Nice animation. Note that the two top crankshafts should rotate clockwise and the bottom crankshaft anticlockwise. The exhaust piston leads the inlet piston by 20 degrees, and charge air is supplied to all three banks by a single blower.
Thank you. I honestly wouldn't have known that. I appreciate corrections (so long as they're correct, of course) VERY VERY much!! ...and so do a LOT of others! I felt someone should at least take the time to say thanks, if you took the time to explain that. Thanks again 👍
Napier and sons never shied away from a challenge and created some legendary engines in their time. I love how the Deltic’s opposed pistons offset makes one piston working as inlet valve and the other as exhaust. The gearing needed to connect cranks and driveshafts to the blowers must have been very complicated, The noise probably incredible, servicing a challenge and the lubrication system must have been a plumber’s nightmare. I’ll probably never lay my hands on one of these brutes, but it is an absolute favourite.
As a child I would wave my father off as he took the train to London, powered by one of these engines. To this day it is one of the best sounding engines I have ever heard, a truly unique sound that just reeks of power, that pounds through your chest and into your soul.
yeah, and no HAXM series Paxmans were ever fitted to a locomotive only marine applications.I assume you mean the Paxman Valenta RP200L that was in the HST's?Even so, they don't come close, not even in the same ball park as a Deltic!
I mean 12YHAXM. I own, and live on, a retired minesweeper. I started out with the original engines, albeit de-rated following the removal of the turbos. Too big to manage for one person though, everything about them was overcomplicated. Fuel pipes were a nightmare, as was the cooling system. They did sound lovely, even from 200meters away. I have only once heard Deltics, and they were similarly orgasmic.
@R75Sidecar The there crankshaft know as AB, BC and CA are geared at the back end of the engine. These gears are called as 'phasing gears' and keep three crankshafts synchronized and used to drive additional components such as oil and water pumps. The output power is transmitted to a single shaft located at the center of the engine from phasing gears.
Thank you for your clarification. When I do these animations I do to best of my knowledge at the time. I spend quite a long time pondering on the drawings without seeing any real mechanism. As a result I make mistakes. Thanks to comments section of UA-cam people correct my mistakes.
I think actually these amazing opposed piston engines are similar to split-single engines. They are a straightened versions of the split single. So this tri-opposed piston engine is analogous to a split single with 3 combustion ports 120° apart and they power a swash/wobble plate or a spider gear underneath them (as crankshafts)
una volta sola mi è capitato di mettere le mani su uno di questi motori , era un motore navale montato su una barca da pesca molto interessane e molto compatto , con un " rumore " molto particolare ... complimenti per il video e le spiegazioni grazie
Exhaust piston leads intake piston by 20deg, fixed by geometry. One crankshaft turns backwards (should be bottom one, not righthand one as shown in this animation.) If the two cylinders connected to this had pistons perfectly in phase, 3rd cylinder would have pistons 60deg out of phase. In practice the 60deg is spread evenly between 3 cylinders, 3x20deg. Max compression occurs with one piston at +10 and the other at -10. Both pistons are at cos(10)=98.5% of the way to top deadcentre. Ingenious.
This engine in minesweepers had a 2 stage supercharger on the front driven by a shaft through the hollow center triangle from the gearbox on the back. The shaft could twist 3/4 of a turn without snapping. The engine was started with a cartridge in a 6-barrel starter pack, like a 6-gun. It had a dry sump, an oil supply tank and a scavenge pump to take the oil out of the engine.
@AwesomenessPrime427 There has to be timing gear set keeping all the crankshafts as well as blowers operating together.That engine must have had quite a large gearset to withstand all that torque,but with that design it must have had a great power to weight ratio.
@ben44rain Here are two comments that I find from internet about these engines. The first comment is "These engines were very powerful for weight, and efficient, which made a single railway engine able to sustain 3,300hp., unlike to conventional engines, 2 or 4-stroke which could make little more than 2,000hp." The second comment "Deltic Engine only real Achilles Heel was a tendency to leak oil from the crankcase into the bottom cylinders when not running:."
It does have a very good power/weight ratio, even by two stroke standards. Although it has three cranks it has no cylinder heads, no valves and only the bottom crank has to be built up as a proper structural crankcase and sump. The layout is also perfectly balanced which allows higher RPMs than a conventional diesel of the same size. The loco with two Deltics in was 3,300 horsepower for 99 tons, whilst the next most powerful was 3,250 horsepower for 123 tons, and that only had one engine.
2 fuel injectors per cylinder,Royal Navy VET ,3 years on minesweepers,we could swap an engine in 24 hours ,engine weight about6 tons standing between 2 of them at 1800rpm would clear your head even with ear defenders on GREAT engineBTW we had a 9 cylinder also as a pulse generator
In ANL on the Bass Trader we were swopping engines out within 6 hours, the best we every got was 2,500hours between engine failures - brilliant concept, worker dis-satisfaction within Napiers prevented development of engine's full potential - sadly no engine builder today is willing to build such a complex engine - more practical to increase boost pressure on a more conventional engine
so the blower/supercharger supplied the intake pressure instead of it coming from the case pressure; nice. What made it so dirty? Was it the type of fuel, or the way a 2-stroke sputters before it starts to build RPM? I am a big believer in the simplicity and lightweight of the 2-stroke and the low costs compared to 4-stroke engines. A 2-stroke can be made cleaner running if ran on alternate fuels. The 2-stroke isn't dead yet.
Today’s 2 stroke oil burns hotter and cleaner than before, I have tube mobile guard 410 at 50:1 in my yz 250 ad I get it from the 2 stroke boat I work on , EMD and Detroit
Also oil injection is more precise metered today. A Deltic today with silkolen pro 2 ax synthetic 2 stroke oil with modern oil injection will burn cleaner
I spent a lot of time both working on and testing the L60 Chieftain tank engine. Unfortunately the contract had been given to BMC (remember Red Robbo) enough said. After 'brand new' engines had been stripped and assembly faults corrected the engine was reasonably reliable. It had 2 crankshafts in a vertical configuration but otherwise very similar in principle to the Deltic. It used a Rootes blower. The max output was pretty clean at 700BHP. It had a totally scavenged oil system with oil cooling to the piston crowns. By the time the Chieftain ended as a MBT it was quite a good engine. The smaller version, the K60, was made by Rolls Royce. These were used in the FV430 series and Swedish S tank. I never saw the inside of one, never needed to. Both engines were multi fuel which is not easy to achieve in a diesel injection running on petrol but the modifications worked very well. The L60 was simple and easy to work on. Pity about the plonkers that made it.
