Corsair Engine Technologies recently completed a 200-hour flight test program on its aluminum V8 engine, an automotive engine being modified for legacy piston aircraft.
A redundant electronic fuel injection system flat rates the normally 500 hp engine to 220 hp for the Cessna 172 test aircraft, according to officials with the company, which is based in Colorado Springs, Colorado.
Company officials are developing the alternative engine to meet FAA Part 33 certification standards for an STC, which would allow the engine to replace original aircraft engines of legacy GA piston aircraft.
“The engine offers leaps in technology, such as being flex-fuel rated, which allows it to burn multiple fuel types, including automobile gas, with and without ethanol, as well as avgas,” company officials said.
The engine also features push button start, digital engine diagnosis, a digital engine display that monitors more than 50 parameters for faults, officials noted. The new engine also would eliminate the need for pre-takeoff engine runups and “cost 60% less to own and operate,” they say.
“The goal is to significantly reduce cost of flying and eliminate the need for leaded fuel,” they add.
Because the engine is software controlled, the same design can be installed on multiple types of aircraft models up to 350 hp, including twin aircraft.
“This, and the ability to burn cheaper automotive gas and mass-produced components, can significantly reduce the cost of owning and operating small aircraft,” said Corsair co-founder Rich Macmullin. “Our cost to fly the test C172 is less than $19 an hour with fuel and engine reserves, compared to over $60 with the original Lycoming engine.”
Efficiency is increased by modern electronic fuel injection that incorporates several layers of redundancy, which also eliminates mixture and carb heat controls, which also reduces pilot workload, he noted.
The flat rated 220 hp can be maintained until over 6,000 feet altitude, according to company officials.
“Efficiency is further increased by Corsair’s prop gear drive (PGD), which allows both the engine and fixed-pitch prop to operate at their most efficient speeds, as well as reduces noise levels,” they add.
Flight testing will continue to monitor wear on components, perform oil and vibration analysis, and further lower noise emissions.
There is now an aircraft engine based on a modern Suzuki engine with it’s own PRU that may be a game changer. It began in 2008 as a replacement for Lycoming engines on airboats that are run just like airplane engines pushing a propeller. I really hope they can make a dent in this market, bring the costs down and maybe attract more people into aviation.
DISCLAIMER: I personally know the owner and chief engineer of Aeromomentum Aircraft Engines.
https://aeromomentum.com/index.html
There are a lot of pipe dreams in GA, but this is about as basic as it gets, this engine is probably based on a Chevy LS engine with some redundant systems and a PSRU. The company is trying to prove the total conversion similar to a factory overhaul of an O-320. Then fuel cost is $2.50/gal cheaper, HP increased 35%, hopefully TBO on a very derated engine exceeds the current norm but when it is time to overhaul the V8 it could be as easy as ordering a crate engine from summit racing and re using all the components.
The electric motor is a pipe dream, only 1 in 5 electric car buyers buy another electric car! They are impractical, expensive and they only shift the carbon footprint from the tail pipe to the coal burning power plant and the mines digging for lithium, copper and petroleum products to produce wind solar and batteries.
Bravo to Corvair, I hope their STC is a major success!
I hope this can be approved because I have 2 planes i would love to have them installed in. Good luck the aviation community sure needs this.
Battery technology has a long way to go to provide a viable alternative. For now electric airplanes are mostly novelties . The aluminum vs lithium based batteries in development show great promise with much faster recharge times and availability of the metal . That said , size and weight/mass will still be huge challenges for a viable non fossil fuel aircraft . The energy density of avgas and jet fuel is still exponentially higher than any battery produced as yet .
We are making progress though
No remarks on how its weight compares with the Lycoming or other aircraft engine it replaces, or whether its configuration allows it to fit into the existing cowl without modification to the airframe. Presumably these concerns would be addressed in the approval of the STC, but it would be nice to know before getting our hopes up! Owner of a Lake Amphibian here.
