Category: Engine

Builders,

On October 10th 2012, I wrote the first part of this. The story was formed around showing builders that the style of intake manifold that we have used for years on Corvair flight engines is actually a very well engineered design that appears over and over again on purpose designed aircraft engines built by large Aircraft industry giants like Alison on the 1710 V-12. I was looking for a particular photo on our Flycorvair.com main website and came across this photo that I took at the Pioneer Airport side of Oshkosh in 2008. Get a good look at this engine and see that the intake is a systematic copy of the one we use on a Corvair.

Above is a 440 cid air cooled Ranger inline six  It is a 200 hp engine of WWII vintage. They were on Fairchild 24s, PT-19s, Grumman Widgeons and a number of other classics.  Note how the feed pipe for each group of three cylinders is offset just like a Corvair head. The center part of the manifold is a Tee section to hold an updraft one barrel carb, just like we use on the majority of flying Corvairs. If you look at the system, the proportions of the components are much the same as we use on the Corvair.

I dug out the original information in part one because an internet ‘expert’ with the named “Toolbuilder” was pontificating that he knew how to get a 20% increase in output on the Corvairs heads by using individual runners, Complete BS, as demonstrated by the dyno runs I pictured in part one. The next time an armchair expert tells you that the Corvair’s head is not well designed, or has poor fuel distribution, save time and tell him he is a genius, then walk away knowing that many aircraft have the exact same design as the Corvair.

You may wonder what kind of group of people would tolerate a person like “Toolbuilder” who goes around making baseless claims about aircraft systems he has never seen in person, far less has any understanding of. Wonder no further. The guy is a fixture on the Van’s Airforce website. The format of this webpage has a management section that tells me how many people a day read it, and it has a section to show how many people came from a hyperlink on another site. For example, in the 24 hours between 7pm sunday and 7pm tonight (It works on a 24hr zulu time clock) we had 932 readers. 66 of them first went to our Flycorvair.com page and used the ‘click here’ hyperlink to arrive here. Those are about average for a Sunday/Monday. What stuck out was that 40 people came to the site from the Vans Airforce discussion groups yesterday.

I went there and found a lot of the discussion was started about A twin-engine Corvair powered airframe that started out life as an RV-6A, being built by a friend of ours. I fully understand that there are 20,000 RV builders so it’s not safe to generalize about them just because 75% of the comments about the twin project were some of the saddest knee-jerk/internet expert/ drama queen comments I have read in a long time, but that’s a pretty high percentage for people who are alleged to understand what EXPERIMENTAL aviation is about. As you may have guessed, Mr “ToolBuilder” was right in there. Two or three people had something positive to say, many of the others were operating at the hyper-dramatic doom speculation level I refer to as “Mother-in-law on Methamphetamines.”

As I read some of the comments, one of the things that came to mind is that Fans of the RV designs are woefully ignorant of the origins of their own airplane company. (The RV-1 was a modified Stitts design. If Ray Stitts took the attitude of the people on the Vans airforce site, there would be no RV anything today.) Secondly, I have heard RV fans say things about the position of Dick Van Grunsven countless times as if each of them were his paid press secretary. Mr VanGrunsven is a publicly reserved guy, but I have sat through a number of industry meetings with him. At this last Oshkosh, I was one of 16 people who went to a 4 hour kit industry think tank meeting. Mr, VanGrunsven was the Chairman and spoke with frankness about many issues. Know what? After listening to him in this setting, I will tell you that 50% of the things his followers say don’t come close to positions he actually holds. It is oddly Ironic that I have much better insight to the perspectives of the man than the great majority of the people making endless posts on his official webpage, but a small detail like that never stopped an internet personality with a silly name.-ww

 

If any of the photos are small, try hitting the F5 key at the top of your keyboard.

Builders,

After Dave left on Saturday night, the test stand was cool for a mere 12 hours before the second engine run of the year. 601XL builder Rick Koch brought his engine over for a run on the stand. It fired right up and ran perfectly smooth. The engine isn’t a new build, just like Dave’s, it’s an upgrade with a generation one Dan bearing. The engine’s arrival on the stand is a bit of a story, but a good one with interesting lessons and a bright future flying in Rick’s 601XL later in 2013.

Above, I congratulate Rick on an instant start-up after his upgrade. The improvements were largely done at Corvair College #24 in Barnwell in November. At the College both Dan and I noted that Rick went out of his way to help other builders, and let others use tools ahead of him. It’s the kind of small gestures that you notice in a busy College, a sign that the builder really understands that the event is about learning and the shared experience, and not some type of “get william to build my engine for free” thing. Noting this, both Dan and I took Rick aside and said that we would be glad to have him down at out place for test run after the college.  It was an acknowledgement of his positive attitude at the college, and Grace and I were glad to have him down for a test run.

Above, Rick monitors the engine. I actually built this engine for another gentleman in upstate New York in 2006. The original owner was a very nice guy who installed the engine on a Zenith 601XL that he built 95% of. Last year, his family contacted he to say that he had passed away, and they were looking for assistance on selling his project. I told them that I was glad to help, under the sole condition that Grace and I were not financially compensated in any way shape or form. The man was our customer, and I told his daughter that for all my faults, I have a good understanding of loyalty, and helping them was something I was going to do for her Father, not for money.