When I left the Navy in 2010 they were still in widespread use in the Hunt class minesweepers. They may still be powering them. Never had to use them, although in training we spun one up and balanced a coin on top. I think they were very good for the 1950s but defiantly dated today.
it is, but not because of the lack of valves but because it makes power every second (ie outward) stroke. There are two strokes with valves, big diesel engines.
You are correct, the air does go around the outside, same type of blower have been used on every 53, 71, 92, 149 series G M two stroke diesel made since around 1940.
@jamzie89 No sir. The top and left superchargers are turning in the wrong direction. Due to their rotation, they are appear to be drawing away from the engine.
No. 2-S inherently has better power to weight ratio but less efficient use of fuel. Put simply cramming induction, compression, power stroke and exhaust into 2 strokes (one complete rotation of the crankshaft) gives twice as many power strokes at a given RPM but involves compromises resulting in none of the processes being as efficient as in a 4-S where each is completely separate. Hence uses more fuel to get the same result and dirtier exhaust. As I said though these were very good for a 2-S.
I have worked with opposed piston engines [but not deltic]. As far as I'm concerned they are great. Power outputs were very high in relation to capacity and weight. As two strokes they out performed the GM with its exhaust valve in the head. Unfortunately one brand, the Doxford marine engine, wouldn't scale up to the large sizes in current use and has now disappeared. The other, the Commer TS3 suffered from a hostile takeover and was abandoned by the new owners in favour of their own substantially inferior in-house engine. The Commer out-performed much larger engines with a comparatively low fuel consumption. They weren't totally reliable but probably the next edition would have remedied that. Incidentally the deltic can still be found in service. It has not yet faded away.
+Gareth Tatler As I understand it , the Royal Navy still uses them. They may however be legacy units which will eventually be phased out rather than be replaced. The RN's policy is to use Gas Turbines instead. Because the Deltic was largely developed with RN funding, the switch to Gas Turbines for the same classes of ships cut rather severely into the Deltic market. As great a fan as I am for opposed piston engines, I have to admit that Gas Turbines are probably more suitable for RN purposes. More power and lighter weight. Much increased fuel consumption though so that might result in a return to diesel propulsion as fuel becomes more scarce. In the 1950's the Shell Oil Company had a tanker fitted with four diesel-electric motors [not deltic] and one Gas Turbine. On the voyage from UK to Valenzuela the diesels were shut off and the Gas Turbine propelled the ship.. On the return trip the turbine was shut off for repairs and all four diesels were used. The turbine suffered severely from gyroscopic forces in rough seas but that problem has, I would think, been overcome now.
Derek Spender Thanks for getting back to me that was very interesting. I think they sometimes still run some locomotives, but just on special occasions. I will do some research and see if I can find one this coming summer, perhaps at some sort of RN open day. I think that I would enjoy that as a day out. Thanks again.
Deltic is a development of the uniflow inline 2 stroke diesel which has long cylinders with 2 crankshafts, top and bottom. Top piston uncovers inlet port and bottom piston uncovers exhaust port, giving excellent exhaust scavenging. The deltic adds a 3rd crankshaft and 2 extra banks of cylinders to the inline uniflow diesel. If you decide on uniflow (for scavenging), deltic offers even more savings in crankshafts than a V would over a normal inline engine. Deltics were 9 or 18 cylinder (never 3!)
It was rocketing fuel costs as much as complexity or reliability problems that spelt the end of the Deltics for Railway use. For 2-strokes they were efficient but could not match the fuel efficiency of a 4-stroke. In passing can we also pay tribute to the vision of the man responsible for the Deltic locomotives making such an inpact., Gerard Fiennes the BR NE division controller who by dropping obsolete steam era practises revolutionised the entire East coast main line with just 30 locomotives.
No it didn't, plenty of diesel locos predate the Deltic locos, some by close on 20 years... Deltic engines were only used on locos in the UK, 10 "baby deltics" were built using 9 cylinder engines, and 22 class 55 locos were built using twin 18 cyl engines, that was it for the Deltic engine in rail application.
I was thinking about why Napier went with a triangular engine layout. This engine is based on the Junkers Jumo 204 aero diesel (Napier had a license to build them). By doing this, they reduced the number of crankshafts per cylinder (in a one-bank engine) to one (the 204 had two per cylinder) at the expense of "wasted volume" (the area inside the triangle). They could have made a "quadratic", but that would have resulted in even more "wasted volume" and no reduction in the crankshaft/cylinder ratio. Junkers apparently did develop a "diamond" layout engine with four crankshafts.
it is basically an opposed piston engine with three times the power from the extra cylinders to make sure you can pull heavier loads without too much strain on the engine an interesting concept oh and im only 16 years old.
Radial aircraft engines also had an issue with oil seeping into the lower cylinders when at rest. Failure to pull the spark plugs and make certain the cylinders were not full of oil before starting sometimes resulted in a blown engine as oil does not compress.
SAN had ex RN minesweepers with Napier Deltic engines, had to turn engine over manually before starting as oil collected in combustion chambers, approximately 300 cranks by hand via reduction gear for one engine revolution.
+Harvey Millar Wow, If you do one crank action for every second, It takes 5 minutes work. It would be very good exercise for the operator. Every day I am learning something new about this engine. Thank you for the info.
Supercharger @ 5 oclock is going the wrong way ! I like the way the intake is taken care of by One piston and the exhaust is taken care of by the Other Piston. Sound Idea's !
With engine correctly drawn, bottom crankshaft is the one that rotates backwards. Max compression occurs in top cylinder with bottom crank vertically upwards and other crankshafts 10deg below the horizontal. In the other two cylinders it occurs 40deg earlier and later. Therefore an even firing engine can be made with 9 cylinders (three throws on each crank 120deg apart, firing order 1A-1B-1C-2A-2B-2C-3A-3B-3C) firing every 40deg. Alternatively an 18 cylinder is also even firing (every 20 deg.)
You don't waste power against a non moving head. All the power generates motion, that is the first advantage then having a delta form balances out all the movement. This is what made the commer three cylinder, six piston two-stroke diesel lorry engine so good.
@machokyle45 I guess Napier of Manchester, England would not agree with you. His engine had excellent power-to-weight ratio and was very compact and used in variety of marine vessels.
