Great tales from discussion groups…….part #1


I often complain about disinformation on internet discussion groups, but I don’t often provide examples. Well, in the interest of humor, maybe we should look at a few…..


The internet isn’t new anymore, and you would think that by now most people writing to discussion groups would know their comments will have a very long shelf life, and this equally applies if they are brilliant or if they are Bull.


Actually, I suspect many of the people on these groups know this, and that it why the don’t use their names. Yesterdays “Flyboy26” who said something stupid becomes “Conexpert21” with a clean history tomorrow.


OK, here is one of my favorites: Couple of years ago on a Pietenpol discussion group guy gets on and says he is going to use a Corvair, (Mind you, the Corvair is the designer, Bernard Pietenpol’s choice for the airframe.) He immediately  gets a negative reaction from Continental fans. Below is a sample:


“Car engines are not designed to operate anywhere near full power for more than a few seconds at a time, whereas an aircraft engine must be capable of full power continuously.  That’s why Corvairs require such little tricks as painting the pushrod tubes white to try to keep the oil down to a manageable temperature.  Putting that engine in an airplane is asking it to do something it was simply not designed to do.  Now the Corvair guys are adding a 5th main bearing (at significant expense, negating the supposed cost advantage of using a car engine to begin with) to handle the loads that a propeller puts on the crankshaft.  There have been numerous cases of crankshafts breaking in Corvairs in aircraft, although I don’t know of any in a Pietenpol, other than Shad Bell’s. Car engines (other than the Model A) also tend to get their power at higher RPMs than are useful for driving propellers.  Props really loose efficiency when the tips start going supersonic (to say nothing of being VERY noisy – ever hear a T-6 takeoff?) and with the size props used on planes of our size that happens at about 2500 RPM.  Power generated at speeds faster than that is not very useful and there needs to be substantial torque in the 2000 – 2500 RPM range.  That’s why so many auto engine conversions require gearing to reduce the propeller speed, which adds cost, weight and complexity, and hurts reliablity.”


OK, where do we start? – We don’t run the engine at it’s automotive power setting nor rpm limit-Painting the pushrod tubes is to protect the O-rings, has nothing to do with oil temps- It wasn’t designed as an airplane engine, that is why we converted it into one – Dan’s bearing is $1,050  and building a cheap engine wasn’t a goal, building a good one is. – Two Piets with no radius on the grind broke a crank , no damage to either plane. More than 100 Corvair Piets have flown, less than 10 have a 5th bearing.- I have well documented examples of dramatic performance increases with Corvairs and 68″ props over small Continentals with 72″ props.- 2500rpm on a 72″ prop at 60mph is barely above .7 mach at the tip. All direct drive certified engines since WWII are either 2700 or 2800 rpm rated, often with props well over 72″ in diameter. Steve Wittman disproved the slow prop myth with his Buttercup…in 1937. (He used a 64″ prop at 3,400 rpm on a plane that flew slower than a Piet) – you only need torque at 2000-2500 rpm if you have to run it at that rpm, and you would only do this if it is a pre-war design with old metallurgy like cotter-pined rod nuts.


OK, why am I bringing this up? First, because if anyone Googles “Pietenpol Corvair” that top quote comes up as if it was written yesterday. I write a lot about how builders are subject to continuous disinformation in the guise of helpful advice. If that is what they hear all the time, and they have not see a Corvair fly a Pietenpol in person, ‘theory’ like this seems real.


The same list has lots of stories about affordable Continental engines that are  available with accessories for $6000, and in some cases it is said these engines are “Zero timed”.  What these people don’t understand is that the original manufactured is the only person allowed to claim “Zero timed.” Below, from the Continental website:


“Because it’s an exact science.

Continental produces a rebuilt engine to factory-new engine specifications, and we are the only facility authorized by the FAA to build zero-time Continental Rebuilt Engines.”


And yes, it’s in the regs: “This only applies to the original engine manufacturer and may not be represented by field overhaulers.”


 You can’t call up Continental in Mobile AL, and get a Zero time C-85 for $6K. (Small problem, they have not made a C-85 in 44 years and do not offer Zero time ones) It is worth noting that the 85 has a nearly identical parts count to a 0-200, and a zero time version of the latter is well over $18K…if you already own a good core.


Let’s just say that a builder doesn’t know the difference between the FAA terms, Zero time, Overhaul to new limits, and overhaul to service limits. The last is not even vaguely comparable in quality or lifespan compared to the first, and I do not believe that there is a single C-85 for sale in the country with an actual legal logbook with an entry that that meets even the definition of overhauled to service limits, with the yellow tags and the accessories for $6k. Not even close. Grace’s Taylorcraft has a C-85 engine in it, and the parts alone to overhaul it correctly cost $8800 in 1999, and this did not include buying the engine nor any labor,  just the parts to overhaul it.