The to an fro’s of the piston remain a problem. By reducing the masses for example model enginges reach 40 000 rpm. So the electric motor remains first choice. Perhaps the trend goes to electric turbo generators saving gearboxes.
electric is coming, but not for a while for most uses. electric airplanes are new, made is relatively small numbers for the foreseeable future, and most likely won’t reach flying clubs or rental fleets at reasonable cost for many years. These guys have the right approach…. we still have plenty of old Pipers and Cessnas that are being parting out every day because they are just too expensive to operate. A club or rental fleet could convert to this when each plane comes to TBO. At about a $20/hr cost, figure a C172 could rent out about $40-50/hr. This would bring a lot more pilots into GA and reverse the GA’s downward trend.
Certified diesels are Mercedes Benz car engines. Don’t see why a V8 wouldn’t work just as good. Glad to see someone trying something new.
Could you detail the $20/hr cost ? Is this after buying the motor, controller and battery, and converting the aircraft to ‘experimental ‘ ?
BTW, the only Cessnas and Pipers that I hear of being ‘parted out’ are the ones that have crashed.
Used SEL a/c have increased in value.
At the root of the “why can’t we convert a car engine to airplane use?” problem is the fact that propellers like to be big and slow and engines like to be small and fast.
If you want to turn a propeller slowly (for best aerodynamic efficiency), you either need a large displacement direct drive engine or a gearbox to allow you to use a small displacement engine which revs faster to get the same horsepower as the big, slow direct drive engine.
Big, slow engine are heavy, there’s just a lot of metal there. Little fast engines (of the same net horsepower) are lighter, but require a gear or belt reduction system of some kind, which is invariably heavy and not especially reliable.
The lure of automotive engines is that the unit cost is low, GM makes more engines in a month than Continental, Lycoming, Rotax, etc. have made in forever. “Core” engines to convert are even cheaper, junkyards are full of them, they come from running vehicles which have been wrecked (and if they hadn’t been running, they wouldn’t have been wrecked).
While the engine parts are cheap, the conversion parts are NOT. By the time you’ve done a proper aero conversion of an automotive engine, it isn’t cheap any more, it isn’t simple any more, and it usually isn’t as reliable as a certificated aircraft engine.
(There are a few – very few – exceptions. Some Corvair and VW conversions work pretty well, there’s a Honda Fit conversion that has a good reputation. The Thielert engine was a Mercedes A series engine, but the gearbox and some [a LOT of] creative accounting did them in. Note that none of these engines other than the Honda Fit engine are available new, off the shelf. A very low mileage used Fit engine is orders of magnitude less expensive than a new one.)
Given that we canna’ change the laws of physics regarding propellers, our most viable option for affordable engines may just be electric motors. They are quite happy turning slowly (they make maximum torque at zero RPM), they are simple and last almost forever.
Motors and the controller electronics are pretty well figured out, “all” we need is viable, powerful, and quickly rechargeable batteries. Once that happens, and sooner or later it will, our airplanes are going to be a LOT cheaper to buy and run than they are now. The stone age didn’t end because we ran out of rocks, we found something better . . .
Sure hope that the research continues to development of a inexpensive lightweight battery, to power aircraft, certainly more reliable, powerful and quite power.
If a small, light weight battery is developed that fits in a shoe box, there is still the problem of the time it takes to recharge it.
To get the range of the typical SEL aircraft, about 5 hours. A 500 kWhr battery is needed….[ I’ll let others try the math ].
Recharging it using a DC fast charger, which is usually 50 kw, running on a 480 vac connection, will take 10 hours…Which really hits the utility of an electric aircraft.
There’s one thing people forget about batteries: we’ve been developing them for well over 100 years. We’re near the pinnacle of what we can do. A “small cheap powerful” battery is a pipe dream. They are about as powerful as they’re going to get. The laws of physics with regards to a cathode/anode can only be bent so far. Electron shells can literally only hold so many electrons.
And honestly the big fuss about gearing systems is outdated. PSRUs can be made plenty reliable. The old GIO engines from Lycoming had their issues because of the way the pilots flew them and because of terrible tolerances. Most WWII fighters and bombers used gears. Most prop driven airliners did too. Spoiler alert, so does EVERY SINGLE TURBOPROP EVER MADE. So just stop with that.