+thrunsalmighty - In 1956, I Drove a Commer Lorry with the TS3 ( Tilling Stevens 3 Cylinder) 2 stroke diesel engine. As you say with 2 horizontally opposed pistons in each bore. A not too reliable engine I`m afraid but it had a really sporty roar from the exhaust. This was in the Max. 20 MPH period. Another drawback was the complete lack of engine braking going downhill, which was hairy in snowy weather as when braking the engine was prone to stalling.. A good long distance truck to drive though in good weather. Barrie Clark..
excellent video, but it does look like the exhaust piston and inlet piston reach TDC at the same time where as the exhaust piston should lead by 20degrees.
Interesting design! Question; if I may... Do the crankshafts play rock/ paper/ scissors to decide who's gonna be the "odd" one and counter-rotate, or how do they decide it, if not?
i saw an engine in a 1977 encyclopedia Britannic called a shuttlecock engine it had two opposed heads with normal valves on either end of a single piston cylinder with a signal double headed piston inside iit. the power was off the exhaust to a turbo. it had hp at high speed but no torque. wondering how it would work to put an electric generator off that turbo foe a hybrid.
From the ones I could actually see the engines in, they look like normal inline engines. You can even see intakes and plug wires where they would be on any inline engine. The only one that looked anything like the video was the giant one with all the gear drive on the back.
I'm no engineer just a Deltic fan however the engine was relatively compact and gave lots of power for its size and weight. The Napier Deltic engines were first used in fast patrol boats and mine sweepers, the latter because being made of aluminum they had a low magnetic signature. When English Electric were looking for power packs for the Class 55 locos these became an obvious choice. However for all their power they were difficult to maintain and threw pistons now and again.
kev lapper Good question.. There has to be more to the cylinder functions than we can see here.. I mean, when the two opposing pistons are at the farthest away position the diagram shows both intake and exhaust happening at the exact same time... I dont see this being a possibility, how can you be spraying in air and fuel and exhausting inside the same cylinder at the same time.. I must be missing something.
The Deltic uses supercharging for scavenging, it wouldn't work otherwise. You can actually see the blowers in the drawing. The "exhaust" crankshaft is supposed to run 20 degrees ahead of the "intake" crankshaft so the exhaust port opens before the intake port opens, AND closes before the intake port closes. This same animation is on the Wikipedia page, and for some reason they left the "timing advance" out (you'll notice both pistons reach BDC simultaneously, they should not). This engine is based on the earlier Junkers Jumo aero diesel engine, that one just had one bank of cylinders and two crankshafts. Iskandar
+Buddy Box The exhaust port opens slightly before BDC and is 20 degrees ahead of the inlet. Scavenging takes place clearing out exhaust as air is admitted by the inlet piston. Since it is not a petrol engine but a diesel there is no fuel lost in the exhaust scavenging. The exhuast closes while air is still admitted for another 20 degrees. The pistons then come together and near TDC diesel is injected to create the combustion and power stroke of both pistons. These units were built up into 9, 12 and 19 cylinder units, so a proper engine would have been made up of a number of these units you can see here. They were used in trains and ships for sixty years.
+Tonyv1951 Thanks a lot for the info. I did not know there would be 3, 4 even 6 rows of these units. It must be an awesome sight to see one of these 6 rows in operation.
Perhaps the most awesome engine I have ever witnessed...maybe adapting modern computer control injection might improve performance and reduce smoke. Maybe a natural gas fuel could be used instead of diesil oil with a spark ignition system.שלום
The Napier Deltic did not use Rootes type displacement blowers as you show. The Deltic used one centrifugal blower, mounted at on end. See Wiki on the Napier Deltic.
Napier test-ran a Turbo Compound Deltic - the same engine but with the exhaust gases driving a turbine which was coupled back to the engine's output shaft for even MORE power (5,000 hp+). They could dream up some crazy stuff indeed.
Napier Deltic Engine was used in Cars, Trucks, Airplanes and Ships. Replace the {dot} with actual "." in the fallowing link to visit the page. picturegallery{dot}imeche{dot}org/AreaIndex{dot}aspx?ViewArea=30
Chapter 4 page 2 of that website explains what I said much more clearly. The main page also shows complete firing order for an 18 cylinder engine (delete every other cylinder for a 9 cylinder engine which is much easier to understand.)
Don't know if anyone noticed, but the lower right blower is the only one turning correctly in the animation. The other two are sucking the air out of the cylinders.
Actually the lower right one is spinning the wrong way. Blowers of that style don't squeeze air between the lobes but around the outside, and it compressed as it exits by the lobes meshing with each other.
+Tom Jackson Actually, the rotation of the lobes are correct, however time to time they are seen as though they are rotating in the wrong way. This is due to stroboscopic effect, just like in the movies the carriage wheels rotating in the wrong way, there is nothing an animator can do about that.
What are you missing? The historical use of this engine in motor torpedo boats, and trains for half a century. It was one of the most efficient diesel engines made. The three cranks were geared to central shaft that ran through the engine and drove a centrifugal supercharger at the rear of the engine. The advantage? no valves, perfect balance and despite appearance compact for it's capacity. They had 12 cylinders.
So.... This is (sort of) 3, 60° v-6 engines bolted head to head, sort of thing? Sleeve valves, I surmise? How does the power get to anywhere it can do some good?
My concern is in the use of three super chargers feeding three chambers. Essentially blowers tend to work best in an engine with multiple cylinders such that one cylinder is always accepting through put of air. In the drawing the way the cylinders are fed a large plenum would be needed as the flow of air would be blocked during part of the cycle. That would knock efficiency on its fanny.
@ben44rain Yeah, lucky then that it became one of the world's most successful marine-train-and electric powerplant engines then, isn'y it? The Napier sold in vast amounts and was used for decades and decades and still is in places. It was and is a brilliant engine and a wonderful pieve of engineering. No wonder the good old Napier has so many fans, me included!:)
What I do know Boxer/Flat engine is more efficient than V. But unlike conventional Diesel engine that need heavy strong industrial strength parts specially for cylinder head, the opposed piston engine don't need to use cylinder head because of the air is compressed with another piston. And that also gives more power.
You are quite right sir, I try to visualize it but I don't get a good sense of it. The lack of cams & pushrods etc certainly simplifies in that department. Very clever indeed!!! Is anyone building these anymore?
I don't know why British Engineers Designed the Napier Deltic Engine this way. I am sure there must be some solid reason for them to do it this way. Since I do not know their reasoning, I can not answer your question clearly. I am sure someone with more knowledge comes along and answer this.