The only C-85 you will find for $6K is one made of well used parts and a fresh paint job. That isn’t “Zero timed”.  The key words are “experimental only” and “no logs” when you see these engines for sale. That means they contain parts that are not legal for use on Certified planes. Such an engine will never make TBO, and if you are unlucky, it will break. When it does, you will then find out that many aircraft shops and mechanics will not touch your $6K engine. Ask any person who works in a FAA licensed repair station about having out of spec parts in the shop. When I ran the MT propeller repair station the FAA inspectors required all out of spec parts to be marked with a stamped X and kept in a locked room for condemned parts that only the director had keys to. If you have out of spec parts around, they might get into certified engines, and then the repair station gets it’s ticket pulled. That is why professional shops don’t work on junk.


I like Continentals, and have a lot of time flying behind them. Their primary quality is reliability. but you only access this quality by spending top dollar to keep the engine the way that it was from the factory.  Anyone who thinks that you can have the reliability of a certified motor when you buy one that is advertised as “no logs” or “experimental only” is on drugs. You don’t get to have it both ways.   Continental’s reputation was not built on engines made of junk and spray painted. If the engine was just as reliable with out of spec parts, then they wouldn’t be out of spec would they?


There are always people who argue that they have to have “a reliable certified engine” and that they will not fly auto engines. Then the first thing they do is go out and look for the cheapest collection of parts bolted together that are masquerading as a “certified”  engine. That behavior isn’t rational, but people who are compulsively cheap often are satisfied with the illusion of reliability instead of the real thing.


Want to know who isn’t fooled by this? Our old friends Physics, Chemistry and Gravity. If the FAA considers the engine un-airworthy in a certified plane, it is just as un-airworthy in an experimental one. Physics, Chemistry and Gravity don’t care if the plane was built in a factory or your garage.  An engine built of out of spec parts doesn’t magically become airworthy when it is bolted on an experimental.


So now, when you read something like this actual quote from the C-150 discussion group:


“I have a recommendation for an excellent shop in Canada, with whom I’ve worked for 20 years. My O-200 was zero’d there few years ago, and I’m very happy with it. PM me if you like.

Pilot DAR”


That the “pilot DAR” doesn’t know what he is speaking about, because you can’t get a zero timed Continental from anywhere but the factory, and the factory is 1,400 miles south of the Canadian border.


There is some realistic advise on the net, for example the comment below:


“You don’t really know until you open the engine up; a bum crankshaft can add thousands to the overhaul cost.  Figure on a bare minimum of $12,000 up to slightly over $20,000 depending on what you are doing and what comes up.  Remember the accessories are part of the cost and the old ones can be mostly good or all junk.”


If you are building a Corvair and looked at Dan’s $2,200 new billet crankshaft and thought it is a good value, you are right. If someone thought that was expensive, they better not buy a worn out, undersized or previously prop struck Continental, because their new cranks cost a lot more than that, and don’t forget, they will have spent $6,000 on their ‘core’ engine, not the Corvair average of $200.


Below is an advertisement for Don George, a respected, but fair priced FAA overhaul shop in central Florida. Note the fine print that says the core parts from the engine you already own must be reusable. If you had an engine with an “experimental only” crank in it, they would not accept it, and the price would be even higher:

Overhaul    Your Engines Price includes fuel system, magnetos, starter, new harness and spark plugs. Price is contingent on repairable crankcase, crankshaft and cylinders and    subject to applicable air worthiness directives and service bulletins.

O-200-A  (New Cylinders)



I don’t want to leave anyone with the impression that I think the internet is all bad. After years of having damage done by bull stories on the internet to my work with the Corvair, my new approach is to directly point out disinformation in hopes of getting people to recognize this type of story comes from people who are not an asset to home building.

11 Replies to “Great tales from discussion groups…….part #1”

  1. William,

    His website describes him as a “retired mechanical engineer and a flight instructor. He even advertises he can give you your “Bi-annual flight review” when you come stay there. I don’t want to fly with him as he wants to do it twice a year (bi-annually) when all the FAA says I need is a Biennial review (once every two years). Attention to detail…

    Saying you know a lot about mechanical things of all types (i.e. corvair engines) just because your job description has the words mechanical engineer is like me saying that, because my job is as a professional pilot, I can strap in and safely go fly a Spitfire. Similar skills are not equal skills.

    1. Excellent post William! As a builder of a one-off twin engine Corvair powered homebuilt, I deal with these Yahoos all the time! The internet is an awesome source of info for homebuilders, with your sites at the top of the list. A builder or potential builder just needs to be aware that anyone can be an “expert” behind a keyboard. Make sure you verify everything you read…

    2. Terry,
      Since your a Piet builder on that list I am sure you have seen a steady stream of anti-Corvair comments from that guy. As I have long pointed out, I detest negative people, especially ones who seek to intimidate and instill fear in others, keeping them from learning and seeking their own adventures.

      My Father holds a mechanical engineering degree from graduating in the class of ’49 at the Naval Academy. (where he learned to fly in N3n’s) He did his post graduate work at Columbia and RPI. He did 33 years in the USN, much of it working in the design on nuke reactors. After retiring, he worked for both Ebasco at the Princeton Plasma-Physics lab and then as Raytheon’s Director of Advanced Technology He only stopped working because his office was on the 89th floor of the World Trade Center. My Father has impeccable engineering credentials and experience, yet he doesn’t see them as qualifying him to offer advice on everything mechanical. He has often said the only three mechanical devices he has recognized expertise with are the M-1 Garand, the Colt 1911 and the Pressurized Water Nuclear reactor.