Yes, the Allison and Merlin both had planetary propeller gear reduction units. The Merlin ran at 3,600 rpm with a prop turning 1,800 rrpm.
I fly a 1961 Cessna 175 with the GO-300, which has a 4:3 spur gear reduction . The engine will run at 3,200 rpm, making 175 hp, with the 84 inch prop turning 2,400 rpm. Pilots were not comfortable running it at 2,900 to 3,000 rpm.
It has been very reliable and is now way over tbo, and running strong, and 7 hrs per qt of oil.!
Yes, a PSRU can be made reliable, but it is going to be EXPENSIVE to do so. Turboprop reduction units are reliable, but you might want to sit down before you ask what the reduction unit costs. The *entire* point of this exercise is to decrease cost to increase the market, not increase cost.
Here’s the problem – piston engines don’t have smooth power delivery. Each cylinder is push-coast-coast-coast (power, exhaust, intake, compression), so the gears are “banging” back and forth as the engine runs (times how fast it is turning times the number of cylinders times anticipated – or hoped for – TBO). Since many of the crankcases and gear cases are aluminum, the clearances change with the engine temperature and it is almost impossible to avoid gear chatter and eventual spalling of the tooth faces. Hypoid 90 oil helps, but then you can’t share the oil with the crankcase oil, so complexity and cost go up yet again.
With a turbine engine, the power is continuous and smooth, and the gearbox only runs in one direction (most of the time), so it lasts a lot longer.
So I guess I should rephrase it – reduction gearboxes that people can afford aren’t very reliable. Reliable gearboxes (as in turbines) are unaffordable for general aviation.
Article in Forbes three days ago, researchers in Australia have developed an aluminum-ion battery (as opposed to lithium ion) in a graphene matrix. We have plenty of aluminum, unlike lithium, which mostly comes from China and Chile. The battery has high power density, and offers really fast recharging. They are saying an iPhone size battery can be recharged from dead to full in ten seconds. They are hoping for automotive-use cells by 2024. I’m keeping my fingers crossed, and remember, they are not the only people working on this.
Best Regards
Rotax seems to have designed a reliable gearbox on the 900 series engines, using some torque pulse absorbing springs and a clutch.
My GO-300 has 3,000 hrs on the gearbox with no problems.
Continental added a ‘quill shaft’ between the crank and the drive gear to absorb the torque pulses.
What ever happened to this aluminum V-8?
https://generalaviationnews.com/2010/01/17/trace-debuts-750-hp-engine/
Rotax made it’s mark in the Homebuilt industry before entering the Certified world. I would recommend Corsiar do the same.
TraceEngines.com domain name is for sale at $1695. Guess TraceEngines is no more.
We wait for Oswald electric engine with cryo magnets. Farewell for combustions.
Oswald has an interesting super-conducting motor of 1 mega-watt.! [ 1,330 hp ].
But using hydrogen and liquid helium seems more complicated than a conventional motor with liquid cooling.
Then, there is still the battery capacity and weight, along with the problem recharging it in a reasonable time.
This should have been done many years ago with all this crazy cost of flying today , in the early 70 th my brother in law bought a Cessna 172 from the dealer that had never been sold with demo hours for $10.000 dollars , look what it costs to rebuilt 172 engine today ,About $18.000 thousand , In 1973 I had a complete engine rebuilt for $3.500,00 in Tulsa OK ,on a 1969 Cessna 210 centurion , That why you see small airports Quite with very few average Joe able to own and fly today ,
The aluminum engine in my Chevy Vega was a disaster. I hope this engine has progressed beyond that technology.
Aluminum block V8’s and V6’s have been around for decades, performing well, typically with iron liners. The Vega engine failed because they tried to use aluminum for the cylinders, and the technology failed to meet expectations. It was a singular failure for GM, one among so many. GM loves to test new things on their customers, ala Corvair. By the time they got done fixing it, it was a great car, but by then nobody wanted one.
the Vega was produced in the 1970’s. Yes, the technology has slightly advanced.