Why has this engine type never been used in a car/truck?

[300bhp/ton]

Not sure what limitations exist, but a Deltic engine certainly sounds very interesting. In terms of power to weight and fuel efficiency.

One wonders what more modern technology might bring to such an engine design and how it might mate up with modern 7 or 8 speed transmissions or event CVT's. Evidently it'd have to be a lot smaller physically but trucks, pick ups and large saloon cars could be potential options.

I'd much rather see car makers look at options like these than the current electric hybird fad.





Further reading: http://en.wikipedia.org/wiki/File:Napier_Deltic_En...


Or am I just a little bit mad???

[Hugo a Gogo]

not quite the same, but Commer trucks had an opposed piston engine
like a bank of three of those cylinders, six pistons

[shalmaneser]

They look clever but it's a hell of a lot of complexity for what gain? Three crankshafts for a start looks expensive! And the sheer size would be a nightmare!

Would be cool to see though.

[300bhp/ton]

shalmaneser said:

They look clever but it's a hell of a lot of complexity for what gain? Three crankshafts for a start looks expensive! And the sheer size would be a nightmare!

Would be cool to see though.

Don't know about costing, although no heads means less cost on that component. Yes the boat and train examples are huge, but so are boat and train in-line diesel engines. I was meaning more to downscale it a lot so that it physically is a similar size to a current DOHC V8/10.

[300bhp/ton]

doogz said:

and compared to modern day diesel 4 pots, it won't be all that efficient.

And your evidence for this is where....?

[8400rpm]

I can just see this being so horribly complicated to fit in a car, that any efficiency savings would be cancelled out with the extra production costs associated.

Nice idea though.

[HellDiver]

As huge and pointless as the V8 junk you seem so fond of, 300hp/t.

[dan19evans]

never seen that before. i think it would be too complicated to use in a car, such as trying to get 3 crankshafts to drive a single input shaft on the gearbox

[300bhp/ton]

doogz said:

300bhp/ton said:

doogz said:

and compared to modern day diesel 4 pots, it won't be all that efficient.

And your evidence for this is where....?

I don't have any evidence to show you. I had a discussion a while back with one of the lead power and propulsion engineers in work regarding these engines, as i'm sure you'll know, they have previously been used on warships, and he knows rather a lot more about them than i do, and i'd imagine, than you do.

Since you appear to be disputing this fact, do you have any evidence that suggests otherwise, or are you just being your usual argumentative self?

I believe I was asking, in which you have now answered. Cheers (no sarcasm intended).

[300bhp/ton]

HellDiver said:

As huge and pointless as the V8 junk you seem so fond of, 300hp/t.

wow that's a carefully, constructive comment you've made there

[The Wookie]

Perhaps rather ironically considering the OP, the only way I could see that being remotely feasible in terms of practically installing it and transferring the outputted power to the wheels without the vehicle being the size of a truck, would be to use a downsized version attached to a generator to use it as a range extender

[Superhoop]

Where to start.....

Three crankshafts - These would need to run through a gearing syetm to supply drive to one common flywheel

Size - I would think that plumbing it in would be a nightmare - Think what the exhaust system would look like

Lubrication - I would imagine that supplying lubrication to one that is pretty much static isn't a concern, but trucks are never stationary for long

Centre of gravity - Would be far higher than a conventional engine when mounted in a truck - It would also have at least one crank (high reotational mass) mounted very high up in the truck - Not good.

Modern Truck engines - Have been in development for years - They are now far more advanced than the average road car diesel engine, and far cleaner (For their size) All of this development would now need to start again

Maybe Rover should have taken up the idea though - No head gasket failures then......

[s2art]

I am sure you could make one thats small and light. And very efficient. But the cost would be much higher than a standard diesel. I dont see big packaging problems, it would be of comparable size to a V configuration of similar capacity.

[s2art]

doogz said:

s2art said:

I am sure you could make one thats small and light. And very efficient. But the cost would be much higher than a standard diesel. I dont see big packaging problems, it would be of comparable size to a V configuration of similar capacity.

The block might be, but as has been said, the cooling, inlet and exhaust systems, and gearbox will be a lot more complex and take up a lot more space than a V8, say, of similar capacity

I dont think so. Because of the double acting pistons,and the 'extra' cylinder across the top, you should be able to make a smaller engine than a similar capacity V8. That was one of the advantages of this configuration. Agreed some of that saving will get taken up with more complicated plumbing.

[300bhp/ton]

doogz said:

s2art said:

I am sure you could make one thats small and light. And very efficient. But the cost would be much higher than a standard diesel. I dont see big packaging problems, it would be of comparable size to a V configuration of similar capacity.

The block might be, but as has been said, the cooling, inlet and exhaust systems, and gearbox will be a lot more complex and take up a lot more space than a V8, say, of similar capacity

But would it?

The animated pic above shows a 6 cylinder engine. But it's only one cylinder deep in terms of size. If the Vee was of similar dimensions to a current V6 then it would be compact. I don't know what displacement this would actually be, but if the claims (Wikipedia) that is it more efficient in terms of power to weight you actually wouldn't want the same displacement to compare like for like or if you did, then a Deltic of the same displacement, built to the same scale would be physically smaller.

Plumbing would then only be slightly more complex, but I can't see it being insurmountable, it's only one extra intake and one extra exhaust. And many straight 6 engines use 2 into 1 tubular exhausts and twin turbo Vee engines have plenty of pipes.

