Deltahawk's Jet Fuel Piston Airplane Engine Explained

this engine is an inverted 90° V4 two stroke diesel direct drive turbo and supercharged fuel injected engine with no Electric System it sure sounds like an odd combination but this engine is actually quite revolutionary for an airplane engine I'm of course talking about the Delta Hulk V4 which has been in development for almost 25 years but finally the first deliveries are scheduled to happen in early 2024 so while it's not breaking news I find this engine fascinating because at first glance not all those characteristics I've mentioned would seem to work well together the liquid cooled V4 engine is 3.3 l in displacement weighing 162 kg that produces 180 horsepower Delk claims this engine to be 35 to 40% more fuel efficient than an half gas engine as well as an engine that is incredibly easy to maintain so if you're thinking this all sounds too good to be true and is probably just another fad engine that will never be successful consider that this engine has already overcome perhaps the single biggest roadblock that any new Aviation engine faces which is FIA certification so let's look at some of the mentioned characteristics in isolation before bringing it all together for us to make sense what exactly the hype around this Delta or engine is all about so first and foremost the delta or is a two-stroke engine and while it's probably not like any two-stroke you've encountered before two-stroke engines has several advantages over fourstroke engines since a full revolution of a fourstroke engine is 720° rotation of the crankshaft and it generates power on only one of the four strokes it goes through means only 25 5% of its full Revolution creates torque namely the combustion stroke the other 75% or three Strokes of its revolution consumes torque being a parasitic load on the engine of course being the intake compression and exhaust stroke a two-stroke engine's full Revolution is 360° 180° is the Piston going all the way down and then another 180° takes it all the way up that's a full Revolution this means that 50% of the full Revolution creates torque and only 50% consumes torque in other terms the two-stroke engine has twice as many power strokes per 360° of crankshaft rotation as a fourstroke engine another advantage of the two-stroke engine is it doesn't have or need any valves which means it doesn't need a camshaft or any other of the valve train components needed for the operation of valves this results in a two-stroke engine not only being lighter and smaller than a fourstroke but it is also less complex as it has fewer moving Parts the valve Trin system uses some of the torque created by the four-stroke engine to move the camshaft to open and close the valves this means the two-stroke engine which does not have any of those components has less friction and less of the torque the engine creates are spent doing something other than rotating their crankshaft or in other words creating power combining the lighter nature of the two stroke with its ability to create torque on every second stroke results in them having very high power to weight ratios but two struck engines also has some negatives and ironically the very properties that make them less complex and lighter are also the reason for its disadvantages since the two stroke engine only has two cycles and no valves and an internal combustion engine has four stages being intake compression combustion and exhaust it means these four stages all happen in only two cycles of the engine this results in a stage as overlapping with each other meaning none of the four phases are particularly efficient in the two-stroke engine not having any valves also results in less control of air intake and Outlet affecting deficiency this also results in very high emissions as well as having bad fuel efficiency another disadvantage of a common petrol two-stroke engine is it usually needs to be overhauled much more frequently than fourstroke engines this is partly due to usually being high riving engines and partly due to not having dedicated lubrication and instead the oil is supplied mixed in with the fuel the Delta H is however different from a petrol two-stroke engine in some way R for one it doesn't mix oil with the fuel but are lubricated with internal oil Jets via a gear driven oil pump supplied by a dry sump system this is possible because air isn't drawn through the crank case like common two-stroke petrol engines but makes use of loop Scavenging with the fresh air away from the crank case and the fuel injected directly into the combustion chamber means that only oil is in the crank case which should make the engine last longer than your typical petrol two-stroke but being a two-stroke engine isn't the only thing that sets the Delta hwk apart from your usual airplane engine diesel engines are of course nothing new but combining that with a two-stroke is fairly unusual in aviation but let's look at the advantages of a diesel engine over a petrol engine of course the engine we are looking at today will most likely be run on widely available jet a or jet A1 but note that when I say diesel engine for for the reminder of the video I'm referring to compression ignition engines one factor that directly affects power as well as