New engine
8 min read

When I learned to fly in the 1980s, the school’s fleet was comprised of already decade-old Cessna 172s, most of which clearly showed their age and the toll of countless training maneuvers, hard landings, and checkrides. The seats and interiors were already well-worn and faded, seat belts stained and produced odors of the many previous occupants, plastic dashboards cracked and re-glued multiple times, the original 1960s NAV/COM radios scratchy with often only one properly functioning, not to mention the multiple cowling screw heads stripped from a decade of inspections, oil changes, and engine overhauls.

Back then I paid $45 per hour, wet, for a 172. The CFI cost me another $15-$20/hour depending if VFR or IFR training, and there was no requirement to have your own renter’s insurance (the FBO did offer a $3/hr option that would limit max deductible to $500, but few took then up on the offer). My PPL cost me about $3,500 total, including checkride and even a shiny new Peltor folding headset. There were plenty of planes to rent at numerous small airports due to “trickle-down economics” tax laws that made lease-backs make financial sense. Cessna was producing the same 172s at a rate of over 2,000 a year to pacify demand of FBOs, flight schools, flying clubs, as well as personal buyers—who viewed the price tag of about $17,000 as feasible.

Cessna 172

Thirty years later, the same airplanes are flying at flight schools all across the US.

Over three decades later, my daughter expressed interest in learning to fly, and I started calling around to flight schools to figure out where to begin. Although I had a GA background and built time as a CFI, I’ve been flying for the airlines for three decades and have been absent from the GA scene, which I mistakenly assumed had long evolved and would now seem foreign to me.

After just a few calls, nothing had seemed to change except that the same 1970 vintage 172s were now renting out at $115-$125 per hour. Even more unbelievable was that the same engines were used and still required leaded gas—the EPA and FAA seemed hell-bent on eliminating lead’s poisonous emissions in the early 1980s. Somehow aviation became an inverted pricing model compared to all other industries, wherein the older and more worn a plane is, the more it cost to rent, and remained immune from any emissions rules that required all other engine industries to evolve.

Quickly calculating aircraft rental cost alone for a 60-hour private pilot program in my head, it was obvious that there had to be another way. I looked into experimental kit planes, but I had neither the time nor facility to build it, and was uncomfortable buying a completed homebuilt with little way of knowing how or who put it together.

So I began looking into buying a certified plane, but quickly realized there wasn’t all that much savings considering cost of ownership, let alone what I deemed to be ridiculous prices for 40-year-old aircraft in mostly original condition. What used to cost me $45/hour to simply rent and walk away—leaving the ownership cost to some owner who would write it off their tax return—now would cost over $60/hour just for the engine direct operating cost (fuel, oil, overhaul reserves). The engine cost was the real deal breaker, and there had to be some alternative.

The only alternative engines I could find for the 172 were diesel engines that cost over $100,000 for the conversion, and offered little in operating cost savings. My background in marine engineering reminded me how the boat industry develops powerplants. Even the largest marine engine manufacturers use mass-produced automotive engines that they modify for the boat mission, an engineering process I was more than familiar with. This process, called marinization, allows the relatively small marine engine segment access to the newest technologies, state of the art quality control of some of the worlds most successful companies, and at a lower cost of goods then they could even dream of if vertically developing their own product.

I wondered if the same process could work for aircraft engines, and began the experiment of designing and modifying a V8 aluminum marine engine to meet FAA Part 23 and 33 requirements, then install it onto a Cessna 172 airframe. (This wasn’t an original concept, as I discovered. Toyota and Porsche actually certified modified versions of their car engines, but quickly closed the program for a number of practical reasons).

New engine

A new approach to aircraft engines.

Almost two years later, with seemingly never-ending obstacles along the way, FAA regulatory hoops to jump through, and even a few small engine fires during ground test, our 1969 Cessna 172K lifted off for its first flight. Regardless of my experience as a former FAA designated engineering representative (DER) and flight test pilot, I admit questioning the logic of bolting a V8 to a Cessna during that first takeoff, especially without a parachute. But the 210 HP Skyhawk flew off with far better takeoff and climb performance than the original POH said it should have, even with our hand carved wooden prop designed to reduce noise.

Vibration meters read normal, air/fuel ratios remained almost perfect, and the several temperature sensors throughout the engine remained as designed. Our redundant electronic fuel injection system worked seamlessly—restarting the windmilling engine within one second after intentionally failing the main ignition and fuel systems. The backup fuel pump also operated as designed, automatically and immediately returning fuel pressure to normal after pulling of the main pump circuit breaker. The alternator circuit produced enough power with just windmilling prop rotation to power the backup ignition system and restart the engine with both batteries off line. The aircraft flew just as any 172, and the absence of mixture and carb heat controls made it noticeably easier to operate.

After about 30 minutes of working through the first flight test plan, it seemed that not only could an experimental-certified hybrid work economically, it could work in lower noise and tailpipe emissions, all while producing better performance.

