Mail Sack, 10-11-12…..Cleanex notes


On the topic of Intakes and the Internet,

West Coast Pietenpol builder Pete Kozachik writes:

Thanks for the informative (and very entertaining!) piece on vapor-expertise vs. real-world expertise. That rear alternator mount looks great! Have been waiting to see it since you described it some time ago. How does it test out?

Pete, Dan and I are still working out manufacturing details, and then are going to stick it on a test bed aircraft. We want to affirm that the unit spins fast enough and runs cool enough in an actual engine compartment. We will have all the parts at Corvair College #24.-ww

500 hour Zenith Corvair builder/pilot Andy Elliot writes:

“For anyone who would like to learn more about the truly amazing development of piston engine technology during WWII, I wholeheartedly recommend the book “Allied Aircraft Piston Engines of World War II”, by Graham White. It is published by the Society of Automotive Engineers (SAE) and is available on their web site ( for only $60.
The development of the V-1710 is covered in detail, from the first 650 HP version built for the Navy in 1931, through the development of the “ram’s horn” intake manifold in 1935 which resulted in the 1000 HP -C8 version in 1937, through to the G model which made 2200 HP (with ADI) at 3200 RPM, but never saw large production as the war ended. (They are used at Reno, though.)
As is well described and documented, the V-1710 was ahead of the Merlin throughout most of its life, but suffered for its single-stage engine-driven supercharger when Rolls-Royce added the 2-stage, 2-speed, intercooled/aftercooled supercharger with the -60 series Merlins.
Allison introduced the -199 version of the V-1710 for the XP-51J, the fastest of all the Mustangs. It used a 2-stage supercharger with a liquid-cooled aftercooler and was the first to meter fuel directly into the supercharger without a carburetor. It produced 1700 HP, at 3200 RPM ** at 21000 ft! **
Another very good book, specifically about the V-1710 is “Vees For Victory!: The Story of the Allison V-1710 Aircraft Engine 1929-1948″, by Dan Whitney, who provided engineering support for Reno air racers for many years. Available on Amazon for $50. Interestingly enough, if you check out the presentation at, you’ll find about 1/2-way through, a picture of Graham White at Reno in 2002, working with Pete Law, who is more or less the “godfather” of racing engines at Reno! -Andy “


On Cleanexes, builder Jackson Ordean writes:

I’m amazed there aren’t more Sonex powered by Corvair? Beats Aerovee by any measure, not to mention Jab. Anyway, just keep up the awesome work – hope you guys are blessed doing it.

Jackson, Different engines for different people. We try to just present the appeal of the Corvair without getting in to debates about merits. Over the years I have found that guys who just want a by-it-in-a-box  imported engine have very little interest in Corvairs, and people who really want to know every nut and bolt on their airframe and engine will find little satisfaction in engines from companies that are focused on selling a consumer good rather than an educational mission. This is the most important division in engine choices. A guy who really wants to be self-reliant and his own mechanic, but buys a Rotax 912 because its lighter than a Corvair, isn’t likely to be happy in the long run. Neither is a guy whose sole interest in Corvairs is because they are comparatively inexpensive. This is why I spend a lot of time speaking about philosophy and motivation, these are important things to understand before people start shelling out money.

At Oshkosh last year, a nice enough guy, new to homebuilding showed me a spread sheet he had made with every possible 100-120 hp engine on the market. A lot of the data was brochure stuff like liquid cooled engines weighed without water and fuel burns a Cox .049 couldn’t match. This guy even invented new concepts like engine weight divided by dollar cost, not a particularly useful value. I tried to get him to switch gears and think differently by pointing out that his marriage works because he and his wife are a good philosophical match, not because her height x weight divided by her gross income is in some target range on values. I think he understood the point, but I suspect he went home and graphed out the last equation.

On the subject of Cleanexes, There are a lot of photos of them on Dan’s site Hard to believe, but Dans plane has been flying for seven years. Time waits for no one. In the first years, Dans plane was followed quickly by Chris Smiths “son of Cleanex.” At the time there was debate about what the ‘right’ engine was, or how well the Corvair worked in the sonex airframe, mostly driven by people who spent a lot of time on the net and had never seen a Corvair or Dans plane. 

In the foreground Dan’s Cleanex, behind, Chris in the “son of Cleanex.”

In 2009 Dan and Chris flew up to the Crossville fly in for Sonexes. Chris later told me that he and Dan, who fly together a lot, did a full power, formation flyby at 5 feet, 180mph, 3,500 rpm and 12 cylinders, followed by a sharp pull up and a clean break. Chris said after the came back around and landed it was like Lindbergh landing in Paris, they were mobbed and questioned by people who had only heard from internet experts that the Corvair was a heavy, oily, old American engine that made no power. After one look at reality, opinions change. Today there are about 14 Cleanexes flying. many of these were built by people who were present at the Crossville moment, and they cite the sound and the power as the decision maker. All of them report that the performance had been astounding, partially because the internet experts, people who had never seen the Combination fly, had them expecting much less. One of these successful Cleanex builders whose mind was made at Crossville is already regestered to fly his creation into Corvair College #24-ww

Gold Oil Filter Housing, Standard and Reverse


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 website, which is best understood as our library of Corvair information, while this site,, 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 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 at this link:

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.

 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,, 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

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