efficiency is compression ratio in a petrol engine compression ratio can only go so high for any certain grade of fuel before engine knock is introduced the more air is compressed the more it heats up if it gets too compressed and thus too hot detonation of the air and fuel mixture can happen to suddenly and prematurely out outside of its normal combustion process prolonged knock is bad for internal engine components and can eventually damage it and for this reason petrol engines have a limit on how high compression ratio can go in a diesel engine this problem doesn't exist because diesel engines aren't spark ignition engines but compression ignition engines combustion isn't achieved from a spark like petrol engines but from the resultant heat of high compression the more air is compressed the more the air heats up and the diesel engines combustion process starts the moment the fuel is injected directly into the highly compressed air in the combustion chamber it thus isn't possible for combustion to start before fuel is injected into the combustion chamber this gives us full control over when combustion will happen no matter how high the compression ratio and premature combustion isn't possible so diesel engines doesn't have any problems with knock and can thus have much higher compression ratios than petrol engines and we already know that high compression creates more torque and improves efficiency but because diesel engines needs to handle that very high compression ratio they are built stronger and are thus heavier than petrol engines the Del hog engine is a direct drive engine this means the propeller is connected to the crankshaft and Spins at the same RPM as the engine the majority of older petrol airplane engines are also direct drive the advantages of a direct drive engine is it doesn't need the added weight and complexity of a reduction Drive unfortunately that's as far as the advantages of direct drive go and direct drive has one major disadvantage and that is because the propeller is running the same RPM as the crankshaft effectively limiting the engine's Max RPM efficient airplane propellers can't turn much faster than about 2,700 RPM and thus direct drive airplane engines will be limited to a Max of around 2,700 RPM since horsepower is torque times RPM and the direct drive engine is rpm limited means there's one fewer way to achieve higher horsepower since RPM is limited the only other way to increase horsepower is to increase torque which is usually achieved by increasing displacement yes there are other things that contribute to higher horsepower but this is basically what it comes down to Modern petrol engines can run more efficiently with better power to weight ratios at quite a bit higher than 2,700 RPM usually closer to 5,000 RPM running an airplane engine at these higher RPMs thus requires a reduction drive to slow down the propeller speed to less than 2,700 RPM aside from any reliability concerns running at these high RPMs completely offsets the disadvantages of the required reduction Drive being its increased weight and increased friction however this disadvantage of being RPM limited on a direct drive engine is actually less of a problem on a diesel engine than it is on a petrol engine because diesel engines create more torque than petrol engines a diesel can create more horsepower at lower RPM than a modern petrol engine let's look at the pros and cons of another the property of this engine being that it's a V4 configuration a v engine can't achieve perfect primary balance the way that the boxer achieves it the boxer 4 achieves perfect balance with a Pistons being 180° opposed meaning the Pistons itself cancels out each other's momentum this is not only true for primary balance but also for secondary balance and thus a boxer is usually an extremely smooth running engine on the V engine it isn't possible for the one piston to cancel out the momentum of the opposing piston since the Pistons aren't actually opposing each other this means a v engine needs to cancel out the primary and secondary balance in a different way to a boxer engine but if the V has an angle of 90° it is possible to achieve perfect primary balance via the crankshaft counter balance now you might think but isn't that what the crankshaft counterbalance is there for in the first place normally the main purpose of the crankshaft counterbalance is to create a smooth running crankshaft assembly by balancing out the vibrations or momentum caused by the weight of the crank pins and connecting rods the crankshaft counterbalance can only cancel out all of the momentum of the Pistons at top dead center and bottom dead center when the crankshaft counterbalance directly opposes the Piston with a piston in any other position the crank shoft counterbalance does not oppose the p and its momentum cannot be cancelled out this is why an engine layout like a single piston or inline three for example can't achieve good primary balance with the crankshaft counterbalance weights alone however in a 90° V engine it is possible to use the crankshaft counterbalance to cancel out the momentum of both the crank pin and connecting rod as well as the Pistons when one piston is about halfway down the cylinder you can see the crankshot counterbalance opposing the