We continued to improve the design over the next two years to make the aircraft quieter, more efficient, safer, and cheaper to fly. We hired the same engineering firm that worked with the automotive manufacturers on the same EFI system that we use in our design, starting from scratch with blank engine controllers and custom calibration programming specific to the aircraft mission. We worked with certified propeller manufactures to develop even quieter and more efficient designs over the 200 hour flight test plan.

Currently, our 172 costs about 1/3 less to fly (fuel, oil, reserves) compared to the original engine. At current car gas prices, average cost is less than $19/hr, compared to the $62/hr with the original O-320 engine. Added features, such as the digital engine display that monitors over 75 engine parameters and alerts the pilot when something is out of the norm, further reduces workload and distractions. We added the ability to connect to the engine controller by WiFi for reading fault codes, engine logs, and performing remote troubleshooting and tuning to support the product from anywhere in the world.


That ain’t no Lycoming.

My daughter has logged steep turns, stalls, slow flight, and touch and goes, and I figure her private pilot aircraft cost should be south of $1,500 for about 60 hours when taking the check ride planned on her 17th birthday. We look forward to building time flying to air shows as soon as things return to pre-Covid norms, and exhibiting that there are practical alternatives out there for GA to reignite by thinking outside the certified box.

The project received a FAA G1 issue paper for an STC to install the engine on other 172s, but certification cost requires outside investor funding and we have not found the right partner yet. Certification brings a lot of product liability baggage as well, so simply operating a 172 or other certified piston aircraft in the experimental category may be the answer for many. Our FAA experimental operating limitations are about the same as an amateur-built aircraft, and we don’t plan on leasing it back, renting, chartering, or even landing at any class B airports, all of which are prohibited for experimentals. So, for a personal or equity based flying club (where club members own a fraction of the aircraft), there is little compromise, negatives of which are eclipsed by the 60% lower operating cost.

So, practical solutions to what ills GA may be more of a compromise between certified and experimental, rather than to simply continue waiting for one industry to come up with a solution. With just one engine design, we eliminated need for leaded gas, decreased pilot workload of managing archaic engine controls and monitoring gauges, all while increasing performance and reducing cost to a level that most would-be aviators can afford. It may not be a perfect solution, but aviation has a long history of design compromises to produce practical solutions.

Jay O'Donnell
Latest posts by Jay O'Donnell (see all)
71 replies
  1. Brian
    Brian says:

    O.k. o.k. fine – here take my money! Uh… best of luck in getting someone to take the financial aspect under their wing. With as many 172’s flying out there this should be a no-brainer.

  2. Stephen Phoenix
    Stephen Phoenix says:

    Interesting project. I have flown a diesel 182 a bit and find them to be pretty nice (although I still don’t like the smell of jet fuel).
    I am not so sure about your idea of operating these in clubs under experimental. Most experimental categories are much more restrictive than EAB.

    • Amable O. Rodriguez
      Amable O. Rodriguez says:

      Thank you, Mr. Stephen Phoenix for sharing this informative article….I’m interested in this or better conversion for my 1974 Piper Warrior II .!!!!!!!!
      Today, there are far better designed and more efficient engines that could move aviation to the next level.
      Finally, the Futuristic Technology of Hydrogen Fuel Cell Power Electric Engines is Unstopable…..!!!!!
      Aviation needs to move forward.!!!!
      Thank you.!!

      • Tord S. Eriksson
        Tord S. Eriksson says:

        The most modern IC engines out there are not much more advanced than the classic O-240 when it comes to the basic parts, but the electronics and fuel handling is pretty ancient compared to Jay’s engine.

        Using hydrogen power in a used 172 would cost a fortune, if at all possible, and a newly-built hydrogen-powered one will not be cheap.

        Let us hope someone helps Jay to get the manufacturing going!

  3. Sid A Hausding
    Sid A Hausding says:

    I have no favorites over gas or diesel……..BUT, the object was to make flying cheaper and he seems to have accomplished that. I applaud that objective and reality and do hope it will have some affect on GA costs and prohibitive expenditures. We need a shot in the arm and nobody seems to be trying to make it more affordable. Even licensed pilots are all too aware of the restrictive costs for ownership and flying. We are killing ourselves over the God almighty dollar…..

  4. Burt
    Burt says:

    $20/hour to fly a C172? No leaded fuel or emissions? I can use the same gas I put in my car costing 1/2 what my FBO charges for AVGAS ?……. What’s the catch? As far as reliability goes, I haven’t heard of a modern car breaking down in decades and few cars are maintained per the owners manual. Great article, we need some new thinking to resurrect GA. The piston fleet continues to dwindle away and be parted out, and new planes have the same old engines and performance but cost $400K! Are they selling the engine now? It would be great to buy on old Cessna or Piper with a worn-out or prop-strike engine and install it. I wish them the best….please keep us updated.

    • TJP
      TJP says:

      Engine reliability for automotive applications has reached a point of near-perfection. It’s impossible to argue otherwise.

      The one caveat is that in an aviation application the engines would be doing doing more work, as they never get a chance to ‘coast’ — similar to a marine application but arguably more demanding, so that could impact reliability (or at least maintenance intervals).