Junkers, who first used the opposed piston concept, tried to build a three bank motor like this but failed. It was a Admiralty draftsman Herbert Penwarden who realised that one crankshaft had to turn in the opposite direction to the other two to get the correct firing order and work.
m schiffel There are 3 crankshafts which MUST be geared together to a common output shaft. The gearing is essential give the correct timing of the pistons. A key feature is that one crankshaft rotates in the opposite direction from the other 2. In the Class 55 locomotive, there were 2 engines, each rated at about 1750 HP, driving their own generator. There was another class...the Class 23 which had 1 Deltic unit and nicknamed the Baby Deltic. Currently one is being reconstructed using a Class 37 body, Class 20 bogies and a surviving power unit. The Class 55 locos were noisy on account of the 2 stroke engines. I likened it to shaking metal spanners in a metal toolbox.
Um no, the air is actually carried around the outside of the lobes, the small gap between the lobe lip and blower housing limiting leakage is what makes the compression, the meshing of the lobes where the lobe lip runs through the void of the opposing rotor stops the air squirting back out of the blower. What a lot of people don't know is the rotors and housings do not touch, they are gear driven and run with about .005 inch clearances. Same Rootes type blowers is on every G M two stroke diesel.
I don't know. But the Diesel engine use direct injection, that means fuel injected inside the cylinder when both ports are closed/even when near the top (or right or left or whatever) dead center.
+motorhead. Minimal work was done with the engine in-situ. Major work required special tools and equipment. Because they were much smaller and lighter than conventional engines, they were easily lifted out and an engine overhauled in the workshop fitted thus quickly returning the ship or train to service.
The main problem I see is the wear at the ports. Especially the exhaust. In a typical two cycle the exhaust ports wear about twice as fast. In this design I would guess about three or four times faster because there is no cool air coming in.
@mekanizmalar Google Translate: MDE, the huge volume occupied, questionable reliability, three pumps, three crankshaft, and how their movement on a shaft to transmit. Efficiency through the floor.
hmm power to weight & size improvment from being 2 stroke. power to weight loss not changing as the linking gear equals a flywheel power to size. bigger but flatter. all evens out efficiency, 2 stroke diesels do not lose efficiency like 2 stroke gas, a little efficiency lost having to gear link 3 separate drive chafts. improvement... a single blower to feed all 3 would not spend as much time fighting sealed valves. I like it. aside from geometric needs what are any disadvantages?
+Adrian Perez There is a gear train on one end of the engine known as 'phasing gears'. This takes the 3 crankshafts into one common output shaft.If you type "deltic phasing gears" into google images, you'll see a few pictures of the gear train.
+Adrian Perez Your welcome. The designed power was 2500HP but it was de-rated for rail use to extend its life between strip downs. It is expensive and complex to maintain but it gives a lot of power for its size and weight. It gives a power stroke every 20 degrees of crankshaft rotation so that's 18 power strokes for each turn! There are some Naval crafts that still use them today, 60 years from their inception.
I'm guessing this is not intended for cars/trucks. It would be very large and heavy from the looks of it. Also hooking up a transmission would be a bit of a trick since you have three cranks. Simple method would be one big central gear, I guess. Just seems awkward.
Yes. All straight six designs are balanced by definition. This is 6 banks of 6 pistons each. Crank throws are balanced additionally as with automotive engines.
Nice animation. Note that the two top crankshafts should rotate clockwise and the bottom crankshaft anticlockwise. The exhaust piston leads the inlet piston by 20 degrees, and charge air is supplied to all three banks by a single blower.
Thank you. I honestly wouldn't have known that. I appreciate corrections (so long as they're correct, of course) VERY VERY much!! ...and so do a LOT of others! I felt someone should at least take the time to say thanks, if you took the time to explain that. Thanks again 👍
Napier and sons never shied away from a challenge and created some legendary engines in their time. I love how the Deltic’s opposed pistons offset makes one piston working as inlet valve and the other as exhaust. The gearing needed to connect cranks and driveshafts to the blowers must have been very complicated, The noise probably incredible, servicing a challenge and the lubrication system must have been a plumber’s nightmare. I’ll probably never lay my hands on one of these brutes, but it is an absolute favourite.
Thank you for your informative comment.
As a child I would wave my father off as he took the train to London,
powered by one of these engines. To this day it is one of the best
sounding engines I have ever heard, a truly unique sound that just reeks
of power, that pounds through your chest and into your soul.
+Gareth Tatler Indeed! And you can still travel behind them today via special trains.
Ever heard a Paxman 12YHAXM ?
yeah, and no HAXM series Paxmans were ever fitted to a locomotive only marine applications.I assume you mean the Paxman Valenta RP200L that was in the HST's?Even so, they don't come close, not even in the same ball park as a Deltic!
I mean 12YHAXM. I own, and live on, a retired minesweeper. I started out with the original engines, albeit de-rated following the removal of the turbos. Too big to manage for one person though, everything about them was overcomplicated. Fuel pipes were a nightmare, as was the cooling system. They did sound lovely, even from 200meters away. I have only once heard Deltics, and they were similarly orgasmic.
Fork and blade conrod? No thanks.
@R75Sidecar The there crankshaft know as AB, BC and CA are geared at the back end of the engine. These gears are called as 'phasing gears' and keep three crankshafts synchronized and used to drive additional components such as oil and water pumps. The output power is transmitted to a single shaft located at the center of the engine from phasing gears.
@RamsesTheFourth This engine invented by Napier of Manchester, England. It has been used in some military ships and diesel locomotives.
Invented by Junkers Jumo in Germany and licensed by Napier in 1932.
Thank you for your clarification. When I do these animations I do to best of my knowledge at the time. I spend quite a long time pondering on the drawings without seeing any real mechanism. As a result I make mistakes. Thanks to comments section of UA-cam people correct my mistakes.
I think actually these amazing opposed piston engines are similar to split-single engines. They are a straightened versions of the split single. So this tri-opposed piston engine is analogous to a split single with 3 combustion ports 120° apart and they power a swash/wobble plate or a spider gear underneath them (as crankshafts)
una volta sola mi è capitato di mettere le mani su uno di questi motori , era un motore navale montato su una barca da pesca molto interessane e molto compatto , con un " rumore " molto particolare ... complimenti per il video e le spiegazioni grazie
Exhaust piston leads intake piston by 20deg, fixed by geometry. One crankshaft turns backwards (should be bottom one, not righthand one as shown in this animation.) If the two cylinders connected to this had pistons perfectly in phase, 3rd cylinder would have pistons 60deg out of phase. In practice the 60deg is spread evenly between 3 cylinders, 3x20deg. Max compression occurs with one piston at +10 and the other at -10. Both pistons are at cos(10)=98.5% of the way to top deadcentre. Ingenious.
