Those were the conditions, and I let the test engine idle with no carb heat for 5 minutes at 850 rpm. We were testing the Stromberg the builder is going to use on this engine. Look at the white patch of ice on the manifold. …… and no, this isn’t a Corvair thing, Continentals are prone to this also, and if your going to be a real airman, you need to have a good understanding of the physics here.
One of the things I do to test motors after their first run is a quick differential compression test. The two gauges show the regulated supply air at 80 psi, and the other shows the pressure in the cylinder at TDC. there is a tiny calibrated orifice between the gauges. If the leak down is less than the tiny orifice, the cylinder is said in A&P slang to “Blow 80 over 80”.
In reality this is not common, and many manufacturers have service limits like 60/80 (said “sixty over eighty”) . These are the numbers you see in log books of planes at annual. My MOP manual discusses these at length, but here is a quick look at the test run motor blowing 79/80, a near perfect score, after a one hour break in run.
Other engine companies talk about what they can sell you, and that’s OK if you are just going to buy a motor, and honestly that is what the majority of todays builders want. But I’m not a salesman, I’m an instructor, and for this reason, I mostly speak of learning.
This 2,700cc Corvair puts down a perfect break in run in my front yard. A super nice winter day in Florida, a very nice setting for an auspicious start. This engine is slated to be flying in a Canadian Piet my early summer this year.
This is the replacement engine for the “Jewel of Barnstormers”. I assembled it for the trusting neighbor to the north who put too much trust in the brotherhood of aviation. This engine will serve him for years, and provide countless great memories.
If you have not seen it, here is a link to the video of the original rip off engine sold on Barnstormers for $5K. After I made the video, the seller refunded the great majority of the $5K. Perhaps because he understood what he had sold, or perhaps he saw how many of you watched the video, and wasn’t looking forward to seeing a sequel with his name used in it. In the words of Prince Faisal: “ I’ll let you decide which was the more reliable motive”
Below a look and an integrated system I developed. I’m holding a front alternator bracket. Threaded into the bracket is a very high quality sensor for a tach. It is tripped by two small AN-3 bolts, in precision CNC drilled holes in the ring gear. This is a compact arrangement using parts like the bracket and ring gear which are already doing a primary task. This gives 2 pulses per revolution, compatible with virtually all glass cockpits.
The sending unit is not cheap. It is made in the US by a very reputable company. I have it on my website as a service, the price I sell them for is $2 over what it costs me to buy them hand have them shipped to my place. But I like the way it works with the other parts to be a very simple and elegant installation. If you got a ring gear from me in the last few months, it came with the 3/16″ holes, alternator brackets have the 3/8-24 thread for the sensor. If you have earlier brackets or ring gear, you can drill these holes carefully in your shop. I’ll include the locations in a later video.
Several months ago I shared a look at testing eight different pickups and various locations on the ring gear. The is the final result for anyone building a plane with a glass cockpit.
Below is a Nason switch, something I pioneered into an aircraft safety system nearly 20 years ago. It is a very high quality pressure switch, from a company with makes very rugged electrical sensors. Its job is to cut off the primary electrical fuel pump automatically, in case the pilot has a mishap and forgets to or is unable to shut off the critical master putting power to the primary fuel pump.
Picture a 650 just touched down at a busy airport, and running into the wake of a jet that had landed previously. Aircraft gets blown off the runway and the pilot gets knocked out. In this instance, any airplane with a running electrical fuel pump, (not just a Corvair powered one) will continue to pump fuel. If a line is ruptured, it’s a very bad leak. Here is where the Nason switch works: It cuts off the power to the primary pump when the oil pressure drops below 5 psi. Engine stops, fuel flow by the primary pump stops.
I say primary, because on a corvair installation, the Nason switch is just on the primary pump, the back up pump has no switch, to make it as simple as possible. This also allows the engine to be primed and started on the back up pump, as it will flow fuel on command, even without the engine running.
Cars have similar systems, but they don’t have simplicity shown here. 15 years ago I had one builder who loved German things go out of his way to show that he could rig the ignition timing switch from a VW Jetta ( A car that makes the MGB appear to have a reliable electrical system) to do the same function with a bunch of relays and wire. Yes, the Nason switch isn’t the only way to do this task, but when people put their ego aside, its probably the best way.