      But either way it’s a huge step up from what we’re currently dealing with.

      • ShuRugal
        ShuRugal says:

        This is the point of downrating. a 300HP auto engine could be de-rated to 200HP for aviation use and should eliminate any “over-stressing” concerns.

    • Bob G
      Bob G says:

      Your FBO is only at a multiple of 2x Mogas to100LL? Sweet. :)

      Here in South Jersey (KVAY) has been charging $5.50 for an eon, then they reduced to $5.25, now they just graciously dropped it to $5.10. This is in an area where mogas is generally in the 2.05-2.15 range, some are down at 1.99.

  5. jay
    jay says:

    Not sure on final weight yet as currently working on using lighter weight composites in several areas, but expect about 130-150 Lb more with extra battery. Our target C172 empty operating weight after conversion is 1,680 lbs.

    The weight increase can be cancelled out on older C172 models with lower max gross weight limits by riveting 3 stringers in tail (already installed on most airframes after L and M models), limiting flaps to 30 degrees, and using 6 ply tires. This upgrade has already been FAA approved for other STC’s for increasing EOW to 2,550 lbs with higher HP engines needed to meet minimum climb gradients.

    There was an article typo on my part regarding operating cost: Cost is about 1/3 of original Lycoming cost, not 1/3 less. Currently our test C172 demonstrated cost is less than $19/HR with engine reserves, without including MOGAS off highway tax rebates. Using AVGAS obviously increases fuel cost, as well as periodic maintenance cost, and requires an engine run-up to burn spark plugs clean.

    Thanks for the interest in our project everybody. We will post progress updates on our website and plan to attend fly-ins next year.

  6. Jonathan Oliver
    Jonathan Oliver says:

    I assume that you’re currently operating the aircraft under Experimental – R&D. Would you be willing to share the issued Operating Limitations for this aircraft?

    In addition, will you be changing the ticket to a different use, such as Crew Training or Exhibition?

  7. Jay
    Jay says:

    This second aircraft and has a multipurpose airworthiness certificate including crew training, R&D, exhibition and market survey. There’s more specifics on the website but the exhibition is about same limitations as amateur built. We had to operate in R&D for about 14 months for development and then to complete test plan and to fly in different ambient seasonal conditions.

    The R&D category is quite restrictive and not a good choice for a private plane, has a max time between FAA inspections (not simply A&P) of a year, and not as easy to get as one would believe as you have to demonstrate you meet the requirements for a program… cannot get an Experimental certification simply because you want to install experimental components or reduce cost.

    This is where experimental really makes sense for recreational and non-compensated training….. by offering a conversion with all the engineering, manuals, structural analysis, etc, complete and ready to bolt on, it makes sense for the average private aircraft owner.

  8. Jeffrey Rodriguez
    Jeffrey Rodriguez says:

    It’s fair to say I am a newbie to flying and have been in and out of 172s for training for last year then COVID hit and put a hold-short on my progress. I agree with all the entire experience of stepping into an old 172 including the expense and have to say, it was a bit nerve-racking for me to look at the aging components of this plane, and can’t help wondering if this will stay together in flight.

    I think it’s time for a refresh, no doubt! This is a cool concept and most of all disruptive.

    Flying for $20/hr?? That’s crazy!! It’s no secret that the expense of learning how to fly is what prohibits a lot of people from getting their private pilots’ license…but this, this is a serious game changer!

  9. Benton Kirk
    Benton Kirk says:

    What are the requirements for taking a certified airframe and turning it to experimental? I have owned a 172 and a Mooney (the 172 was an N model and I upgraded to a 180hp engine using an STC)…I always understood that the FAA took a very dim view on wanting to take certified airframes to experimental….I am currently biting nails waiting to see if the new Mooney ownership will un-orphan my 2008 legacy G1000 panel which has no upgrade path. They are saying they will support a future upgarde to the NXi panel but currently it is ridiculously expensive to upgrade it to WAAS using GIAs that will not be supported in the future and are no longer manufactured, and because the G1000 is part of the airworthiness certificate you can’t change … anything.

    • David
      David says:

      I have limited experience with GA, I have soloed in I believe to be a ’74 172. (‘Bama ended my financial ability before I could get my ticket)That said, I have also been an automotive machinist as well as an aerospace machinist making turbine engine parts, from nozzles to axial flow wheels. I have seen both sides (I retired from my automotive diagnostics business last year) and all I can say is that bureaucracy has severely limited light aircraft progress. The example given is obviously based on an inferior engine design. General Motors has always about making the most money with the least investment. That said I know that most automotive gas engines could easily surpass any GA aircraft engines in durability/weight/torque/horsepower and NVH for a given displacement. GA engines are just so unrefined that it’s laughable.
      Oh, and I forgot to mention my limited experience with GA pilots has also shown me that they treat their dinosaur engines with the same care most people give their lawn mower engines…like change the oil? WTH…it’s a lawn mower…
      Not trying to start a fight with anyone, just an outside observation, BTW early in my automotive machinist career I had a WW2 vet bring in his prop off of what I remember he said was a J-2 that he had nosed over and bent (at roughly 45 degrees about 6 inches from the tip) it was aluminum and he wanted me to “press it flat” in our press…I refused to do it for fear of it fracturing and causing a crash… well, he was buddies with the manager and I was told to take a break from the shop while they “fixed it!” I worried about that for 6 months waiting for the news to announce that someone had crashed in Glendale or Goodyear AZ. That’s where he was from.