One of my all time favourite engines, thank you for the animation.
The annotation has been added for the correct it. Thank you for your support.
This engine in minesweepers had a 2 stage supercharger on the front driven by a shaft through the hollow center triangle from the gearbox on the back. The shaft could twist 3/4 of a turn without snapping. The engine was started with a cartridge in a 6-barrel starter pack, like a 6-gun. It had a dry sump, an oil supply tank and a scavenge pump to take the oil out of the engine.
@AwesomenessPrime427 There has to be timing gear set keeping all the crankshafts as well as blowers operating together.That engine must have had quite a large gearset to withstand all that torque,but with that design it must have had a great power to weight ratio.
@ben44rain Here are two comments that I find from internet about these engines.
The first comment is "These engines were very powerful for weight, and efficient, which made a single railway engine able to sustain 3,300hp., unlike to conventional engines, 2 or 4-stroke which could make little more than 2,000hp."
The second comment "Deltic Engine only real Achilles Heel was a tendency to leak oil from the crankcase into the bottom cylinders when not running:."
Interesting. I guess they must be expensive to build, but it is facinating to see the different ideas that people come up with to make things go :)
Left or right hand 🖐
It does have a very good power/weight ratio, even by two stroke standards. Although it has three cranks it has no cylinder heads, no valves and only the bottom crank has to be built up as a proper structural crankcase and sump. The layout is also perfectly balanced which allows higher RPMs than a conventional diesel of the same size. The loco with two Deltics in was 3,300 horsepower for 99 tons, whilst the next most powerful was 3,250 horsepower for 123 tons, and that only had one engine.
2 fuel injectors per cylinder,Royal Navy VET ,3 years on minesweepers,we could swap an engine in 24 hours ,engine weight about6 tons standing between 2 of them at 1800rpm would clear your head even with ear defenders on GREAT engineBTW we had a 9 cylinder also as a pulse generator
In ANL on the Bass Trader we were swopping engines out within 6 hours, the best we every got was 2,500hours between engine failures - brilliant concept, worker dis-satisfaction within Napiers prevented development of engine's full potential - sadly no engine builder today is willing to build such a complex engine - more practical to increase boost pressure on a more conventional engine
i have learned some thing new today.
Tks from team TechTrixInfo
@simaritalia Thanks to Google translate for translating your comment for me. Thanks for your nice comment and explanation where you used this engine.
so the blower/supercharger supplied the intake pressure instead of it coming from the case pressure; nice. What made it so dirty? Was it the type of fuel, or the
way a 2-stroke sputters before it starts to build RPM?
I am a big believer in the simplicity and lightweight of the 2-stroke and the low costs compared to 4-stroke engines. A 2-stroke can be made cleaner running if ran on alternate fuels.
The 2-stroke isn't dead yet.
I love 2 strokes as well. Less parts means less things that can break, and no valves means much easier maintenance.
Today’s 2 stroke oil burns hotter and cleaner than before, I have tube mobile guard 410 at 50:1 in my yz 250 ad I get it from the 2 stroke boat I work on , EMD and Detroit
Also oil injection is more precise metered today. A Deltic today with silkolen pro 2 ax synthetic 2 stroke oil with modern oil injection will burn cleaner
Also modern fuel injection helps to run cleaner with broad power, just like the rotax 850 turbo sled and new evinrude etec
I spent a lot of time both working on and testing the L60 Chieftain tank engine. Unfortunately the contract had been given to BMC (remember Red Robbo) enough said. After 'brand new' engines had been stripped and assembly faults corrected the engine was reasonably reliable. It had 2 crankshafts in a vertical configuration but otherwise very similar in principle to the Deltic. It used a Rootes blower. The max output was pretty clean at 700BHP. It had a totally scavenged oil system with oil cooling to the piston crowns. By the time the Chieftain ended as a MBT it was quite a good engine. The smaller version, the K60, was made by Rolls Royce. These were used in the FV430 series and Swedish S tank. I never saw the inside of one, never needed to. Both engines were multi fuel which is not easy to achieve in a diesel injection running on petrol but the modifications worked very well. The L60 was simple and easy to work on. Pity about the plonkers that made it.
Actually some people like the sound of this engine.
Thank you for your informative comment. I wish that I knew what I know now, when I was doing this animation.
When I left the Navy in 2010 they were still in widespread use in the Hunt class minesweepers. They may still be powering them. Never had to use them, although in training we spun one up and balanced a coin on top. I think they were very good for the 1950s but defiantly dated today.
Thank you for your visit and comment. I appreciate your contribution.
I think a modern mapped electronic fuel injection system would clean up the exhaust and make the engine more economic.
Looks like a 2 stroke,seeing as there is no valve gear, is it ?
it is, but not because of the lack of valves but because it makes power every second (ie outward) stroke. There are two strokes with valves, big diesel engines.
This engine was also used in 81 ft Patrol boats , US Navy had some in Vietnam,
You can probably make 600 CID one out of 3 60 deg mercury optimax v6 our board engines. They are about 3.2 l so it would be 9.6 liter mini deltic
“Nasty” class.
@fairyscout1 Thank you. Yes I know the problem. I have to put annotation for that.
You are correct, the air does go around the outside, same type of blower have been used on every 53, 71, 92, 149 series G M two stroke diesel made since around 1940.
@simaritalia Thank you for your nice comment.
@jamzie89 No sir. The top and left superchargers are turning in the wrong direction. Due to their rotation, they are appear to be drawing away from the engine.
No. 2-S inherently has better power to weight ratio but less efficient use of fuel. Put simply cramming induction, compression, power stroke and exhaust into 2 strokes (one complete rotation of the crankshaft) gives twice as many power strokes at a given RPM but involves compromises resulting in none of the processes being as efficient as in a 4-S where each is completely separate. Hence uses more fuel to get the same result and dirtier exhaust. As I said though these were very good for a 2-S.
Thank you for your support.
I have worked with opposed piston engines [but not deltic]. As far as I'm concerned they are great. Power outputs were very high in relation to capacity and weight. As two strokes they out performed the GM with its exhaust valve in the head. Unfortunately one brand, the Doxford marine engine, wouldn't scale up to the large sizes in current use and has now disappeared. The other, the Commer TS3 suffered from a hostile takeover and was abandoned by the new owners in favour of their own substantially inferior in-house engine. The Commer out-performed much larger engines with a comparatively low fuel consumption. They weren't totally reliable but probably the next edition would have remedied that. Incidentally the deltic can still be found in service. It has not yet faded away.
