. A British design from 40-50 years ago. Similar to the Bourke engine with a cylinder on each side at 90 degrees to each other. But employing a disc yolk not a sliding Scotch yolk. No sliding parts in the yolk, all rotational. No swiveling con-rod. Two horizontally opposed pistons in all one solid casting. A version had stepped top hat pistons, with two chambers working as a two-stroke. One chamber was to scavenge. A wow design at the time, and still today.
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  12. Wavey thing = Swash plate. Not a new idea. But I like it. Used in Stirling engines.
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  13. So a smaller engine can be used, which is the prime advantage.
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  14.  @MeNanWazaHowitzer  One stroke is a power stroke with one stroke of the piston in a single cylinder engine.
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  15.  @whatelseison8970  We recognize strokes using a one cylinder engine.
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  16.  @midnight.a3  Difference please?
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  17. This design eliminates secondary vibrations, the prime aim. It is a compromise. For eliminating secondary vibrations the negatives of the sliding Scotch Yolk have to be considered and accepted. The negatives of the Scotch Yolk may be worth it because of superior gains elsewhere. In short, it depends on the target application of the engine.
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  18. Such high tech to make an extremely low tech product.
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  19. The eight cylinders is really four cylinders. The opposed cylinders have the same centre line. It is four cylinders with the crank take off in the middle of the cylinder. The arrangement reduces piston side thrust, and hence friction.
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  20. The Volvo 100 series introduced in 1966, was to compete with the Austin Cambridge which was a big seller in Sweden.
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  21. The application of a constant speed generator (range extender) is ideal for a Scotch Yolk. As a range extender, the engine by nature will be a part time engine, giving longevity. The problem with a Scotch Yolk is the lubrication of the yolk at high revs and varying speeds. This problem can be eliminated using it at a constant speed, with revs as low as can be. Lower constant revving is possible as the engine generates more torque at lower revs. A lot of oil is lost from the yolk bearing to the sump pan, as oil drops from the yolk bearing to the bottom of the engine, compared to traditional big end bearings, so a larger pan of oil may be needed. Unlike traditional big end bearings where a small amount of oil gathers in the bottom of the bearing when the engine is off ready for turning over the engine, no oil gathers in the Scotch Yolk's sliding bearings. The oil pressure may need to be primed, with a small electric priming pump, before the engine turns over, to get sufficient oil to the yolk bearing before movement. This gives a small light package for fitting in out of the way locations in vehicles. The only other engine of this size and weight will be the new Wankel engine being used as a constant speed range extender in the new Mazda MX-30
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  22. The long combustion stoke of a Wankel engine helps here, but only when burning hydrogen. When burning hydrogen Wankles are around 23% more efficient as hydrogen burns far quicker ensuing all the mixture in the chamber is burnt. Current fuels are not suited for Wankels.
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  23. Turbo is taking energy out the back of the engine then putting it back into the front (including a turbojet). This could be in the form of pushing more air into an engine, or sending the waste energy back into the output shaft giving more power. The centre compound cylinder falls into this. When you add extra centre compound cylinder, there is extra weight, size and friction losses. Exhaust turbos sending more air into the cylinders, are about the best at sending energy out the back and putting it back into the front. I do believe an aero engine had an exhaust turbo that was mechanically attached to the crank, not sending more air into the cylinders. I believe it was more efficient but only when operated under certain revs and conditions.
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  24. The ICE is slowly dying. The end will be quick.
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  25. Modern fully synthetic oils have a very high boiling tempetature.
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