  10. Eric Johnson
    Eric Johnson says:

    The experimental world has been converting auto engines for years, as everybody knows, with varying degrees of success. Lately, one of the most successful has been Viking aircraft engines, which has a pretty good track record with their converted Honda Fit engines. They use the same idea of “marinization”, convert a dependable auto engine for aircraft use. I decided to buy one of their first Honda L15B Turbo engines for my Zenith 801. Being the first person to attach this engine to this particular airframe took a couple of years(in my spare time). During ground runs it was very smooth and quiet, but then I over-boosted it and melted a piston and destroyed several sparkplugs from detonation. It still ran though! Now my winter project is to remove it and replace it with a little newer L15B model, add some more monitors and remap the ECU. Such is the world of experimental aviation. In the meantime, I purchased a Zenith 701 with a ULPower 260i, a 4 stroke, 4 cylinder, horizontally opposed direct drive engine with FADEC, dual ignition and fuel injection. The aviation world is moving on from the 1930’s technology that has dominated for so long. Good luck, I wish you success in advancing aviation powerplant technology.

  11. Benton Kirk
    Benton Kirk says:

    Jay, after reading this I hopped over to your website and found the page on converting to an experimental airframe so no response needed here unless you want to link to it for someone elses benefit…thanks!

  12. Mike
    Mike says:

    Excellent and promising work, Jay. I, too, began flying at the same rates you mention and, after years of family commitments, am disillusioned at the cost to get back to flying.

    There are two things missing from this summary of your project that may or should be included. 1) What is the real reason(s) that this design is not being adopted throughout the GA industry, and 2) What is the approximate cost (needed from investors) for the certification and “liability baggage” you mention?

  13. John Haffner
    John Haffner says:

    Hi Jay,
    What is the link to your company?
    I just did a search for Corsair Aircraft Engine Company, but my search engine could not find it.
    Thank you.

  14. Joe
    Joe says:

    I have restoring a 1968 C150. I have gone the extra mile, dis assembly stripping repainting replacement of all plastic parts and new glass. A new interior and soon a new updated panel. The issue is the O200 @ 100 hp. I ve heard of the 150/150s but the fuel burn and range issues do not fit.
    I discovered that Cessna in conjunction with Reims in France produced with A O240A 130 hp rolls Royce engine but the engine is no longer in production. The IO 240 is in production and is used in the Diamond DA20. I have sought to put the IO240 into the 150 but have just run into a Bureaucratic wall. Any words of encouragement?

    • Jay
      Jay says:

      Hi Joe
      The FAA has been trying new ways to help out owners with orphaned components…. There’s an AC on the subject. REIMS likely built the plane under a licensing type agreement based on existing US model. I would contact a few DAR’s that could help find a way to install one of the other engines included in its type certificate. Good luck.

  15. Steve
    Steve says:

    Wow is that cool! I haven’t followed in recent years, but I thought in general the obstacle to higher power applications was that aircraft engines were by design better able to run at consistently higher power settings, such as cruising for hours on end at 65% or 75% power. Curious how that applies in this case? Also the whole fuel vapor pressure thing for higher altitude ops? – Maybe that’s more of a lead vs unleaded issue than an engine issue…?

    If you could strap a couple of 230 hp turbo-normalized auto engines onto a Twin Comanche you’d have an unbelievable machine…

    • Mike Perun Jr
      Mike Perun Jr says:

      Robert you don’t know Jay he is a lot more than an Airline Pilot – that is just one of his many accomplishments – This is a great breakthrough for GA Aircraft so yes I do agree with you it does sound about right!

  16. Scott
    Scott says:

    I have to wonder if the true cost of the conversion has been factored in. In the end, is it really $20/hour? Or $220?

    Also, this statement from a commenter: “As far as reliability goes, I haven’t heard of a modern car breaking down in decades.” Wow, you’re kidding, right? Modern cars break down all the time. In particular, having had a Subaru, I would NEVER trust one of those engines in an aircraft.

    • Manny
      Manny says:

      Without any scientific or statistical evidence, I have to agree with you. Based on the number of cars I see being towed by AAA and how busy car repair shops are – there are some concerns about using a car engine in an airplane… at least for me. Also, a look at any car’s online forum will reveal the vast number of problems owners have to endure.
      Some people will say that a statistical analysis will show tremendous reliability of car engines, but I’m not there yet.

