In the last few days, A guy on the West Coast named Alan Laudani, who has questions about his running Corvair engine, went on the Corvaircraft Internet Discussion Group and wrote a story about his engine failing to turn enough RPM with a ground adjustable prop set at a very high pitch setting. He received a lot of speculative “advice” from people who have never seen the engine in question, and in all likelihood have never met Alan.
They offered the following “Ideas”
Ed Lee said the cam timing might be wrong and said he was certain it should turn more rpm because his much smaller wood prop does……..
Mark Langford gave an example of a person with the wrong cam in his engine, referenced a computer predicted result, and suggested the engine be tested with a known prop previously run on the same size Corvair. He went on to suggest running the engine without a prop to check the timing, because it was ‘less risk to life and limb’…….
Roy Szarafinski said several things, but suggested checking the compression, he went on to suggest the mixture could be very wrong on the motor……….
Earnest Christley chimed in to suggest a compression check, asked if there was a lot of blow by, and went on to speculate that it had the wrong head torque, and Alan should seriously look at the possibility that the engine has broken piston rings………..
Somewhere in there Dan Weseman, pointed out that the engine had been run already at a Corvair College, ……but this comment was ignored by the speculators who had never seen the engine, but were sure they knew it had something wrong. Notice how quickly they escalate to ‘broken piston rings’.
Above, a picture I took myself, May 9th 2016 in Cloverdale California, where the engine in question had just been run on my test stand. Unlike the people on the discussion group, I had seen the engine run in person, and had worked directly with Alan. I even documented it on my website. The picture is Alan standing beside his engine just before the run. Read the story: Alan Laudani 3,000 cc runs at CC #38, and in case you think it is a hoax, read the Comments also, where Alan includes his email address and thanks several people, including myself and Jerry Price for working on the engine. I’m kind of wondering why Alan went to the internet to find strangers to comment on his engine instead of contacting myself or Dan, and I’m really wondering why he failed to mention to anyone on the net that I had driven all the way from Florida on a 7,200 mile circumnavigation of the US, and Alan’s engine, and all the others on the trip, were run at for free at the events. Evidently he values the speculation on the net over direct in person assistance.
In case you are wondering:
I ran the engine myself and it was in fine working order.
The cam timing was not wrong, I can spot this in an instant by watching the motion of the #1 intake rocker and looking at the timing mark on the balancer.
The warp drive prop on Alan’s plane can not be compared to the wood props mentioned. The diameter of the Warp prop will not allow it to turn the rpm of a 54″ wood prop.
The engine was run with the prop pictured, my test prop, which has run more than 300 Corvair engines in the last 14 years. ( It has been repainted, but it just ran 4 more engines last weekend) I always have an optical tach, my $79 Equis timing light has a built in digital tach, and after 300 engines on the same prop, I can usually call the rpm of a Corvair plus or minus 35 rpm by sound and throttle position alone. ( If you want to lose $100, bet me I can’t do this at the next Corvair College). I have said this countless times, no Corvair should be run without a prop. There is no cooling, but more critically, the prop is the ‘governor’ which prevents the motor from hitting 7,000 rpm in the blink of an eye.
I can also tell the compression of a Corvair by turning the prop over by hand. In setting an engine up on my stand, I always do this, and after hundreds of them, it is easy to tell by turning the prop if each individual cylinder has compression. Also the suggestion the motor might be running with the wrong mixture comes from the very person, who along with Ron Lendon, caused this mess: Safety Alert: Excessively Rich MA3-SPA Jetting..
All engines run on my stand are observed for blow by out the vent tube, 15 years ago I did extensive volume measurements by timing the flow to inflate a 30 gallon trash bag. I an say that Alan’s motor had completely normal blow by for an engine breaking in. There is no way, short of heads so loose it didn’t squeeze the gaskets, that low rpm could be caused by head torque. Know this: an engine with a blown head gasket will make more than 90% of the rated static rpm. Leak down has very little effect on static rpm. ……and let me add that it 29 years of doing this, I have had an occasional builder break a ring putting the piston in a bore, but never, not once, have I ever had a builder break any piston ring on the test run, not once in hundreds of runs.
OK, so what is wrong with Alan’s motor?
Simple, he is using a junk tach, that he says in his post will not even read above 2,000 rpm, additionally he mentions trying to run it directly of his MGL “glass cockpit” although I have very specifically warned people to NEVER do this: MGL vs Corvair ignition issue. In short, Alan has no idea what rpm his engine is turning. He could just use a cheap timing light to get real numbers, but he would rather short out his ignition by wiring it to a South African “Glass Cockpit” maybe time to pay attention to basics and buy a timing light. Spending thousands of dollars on an imported screen that has a notorious ability to hurt ignitions, and then trying to run a junk Westach tachometer is an example of poor decision making.