I told them what I thought the value of the project was after reviewing all the records. They sounded a little surprised, they had been told by local airport people, alleged ‘friends’ of her Dads that you “couldn’t get much for an incomplete kit with a car engine.”

Enter, Rick Koch.  I had met Rick before at an aviation party. He has been a commercial instrument pilot for a long time, and he had owned experimental aircraft before. He is a complex, thinking kind of guy; He can be drinking a beer and following the football game and then turn and discuss the last book he read on historical economics. In a world that teaches people to dumb it down if you want to be popular, that’s refreshing. I tell Rick about the plane, and he is real interested. I tell him I will fully support him in coming up to speed on Zeniths and Corvairs, under the sole condition that he respect the man’s family, and not go bargain hunting. Right off, he said he understood that behavior like bargain hunting was within some people’s ‘morality’, but not his.

 Inside a few weeks, the plane was paid for and moved 1,000 miles to Rick’s hangar. The family called to say thanks, they noted that Rick first class and that he had paid the full price without asking for any kind of bargain. This last point surprised them because The price was four times what the ‘local expert’ was offering to pay (‘because he was going to help them out ‘) I mentioned this to Rick, and he simply said that he paid what it was worth, and what others would or would not do, didn’t concern him. He didn’t think he needed to be thanked nor applauded for doing the right thing.

 If there is a single thing I detest in aviation, its people who take advantage of builders families. Rick and I could spend hours arguing over what Herman Melville’s essential message was, but on ethical behavior, he is my kind of guy.

Grace took this photo of the sky above Rick’s running engine. She showed it to me and I said it looked like the Spruce Goose flying at us with a cats face below it. Grace said she thought it was a perfect blue day out, the engine ran great and maybe the Cross in the sky was a beautiful omen for Rick. Soooo…I’m not really the spiritual half of the marriage….

Adding the original retrofit Dan bearing to the engine was an easy and cost-effective improvement that did not require disassembling any of the engine. Because it was on the bench, Rick elected to pull the pan and replace the gasket as a unit, rather than just the front of it under the housing, The engine already had a Gold oil system on it. The only other upgrades Rick went for was a high volume pump, a new style ring gear and exhaust rotators. For a little bit of time and not too much money, ricks engine was upgraded 7 model years worth of improvements. The fact that the engine had been stored for years had no effect, it started right away and ran cleanly. The compression was perfect on the post run check.

He has some work to do on the airframe, but there is a good chance we can see the plane make its first flight in the spring. When you see Rick out on the flight line, be sure to say hello, he is a fellow Corvair guy I am very glad to have aboard.-ww

If the pictures are small, press F5 at the top of your keyboard.

Friends,

Below is the story of Greg Crouchley. He is a Waiex builder from Rhode Island. Many people in the movement have met Greg at the past few Colleges or at Brodhead or Oshkosh. He is a very friendly and outgoing guy. At first glance you might not see the inner motorhead. Greg’s normal stomping ground is in international manufacturing, and I have never seen him without a collared shirt on, even when he was building his engine at Corvair College #24.  But this is camouflage for a guy who has a long background of getting his hands dirty. Spend a few hours with him and listen between the lines, and you will understand that the things he is most proud of accomplishing were all things he did with his own hands. The Corvair is a natural match for anyone who understands this. Below is a link to a video of Greg’s engine running a few nights ago. While you watch this, understand that Greg is a man who has worked for and earned his share of success in life, but building and running your own engine is still a triumphant moment:

Greg’s engine is a 3,000 cc powerplant that features one of Dan Weseman’s new Billet Crankshafts. This is the second one to run after the Panther prototype engine. For this reason Dan and I invited Greg to bring the engine down to Florida for a supervised test run. Greg did 80% of the assembly at CC#24, went home for the rest of the assembly, and drove back to Florida for the test run (he is a serious road warrior). Dan pointed out that the engine has new forged billet rods in it which are slightly stronger than the original GM forged rods, so to be technically correct, Greg’s engine can now be said to be the world’s strongest Corvair flight engine. The engine features all of our Gold components, our High Volume Oil Pump, Falcon heads, our Powdercoated Valve Covers and an E/P Distributor.

One of the things I find interesting is Greg’s arrival in the Corvair movement. He has been flying light aircraft for about a decade. Almost all of it was done in LSA aircraft with many different types of engines. Greg actually built and owns a Jabaru 3300 powered Lightning that he likes and flys a lot, but for this round he was searching for access to a very different experience, an angle only covered by the Corvair. His Jabaru may say something about what he can afford to buy, but his Corvair says a lot more about who he is. If a homebuilder is just looking for an engine that will run and operate, than a Rotax or a Jabaru will do just fine. However, if he is looking for something he can understand, build and master, then the Corvair is the only game in town. How many people have you heard say, “We built our last home.” Now think about how few of them actually meant they drove the nails and wired the light switches. When Greg speaks about building his first house, he is speaking of driving the nails. People speaking of houses at cocktail parties don’t know the difference, but carpenters and framers can tell the difference at 100′, and collared shirt or not, you get the impression that Greg would rather find himself on a job site with carpenters than at a cocktail party with posers. Even if you don’t have a mechanical past to identify with, understand that the most important single element of my building philosophy is that I run the Corvair movement and all of our Colleges as a Pump, not a Filter.  We are working to support builders who are seeking to develop or improve their personal mechanical capabilities and experience. It is about developing any standard that you set for yourself. I am not here to run a program for people who have some mechanical background, but are too lazy or closed-minded to learn today. A filter is about calling some people ineligible, and to my way of thinking, that is B.S. I am here to assist anyone interested in personal progress. I don’t care what your starting point is. I have vastly more respect of an absolute beginner who has never changed the oil in a car but wants to learn than I have for a “know it all” guy who is reluctant to learn anything from me because his ego wont allow it. 