+Derek Spender Thank you for such a lengthy explanation an supportive comment.
+Derek Spender May I ask where they are still in service, I think they sound gorgeous.
+Gareth Tatler As I understand it , the Royal Navy still uses them. They may however be legacy units which will eventually be phased out rather than be replaced. The RN's policy is to use Gas Turbines instead. Because the Deltic was largely developed with RN funding, the switch to Gas Turbines for the same classes of ships cut rather severely into the Deltic market. As great a fan as I am for opposed piston engines, I have to admit that Gas Turbines are probably more suitable for RN purposes. More power and lighter weight. Much increased fuel consumption though so that might result in a return to diesel propulsion as fuel becomes more scarce. In the 1950's the Shell Oil Company had a tanker fitted with four diesel-electric motors [not deltic] and one Gas Turbine. On the voyage from UK to Valenzuela the diesels were shut off and the Gas Turbine propelled the ship.. On the return trip the turbine was shut off for repairs and all four diesels were used. The turbine suffered severely from gyroscopic forces in rough seas but that problem has, I would think, been overcome now.
Derek Spender
Thanks for getting back to me that was very interesting. I think they sometimes still run some locomotives, but just on special occasions. I will do some research and see if I can find one this coming summer, perhaps at some sort of RN open day. I think that I would enjoy that as a day out. Thanks again.
It was sad that the fuel efficient reliable Commer knocker was killed by a hostile take over by Chrysler and their inferior in-house engine.
@kodiak410a thats the way they spin, they spin with the air goin around the outside, because the air cant go through where they mesh together
Deltic is a development of the uniflow inline 2 stroke diesel which has long cylinders with 2 crankshafts, top and bottom. Top piston uncovers inlet port and bottom piston uncovers exhaust port, giving excellent exhaust scavenging. The deltic adds a 3rd crankshaft and 2 extra banks of cylinders to the inline uniflow diesel. If you decide on uniflow (for scavenging), deltic offers even more savings in crankshafts than a V would over a normal inline engine. Deltics were 9 or 18 cylinder (never 3!)
It was rocketing fuel costs as much as complexity or reliability problems that spelt the end of the Deltics for Railway use. For 2-strokes they were efficient but could not match the fuel efficiency of a 4-stroke.
In passing can we also pay tribute to the vision of the man responsible for the Deltic locomotives making such an inpact., Gerard Fiennes the BR NE division controller who by dropping obsolete steam era practises revolutionised the entire East coast main line with just 30 locomotives.
@RamsesTheFourth This engine pioneered diesel locomotives, i have been around for decades! I dont think a youtuber can question it!
No it didn't, plenty of diesel locos predate the Deltic locos, some by close on 20 years... Deltic engines were only used on locos in the UK, 10 "baby deltics" were built using 9 cylinder engines, and 22 class 55 locos were built using twin 18 cyl engines, that was it for the Deltic engine in rail application.
This engine is used in the Class 55 diesel locomotive.
I was thinking about why Napier went with a triangular engine layout. This engine is based on the Junkers Jumo 204 aero diesel (Napier had a license to build them). By doing this, they reduced the number of crankshafts per cylinder (in a one-bank engine) to one (the 204 had two per cylinder) at the expense of "wasted volume" (the area inside the triangle). They could have made a "quadratic", but that would have resulted in even more "wasted volume" and no reduction in the crankshaft/cylinder ratio. Junkers apparently did develop a "diamond" layout engine with four crankshafts.
Sadly they never built it.
it is basically an opposed piston engine with three times the power from the extra cylinders to make sure you can pull heavier loads without too much strain on the engine an interesting concept oh and im only 16 years old.
So now you're 25-ish.
How do you feel about things now?
Radial aircraft engines also had an issue with oil seeping into the lower cylinders when at rest. Failure to pull the spark plugs and make certain the cylinders were not full of oil before starting sometimes resulted in a blown engine as oil does not compress.
@mekanizmalar Except to keep the engine balanced, they designed it to have two cranks go one way, only one go the other.
SAN had ex RN minesweepers with Napier Deltic engines, had to turn engine over manually before starting as oil collected in combustion chambers, approximately 300 cranks by hand via reduction gear for one engine revolution.
+Harvey Millar Wow, If you do one crank action for every second, It takes 5 minutes work. It would be very good exercise for the operator. Every day I am learning something new about this engine. Thank you for the info.
Supercharger @ 5 oclock is going the wrong way ! I like the way the intake is taken care of by One piston and the exhaust is taken care of by the Other Piston. Sound Idea's !
+jackpontiac52 it'll be some kind of strobing effect. when the simulated speed is high. When the simulation ran at lower speeds it's fine.
With engine correctly drawn, bottom crankshaft is the one that rotates backwards. Max compression occurs in top cylinder with bottom crank vertically upwards and other crankshafts 10deg below the horizontal. In the other two cylinders it occurs 40deg earlier and later. Therefore an even firing engine can be made with 9 cylinders (three throws on each crank 120deg apart, firing order 1A-1B-1C-2A-2B-2C-3A-3B-3C) firing every 40deg. Alternatively an 18 cylinder is also even firing (every 20 deg.)
You don't waste power against a non moving head. All the power generates motion, that is the first advantage then having a delta form balances out all the movement. This is what made the commer three cylinder, six piston two-stroke diesel lorry engine so good.
@machokyle45 I guess Napier of Manchester, England would not agree with you. His engine had excellent power-to-weight ratio and was very compact and used in variety of marine vessels.
@VoenOVG I wish I could understand what you were saying.
Does anyone remember the old Commer lorries with opposed piston engines?
+thrunsalmighty - In 1956, I Drove a Commer Lorry with the TS3 ( Tilling Stevens 3 Cylinder) 2 stroke diesel engine. As you say with 2 horizontally opposed pistons in each bore. A not too reliable engine I`m afraid but it had a really sporty roar from the exhaust. This was in the Max. 20 MPH period. Another drawback was the complete lack of engine braking going downhill, which was hairy in snowy weather as when braking the engine was prone to stalling.. A good long distance truck to drive though in good weather. Barrie Clark..
I have a pair of Aluminium Foden FS6s if anyone is interested.