On the internet Alan now states with the tips at 6 degrees, ( a setting way too low to fly ), it only turns 2,710 rpm. A Standard 2,700cc Corvair can turn the same prop that rpm with 2.5 more degrees of pitch. The only reasons why Alan’s 3,000cc Corvair would yield that number are 1) the tach is wrong 2) He isn’t measuring the pitch correctly, 3) If he actually did try to extensively run the engine with 15 degrees of pitch, and held it at wide open throttle with the rpm below 2,200, he very well could have damaged the engine by detonating it. There is a reason why I tell people the 2,700rpm should be the minimum static rpm used. read:Critical Understanding #2, Absolute Minimum Static RPM., which includes the quote “The primary group violating this Critical Understanding of Corvairs are builders who have made their own props and builders using a ground adjustable props with too much pitch in the setting.“
Alan started out with a ridiculously high pitch setting, and now is trying a ridiculously low one. I would have told him this if he bothered to call.
Hey William, if you have all the answers, why don’t you go on Corvaircraft and set Alan straight?
14 Replies to “Internet speculation vs First hand experience…..”
I had two comments prepared for this email chain but flying 17 hours to my deployed location prevented a swift response. One: go to your local RC shop and buy an optical tacometer to verify RPM. Two: make sure your prop pitch is set correctly. It is comical to see how many “fixes” can be suggested in one day.
Chris, did you catch the part that your dad did a lot of the wrenching on this engine a College #38? It was a good day.
I did. A quick plug for my Dad: He’s an A&P/IA that has years of experience. He taught me how to be meticulous when it comes to wrenching on things.
It seems to me that the goal of sites like Corvaircraft is NOT to support other builders and flyers, as much as that goal might be stated. I think it is simply a “virtual hangar” where a bunch of guys sit around and yack about aviation, and how their superior knowledge makes a difference. As long as you see it for what it is, then you are fine. But when you start listening and thinking that there is real knowledge there, that is when trouble starts. Would you build your airplane based upon what a bunch guys sitting around a hangar at your local airport told you was THE way to build. You listen, nod politely, then ask the people who really know the answers. Like William…
I commented on the post before I had any idea that the engine had already been run at a college. Cam timing can be gotten wrong. Certainly Alan should have contacted WW or Dan considering the engine had already been proved to be a properly built one. Yes, internet forums are a source of all kinds of misinformation as well as good information, but it is just that, information, that must be considered as what it is, not necessarily as fact. Just recently, Dan saved me considerable grief and money when reviewing an order I placed based on internet derived information. Many thanks to Dan and to William for their contributions to successful Corvair flight engines. I would not be flying one were it not for them.
Ed, thanks for the note. The primary issue here was Alan electing to leave out the detail I had run the engine for him, perhaps because he was willing to use my free assistance, but didn’t want to mention that in a setting I am banned from. It’s also a good example of the limitations of discussion groups as viable ‘training’ instead of, as Terry pointed out, a virtual substitute for the Bs sessions of ‘experts’ at physical airports. -ww
I was tempted to suggest the perhaps his flux capacitor was out of alignment. But then I decided to stay out of it.
Your friend Bob Lester
This made me smile. 🙂
Hello WW JR.– How do you do it —is it the challenge of trying to educate peop
If I read the post from Tuesday correctly the Alan had determined that it was a timing issue that left the engine retarded. It was reported to have turned 2680 RPM with the prop set to 8.5 degrees. That is just what I read and how I interpreted it.
I know Alan and I know the history of his engine so I too was surprised by the way off base comments and suggestions that were coming in on the list
I have been reporting tach readings from my timing light. Also having tach problems with my MGL MAP-1 does confuse the issue. But in timing my engine and attempting to get minimum RPM all measurements were using the timing light tach.
Corvaircraft answers are interesting and I weigh all input. Sorry, I assumed corvaircraft people read flycorvair.net like I do and know I went to Corvair College to run my engine. I appreciate WW’s trip to California and the privilege to attend the CC. I am honestly trying to gain experience to safely test fly my airplane. Much like Terry Hand said above, I don’t expect golden answers from a forum, but I am interested in hearing from all. I don’t have the experience to shut off input from those that have gone before me like ML and RS. I know my engine’s cam, heads and rings are good. I never ran the prop set at more than 12°. It runs smooth and starts easy. Pulling the prop thru by hand realizes compression, no adverse metallic sounds. My first oil and filter change at 2 hours running showed very little substances trapped in the oil filter. After warm-up at 2000 rpm or more, I see 40 PSI at 150°F oil temp. I have only been using 100LL aviation gasoline.