  17. desmd
    desmd says:

    I have been flying behind a semi-modern engine, a FADEC IOF240 (TCM) in a Liberty XL2 for some 15 years now. Yes – modern electronics do make an aircraft engine both more reliable as well as more efficient – my real world fuel burn is about 4.5 GPH. When I started flying, I assumed that, in short order, dependable solid-state electronic ignition with variable timing and mixture based on MAP, MAT, power setting, and RPM would become the norm. Not to be. It’s hard to fathom buying a new composite speedster with a cost nearing the stratospheric 1M range (when equipped as seen in the ads…) and find a mixture control, a prop control (or hidden version of same) and mags with fixed timing!
    My hope is that, ultimately, a hydrogen fuel cell will have the energy density to power light aviation in an economical and sustainable manner. In the meantime, the Corsair effort is a great step in the correct direction.
    (One final thought – I drove behind a Subaru Boxter engine for many hundreds of thousands of miles – with great dependability. Despite one of the above comments.)

  18. Jim Brewer
    Jim Brewer says:

    Once a previously certified plane has an experimental certificate, does that open the window to using non-STC’ed avionics, too? Great to get rid of the 100-year-old technology engine. Even better if able replace the avionics / instruments with the lower cost radios and navigators and instruments that are common in the experimental fleet.

    • Jay
      Jay says:

      Yes, once converted to EXP you can add non certified components such as avionics. Because aircraft was previously certified, work must be done or signed off by A&P.

  19. Matt
    Matt says:

    Just yesterday, we removed a GM V6 from the used Vans RV6A we just bought.
    With only 400hrs this new engine had burned the valves out twice, despite upgrades.
    It was also dramatically heavier. The performance way less than Lyc.

    So, we put on a Lyc 320. Electronic ignition will go on as well.

    I know of several planes using Aluminum Chev corvette engines. They seem to have reliability and over-temp issues that have to be worked through.

    Aircraft are unique when compared to cars and boats in that weight is a major consideration. Also, usually hard to just pull over when the engine fails.

    Some day, someone will come up with a great solution…

  20. Karrpilot
    Karrpilot says:

    The 172’s where i fly go for $150.00 an hour. You want a glass cockpit one? Set you back almost $200.00 an hour. For that $200.00 an hour price tag, i fly the 182 RG with steam guages.

  21. Rich G
    Rich G says:

    When I returned to flying GA, I found some things did change. The C172 I learned a flew 20 years ago is not the same C172. The same can be said for the R22 helicopter I learned in. Yes, the price has doubled or even tripled in price. Many changes have been made to the aircraft, mostly due to lawsuits.
    What I found was the driving price increase was the insurance. This is included in the price of the new planes. Companies must charge ten times what it should cost because the companies know eventually they will be sued.
    Long ago, People were getting sued. Just not as much as now.

  22. Rich G
    Rich G says:

    When I returned to flying GA, I found some things did change. The C172 I learned in and flew 20 years ago is not the same C172. The same can be said for the R22 helicopter I learned in. Yes, the price has doubled or even tripled in price. Many changes have been made to the aircraft, mostly due to lawsuits.
    What I found was the driving price increase was the insurance. This is included in the price of the new planes. Companies must charge ten times what it should cost because the companies know eventually they will be sued.
    Long ago, People were getting sued. Just not as much as now.

  23. OttawaCanuck
    OttawaCanuck says:

    Very creative work on the engine!

    Note that $3,500 in 1985 translates to $8,500 in 2020 with inflation, so your PPL was a bit less expensive back then, but not really that much of a difference.

    Most of my cost of flying with the O-320 in my PA-28 is insurance, tie-down, and maintenance, not fuel or engine reserve, so, sadly, even if I cut those last two by 2/3 like you did, it would probably still be only a 10–15% hourly reduction in my total flying cost (at best).

    • Manny
      Manny says:

      Correct. A lot of people forget about inflation. When I learned to fly – many eons ago – the 172 cost me $12 / hour – wet. But it was still a lot of money for me then.
      And today there are many more options for spending one’s money. If someone wants to fly an aircraft with a $50,000 – $100,000 avionics package, someone has to pay for it… either the owner or the renter.
      Regarding the engine discussed in this article and it’s very low projected operating cost, I’m not sure how low maintenance costs will be for this type of engine when there will be relatively few people who can or will work on them. I applaud the creativity and effort, but I think it will be useful for a small number of users, which is fine.

  24. Rance
    Rance says:

    Ethanol. I would be very hesitant to operate an aircraft on any fuel containing ethanol due to its effects on lines and seals and its poor ability to sit for long periods without deteriorating.

    • Barry T Borella
      Barry T Borella says:

      Ethanol would not be a problem if the fuel lines and seals were changed to be compatable with mogas – as they are in Rotax powered aircraft. I’m assuming that was an integral part of the conversion. I remember hearing explanations in private pilot ground school in the 1960s about why autogas was unsuitable for aviation uses. With all the mogas STCs around that turns out to be another old wive’s tale.