I do - was lucky to get a ride in one once. Weird sound compared to other lorries.
Correction, FD6
That's what I thought of when I saw this.
How small can this engine get?
excellent video, but it does look like the exhaust piston and inlet piston reach TDC at the same time where as the exhaust piston should lead by 20degrees.
May I ask? What is the degree difference between left intake piston (1st ignited cylinder's intake piston) with left (2nd) intake piston?
I wonder when, or if, someone will make an RC version of this thing.
Remember those 3 crankshafts have to stay in sequence with one another which probably means a gear set.
Yes, there is a a gear set at the back.
+mekanizmalar are they in heavy production or just testing in the states
Interesting design! Question; if I may...
Do the crankshafts play rock/ paper/ scissors to decide who's gonna be the "odd" one and counter-rotate, or how do they decide it, if not?
i saw an engine in a 1977 encyclopedia Britannic called a shuttlecock engine
it had two opposed heads with normal valves on either end of a single piston cylinder with a signal double headed piston inside iit. the power was off the exhaust to a turbo. it had hp at high speed but no torque. wondering how it would work to put an electric generator off that turbo foe a hybrid.
From the ones I could actually see the engines in, they look like normal inline engines. You can even see intakes and plug wires where they would be on any inline engine. The only one that looked anything like the video was the giant one with all the gear drive on the back.
I'm no engineer just a Deltic fan however the engine was relatively compact and gave lots of power for its size and weight. The Napier Deltic engines were first used in fast patrol boats and mine sweepers, the latter because being made of aluminum they had a low magnetic signature. When English Electric were looking for power packs for the Class 55 locos these became an obvious choice. However for all their power they were difficult to maintain and threw pistons now and again.
This engine may still be used? it was used in trains...
Holy crap!!! Turbos on top of it all?? Amazing.
Having trouble getting my head around this. :/ Fascinating!! Thanks for the cool info.
does the exhaust gas get pushed out by atmospheric pressure
kev lapper Good question.. There has to be more to the cylinder functions than we can see here.. I mean, when the two opposing pistons are at the farthest away position the diagram shows both intake and exhaust happening at the exact same time... I dont see this being a possibility, how can you be spraying in air and fuel and exhausting inside the same cylinder at the same time.. I must be missing something.
The Deltic uses supercharging for scavenging, it wouldn't work otherwise. You can actually see the blowers in the drawing. The "exhaust" crankshaft is supposed to run 20 degrees ahead of the "intake" crankshaft so the exhaust port opens before the intake port opens, AND closes before the intake port closes. This same animation is on the Wikipedia page, and for some reason they left the "timing advance" out (you'll notice both pistons reach BDC simultaneously, they should not). This engine is based on the earlier Junkers Jumo aero diesel engine, that one just had one bank of cylinders and two crankshafts.
Iskandar
+Buddy Box The exhaust port opens slightly before BDC and is 20 degrees ahead of the inlet. Scavenging takes place clearing out exhaust as air is admitted by the inlet piston. Since it is not a petrol engine but a diesel there is no fuel lost in the exhaust scavenging. The exhuast closes while air is still admitted for another 20 degrees. The pistons then come together and near TDC diesel is injected to create the combustion and power stroke of both pistons. These units were built up into 9, 12 and 19 cylinder units, so a proper engine would have been made up of a number of these units you can see here. They were used in trains and ships for sixty years.
+Tonyv1951 That should say 18 cylinders not 19.... fat fingers....
+Tonyv1951 Thanks a lot for the info. I did not know there would be 3, 4 even 6 rows of these units. It must be an awesome sight to see one of these 6 rows in operation.
So, it's supercharged 2 stroke?
Wonderful howl at full tilt! As a child I first wondered what it was in the distance!
Perhaps the most awesome engine I have ever witnessed...maybe adapting modern computer control injection might improve performance and reduce smoke. Maybe a natural gas fuel could be used instead of diesil oil with a spark ignition system.שלום
The Napier Deltic did not use Rootes type displacement blowers as you show. The Deltic used one centrifugal blower, mounted at on end. See Wiki on the Napier Deltic.
Napier test-ran a Turbo Compound Deltic - the same engine but with the exhaust gases driving a turbine which was coupled back to the engine's output shaft for even MORE power (5,000 hp+). They could dream up some crazy stuff indeed.
Jack Grover Wright aircraft engines did the same thing with the R3350 turbo compound engines on DC6 aircraft.
Napier Deltic Engine was used in Cars, Trucks, Airplanes and Ships. Replace the {dot} with actual "." in the fallowing link to visit the page.
picturegallery{dot}imeche{dot}org/AreaIndex{dot}aspx?ViewArea=30
Chapter 4 page 2 of that website explains what I said much more clearly. The main page also shows complete firing order for an 18 cylinder engine (delete every other cylinder for a 9 cylinder engine which is much easier to understand.)
Don't know if anyone noticed, but the lower right blower is the only one turning correctly in the animation. The other two are sucking the air out of the cylinders.
Actually the lower right one is spinning the wrong way. Blowers of that style don't squeeze air between the lobes but around the outside, and it compressed as it exits by the lobes meshing with each other.
+Tom Jackson Actually, the rotation of the lobes are correct, however time to time they are seen as though they are rotating in the wrong way. This is due to stroboscopic effect, just like in the movies the carriage wheels rotating in the wrong way, there is nothing an animator can do about that.
+mekanizmalar Ah, fair point. it's still a fascinating thing to watch a 6 piston, 3 cylinder engine.
Dave Nelson wrong, that's the one that's not working.
BS. The lower blower is going the wrong way...no 'stroboscopic effect'.
Regardless of that small issue, nice animation!
So the main difference is it provides you with three outputs?? how's the efficiency of this engine?
@marklandynut Thank you for your contribution with your excellent explanation.
Thank you for your contribution and excellent explanation.
Thank you for your excellent contribution.
What are you missing? The historical use of this engine in motor torpedo boats, and trains for half a century. It was one of the most efficient diesel engines made. The three cranks were geared to central shaft that ran through the engine and drove a centrifugal supercharger at the rear of the engine. The advantage? no valves, perfect balance and despite appearance compact for it's capacity. They had 12 cylinders.
So.... This is (sort of) 3, 60° v-6 engines bolted head to head, sort of thing? Sleeve valves, I surmise?
How does the power get to anywhere it can do some good?
My concern is in the use of three super chargers feeding three chambers. Essentially blowers tend to work best in an engine with multiple cylinders such that one cylinder is always accepting through put of air. In the drawing the way the cylinders are fed a large plenum would be needed as the flow of air would be blocked during part of the cycle. That would knock efficiency on its fanny.