Above, Dan Weseman, myself and Greg stand behind the running engine just outside the hangar door. We gave the engine a 40 minute test run, which it did flawlessly. The engine started after 2 seconds of cranking and ran beautifully without the slightest adjustment.

Above, Greg gives thumbs up, and is wound up, just like his engine. Do you think he would feel this way if this were the first run of a buy-it-in-a-box engine with a sticker on it that said “no user serviceable parts inside”? Key point: If someone gives this kind of reaction to an “appliance,” they have a shallow understanding of the words challenge and achievement. This type of reaction is only called for when a man builds a real machine, understands it, and is there to see this achievement confirmed on the first run.

Above, the following morning, Greg and I took the engine off my run stand and put it in the car for his long drive north to R.I. Greg is installing the engine in a Waiex airframe (the V-tailed version of the Sonex), thus the engine has a Reverse Gold Oil Filter Housing. We developed these many years ago to allow the Gold Oil System to clear the fuel filler neck on the Sonex based airframes. The Reverse units also fit a number of other very tight fit applications, but 90% of the Gold Filter Housings we sell are the Standard ones. Every other part on Greg’s installation is common to all of the other Corvair engine installations we teach people to build.

Eight years ago, the very first person to fly a Corvair in a Sonex performed a number of rough modifications to the Corvair to get the engine to use the VW mount and cowl. This included bolting the engine mounts to the top cover and sawing off the intake logs and replacing them with a weak O-ring connection. The plane flew, but it wasn’t a configuration that builders wanted to emulate. Dan Weseman’s approach was very different: For his Sonex airframe he built a new mount and cowl, and used the Corvair just as we built them for other installations. At the time there was an Internet debate about which was the correct approach. The only people who didn’t see the logic of Dan’s method were people who had never built a plane before, people with opinion but no experience.

The simplest way to understand this is looking at Lycoming powered homebuilts. Anyone who said they were going to put an O-320 Lycoming on their plane, but were going to make crudely bolted on adaptors so it could be put on a Continental mount and they were going to put a saws-all on the intake system to get it in a Continental cowl would be regarded as mentally troubled and in need of an intervention. It would be regarded as some type of hoax or comments from a fringe personality. Only in the realm of Internet discussion groups for conversion engines would such actions be heralded as “innovative.”  You want to know why auto engine conversions have a bad name on the surface in some homebuilding circles? It because some auto engine fans, people without experience, would applaud and praise an approach to engine installation that Lycoming fans to a man would all regard as incredibly poor. As long as people without experience praise poor ideas in conversion engines, auto engines will have public detractors. I don’t like it when these people don’t discriminate between the work we do and the misguided efforts of zealots and cheapskates, but this is the origin of many homebuilder’s aversion to conversion engines.

In complete contrast to the poor approach, Dan Weseman has had a tremendous amount of success with his Corvair installation components for Sonex airframes precisely because he was willing to make the two airframe parts that would allow him to use everything we had already proven to work for the Corvair. This may sound like a no-brainer, but it was a big source of Internet debate years ago. Today Dan has about a dozen “Cleanexes” flying, two have nearly 500 hours on them. On the other side of the coin, none of the fans of radical modification to the engine to get out of buying a mount or cowl ever built anything. They didn’t know it at the time, but their philosophy that espoused being cheap as a cardinal rule doomed them to toil without success and then watch from the sidelines as others with a real approach succeeded. Let’s hope they got a lot of satisfaction out of  calling me a “censorship bully” on the Internet for only promoting a path that I knew would succeed. Successful people are willing to learn from others and build on what has been shown to work. The biggest point here is that Dan Weseman has certainly proven himself to be a first order innovator in the Corvair  movement, but eight years ago, people who had built nothing criticized his approach of building on what we had already proven as non-innovative. Far from gone, the same critics are still on their discussion groups today, making comments that will prove just as inaccurate with the passing of time. If you want to win at homebuilding you have to ignore these people and listen to qualified advice from people who have made successful aircraft installations. 