Again, these just apply to Corvair Powered planes running two electrical fuel pumps, like a 601/650. They don’t apply to gravity feed planes.
I wrapped this up on my back porch today, It is most of the components to install a Corvair on a Zenith 750. It heads to southern California tomorrow. The order is only a few days old, and truthfully it should have left on Friday because I had everything in stock, I just wanted to take some time to pack it carefully.
Visible is the gray motor mount, and the stainless intake, below it is a new Rotec 34mm TBI Mk,2 , the long box has the STOL nose bowl and the stainless exhaust. Recent inventory increases, all the way down to having specific shipping boxes mean almost all orders will go very quickly. Remember, we don’t take orders for items that are not on the shelf ready to go. If you order it on my shopping page, it’s going, the system is set specifically not to accept payment for anything not in immediate inventory.
Shipping several items together like this has its economy: The 750 mount needs a 40″x30″x30″ box, but there is a lot of left over room for the other items, and the cost dent go up because the weight rarely exceeds the threshold allowed for the volume.
Although the cost to cost shipping on this came up as $322 on UPS’s calculator on my site, we were actually granted an $80 rebate on the shipment by UPS because the package was lighter than their algorithm projected. We refunded this to builder. I’m in the engine education business, I’m not doing this work to mark up shipping costs. If you have questions, call 904-806-8143.
First engine of 2021, on my run stand, It needs a 5th bearing oil hose to prime it, but otherwise its about ready to check oil flow to all the rockers and to pre oil it for 15 minutes. Starter goes on in the am, some other details and a break in run in the afternoon. Next week this engine heads to western Canada.
This engine is actually the replacement for the “Jewel of Barnstormers” engine this trusting builder bought sight unseen from a guy in the eastern US. To his credit, and maybe because he understood the next video might use his name and location, he refunded most of the buyers money.
After some phone time, the builder and I came up with this engine as a replacement. It is a 2700cc, It has virtually all of my gold parts on it, but the cost was held down my utilizing some very lightly used stuff that I had in my hangar. I built the engine from having every single part separated and inspected, before reconditioning and careful reassembly. The Jewel of Barnstormers as more than $5K for absolute junk; this engine has finished below $8K for a very solid power plant.
The test run, the compression test and the oil sample will confirm the engine to be in first class shape. a Few hours on the stand and into the crate it goes, along with a new motor mount and a few other items. I good start to a new year in aviation, my 32nd working on Corvair flight engines.
Red oil pans catch the priming oil that will drip off the valve train. Green fuel tank is on brackets that parallelogram to raise it up 12″. The retracted position allows it to go in my trailer. The car is my 1966 Corsa I have owned for 25 years. I restored it in the late 1990s, but it needs it again. The car will do a little more time as a driver, but will not get much attention this year, as I am planning a very busy year in Corvair powered flight.
As a second look at inventory increases, here is a look at my back porch. This is how I store mounts in inventory. My house and hangar are 10 feet apart, but for sake of organization, all the finished parts live in the house. There are 11 mounts in the picture, but I also have another batch at the powder coater now. I have no back orders on any part now. These are all available, you can look at what is available at the link to my ‘shop’ page below.
If you look at the mounts, and put one in your shopping cart, but the shipping looks expensive, understand that I have a special arrangement with UPS for high volume/ low weight items like mounts. The UPS computer algorithm does not take this into account, and in many cases we can refund a substantial portion of the auto-quoted shipping cost.
In the last 7 months I have devoted a lot of time and funds to increasing the inventory, so almost all parts can be shipped the same day they are ordered.
Above 14 Gold Sandwich Adapters. These took a few hours to assemble. They are made from parts coming from 4 different sources. In creasing inventory has challenges beyond just ordering and building more parts; coordinating all the subcomponents of each part takes some planning.
The increase in inventory comes slowly, but I work on it nearly every day. So far, the results are paying of with strong sales, as builders are far more likely to purchase parts when they know they will see the components in just 48 hours.
Here is a quick glance at Vincent Maggiore’s Zenith 750. He has been flying it about a year. It is a simple plane, a smooth runner. He as already won two local spot landing contests, and reports the plane is pure fun to fly. He is located in Kingston NY and flys the plane year round. More details and numbers coming in a later review.