This person lost a lot of credibility over decades of promoting corsair engines which failed.
Many people are complaining about the ancient technology, but newer ones offer very few advantages.
An piston GA airplane runs basically at two speeds: flat-out for take-off and cruise. For both the fuel/air mixture is easily optimized to optimal, and the slow engines reduce waste. Benefits from EFI are decent but below 10%. Supercharging helps a lot at higher altitudes, but most planes aren't pressurized or carry oxygen, so even that has limited benefit.
The main benefit of the current engines are robustness: I know people who have even flown without oil or with a blown valve. Many experimental builders combine mechanical magnetos with electronic ignitions, partly for fuel efficiency but mainly to lower idle speed on the runway when landing.
The real difficulty is not technology but service. There are very few engine rebuilders, and they are happy with the current limited supply of engines keeping prices up.
And unless you built your own experimental plane, or you get an experimental where the FAA permits owner inspections, the main cost of flying is service on the plane.
Aside 1: many engines have STC's to run car avgas. All require there to be NO ethanol for its impact on the fuel system. The studies I've seen of those engines report bottom rebuild times more like 800-1000 hours rather than 2,000 hours, and of course a higher incidence of valve-related problems.
Aside 2: experimental planes are not a subculture. They form the largest number of new planes. The $200K+ alternates only go to the wealthy. And after 50 years of competing companies, only one has been the overwhelming success, in both popularity and numbers: Van's aircraft. They use old-style, simple designs and construction, and (mostly) old-style engines, preferring the Rotax for their RV-12.
> This person lost a lot of credibility over decades of promoting corsair engines which failed.
As someone not familiar, can you explain? How have those engines failed and how does that impact credibility regarding this, rather than just being something that didn't work out?
> ...but newer ones offer very few advantages.
From the article, it seems like cost is the biggest advantage (70% cheaper to run), followed by ease of use. And then of course the lack of toxic lead, although I don't know how to quantify that.
What am I missing?
You make a lot of points, but it's not immediately clear to me how they refute the article.
The engines don’t require lead, it was just the only high octane fuel available. We do have a 100LL replacement now, and work is being done to get it into service. Lower compression engines run just fine on mogas where it’s available too.
The engines are fine with ethanol. The problem with ethanol is the issues related to it eating at materials in the fuel system (e.g. fuel lines) that aren't alcohol tolerant.
I think that is just the reality of non-mass manufacturing. In the 50's those engines were going into production cars in the tens of thousands, or hundreds of thousands. Now they are produced in numbers of hundreds, maybe thousands, and as such they are hand-built specialty engines, even as primitive as they are.
This is what most people miss. Yes the FAA is slow, certification is costly, and liability messed things up in the 80s -- but you can't get the huge cost reductions we see in the automotive sector without mass-production. Aircraft are essentially hand-made in a labor intensive processes, using individually crafted components.
It's not hard to see what certification costs, take an EAB kit, use all non-certified avionics, and even take an automotive engine and convert it for aircraft use if you want. If you spec that out equivalently* to a certified aircraft, taking labor costs into account (you don't get to count the 1500 hours in your garage as free), it's less than comparable certified aircraft, but not orders of magnitude less.
(By equivalent, I mean safety and redundancy -- ifr capable. Not talking about making my own AP with cheap servos and a raspberrypi and navigating with a handheld gps)
I think the mooney bravo had a porsche engine at some point? But otherwise you are correct. It wouldn't make any sense to use engines in both cars and planes because they are such massively different requirements: One needs extreme reliability at basically one RPM and power output and has things like double spark plugs for robustness, the other wants to keep costs down and reach higher RPMs
Price gauging. Same for Rotax 912, the most popular small engine on planes that don't need certification (LSA/ULM) and they are 20,000 Euro for a 1.3 liter engine with an 100 HP output.
9k for a rebuilt Toyota 2f designed in to 50s & meant for a measly ground vehicle. 30k seems about right for an airplane. What do you do for a living? Why don’t you do it for less?
The Toyota 2F is an out of production engine that fulfills a niche market, it costs 3x as much to rebuild one as a new Toyota engine. The parts don’t cost much more and there are fewer of them. They cost more to rebuild because that is the going rate. Should the shops doing 2F rebuilds charge less? As others have pointed out in this thread, car engines are not well suited for air use, so the market will remain small and made up of people willing and able to pay 30k.