A detail of Greg’s Electronic/Points Distributor. I am now sending out these distributors with an optional three pin Weatherpack connector. These are the automotive industry standard connector for modern cars. It is easy to disconnect, but has a positive locking feature. We also send with it the matching connector for the airframe’s wiring harness, pre-wired with 6′ of aircraft wire. This system allows the distributor to be removed or replaced without going after any wiring connections other than the plug. You don’t even need to take the cap off the distributor to remove the points wire. These connections are vastly superior to spade terminals or standard crimps, especially in the engine compartment. They are totally waterproof. During Greg’s engine run it was raining lightly and the engine was soaked by the prop blast, but it did not have the slightest ignition tick. I am going to make this connector also available to any builder who sends in a distributor for inspection or brings an earlier E/P distributor to a College. The connector’s quality is centered on its waterproof nature, but also the specific nature of the wire crimp on the pins inside. The crimping tool that does this costs $145, making this upgrade outside the normal builder’s tool set, but something we are glad to do. We will update our products catalog shortly to include information on Weatherpack connection options for flight Distributors.-ww

Friends,

Below are a few photos of Dan Weseman’s 3,000cc engine for his Panther prototype. The engine was assembled in our shop just before Oshkosh this year. At the time is had a fully reworked GM 8409 forged crankshaft. The engine was seen a photographed on the front of the Panther by thousands of people. Upon returning to Florida, Dan decided to utilize the same engine to flight test his new american made billet crankshafts. Dan pulled the engine apart in a few hours and re assembled the bottom end with one of his new cranks. I offered to help reassemble the rest and get it set up to run on our test stand. The engine is set for Dan and Rachel to run on 11/1/12. We are bringing the engine to demo run at Corvair College #24. I can make a very good case that this is the strongest Corvair flight engine ever built. This engine is purpose-built durability made from American components. It is the result of a very long evolution and gradual improvements to a proven design. Dan opted to build this no compromise engine to match the Panter’s aerobatic capability and strength. This engine cost about 50% of the price of a rotax 912. Every component on the Covair, with some small exceptions, was made in the US; just the reverse it true about the rotax. This challenges the myth that employing Americans in manufacturing is cost prohibitive.

Above, torquing the rod bolts in the engine upon reassembly. Even in this photo the crank looks clearly different from the GM unit. The 5th bearing is a Billet Dan unit. All the parts of the engine are the same as they were at Oshkosh with the exception of the Crankshaft and the bearings which were .010″/.010″ before and are standard now.

Above, a photo from a few weeks ago. The bottom crank is a GM 8409 core for comparison. The top two are new billet cranks with Dan bearings on the front. Dan brought them over to borrow my press to install the gear/bearing journal part onto the crank. After these are warmed slowly for an hour, they are pressed on the crank and allowed to cool slowly.  They are returned to the crank shop to have the slightly oversize journal ground perfectly concentric with the other 4 bearings. This is the process that Dan uses on his “second generation” 5th bearing. Obviously this is not field retrofitable to assembled engines like his very popular regular 5th bearing. However, on a new billet crank, or an engine or short block we build, this system has some advantages. All of the production engines and short blocks we sell are equipped with this 2nd generation design. Dan keeps both of his systems in stock and production. Because this is a CNC production part, the turn around time on a short block is quick. Pietenpol builder/flyer Kevin Purtee elected to change his crank after his July accident, and he opted to get a 2nd gen. bearing journal on a fresh crank and to have us assemble his short block before he does the rest at CC#24. Total time from order to case closed was about 12 days, and we are very busy right now. No one has to wait months to get a 5th bearing on their case.

Above is a close up of a 2nd Gen Dan bearing journal on a re worked GM crank. This is a 2700/2850 ready case we are putting together as a demo unit for CC#24. It will be for sale at the college. This is a precision 5th bearing mated to an inspected case, assembled with an OT-10 cam, available on an exchange or outright sale. This represents the wait time on a 5th bearing bottom end being reduced to zero days.

Above, the Panther’s engine on the test stand, about to be pre-oiled. The red parts are there to catch the oil that drips off the rockers during pre oil with the valve covers off. I choose to do it this way because I can watch each rocker to make sure it passes oil and that there are no delays in oil being delivered to the valve train. The catch pans are old valve covers modified by Vern. If you look closely, many of the fasteners used to mount test engines have been changed to tee handles and captured hardware. We are very serious about quick turn arounds on engine tests at the college. It is hard to see in the photo, but the gas tank has been modified to telescope down and there are casters under the mount to now allow it to smoothly roll sideways into my low trailer, even with an engine on it. When we get to #24 we plan to deploy the engine out of my trailer and have it running in 4 minutes flat.

Above, a look at my hangar at 10pm on Halloween.  In the foreground the Panther engine is 12 hours away from test run. Behind it is Grace’s 1965 Corvair van getting a transmission transplant.On the left is the old Wagabond, most of the way through a modification and update program. Grace and I bought the plane back, and have been working on it to have it be our test mule/demo aircraft for 2013.  CC#24 is the last public event we have for 2012. The season slows down quickly after that we most builders focused on family through the holidays. This is the time of year we make progress on special projects. The Wagabond should be done a few weeks after the College. I have told Dan that the aircraft will be at his disposal to flight test the Panther engine and log some hours on it before he installs it in his prototype. The past few weeks have seen the culmination of a number of things that took many years in development. We are headed to a very good college and I look forward to  several milestones of progress before the end of the year. I stood in the hangar at midnight an looked around for 3 more minutes before shutting off the lights at midnight. Most days my hand brushes over the switch on the way back to the house, just tired, but there are a handful of special days where I spend a minute or two to think about things to come, good times with good people and neat planes. 2013 is going to be a very good year.-ww.