  25. Paul Wisgerhof
    Paul Wisgerhof says:

    Let’s be clear that you are not building an Experimental/Amateur Built aircraft. You are modifying a certified aircraft and obtaining STCs from the FAA to support your efforts. Your aircraft’s operating airworthiness certificate may very well be Experimental/Restricted, but that is not the same as E/AB. In fact, the FAA never grants an E/AB airworthiness certificate to a modified version of a certified aircraft.
    If your 172 is not allowed in Class B airspace that is due to restrictions on the airworthiness certificate, probably placing the aircraft in the E/R category while they sort out your various STC applications.

    • Jay
      Jay says:

      Yes, let’s be clear. Never mentioned the c172 was E/AB which is impossible as it was previously CAR3 certified…. Not sure how you came to this conclusion. Only mentioned op limits about same (for exhibition cat), not that it was in E/AB….again, not sure how you so misunderstood. Also, didn’t mention anything about restricted from B airspace, only from landing in a class B airport itself, which is FAA national policy for experimentals with few exceptions. But thank you for clearing such matters up on our project.

  26. Gary Green
    Gary Green says:

    In the last paragraph it says the need for” leaded gas is eliminated.” Should’nt it be
    “need for unleaded gas?”

  27. Paul Copenbarger
    Paul Copenbarger says:

    But what can I use the plane for? Vacation, visit friends, relatives? What constitutes “Exhibition?” Can I park it in the flight line with explanatory materials/signs etc and call that an exhibition? If I want to go on a long xc trip can I call that training? Is prior notice needed.

    • Jay
      Jay says:

      Experimental exhibition allows for proficiency, maintenance and flight training, with about same restrictions as a kit built aircraft (for small piston aircraft like the c172). Exhibition events are described in FAR 21, but essentially, any fly in event or even a mall opening (the regs are old), but there is no requirement to attend any events.

  28. William Helfand
    William Helfand says:

    “Inverted pricing?” You simply neglected basic inflation.
    Your $45 per hour back in the 1980s is simply worth about $135 now. It’s not the industry – although most who lease aircraft on a small scale seem to be ignorant of basic business sense – but rather the simple effect of inflation.

  29. James T. Kirk
    James T. Kirk says:

    I received my ppl in 1976. I think the 70’s and 80’s were the hay days of Gen Av. I built time in a Grumman Yankee for $10 / hr wet. Took my check ride in a Tiger for $20 / hr wet. The big disruptions I’ve seen is in GPS and Avionics. The rest is the same, including a closed system for fuel, fbo’s, mechanics, training, etc. Having new engine choices is better, and having new energy sources will be what’s needed for any future leap. I like the piloted drone looking aircraft.

  30. Stephen Mullin
    Stephen Mullin says:

    I see nothing in the regulations that says no experimental aircraft can land and takeoff from a Class B airport…..I asked this question in the FB ATC forum and they agree that experiments can land at Class B if the PIC has a PPL license.

  31. Chris
    Chris says:

    How do you see this affecting annual maintenance? The thought of tearing into my relatively simple Lycoming 0-320 already terrifies me as maintenance induced failures are most certainly real. Doing that to a modern engine with all the sensors and tighter tolerances seems particularly dangerous.
    I’m no mechanic and might be overthinking it…?

  32. Jay
    Jay says:

    Thanks again for interest in our project. I’ll try to address some of the questions posted above.

    RE encouragement for installing IO-240 engine on a C150: I am afraid I have little words of encouragement to offer as you will most likely need a STC for either part 23 or primary category or maybe future LSA regulations which will require considerable expense and grief. You could put it in to experimental for R&D but it’s very limiting. Exhibition would require specific reason to meet the requirements and lowering cost won’t meet it. The FAA does not like swapping certified to experimental and it will be difficult . Canada does have such a method for owners to do just this, and FAA is rewriting LSA rules that may make it easier but it’s likely years away. I am a former FAA designated engineering representative (DER) and familiar with the process and I felt like giving up more than once due to the bureaucracy. To do an aircraft swap like you plan would likely require an STC or converting to new/proposed LSA or even primary category, requiring substantial cost. I would start discussing it with a part 23 power plant DER…..but it will be far cheaper to simply buy a more ideal airplane…. and a new one at that.

    RE why is an airline pilot griping about renting and doing this: good question, I wish I had a logical answer. My background as a DER and in marine engineering and challenge of improving suckered me into this. Also, believe it could be viable option to lower cost and help reignite GA.

    RE fuel vapor concerns: AVGAS vs MOGAS properties have been a reoccurring question from the beginning to the point we added specific info on our website which should answer most questions. But essentially, ethanol is far more prone to vapor lock but is controlled within a pressurized fuel system which keeps vapors within liquid, as well as system constantly circulates fresh/cool fuel throughout system. The bigger concern when introducing ethanol fuel into airframes is ethanol’s solvent property which can break up old existing contaminants, degrade original seals (our kit includes new o rings and seals that are ethanol compatible) and clog filters, and it’s ability to absorb water which limits how long fuel can safely remain in tanks.