+ if the Toyota engine fails in a car you tow it to a shop -- if the 172 engine fails you emergency land in the best case (or crash in the worst). There is just a whole lot more onus to work on plane engines and that should and does come with a price tag...
(The slightly longer answer is it's a cottage industry. Small shops, small quantities. Car buyers are spoiled, general aviation is more like buying a built motor from a tuning shop.)
There are still many other things in certificated aircraft that are changing regularly based on ADs. This means “we found something in this decades old design that shows up when the fleet is in its 30s.”
Aircraft have VERY long lifetimes in comparison to most things. I own a 1962 Cessna - it is on its second engine, the first having been overhauled once. Some Cessnas from the 70s are still running on their originally installed engine.
Defects and issues are still addressed ongoing, and maintaining the certification for things like modifications for improved power generation still means significant work. It’s definitely not a one-and-done thing - part of the value of certification is in the continuous future improvement that comes from NTSB findings or inspection reports sent to the FAA.
It’s like an engine fault light spread across the whole fleet. The certification keeps the light working.
Even if the design is certified, I’d imagine the shops that produce them would still have ongoing certification costs to validate the equipment, tooling, etc. On going costs that would have the distributed across a limited number of engines.
I'm a fan of the Rotaxes. I fly one in our club's Tecnam. I prefer it over the old tractor engines that run the Piper I fly sometimes.
Curious if you have any thoughs on Sling for kit builds? I'm very serioulsy considering building their new HW (https://slingaircraft.com/aircraft/sling-hw/) that has the new Rotax 915 (turbocharged) in it in the next 12-18 months.
Unleaded avgas is now fully approved for the GA fleet with existing engines and is actively being rolled out this year with more widespread adoption next year. https://gami.com/g100ul/g100ul.php
That's good, but if the FAA had been more permissive in allowing automotive-derived engines with electronic fuel injection and ethanol fuel mixes, we could have phased out 100LL back in the 90s.
Really? Electronic ignition and fuel injection alone are advantageous enough, not to mention the ability of at least one Rotax engine to use true automotive gas (gasohol).
As the article points out, the writing was on the wall for leaded fuel decades ago. The GA industry killed itself by dragging ass on eliminating the need for it, abetted by the burdensome FAA certification process for any aviation advancements.
It may be too late to save GA. BasicMed was a big help, and the increased pace of STC approval has been a boon. But with the FAA derelict in its duty to protect airports (see the sellout of Santa Monica as an example) and corrupt local governments eager to destroy our public airports and sell their land to developers... the future looks grim indeed. Just as electric training aircraft, unleaded fuel, and less-polluting and more-efficient engines render the anti-aviation cabal's excuses moot.
Many people are complaining about the ancient technology, but newer ones offer very few advantages.
An piston GA airplane runs basically at two speeds: flat-out for take-off and cruise. For both the fuel/air mixture is easily optimized to optimal, and the slow engines reduce waste. Benefits from EFI are decent but below 10%. Supercharging helps a lot at higher altitudes, but most planes aren't pressurized or carry oxygen, so even that has limited benefit.
The main benefit of the current engines are robustness: I know people who have even flown without oil or with a blown valve. Many experimental builders combine mechanical magnetos with electronic ignitions, partly for fuel efficiency but mainly to lower idle speed on the runway when landing.
The real difficulty is not technology but service. There are very few engine rebuilders, and they are happy with the current limited supply of engines keeping prices up.
And unless you built your own experimental plane, or you get an experimental where the FAA permits owner inspections, the main cost of flying is service on the plane.
Aside 1: many engines have STC's to run car avgas. All require there to be NO ethanol for its impact on the fuel system. The studies I've seen of those engines report bottom rebuild times more like 800-1000 hours rather than 2,000 hours, and of course a higher incidence of valve-related problems.
Aside 2: experimental planes are not a subculture. They form the largest number of new planes. The $200K+ alternates only go to the wealthy. And after 50 years of competing companies, only one has been the overwhelming success, in both popularity and numbers: Van's aircraft. They use old-style, simple designs and construction, and (mostly) old-style engines, preferring the Rotax for their RV-12.