Friends

In the last week I have been on the phone with Jeff Cochran, who is flying off the test time on his 2850cc powered Zenith 750. Jeff was concerned about a fairly high Cylinder head temp he was seeing on test flights. I knew that Jeff’s engine was in good shape, he had an overhauled MA3 carb, and he was using our standard cowling. This assured that the temp wasn’t caused by a basic issue.  I verified that he had the timing set correctly and was wisely using 100LL for his test hours. In short, there wasn’t a good reason for seeing the high CHT numbers. Jeff’s probes are the kind that go under the spark plugs. Although these work on countless planes, they can have variations in how accurately they reflect the actual temp of the head. In some cases they are a better reflection of the temp of the spark plug. Although the corvairs plugs are on the top/cool side of the head, CHT measurements taken under the plug will often read higher than those taken from the boss on the bottom of the cylinder head, on the hot side, where GM put the CHT probe in the car. I asked Jeff to re-arrange his CHT probes to leave one under the #1 plug, and move the other to be on the GM factory location on the bottom of #1.  Jeff’s letter back below confirms what I suspected, that his engine is actually flying in the middle of the heat range of the engine and that his CHT probes under the plugs were providing a false high number.

“William, Just a quick update.  Yesterday I flew two hours in the morning without any changes. Came back stripped off the nose bowl and cowling, changed oil, relocated sensors and added the cowl lip extensions. On the sensors, I left one under spark plug #1 and moved the one from spark plug #2 to the location under cylinder #1. That way we get a direct comparison. After all of the changes I flew another hour. On climb out the spark plug CHT got to 458 deg. F and stayed over 450 for the rest of the climb to 3800 ft. The sensor under the cylinder reached a max of 349 deg. F for about one minute.at the end of the climb.  During cruise the temps were around 420-425 vs. 325-330. The average difference between the two was normally over 90 deg. F. The largest difference was on climb out when the lower sensor heated up slower and I saw 119 deg. F difference. I feel much better about the engine now.-Jeff “

Above, Jeff stands on the left with his 750 on the day of airworthyness.

   

Above, Jeff sent this photo of the CHT probe moved to the bottom of the head. The hole he put it in is the stock GM location. On a 95 or 110 head this hole is threaded 3/8-16. Get a bolt 5/8″ long with this thread and an area washer, and you can clamp an under plug style sending unit right to the flat boss. If you are starting out from this position, you can use a 10mm spark plug sending unit because they are .400″ in diameter and a 3/8″ bolt is .375″, and it will be a little neater than using a 14mm sending unit. This location is where GM measured the 575F factory CHT limit from. We don’t recommend using that limit on flight engines, but they can take it as long as the engine isn’t allowed to detonate. Very high temps that are caused by detonation will obviously result in engine damage, but a Corvair that isn’t detonating has a very high cooling margin. Jeff showing numbers like 350F may sound very hot to a Jabaru operator, but on a Corvair he is 225F below the proven red line. Jeffs engine is running right in the middle of the thermally efficient zone and also is running a a temp the reduces the amount of lead build up in the engine compared to an engine running cooler. Keep in mind that a 750 is a large slow climbing aircraft and this effectively shows that the Corvair cools very well with a very wide margin in this heat challenged installation. 

Above is Rich Whittington’s fabulous looking 601 HDS at Corvair College #21. Rich actually was one of the first builders to verify the under plug vs GM bottom location temp differential in independent testing last year. Rich’s results were much like Jeff’s. 601’s and 750s have very similar installations, sharing the same cowling and baffling. The 750 is bigger and climbs slower, but still cools itself well using the same parts we now have flying on more than 60 601’s.  Rich’s aircraft has a 3,000cc engine with a Roy bearing

Flycorvair.com: An underutilized resource

Below are some photos and information I pulled from our main website Flycorvair.com. I went to that page, and typed in “spark plug washer” in the search box at the bottom of the front page and it spit out a number of links like the 2008 entry below. The page you are reading right now is Flycorvair.net, which I think of as our daily news paper of the Corvair movement. we have now had it for 10 months, and it had more than 100,000 words on it in 120 articles. But this is puny compared to Flycorvair.com, our main page that we have had for 12 years, which actually has more than 25 times as much information. Granted, it is not perfectly accessible, but many people fail to even try the search engine on it for basic answers. People today are often impulse driven to want an instant answer, rather than reading a little, learning and developing a real understanding of the answer to the question they asked. Flycorvair.com is a main library and the store for our business. It is a resource more builders should use. (note: below is a source info for copper plug washers in 14mm.)

From 2008, “Above is a photo to put a few things in perspective. The eight sparkplugs in the photo are replacements we just got for the Taylorcraft. On Gus’ advice I picked up iridium plugs for the bottom of the C-85 and standard plugs for the top. Make sure you’re sitting down: These eight plugs cost $375. That’s pricey. However, consider this perspective: Small Continentals on classic American airframes are some of the most reliable and trustworthy aircraft ever built. Even with 70 years of age and stingey or inept maintenance, these planes soldier on with an enviable record of reliability. Since this reliability is the foremost attribute of the plane, I am always willing to spend money in order to maintain that attribute.

