how come ?

It was designed very conservatively, without the benefit of modern materials and for 24/7. It will also still be running on its 100th birthday (assuming that liquid fuel is still available then). hth

Design, Manufacture materials, tuning all manner of reasons. The modern engine of today obtains its HP by rpm and being made from light alloys an old CS diesel is basically cast iron through out and to spin for instance a cast flywheel at speed is asking for self destruction.

There isn't a simple answer, so I'll try to be simple in parts!

Firstly, the technology of stationary engines was always way behind the automotive world. Old technology is cheaper to produce, simpler and easier to maintain.

Cast iron was the material of choice. Weight was rarely a factor and the techniques of casting and machining CI were a hundred years old. As the designs were simple, machining could be achieved on out-of-date machine tools. Additionally, a heavy engine is less susceptible to out-of-balance forces and the very mass of the castings serves as a vibration damper.

As Roland has said, they were designed to give long service, far longer than might be expected from an automotive unit. Bearing surfaces were huge and moving parts massively made in relation to the expected loads. Because of this, it is not uncommon to find large engines that only need basic TLC to get them going , although it is true that a lot of the Amanco's (etc) of this world were utterly worn out when they were pushed into the back of a barn after fifty years hard work!

Frugality was an important factor and it has always puzzled me that more time and money was not spent on devising better carburettors. It is probable that this was sacrificed in the interests of build price as there was an expectation that the engine would run at a more or less constant speed.

Finally, the mobile stationary engines would be operated by clumsy farm labourers and inept industrial workers. They had to be simple in a way that we find it hard to comprehend. This isn't true of very large engines and marine units. These were always looked after properly by trained men and are often quite complicated and full of innovative ideas.

I would have expected the Second World War to have been a great watershed and for engines to get more complex thereafter. True, the trend towards light alloys and smaller, high speed units did slowly take over, but units in production pre- (or during) war like Lister D's and Wolseley WD's continued for decades after the war was over and still predominated in the farming markets. Interestingly, there seems to have been a movement to educate the service personnel to look after engines better in the field. However, this met with much less success than one might expect, particularly with petroil lubricated two strokes where "forgetting" to put the oil in the petrol was far more frequent than common sense allows.

A knackered engine might mean a skive, after all!

regards,

Kim Siddorn.

Post hoc, ergo propter hoc!

In message , Motor writes

They were "built to last", that's why. I have a CS 6/1 that came from the factory in 1950. It had run all sorts of things on the farm, and then been left out in the rain for a (long-ish) while. Rain had run down the exhaust and into the pot, sticking up the exhaust valve while it was at it. I got it all apart only to find that under all the muck it was like new - really like new. The big-end bearing looked as though it had just come out of a box full of tissue paper and there was no discernible bore wear. I paid for a set of rings, a reconditioning of the injector and a decoke gasket set. I imagine that it will run for another 55 years once I put it back together :-)

Somehow I just can't imagine my little Briggs and Stratton 2.2KVA genset running for 55 years. I imagine that five years might be stretching it.

Finally, a local scrap dealer of my acquaintance tells me that his dad had Lister CS diesels for lighting plant. They were never decoked mechanically - if they got clagged up, his dad would run them on paraffin for a couple of hours until the flames died down in the exhaust pot. He didn't tell me how long his dad's engines lasted, mind you.

TTFN

Pete

Mostly it is due to evolution and development. My 1930 5 hp Petter M has a cubic capacity in the region of 1300 cc. A 1970's 1300 cc Ford escort aspired to about 35 hp. A modern 1300 cc car manages between 60 hp and maybe

100 hp and more.

Most stationary engines were designed for longevity and were significantly under-stressed to achieve this. As an illustration, my Mini Cooper S of 1966 vintage pushed out about 60 hp (IIRC) and was probably good for 80,000 miles (perhaps), I tuned it to death and at one point it was pushing out just over

100 bhp, it was b*****y quick for the time but fell apart after about 20,000 miles (brand new engine but thoroughly thrashed)! With modern metals and manufacturing tolerances, 100 bhp out of 1300 cc is probably good for 100,000 miles and then some!

It's all down to technology and materials available and desired longevity. What do you want from a stationary engine - 1000 bhp for the equivalent of 3 hours (as in a Formula 1 car) or 5 bhp (which is ample for a lot of 20th century farm related activities) for 50+ years? Personally I'd love a 1000 bhp screamer but then I don't have a need to generate a couple of kilowatts of electricity for the next 50 years! :)

Regards

Mark

Not necessarily. Modern cars have cast flywheels and are safe for 6000 rpm. I have certainly taken a cast flywheel to 8000 with no concerns. Admittedly the diameter is smaller than a Lister but at a higher speed, less flywheel effect is needed.

John