How engines work

[mauvais]

The Mazda RX-8 has two of them.

Two?

It has two rotors, but that's not really two engines any more than a V8 is either two or eight.

 

[pseudonarcissus]

Oh interesting, I had no idea.

And to add a third option to turbocharging/supercharging, a marine long stroke engine generally has a crosshead, a vertical shaft between the piston and the prop shaft. This means the underside of the piston can be used to compress air to help the turbocharger out.

 

[existentialist]

Two?

It has two rotors, but that's not really two engines any more than a V8 is either two or eight.

Ah yes, that could have been clearer

 

[weltweit]

And to add a third option to turbocharging/supercharging, a marine long stroke engine generally has a crosshead, a vertical shaft between the piston and the prop shaft. This means the underside of the piston can be used to compress air to help the turbocharger out.

View attachment 185500

That configuration does permit a more conventional lubrication of the big and little ends avoiding the need to add oil to the petrol as is usually the case with (much) smaller two strokes.

 

[weltweit]

The graphics people have shown on this thread so far are really great, well drawn and showing the principles of their respective engines well.

I would love it if there was one for gearboxes which for quite a while flummoxed me. Eventually I gathered enough confidence to dismantle the gearbox of my 250 Yamaha and it wasn't nearly as complex as I had expected. Still I was very disciplined in laying out the cogs and main and layshaft and dogs etc in such a way that I could put them back in the order they came out.

Another thing I suspect many will not fully comprehend, and is very hard to explain in words, is a differential. The mechanism that converts the prop shaft from a gearbox into drive split between two rear wheels. (or front or 4wd even).

 

[StoneRoad]

Anyone got a graphic of a Napier "Deltic" to hand ?

 

[peterkro]

Oh interesting, I had no idea.

Also used in some large diesel locomotives, I worked for Clyde engineering in NSW on locomotives with V-16 two stroke diesel motors.

 

[weltweit]

This is quite good on differentials:

 

[weltweit]

Where did I see this? I saw a claim that cruise liners emit more CO2 than all the cars on the road. It seemed far fetched and I thought had to be wrong. Wish I could recall where I read it.

 

[mauvais]

Where did I see this? I saw a claim that cruise liners emit more CO2 than all the cars on the road. It seemed far fetched and I thought had to be wrong. Wish I could recall where I read it.

Carnival ships produce more sulphur oxide than Europe's cars: claim

The world's largest cruise ship and its supersized pollution problem

such a large ship would probably burn at least 150 tonnes of fuel a day, and emit more sulphur than several million cars, more NO2 gas than all the traffic passing through a medium-sized town and more particulate emissions than thousands of London buses.

 

[pseudonarcissus]

Carnival ships produce more sulphur oxide than Europe's cars: claim

The world's largest cruise ship and its supersized pollution problem

2020 is supposed to herald the era of low sulphur fuel in the shipping industry. Most of Europe is already a special area where low sulphur fuels are required.

The alternative is scrubbers to remove the sulphur from exhaust gasses...this is pretty big from a marine engineering perspective...we are expecting to see a lot of breakdowns...

 

[pseudonarcissus]

That configuration does permit a more conventional lubrication of the big and little ends avoiding the need to add oil to the petrol as is usually the case with (much) smaller two strokes.

I guess the downside is the added complexity of the crosshead sliding bearing, and crank case explosions are not unheard of..

 

[Spymaster]

The Mazda RX-8 has two of them.

RX9 coming out next year looks a bit tasty.