A C-85 has a 6.3:1 compression ratio. This low ratio and its magneto ignition system make it prone to fouling plugs when run on 100 low lead. By comparison, a 9:1 compression ratio Corvair with one of our 35,000 volt ignition systems is immune to plug fouling. Also in the photo is Champion sparkplug lube, Part No. 2612. This is an absolute must for plugs going into Corvair heads. Plenty of people try silver anti-seize, but that’s a mistake because it gets on the plug’s insulator. You can also get 14mm copper washers for your Corvair plugs from Chief Aircraft, Part No. CH-M673, at about 40 cents a piece. If you’d like to experiment with iridium plugs in your Corvair, Denso makes a Part No. IWF16-5359. Please note that we tried platinum plugs with 100 ll fuel and it’s a poor combination.”

Above is a shot from 2006. Evidently I didn’t always have long gray hair. Merrill films Whobiscat and I in front of Rick Lindstrom’s Quick Build Zenair 601XL in our hangar. This aircraft had a glass cockpit. It had purpose made CHT probes that were expensive and threaded directly into the 3/8-16 holes in the bottom of the heads. These were made to feed information to an engine monitor made by the highly respected IK Technologies. These reflected the same temps as 10mm ring style senders clamped down with washers. The photo is a good indication of how long we have been gathering data and techniques on these specific subjects.

Above, a photo of the Wagabond built by the hangar gang at the old Edgewater hangar. This photo is from Corvair College #10. This is a very large plane that climbs slow. To this day, I think that no Corvair powered plane has left the ground at a higher gross weight (1625 pounds) We finished this aircraft eight years ago. It gave us a lot of test data that proved useful on aircraft like Jeff’s 750. Good data and useful answers are not developed in a day, and companies that are here today, gone tomorrow place very little value on gathering information, and even less on teaching builders things for the long run.

Above, is the Wagabond’s front end in a Corvair College #9 photo. Note that it basically uses the same nose bowl and cowl as we use on Zenith 750s (the carb air inlet is different on a zenith). This is how I knew that Jeff’s plane would cool itself well, and why I suspected an instrumentation error. We have long known that this type of cowl works well, even on big, slow climbing planes. We don’t use customers as guinea pigs, we promote things after they are tested.

 

Above, another Flycorvair.com photo from Corvair College #9. The aircraft is the turbo skycoupe, a major test bed of ours between 2001-06. If you look on the cowl ahead of the pilot, the white 3″ outlet pipe from the turbo is visible. Note that this aircraft also uses the same nose bowl we sell. The skycoupe isn’t big, but it wasn’t real fast, and the turbo could generate a lot of heat to go along with the power. (During a static run up this plane could drag the tires on dry concrete with the brakes locked. We tested the combination to 60″ of manifold pressure.) This aircraft sustained 500F CHT’s measured in the GM location. It also ran EGT’s over 1600F. Naturally aspirated Corvairs don’t generate this kind of heat, but it is good to know our favorite engine can take it. Today this airframe is owned by Craig Anderson who is restoring it and installing a 2850 he built up after Corvair College #22. Look for the Skycoupe to be at Oshkosh 2013.

 

Above, Dan Wesemans “wicked cleanex” in 2007. Although powered by a 3100cc engine and flown very hard, this aircraft never had issues with running hot. In a previous post on oil systems, I have a good shot to the engine installation. Fast small aircraft like the Cleanex do not challenge the cooling. Even if they climb only 25-30 mph faster, you have to keep in mind that dynamic pressure increases with the square of airspeed, and the energy of the incoming air is a lot higher, even if the airframe is only a bit faster. In cruise, these planes run very cool. Chris Smith, who built and Flew the “son of cleanex”, often had cruise CHT’s in the low 200’sF. Likewise, fast aircraft like these do well with stock 12 plate oil coolers. The larger and slower the plane, the bigger the oil cooler it needs.

Above, Grace and Mark Langford in front of our house in 2011, when he reached the 1,000 hour point on his plane. Very fast aircraft like Mark’s have less CHT difference between the top and bottom of the head than a bigger plane like a 750. Mark documented many time that his aircraft ran very cool in high cruise flight. Corvair powered aircraft with this wide a speed envelope could be a good candidate for a cowl flap arrangement. Zenith 601 builder-pilot Andy Elliot is experimenting with a cowl flap on his 3100cc zenith, it shows results, but it wold be most effective on very fast aircraft to cut down on the amount of cooling air going through the engine. Running too cool is an issue that few auto conversion engine ever have to face. The very good cooling of the corvair, in combination with the fact we run the engine far below its automotive output and it’s 575F redline make the Corvair a reliably cool engine in experimental aircraft. A statement that we can back up with a long track record of testing verified by our builders. -ww

Friends,

Here is a big chunk of information on Gold oil systems. I have been making these parts for 6 years now, and they are on nearly all of the new flying Corvair powered planes and they have been retrofitted to a large number of engines built before 2006. The information here is a mixture of new comments, but a lot of it is directly off our Flycorvair.com website, which is best understood as our library of Corvair information, while this site, Flycorvair.net, is our newspaper of the Corvair movement. There is a tremendous amount of information on .com, all best accessible through the search box at the bottom of its main page. At Oshkosh this year I actually had a guy complain that there was “too much information” on Flycorvair.com. Yes there are about 1,200 pages of it, and it isn’t perfectly organized, but I think most builders prefer that I publish extensive information rather than less about Corvair flight engines.