I think they use one blower.
@ben44rain Yeah, lucky then that it became one of the world's most successful marine-train-and electric powerplant engines then, isn'y it? The Napier sold in vast amounts and was used for decades and decades and still is in places. It was and is a brilliant engine and a wonderful pieve of engineering. No wonder the good old Napier has so many fans, me included!:)
@FurryWereWolf93 No idea at all
What I do know Boxer/Flat engine is more efficient than V. But unlike conventional Diesel engine that need heavy strong industrial strength parts specially for cylinder head, the opposed piston engine don't need to use cylinder head because of the air is compressed with another piston. And that also gives more power.
They used these things in locomotives too, must have sounded sweet.
Like nothing else.
You are quite right sir, I try to visualize it but I don't get a good sense of it. The lack of cams & pushrods etc certainly simplifies in that department. Very clever indeed!!!
Is anyone building these anymore?
Napier built them for locomotives and warships, some used by the US navy. Full size was 18 rows
@TheH78 Thank you.
I don't know why British Engineers Designed the Napier Deltic Engine this way. I am sure there must be some solid reason for them to do it this way. Since I do not know their reasoning, I can not answer your question clearly. I am sure someone with more knowledge comes along and answer this.
Junkers, who first used the opposed piston concept, tried to build a three bank motor like this but failed. It was a Admiralty draftsman Herbert Penwarden who realised that one crankshaft had to turn in the opposite direction to the other two to get the correct firing order and work.
Three separate crankshafts ?? Or are they connected to a common output shaft ??
This engine is fascinating !
I am sure that all crank shafts are connected to a gear at the back of the engine.
mekanizmalar
Thanks...now this makes sense....What an unusual design !
m schiffel There are 3 crankshafts which MUST be geared together to a common output shaft. The gearing is essential give the correct timing of the pistons. A key feature is that one crankshaft rotates in the opposite direction from the other 2. In the Class 55 locomotive, there were 2 engines, each rated at about 1750 HP, driving their own generator. There was another class...the Class 23 which had 1 Deltic unit and nicknamed the Baby Deltic. Currently one is being reconstructed using a Class 37 body, Class 20 bogies and a surviving power unit.
The Class 55 locos were noisy on account of the 2 stroke engines. I likened it to shaking metal spanners in a metal toolbox.
craftsmanshipmuseum.com/images/clen30.jpg
Um no, the air is actually carried around the outside of the lobes, the small gap between the lobe lip and blower housing limiting leakage is what makes the compression, the meshing of the lobes where the lobe lip runs through the void of the opposing rotor stops the air squirting back out of the blower. What a lot of people don't know is the rotors and housings do not touch, they are gear driven and run with about .005 inch clearances. Same Rootes type blowers is on every G M two stroke diesel.
I don't know. But the Diesel engine use direct injection, that means fuel injected inside the cylinder when both ports are closed/even when near the top (or right or left or whatever) dead center.
How would you service such an engine? Can't pull head off ? Detroit 2 stroke simple easy to service. But this is an awesome design! Thanks
there is no head to remove or service
+motorhead. Minimal work was done with the engine in-situ. Major work required special tools and equipment. Because they were much smaller and lighter than conventional engines, they were easily lifted out and an engine overhauled in the workshop fitted thus quickly returning the ship or train to service.
+motorhead. No cylinder heads. No valves. 18 cylinders and 36 pistons.
how did the top side of the motor stay lubricated?
Oil pumps - same as automotive engines.
does the exhaust gas have enough time to be comletely removed ? i dont see any suck or push-out mechanism to force it out... how is it removed ?
Hi Avtomat, The Roots blowers shown in the video pushes the compressed air to the cylinder chamber when the inlet windows are opened.
combustion pressure forces itself out ?
The main problem I see is the wear at the ports. Especially the exhaust. In a typical two cycle the exhaust ports wear about twice as fast. In this design I would guess about three or four times faster because there is no cool air coming in.
@mekanizmalar Google Translate: MDE, the huge volume occupied, questionable reliability, three pumps, three crankshaft, and how their movement on a shaft to transmit. Efficiency through the floor.
Kenneth Cason Except it didn’t. One of these locos went 125 mph in the early 80’s.
So, is there a bull gear with a single output shaft? How does one determine the RPM ?
+Khadijah Brown They have a single output shaft that drives the traction generator to move the locomotive.
hmm power to weight & size improvment from being 2 stroke.
power to weight loss not changing as the linking gear equals a flywheel
power to size. bigger but flatter. all evens out
efficiency, 2 stroke diesels do not lose efficiency like 2 stroke gas, a little efficiency lost having to gear link 3 separate drive chafts.
improvement... a single blower to feed all 3 would not spend as much time fighting sealed valves. I like it.
aside from geometric needs what are any disadvantages?
How does one take power out of those 3 cranks into any sort of transmission?....
+Adrian Perez There is a gear train on one end of the engine known as 'phasing gears'. This takes the 3 crankshafts into one common output shaft.If you type "deltic phasing gears" into google images, you'll see a few pictures of the gear train.
+formidable38 interesting thanks for giving me that response. Seems like a cool set up
+Adrian Perez Your welcome. The designed power was 2500HP but it was de-rated for rail use to extend its life between strip downs. It is expensive and complex to maintain but it gives a lot of power for its size and weight. It gives a power stroke every 20 degrees of crankshaft rotation so that's 18 power strokes for each turn! There are some Naval crafts that still use them today, 60 years from their inception.
craftsmanshipmuseum.com/images/clen30.jpg
un grande motore ,bello a vedersi e anche molto funzionale navale e ferroviario !!!!
The Napier Deltic did not use Rootes type blowers. Have a look on the wiki.
The Napier Deltic is my favorite :)
I'm guessing this is not intended for cars/trucks. It would be very large and heavy from the looks of it. Also hooking up a transmission would be a bit of a trick since you have three cranks. Simple method would be one big central gear, I guess. Just seems awkward.
When built, they were half the size and ONE FIFTH the weight of an equivalent Mercedes diesel.
very clever idea!!! (...although there is one small mistake in the motion of the air pump pair gears in this video)
Are the forces of inertia balanced?
I am sure it does. Otherwise engine breakdown very quickly.
Yes. All straight six designs are balanced by definition. This is 6 banks of 6 pistons each. Crank throws are balanced additionally as with automotive engines.