    RE modern car reliability: I’m not sure how you can say modern cars break down all the time. Statistically, aircraft piston engine experience a failure about every 3,700 hrs. Modern automotive engines are designed to have less than a .5% failure in 200,000 miles. Modern cars do have issues indeed, but from my research when beginning the project, most do not cause engine failure and most were mostly electrical and emissions related. Also, few cars are maintained per recommendations, and nowhere near that required of an aircraft. Our design uses a redundant EFI system which further increases reliability, and flat rating the engine well below its rated limits increases reliability of the engine components.

    RE installing experimental radios/avionics/equipment in experimental C172: yes, you can, but your experimental limitations will require navigation equipment meet certified TSO to use for flying IFR. It’s important to maybe note that because the now experimental aircraft was previously certified, part 43 is applicable and certified mechanics still must be used to service the aircraft as if still in certified category.

    RE Experimental/AB statement: you are correct, near impossible to put a previously certified aircraft in to amateur built (AB), I never made any statement otherwise in regards to our experiment program. As far as referencing “E/R” which I expect means experimental -restricted category (restricted category is not an experimental category) we did not apply for any restricted category although our C172 could meet the restricted category requirement depending on operator’s mission. The reason our aircraft is prohibited from landing at a class B airport, is the standard issued experimental operating limitation issued to most experimental categories, not because of any FAA certification requirement- such aircraft are issued experimental cert specific to showing compliance.

    RE what can I use the plane for under exhibition: the primary use is to exhibit the aircrafts unique features at gatherings and for movies/television media. However, it allows for pilot proficiency and maintenance flights…. as well as training if not compensated. We went into some detail on this topic on our website.

    RE servicing the engine: it is a bit more complicated than a O-360, but not that much. The more complicated part is the electronic fuel injection system and related sensors. We are completing an app that allows your phone to connect directly to the engine control module capable of displaying real time data of over 100 parameters, display over 200 engine fault codes with specific troubleshooting trees and can connect remotely to qualified technicians that should curtail the technical learning curve. The engine is internally modified for the aircraft mission and our plan is to offer engine core swap for factory new block or a complete plug & play engine swap.

    Hope this helps answer your questions. We added info to our site…which is a work in progress… a Q&A section details a lot of the questions asked here and some I will be adding as a result. Thanks again for all your interest, I’ll try to keep answering questions here promptly.

  33. Joe DIckey
    Joe DIckey says:

    Keep up the good work!! I would anticipate the bureaucrats making it harder to convert a certified plane to experimental…however, I have a 1948 C-170 with a twisted left leg that I’d love to convert just as soon as I get the EA 81 Subaru into my Long wing Challenger but it’s already EAB so that’s easier.

  34. Enderson Rafael
    Enderson Rafael says:

    Enlightening to say least! Sometimes I have a feeling the GA certified engine industry is gonna skip the last 50 years altogether and fall into the electric generation directly from the old and gold avgas days. Thanx for sharing! Even with inflation considered, there’s no sense in the prices we have today.


    Jay, Can you explain the need for the PGD in the 172/PA28? It seems that a 376ci V8 would be able to provide the 160-200 HP at 2700 RPM and not need the gear drive and the 40-80 lb. associated with that gearbox. I’m sure there are thrust issues that would have to be addressed but gear reduction on aircraft has a sketchy history and a fairly significant efficiency penalty.

  36. Jay
    Jay says:

    Gary- RE your question on need to use gear reduction. Our intent was to design an engine not just for the C172, but have the same basic design meet different other models as well, such as C182, C210, twin engines, etc.. with changing software and PGD gear ratios. So, although 180-200 HP didn’t really need the bear box, it does for most others above about 200 HP to prevent prop tips from exceeding efficient tip speeds.

    However, automotive engines were not designed for stresses of direct drive, and props produce asymmetric loads on the drive shaft (due to load differentials on opposite blades) and efficient transfer of harmful vibrations and stresses directly to the engine. In a car, the rugged transmission essentially absorbs these stresses and provides an even load on the engine crank and its bearings.

    There are other reasons as well, such as automotive engines drive shafts are at the bottom of the block, which does not allow for a large diameter prop as it would hit the ground. So for a V8 direct drive the engine would have to be mounted inverted so the prop hub is higher to allow prop ground clearance. This brings other engineering challenges as we found early on.

    We considered and flew different gear boxes each with different issues. We ultimately worked with a well established airboat drive manufacturer and modified their proven design to meet our requirements and gear ratios that matched and optimized both prop and engine speeds.

  37. Markus Warwick
    Markus Warwick says:

    A remarkable step in the direction that GA so desperately needs to move. The shocking expense of light GA is the insurmountable rampart barring so many from accessing their dreams and aspirations. The system itself that is predicted to be severely short of pilots in the future is the same system preventing denying accessibility to tomorrow’s airman.