Don't know about the gearbox, but evidently as these engines where used to drive generators in diesel electric trains and props on boats I'd wager to guess the single output shaft issue has already been solved.

And if the engine was shorter in length (which it would be I suspect) it'd give more room in the engine bay for the transmission and pipe work.

[Thudd]

I was wondering about this, while watching Chris Barrie's Massive Engines. Led me on to wondering about petrol equivalents, and wankels.

As for gearboxes and driveshafts - how about rigging one up to a hybrid car, in a similar way to a diesel electric train?

[s2art]

300bhp/ton said:

doogz said:

s2art said:

I am sure you could make one thats small and light. And very efficient. But the cost would be much higher than a standard diesel. I dont see big packaging problems, it would be of comparable size to a V configuration of similar capacity.

The block might be, but as has been said, the cooling, inlet and exhaust systems, and gearbox will be a lot more complex and take up a lot more space than a V8, say, of similar capacity

But would it?

The animated pic above shows a 6 cylinder engine. But it's only one cylinder deep in terms of size. If the Vee was of similar dimensions to a current V6 then it would be compact. I don't know what displacement this would actually be, but if the claims (Wikipedia) that is it more efficient in terms of power to weight you actually wouldn't want the same displacement to compare like for like or if you did, then a Deltic of the same displacement, built to the same scale would be physically smaller.

Plumbing would then only be slightly more complex, but I can't see it being insurmountable, it's only one extra intake and one extra exhaust. And many straight 6 engines use 2 into 1 tubular exhausts and twin turbo Vee engines have plenty of pipes.

Don't know about the gearbox, but evidently as these engines where used to drive generators in diesel electric trains and props on boats I'd wager to guess the single output shaft issue has already been solved.

And if the engine was shorter in length (which it would be I suspect) it'd give more room in the engine bay for the transmission and pipe work.

Correct. From Wiki;

'Development began in 1947 and the first Deltic unit was produced in 1950. By January 1952 six engines were available, enough for full development and endurance trials. S212[citation needed], a captured ex-German E-Boat powered by three Mercedes-Benz diesel engines, was selected for these trials, since its power units were of approximately equal power to the new 18-cylinder Deltic engines. Two of the three Mercedes-Benz engines were replaced with Napier Deltics, the compactness of the Deltic being graphically illustrated: they were half the size of the original engines. The Deltic weighed one fifth of its contemporaries of equivalent power[1].'

[Superhoop]

300bhp/ton said:

But would it?


Plumbing would then only be slightly more complex, but I can't see it being insurmountable, it's only one extra intake and one extra exhaust. And many straight 6 engines use 2 into 1 tubular exhausts and twin turbo Vee engines have plenty of pipes.

One extra manifold would actually be two (Vee's use a common manifold for both heads)

As for plumbing, it would be a bloody nightmare..... It's likely that it would need turbo's to make it a) as efficient as possible and b) as clean as possible and c) to maximize torque at low rpm. So that's 3 turbchargers (a Vee runs 2) and three lots of interconnected intercooler pipework, going to three manifolds......

In all honesty, as I said earlier, Commercial vehicle diesel engines are far more advanced than road car diesels - If this was a better idea, then it would have been taken up years ago. As for it being shorter, what would be the point?

[warmfuzzies]

God the speculation.

Where to begin, having built a number of these over the years.......


Damned expensive, and I mean expensive. when I left the 42K's that we were building for the Indian navy were over a £1M each, thats in 1984.

The 59ks were cheaper, but far less powerfull.

Very very light, but hugely complex, specific fuel consumption was an issue, we could never get them as good on juice as a simple four stroke, say like the RP200 either 12 or 18cyl versions.

Very labour intensive to build, 1000's of man hours each, the complexity of assembly with large ovens for the crankcases, and small vats of liquid nitrogen were a hoot,(dropping large bearings into the cases etc) the knife edge seals could be daunting if the fit and finish were not 100%, so oil would leak internally and not supply the bearings properly.
Hylomar everwhere, so the face finish of any matting edges was critical.
Big torque wrench and multiplier were the order of the day. the cyl liners were 1000ft/lbs.



But they are a flipping great engine, and I miss working on them.

kevin

[s2art]

Superhoop said:

300bhp/ton said:

But would it?


Plumbing would then only be slightly more complex, but I can't see it being insurmountable, it's only one extra intake and one extra exhaust. And many straight 6 engines use 2 into 1 tubular exhausts and twin turbo Vee engines have plenty of pipes.

One extra manifold would actually be two (Vee's use a common manifold for both heads)

As for plumbing, it would be a bloody nightmare..... It's likely that it would need turbo's to make it a) as efficient as possible and b) as clean as possible and c) to maximize torque at low rpm. So that's 3 turbchargers (a Vee runs 2) and three lots of interconnected intercooler pipework, going to three manifolds......

In all honesty, as I said earlier, Commercial vehicle diesel engines are far more advanced than road car diesels - If this was a better idea, then it would have been taken up years ago. As for it being shorter, what would be the point?

Well, smaller and lighter for a given power output. I dont see that there would be more than one inlet manifold or intercooler. Agreed three turbochargers would be nice, but is that such a big deal?
The main reason nobody took up this configuration is that they are expensive to build and only useful if you need a very high power, lightweight diesel engine.