  2. William:

    I agree with you about misinformation abounding on the Internet. I have been trying to fix my wife’s laptop to rectify an “improvement” made by Microsoft on and off for several months. When I search for additional information on the topic, one of the top-rated entries that always comes up is from a seemingly well-respected source. The problem is – the solution described, with the comment of “how I fixed mine,” flat doesn’t work, and there are no subsequent entries saying that and offering alternatives.

    “Pissing contests” rarely end well. Sorry if I’m out of line with this.

    1. Allen,
      You are not out of line at all, I listen with an open mind to input from other peoples perspective all the time. All I am shooting for is to have a clarification to that man’s dis-information. By the end of the day today, 1,400 to 1,600 new page reads will be on our site. This makes the story arrive in the Google search, and then people will be able to understand you can’t buy a perfect Continental for $6K no matter what a motel owner suggests.

  3. William,
    Just to add another point to the discussion, the problem that I have with this guy or any other self-proclaimed expert is this- he can get on a forum and say, “Corvairs suck, and here is my (incorrect) rationale why,” then get up, turn off the laptop, go to bed, and life is fine. For him, at least. He pontificated out his posterior about something he really knows nothing about, but some new guys think that he is an expert so the damage is done.
    But you, however, have just had your livelihood trashed. His hobby mouth trashed your career business. How would he like it if I got on a travel forum and proclaimed that as an airline pilot I would never land my airplane at his grass strip “motel” because it looked unsafe (even though I have never seen it). So some new pilot thinks that if Terry won’t go, then I won’t either. That’s unfair but that is exactly what he just did to you.
    I am sure you would have a great deal more respect if he would call you and say, “I think Corvairs suck. Now let’s talk and convince me why I am wrong.”
    I know that I would.

  4. Hi William,

    I really feel sorry when you have to defend you’re life’s work to internet misinformation. It has to be very frustrating. Unfortunately too many people these days want to hear about the negative without seeking the facts. For example, there are far more UTube hits for videos on air crashes than any other aviation related video. That is the society we live in.


  5. William,
    As a professional A&P/IA who operates a well established maintenance shop working on everything from piper cubs to Cessna 340’s and Pressurized Barons………I nearly fell out of my chair at the thought of a “Zero” time engine for $6K!!! As a side project right now, I am assisting one of my EAA Chapter members with the overhaul of his O-235. The Chapter worked together as a group to tear down the engine and I took charge of getting all the parts to the correct vendors for inspection and repair. Here is a break down for informational purposes.

    Cylinder inspection and repair including piston pins and shipping……………….$3136.80
    Crank case inspection and repair including shipping………………………………………$925.00
    Magnetos overhaul, required a coil replacement each …………………………………………$850.00
    Steel parts (crank, cam, lifters, cam followers, gears etc…………………………………$1450.00


    Not included in cost so far

    carb overhaul………………………..$6-700
    vacuum pump………………………..$250
    new hose assemblies………………$450
    new spark plugs……………………..$200
    Engine gasket set…………………..$125.00
    Starter overhaul or replace……..$2-500
    7 qts of mineral oil………………….$50.00
    New engine mount isolators…….$2-300
    Labor…………………………………..No Charge Chapter project

    Grand total with free labor……….$8936.80

    No doubt I am forgetting items as I sit here typing. This would be base cost, no labor charge and you end up with an engine that is “0” hours SMOH (since major overhaul) The engine total time remains at 3465.5 hours.

    Some will argue that it’s not a fare comparison as I am overhauling an O-235 and he is talking about a C-85. My experience is that almost (if not all) of the parts between the two engines are going to cost the same to inspect, repair and overhaul. I rarely see a difference in the cost between a O-235, O-200, C-85, O-320/360 when it comes to general inspection and repair of engine components.

    1. Arnold,
      I wanted to draw attention to the fact that your $8,900 price does not include owning the engine to start with, which adds at least a few thousand dollars. I saw that engine at CC#25, assembled before it was taken down, and it was complete and externally good. If it was in a flymart in that condition it would have sold as is for $5,000 in a day.

  6. Hello, for the last year I have been looking into building an aircraft of some type. I was initially excited about auto conversions because that was what I could afford. I ran across that particular fellows dismissal of autoconversions and thought that option was a no go. Then, my lucky day, I discovered Flycorvair. Your expertise and generous sharing of your knowledge is just what a guy like me needed. I am reading every word on your two sites and I am excited to know there is a road to follow and great people as well. Just thought you would like to know that I appreciate the opportunity you provide for others. Scott in San Diego.

  7. The internet gives any old blow hard a mouth, a mouth equal to any and everyone, they could be 10-100 years old but we don’t know that. So much good to learn on the net but yet it can be the most evil too, there is something for every one. There are aircraft enthusiast of all kinds an a lot of people are interested in only a certain area and some are interested in every area and enjoy all of it. Ifonly we could stop the cry babies and malcontents!!!

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