  38. Roca
    Roca says:

    Kudos to you and your willingness to work on this worthy project. However, as a career CFI, it frustrates me to hear people complain so much about cost, much less someone who is in a comfortable position to pay for the costs. Getting a PPL averages around $10,000; please compare that to a year of college or getting any kind of professional certification (such as welding). It’s very affordable in that context. We need to raise the costs if anything, since CFIs still get paid poorly and any price pressure is usually squeezed out of us instead of airplane costs. I’d like to see a PR campaign from AOPA around raising people’s expectations of flight training costs, rather than keeping costs down and continually putting downward pressure on CFI pay. To go along with that, the industry needs to provide low cost loans towards flight training to make the costs attainable for more people.

    • Jay
      Jay says:

      As a 30 year CFI, I get the point all too well. A good CFI can save a student thousands of dollars and really make a difference, especially for career bound pilots.

  39. John Trimble
    John Trimble says:

    Thanks for sharing your efforts, Jay. Great seeing people doing things to help lower the costs of flying, and what a neat adventure to share with your daughter.

  40. Gregory Travis
    Gregory Travis says:

    The Porsche PFM engine failed because it used more fuel, was dramatically heavier, was less reliable, more complicated, more expensive and presented more cooling drag than the Lycoming it replaced.

    It was in every way a worse aircraft engine than the Lycoming — which is pretty much the story of every automotive/marine conversion.

  41. Richard
    Richard says:

    Seems like to me that a lot of the hurdles in the way of this very timely project are bureaucratic. I hate to sound unpatriotic, but perhaps its time to plant this seed on foreign soil where regulators are often more receptive to new ideas. We forget that the Wright brothers had to do the same, taking their Wright Flyer to France when it was -at least initially- very tepidly received in the US.

  42. Jim+H
    Jim+H says:

    Thanks for sharing this story and returning to answer questions. Looking forward to seeing your display at OSH ’21. I hope you do a few seminars, too.

  43. Richard
    Richard says:

    Thanks for this story. It’s really a shame that the manufacturers do not offer new modern engine retrofits. Legacy engine technology is primitive compared to the modern automobile engine as are the seats, interiors and just about everything else. Seems the the upgrade market would be greater than the new airplane market.

  44. Nik
    Nik says:

    No offense Jay but your living in a fantasy world if you think “norms” of any kind are coming back. This is the great new world order, economic great reset planned over 60-70 yrs ago. Aviation will never return to where it was pre cov. Infact it’ll barely get back to 30-40% of what it was. And as more and more companies successfully test autonomous/AI, pilotless aircraft, the need for pilots will drop by 85% by 2024-26. By then it’ll be just one person upfront doing pretty much what they’re doing today, computer monitors. I was an old school pilot, steam gauges mixed with a little glass, which made pilots proficient. These all glass cockpits make pilots lazy and dangerous, they lose their hands-on skills too. There were numerous studies done in 2015 in the Bravo airspace that found pilots that hand flew the plane to final were much safer, more precise and focused vs those letting automation fly until final. I did the Airbus and Boeing thing and found the bus quieter and abitmote roomy in the front office but the Boeing was a much more REAL plane. The buses were always trying to kill us and controlling themselves often with to many systems to turn off to fully disconnect the autopilot, not so with a Boeing. And when Boeing tried to copy Bus, 73-Max happened and two fatal accidents and a CEO getting fined for concealment of aircraft safety was not enough. Also, farming out maintenance is a recipe for disaster.

    I love your persistence in this project but with aviation going down the tubes and US Airlines hiring foreign pilots, many Chinese there’s no future for wannabe pilots. I don’t want people to get their hopes up when the end of aviation for humans is close at hand, 5-10 yrs at best, and nobody wants to fly the airlines anymore when flight attendants carry handcuffs, people are FORCED to wear a useless mask and the politics and greed is so thick on the corporate level and stressful. Being a part of the crew and or passenger use to be enjoyable, circa pre-2000 back to the mid 60’s. Now it’s a decrepid zoo. The technology is destroying humanity and many businesses right under the world’s noses. 4 billion people will be replaced by AI, drones and robots by 2025 and mass genocide with the soon to be forced vaccines is the future. So enjoy it while you can because it’s all coming to an end in under 5-6 yrs. I have heard what some of the globalist billionaires are pushing.

  45. David Vicari
    David Vicari says:

    Flying a 2100 hr O-300 in my 1957 172, this does draw attention. I have UL 94 available for local flight in my mogas STC equipped bird, though the price advantage over a gas is now gone. I’ve flown from VPZ to the Gulf Coast 3 times, finding self serve fuel on the way. Where does this leave me, on cross country, when typically only 100LL is available, with an unleaded only car engine?

  46. Jay
    Jay says:

    Engine is flex fuel rated and AVGAS is approved fuel…..POH calls for performing a before takeoff run up to clean plugs if running AVGAS. Further info on website.

  47. Avant Jenkins
    Avant Jenkins says:

    Who makes the gear boxes required to spin a 2,3,4, bladed propeller also the ECM how is it programed to feather a prop V8 or four cylinders great idea what took the enthusiast so long to realize it financially with in range of the do it selfer.Please send any information to my email address what is required to make the transition. Avant


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