The Filter housing, and the optional Sandwich adaptor and HD oil cooler make up the ‘top oil group.’  It serves many more functions than relocating the oil filter. This system is specifically designed to have an oil temperature monitoring port at the place in the engine where oil temperature is highest. Additionally, the oil pressure ports are positioned to measure oil pressure at the lowest pressure in the engine. Having these measurements taken at these locations offers flyers the most accurate information.

Above, several views of the Gold oil filter housing. It can also be clearly seen on the 3,000 cc Corvair photo on the previous post on Intakes.

There are many more pages of information on these housings on our products page on Flycorvair.com at this link:

http://www.flycorvair.com/goldoilsystem.html

For builders who are not yet well versed in the layout of flight engine oil systems, I wrote a long piece on the best 6 possible combinations. I wrote this in 2007, and it is at the link below. It gives a good over view with photos.  Looking at the dates shows how long we have been working with Corvairs. I made the prototype Gold housing in 2005, yet in the big picture, this is one of our later developments. These systems are on at least 250 running engines. Old and proven is more important than new and exciting if you are actually planning on flying.

http://www.flycorvair.com/hangar1007.html

 Our main mission is teaching people to build engines. An integral part of our system is that I must have some way to monitor from a remote location how well the builder did. Our system for this is elegantly simple. When a builder completes his engine and installs a known propeller such as a Warp Drive, he can perform a full power run-up and tell me what the full static rpm of the engine is and what the oil temperature and pressure is. Because of the standardized propeller, I will know if his engine is correctly assembled and making its full rated power by the RPM that it turns. Additionally, I will be able to tell a lot about the internal health of his engine by knowing the temperature and pressure of the oil. This is only possible if he is taking these temperature and pressure measurements at a standard, known location. This is the true nature of the gold oil filter housing, FlyCorvair.com/goldoilsystem.html, and why I consider it an indispensable part of any engine conversion.

Above, a 3100 cc Corvair I built which we installed on a 750 airframe at a West Coast College in 2009. This engine has a 45 amp alternator sitting where the oil cooler normally goes. We built and flight tested this Charging system on a 601XL in early 2009. It means that the oil cooler must be relocated to the firewall and fed with a scat hose. This has been well proven, but it isn’t where we headed today. This shot clearly shows the Housing and sandwich adaptor in place. There are videos of us getting this aircraft running that day on You Tube.

 In the past, many people would call up and offer data like “my oil temperature is 230°”. If this temperature is after the cooler, it’s a bit too high. If this temperature is before the cooler, it’s just fine. In plumbing unique oil systems, many early builders were unsure whether their temperature measurement was before or after the cooler. A lot of erroneous or inapplicable data was tossed around by people running engines and reporting the results on the Internet. The gold oil filter housing with its integrated instrumentation ports has simultaneously eliminated poor data and allowed us to confirm that builders have done an excellent job with their own engine.

 

 Above, the layout that I much prefer: The Cooler mounted on the engine with the alternator up front. This has been shown to work in the hottest environments, and has a clean simple installation, even with a HD oil cooler. 22 amp alternators work on every plane we have tested, modern electronics use no power by comparison to traditional stuff. Braided hoses work great, but we are investigating having CNC robotically bent stainless hard lines made by an aerospace manufacturer. Since the engine and cooler are fixed to each other, hard lines are an option. Dan and I are currently testing the rear alternator seen on the Panther prototype 3,000 cc engine. It will be able to be integrated into the system seen above. We will have it on display at Corvair College #24. The above photo is also a good look at the inside of an Electronic/points distributor. The baffling kits on both of the engines shown are from Jim and Rhonda Weseman at JSWeseman.com.

Additionally, the housing takes a modern, light weight, high quality, replaceable filter that is readily available. The most frequently misunderstood part of the assembly is the unwarranted worry which some builders have that the system will spill oil when it is being changed. The filter we use is a modern design that contains an internal check valve that prevents it from spilling oil as it is spun off. Holding a small rag underneath it while unscrewing it is all that it takes to prevent a mess.

 To the tiny minority of potential builders who still have trouble imagining touching an oily rag, I suggest that they await the development of electric aircraft that will not require them to have a single masculine moment in aviation.

We offer two different versions of the gold oil filter housing. The standard version points the filter out over the harmonic balancer. The reverse housing places the oil filter over the top cover of the engine. Either of these systems works with our heavy-duty oil cooling system. Almost all aircraft take the standard housing.

Above, Dan Wesemans ‘Wicked Cleanex’ with the first Reverse Gold oil Filter housing mounted in place. The housing did a lot to clean up his engine compartment which previously had a remote filer mounted on the firewall fed by braided lines. Because the Cleanex uses a stock 12 plate cooler, the only external oil line on Dans plane is the one feeding the 5th bearing.

The reverse housing was specifically developed for Sonex airframes to clear their fuel filler neck. It has other applications where space is at a premium, such as a Kitfox Model IV, and on turbocharged Corvair aircraft which use space behind the engine for the additional plumbing. Our gold filter housing comes with all of its mounting hardware, and directions for its installation.-ww

Friends,

Everyone who reads my notes regularly knows that I bitch and complain about how well the internet serves as a venue for anonymous “experts” to pretend they are smarter than people who are actually out building and flying. Maybe it’s been a few days since I shared another example? Heres one that was served to me on a silver platter. It also involves a common myth about engines that is a favorite topic of arm-chair engineers and experts.