I had trouble reading the timing light in daylight. I did talk to Dan about timing w/o a prop as I find it very intimidating to work near a running prop. I arranged to have a competent helper and tie the main gear back and chock it. I now feel more comfortable next to a running prop.
And from my last corvaircraft entry:
“I painted the harmonic balancer black about 2 inches before and after the timing nick. I then painted a white line across the rim at the timing nick. I extended the timing flange with a piece of 0.032″ aluminum and measured back and marked 30 degrees. This makes it easier to see the timing light and set the timing. I ran the engine with prop on and this resulted in 2680 rpm with a Warp Drive setting of 8.5 degrees”. When I get a proper tach set up, I will reset for 2700 rpm.
Data I referenced from flycorvair.net: “Above, Dave Gardea’s CH-650, which has been flying about 4 years. Dave has a 2,700cc engine and reports climb at 85 mph was 800-900 fpm. Level flight at 3500 ft full throttle yields 123 mph at 3050 rpm with the Warp drive prop at 9.5 degrees of pitch. ….” The other data point I have found suggested starting at 12.5 degrees. The Warp drive web site had no instruction published for pitch vs rpm per hp. In setting up for minimum static RPM I did not expect to have such difficulty. Therefore finding that timing was a fault was not a surprise to me. Somehow Propeller 101 for ground adjustable props seems not to be available. I have been studying your Critical Understandings, but it all starts with proper timing of the engine which I was unable to do until fixing my ability to see the timing light.
William, I find myself chagrined to be the center of this discussion. It was not my intention to cause any rancor in the Corvair world. My a/c was signed off by my DAR in August 2017. I am not flying it until I am convinced all systems are go. I recognize that I am in a black hole of experience out here on the west coast. I will call you if I have any further doubts.
Alan, you have built one engine, and you did a good job, this was verified on my test stand. I have built several hundred of these engines. I know what I’m speaking of.
Your comment about getting ‘interesting input’ and ‘weighing all input’ is a joke; your speaking of flying a plane, perhaps you might was correct information instead of interesting information. And, after one engine, please tell me what experience you are using to sort out good advice from bad?
The engine you built, is made of components that Dan and I sell, support and share test information on. Dan and I have done several hundred of these, we build and test them all the time.
ML, who you look to for advice, Built 3 Corvair engines, the last one was 7 or 8 years ago, and they shared very little in common with the engines we promote. He has never owned n example of the prop you have. Do you take a Cadillac to a Toyota dealer for service? When he suggests things that reflect he was unaware your engine was tested, does this readjust your focus of where you should be directing your questions? When the other person suggested your rings were broken, is that persons advice worth say 40% of mine, or do you think closer to 0%. ?
You list RS as a great input, yet he has no A&P, no pilots license, and has never owned a Plane. He was the root cause of the overly rich carb issue. Contrast that I graduated from the worlds finest Aviation University, have long held both A&P and pilots licenses, and had world class training at both. I have built and owned a number of Corvair powered planes. And I was the closest friend of the designer of your plane and built many parts for the design. So explain how my understanding of your motor is so inadequate that you must go to a person with no comparable experience to get information.
Your posts on the net, until I wrote this story have done completely unnecessary damage to the reputation of the motor by implying that it doesn’t run correctly for reasons no one understands, and the motor is not supported by knowledgeable people. You can debate this, but I’m in a much better position to evaluate the impressions given off by and the damage done by people going on line and having a half dozen people speculate at all the far fetched things they can think of about problems that don’t exist. It’s an interesting way to show your gratitude for me driving across the continent to run your motor for free.
there is empirical knowledge and there is bull crap, the problem starts when one cant tell the difference!!!
Let’s face it: everybody screws up occasionally so this Alan’s and I’m sure it stings all the more because you went out of your way to that OTHER coast to help him out.
And we all know, all of the ‘keyboard experts’ offering him advice are just that even if they had experience in the past. William: you’re experience, training, and dedication to this engine is second to none as is your willingness to impart this knowledge to anyone desiring to build a Corvair.
I just saw another ‘expert’ post on the Zenith site claiming Azelea Aviation engines are superior because of “their alternator is in the rear” and “WW’s design is flawed” because of that. I guess he forgot about the thousands of Lycomings with the same setup, or that WW also offers a rear-mount system. The only thing flawed is that gray matter between his ears. Of course he has a Brand “X” motor. Brand loyalty is one thing to be admired. Stupidity and ignorance isn’t.
Don’t let these types of things deter you from your dedication and mission. You have MANY more admirers than detractors and most of the detractors are such because they just can never be wrong and CERTAINLY don’t like being told that.