crank pin and bottom end of the conrod as per usual but in this position you'll also see it opposes the other piston which is at top dead center so by using a crankshot counter balance of the correct weight in a 90° V engine it is possible to achieve perfect primary balance the disadvantage of this is the crankshaft counter balance will be big and heavy which isn't particularly well suited to a very high reving engine but if it a diesel that is low revving anyway these big and heavy crankshaft counterbalances aren't that much of a problem at all however another con of the V engine is secondary balance secondary imbalance is caused by the relative shortening and lengthening of the Conrad's vertical length relative to its length in a fully upright position there changing in relative length means the Piston has to move faster or slower at certain stages of revolution in the same amount of time this creates acceleration and deceleration of the Piston as it moves up and down when the conrod is in a fully upright position the secondary force is in an upward Direction and when the corot is fully angled the secondary force is in a downward Direction since the pance doesn't oppose each other like in a boxer engine they can't cancel out each other's secondary imbalance but it also doesn't stack up like it would in for for example an inline four and instead creates resulting sideways imbalance switching from one side to the other while the V4 does not have great secondary balance this imbalance in the 90° V is relatively small in magnitude and would not require a balance shaft to cancel it out and thus this tiny imbalance would be acceptable looking at the mentioned characteristics cohesively they oddly perfectly complement each other diesel engines are very heavy but making it a two-stroke means it can shed all the weight of the valve Trin system and can now be much more competitive in power to weight ratio diesel engines are also particularly well suited for a direct drive system much more so than any modern petrol engine because diesel engines create more torque and doesn't rely on high RPM to create high horsepower as much as a petrol engine that being a diesel it also benefits more from turbocharging than a petrol engine since compression ratio does not need to be lowered to prevent knock and the only real limitation being the strength of the engine and its internal components as it needs to withstand that high compression ratio and torque and also remain reliable two stroke engines usually require more frequent overhauls but since this is a low revving Diesel with fuel injection and loop Scavenging means it gets dedicated ated internal lubrication which should make the engine more durable what else sets this engine apart the company claims this engine has 40% fewer Parts than other engines that we depend but that seems very plausible for one being a two star engine and not needing a Val frint system alone would much reduce the parts count this also connects to another aim of the company to make maintenance very easy and cheap not having a valve train makes it simpler to get to the Pistons as an example the engine also has replaceable cylinder liners and accessories like the coolant pump and oil pump are externally mounted for ease of Maintenance the engine also has no ignition system which is possible of course because it's a diesel engine and additionally it has absolutely no electronics so no fadec or anything like that even the diesel injector is fully mechanical jet A1 which is the fuel the engine will likely be using the most is much cheaper than fgas but the engine can actually run on a variety of different fuels as listed on their website one problem from using diesel in aviation is it has a gel point of only -9.2 de C while jet A1 has a freezing point of - 47° c since the engine is designed to run on a variety of different fuels it has a fuel preheat system to prevent other diesel types from freezing or jelling these fuels also has zero lead emissions as well as less carbon monoxide pollution than petrol engines deltaw claims break specific fuel consumption of 0.38 to 0.4 to create 180 horsepower and 492 Newton M of torque at 2,600 RPM the engine has a Max RPM of 2,700 as expected of a direct drive engine stated fuel burn is 27.6 lph at 135 horsepower economy cruise and 40.9 lph at 180 horsepower I mentioned earlier that the engine is both turbo and supercharged but interestingly only the turbocharger isn't used during sustained engine run and the twin screw supercharger only provides starting air compression once sufficient RP is reached the turbocharger takes over the supercharger however is reported to be able to supply emergency power in the event of Turbo failure which would then Supply around 50% power one question often asked of new engines is TBO or time between overall I couldn't find TBO stated on the website or anywhere else on the internet but hopefully it is quite long as the $100,000 price tack for a new engine might be tough to swallow if it needs to be replaced often

Channel: Lets Go Aviate

Views: 168,019

Keywords: deltahawk, v4, diesel, jet fuel, jet fuel piston, dhk180, dhk 180, 2 stroke, 2-stroke, compression ignition

Id: uLPym5Xmsow

Length: 18min 0sec (1080 seconds)

Published: Sun Dec 10 2023