Above is a picture of the 3,000cc Corvair we assembled for the Panther prototype just before Oshkosh. The Corvair all-stars shared a display at Oshkosh again this year, and the Panther with this engine on it was the centerpiece of the booth.  This angle shows how GM engineered the intake logs with an offset in them, this is specifically related to the flow vs firing order. These heads have astoundingly good mixture distribution for a carborated  engine. This has been confirmed by a number of flyers with 6 cht’s and 6 egt’s. On his own website, a very nice guy named  Steve took the time to say that he went to Oshkosh, met Dan and myself, that he really liked the Panther, and he put up a number of good photos that he took himself of the airframe and engine.

Enter the Internet expert…..Identified only as”Toolbuilder,”  from California. Although this guy was not at Oshkosh and probably has never seen a Corvair in person, he posted the following comment on Steve’s website. 

” I’m not a fan of the intake and exhaust on that Corvair. I think there is a lot of power that was left on the table when they went with the log style manifolds. To me, that’s the last resort, and you only go that way when the proper individual runner manifolds won’t fit. I’d bet there is 15 – 20 HP hiding in that engine with proper manifolds.”

Where do you start with an anonymous ‘expert’ like “Toolbuilder”? Do you think his friends told him that the email name he selected is also a specific low ranking job on a pornographic movie set? Maybe they knew this when they suggested it to him? Should we talk about how many dyno runs of Corvair engines he has made to offer a HP improvement so specific? Maybe we should just confine it to a small historical comment and a photo of a Corvair on our dyno….

Above, an Allison V-1710 cid V-12 engine from WWII. This engine is a General Motors product, just like your Corvair, Not in today’s Corporate merger sense, but in a very real sense, when GM owned 100% of Allison and all of their engineering was in-house American designs. Like my previous post on Detroit Diesels, this give some perspective when I point out that for 40 years, GM was the worlds largest business, with more engineers and resources than any other company on the planet.

Look at the intake system: Note how it is broken into four groups of three cylinders, just as the Corvair is set up as two groups of three cylinders (each head).  Look at how the incoming pipe is offset on each one of these groups, just as it is on the Corvair. This is not a coincidence, it is engineering. The Allison was originally designed to work well as a naturally aspirated engine just like your Corvair, and this is the proven way to get good mixture distribution at the rpm range we are speaking of flying. Keep in mind that these engines, and radials and Merlins were all “wet flow” engines where air and fuel were flowing through the intake, Just as we set up Corvair flight engines. This is different that modern cars that are only passing air through the intake, waiting to the last moment to inject the fuel. Although many WWII engines were injected, it is done way upstream by the supercharger.

Above is another overhead view of an Allison engine. Look at the layout of the intake pipes in the Vee of the engine and see that they are grouped in four sets of three with the off set in the feed pipe to each group of three. I didn’t invent this, but I am smart enough to copy it, and I am certainly smart enough not to say I know how to make specific improvement on engines I have never seen. Barring that, I know how to avoid having an email name with double meaning.

Above is a good illustration of the Allison’s system. There is a giant myth that the Rolls Royce Merlin engine was a fantastic design and the Allison was a second-rate engine. This myth is held by people who love all things British.  (Yes I appreciate, MGAs, Triumphs, Rhona Mitra, and Led Zeppelin, But not as much as Corvettes, Buells, Raquel Welsh and Chuck Berry.) The Allison is an outstanding design. For Fans of P-51 Mustangs, go read up on F-82s and realize that the prototypes had Merlins, but the production planes, the ones that did 480 mph and shot down jets in Korea, had Allison engines.

Above, the EFI 2,700cc Corvair built by Mark at FalconMachine.net in 2007, at power on my dyno.  How do I know that header pipes and independent runners will not make the “15-20 hp” that “Toolmaker” claims? Because here is that test, actually done in reality, years ago, not on vapor ware or in the imagination of an internet personality.  Note that this engine is using headers with collectors. We also tested it with cast iron manifolds and mufflers. It has distributorless ignition. Six LS1 coils are mounted on the sides of the black airbox. After a lot of careful calibration runs, this engine achieved a 6 percent power increase over a Corvair running on a carb, it’s simple measured facts, but it also ignores the fact that such an exhaust fitted in a cowl will offer a lot of surface area for heat issues and weigh more, and it cost 2.5 times as much to build as a regular Corvair. (A plain old 2850 makes more power than this elaborate 2700. Displacement beats electronics and theory.) Because of the structural strength of the stock log was lost with the individual runners, this engine actually popped a head gasket on its first run. Mark later made thick reinforcement plates and welded them to the heads as stiffeners to do what the cast in log does.

Before questioning the test methodology or results, consider that Mark has earned his living with these systems for the past 20 years and the instrumentation included such niceties as a $500 laboratory grade digital oxygen sensor. Anyone who says that having an intake or exhaust change will make 15 -20 more horse power is just making their information up.

The internet will serve up a continuous stream of such experts who think that they can look at a photo and instantly improve 20 years of testing and development by 15 -20%. I am sure if you asked this guy, he would also tell you he knows how to make a Van’s RV-4 go 300 mph and how to make your car get 100 mpg.  People like this have never done anything to share useful information that gets rank and file homebuilders into the air with proven information they can count on. -ww