Sources: Choosing a displacement.

This is part three in the ‘new sources’ series.

.

Builders:

The second decision to be made when building an engine is which displacement to use. The Corvairs Pistons, Rods and Cylinders are covered in Group 1300 and Group 1400 in the conversion manual. Here are the ‘Common’ displacement choices for builders: 2,700 cc’s,  2,850 cc’s and 3,000 cc’s.

( Additionally there are two other displacements on the availability horizon, 2,775 cc’s and 3,300 cc’s. )

.

The conversion manual covers the choices in great detail, and we have links below the pictures to specific stories for builders who would like to read more in detail. To stay focused here, I want to concentrate on where a builder goes to get the parts for each of the Groups involved.

.

2,700 cc: Traditionally, these parts are ordered from Clarks Corvairs in MA. ( http://www.corvair.com/user-cgi/main ) . Clarks offers two brands of forged pistons, and all the specific part numbers are contained in the conversion manual. We have always guided builders directly to readily available source rather than trying to ‘middle man’ these parts.

.

2,850 cc: We have been selling these kits for a number of years, and they are flying on a large number of aircraft . In the last 24 months, we have had trouble getting the proprietary new cylinder that these kits are based on. This has caused delays in deliveries. We can still get them in a trickle, but in the long run I am working to replace this option with the 2,775 cc kit, which is based on the original 1965-69 GM cylinder. The 2,850 kit pricing is on our page : http://www.flycorvair.com/products.html

.

3,000 cc: The person who originated this displacement and kit is Dan Weseman. Not only did he place the original piston order with R&D costs, it was his particular experience base and flight testing that refined the design and set the displacement. Although I have sold 3,000 cc kits, and I have used the same machine shops here in Florida for the work, I am now steering builders buying a 3,000 cc kit to get it directly from Dan Weseman at his site: https://flywithspa.com/corvair/ .  He has invested to buy a great number of piston sets, several hundred cylinders, and he is the source for new billet connecting rods. He also has on the shelf, exchange cases pre-machined to the 3,000 cc cylinder size. The pay off is that any builder can now just buy the parts right off the shelf.  I will still be building complete production 3,000 cc engines, but when I need the parts to assemble one I will just get the from Dan, just like builders .

——————————————————–

As a courtesy while he was focused on developing the Panther aircraft, Dan Weseman allowed Mark at Falcon and Roy’s Garage to order the piston sets off his original design card. In order to insure interchangeable parts, Dan, Mark and Roy agreed to a set of dimensions for the machine work on the cylinders, but each of them had cylinders made at a different location. Although it would have made more sense for Mark and Roy to try to get caught up on their backorders on heads and 5th bearings respectively, they didn’t choose that path. In the end, they, as one person shops were spread too thin to do any of the jobs well, and they don’t have the resources to stockpile parts and kits on the shelf. Thus, any builder who wants to build his own 3,000 cc engine without long delays should just get all the Group 1300 and Group 1400 parts from Dan Weseman.

————————————————————–

.

.

Above, Dan Weseman and I at the test run of his 3,000 cc Panther engine. No person flies a Corvair harder than Dan. His engine has performed flawlessly through a full 18 months of aerobatics. To Learn more about 3,000 cc engines read these links: Why Not the Panther engine? and The Panther’s engine, worlds strongest Corvair flight engine.

.

IMG_2296

.

Above, a 2,850 in my front yard. I built this particular engine around a Weseman billet crank, thus,the only used parts in this engine are the case halves, the head castings, the oil case casting, the distributor body and some misc. hardware. The rest, including the cylinders, pistons rods, crank, and all conversion parts are brand new. Read more here: New 2850cc / 110hp Corvair in photos. to read a bout the first 2,850cc engine, now with hundreds of flight hours, read this: Woody’s 2,850cc Corvair/601XL hits 400 hours.

.

 Above, Dan and Rachel stand on either side of their 3.3 engine at Oshkosh.  Read the story at this link: SPA / Weseman 3.3 Liter Corvair now running

.

.

Above, our 601XL pictured at Brodhead WI in 2004. The first 200 flight hours on the plane were done with a 2,775 cc Corvair that we specifically built to test the displacement.  The combination offers a slight power increase over a 2700 cc engine, but is specifically aimed at using standard automotive gasoline. We are bringing this combination back to an off the shelf kit in 2015.

.

-ww.

.

Sources: Closing a case

This is part four in the ‘new sources’ series.

.

Builders:

In part three of the new sources series, I want to draw attention back to a trio of stories that focused on the parts required to get through the first milestone in engine building, a “Closed Case”.  Getting to this point is a natural goal of attending a single College and working at a relaxed pace. Having a closed case done already when you show up at a College is an easy path to having a running engine at that college. While plenty of builders have done the whole thing in one College from bare case to running engine, the two step processes is much more common.

.

Remember that half of all engines are finished at builders workshops, not at Colleges. Many builders opt to gather the parts for a Closed case, attend a College, get through that work, and still have time to closely study other engines being finished through the test run. Armed with their closed case, these observations and learning, they head home to finish their motor. There are many paths to success, you need only choose one that suits you.

.

IMG_8811

Above, Rear quarter view of “Closed Case” that has just had the pistons, rods and cylinders (groups 1300 and 1400) added. It is a 3,000 cc engine with a GM 8409 crank prepped by the Weseman’s with one of their Gen II  5th bearings. Visible in the photo is our #2000-HV rear oil cases.

.

Below are links to the three parts of the “Closed Case” story. I highly suggest that anyone heading to a college review these in detail:

.

Closing a case at a College, Part #1

.

Closing a case at a College, Part #2

.

Closing a case at a College, Part #3

.

-ww.

Sources: Choosing a 5th Bearing

This is part two in the ‘new sources’ series.

.

Builders.

The most basic decision on building a Corvair Engine is which 5th bearing to use. While people still do build 4 bearing engines, and it is possible to later upgrade these with Weseman Gen I retro-fit 5th bearings, my conversion manual outlines the logic of why it is preferable to start the build with a 5th bearing, and why in the big scheme of things why builders on a budget should elect to delay things like radios or elaborate paint jobs instead of putting off a 5th bearing.

.

5th bearings have been around Corvairs for more than 10 years. Between 1960 and 2005 virtually no Corvair used a 5th bearing, but with the increasing output and wider range of applications we used the Corvair for, it because understood that they are a very good idea on modern engine builds. Because the Weseman Gen I bearing is retrofit-able and very affordable, almost half the fleet flying before 2005 has be retrofitted with them, and with the addition of Gen II bearings for new engine builds, Weseman 5th bearings have come to completely dominate the fleet of flying Corvair powered planes. The Weseman’s have produced hundreds of them, they work, they are affordable, they are field installable by the builder in a few hours, They are built of the highest quality CNC equipment and they are well supported. For these reasons, they outnumber any other design by more than 10 to 1.

.

In our Conversion manual, We discuss three different bearing designs. They are Group 3000 Weseman Bearings, Group 3100 Roy’s garage Bearings, and Group 3200, my 5th bearing design. This article series is on making good source choices for progress. I will cut to the chase here and say it plain: If you are serious about building and flying, Choose a Weseman Group 3000 bearing (either a Gen I or II) for your project, period.

.

IMG_2313

.

Above, Close up showing Weseman Gen II billet 5th bearing. Early models had heat treated cast housings, but for many years, both Gen I and Gen II Weseman bearings have Billet aluminum housings made on CNC machines by a major aerospace manufacturer. These housings have bearing inserts from an American V-8 that are easily and inexpensively replaceable, without having to split the case. The housing is indexed to the case, and can be removed and replaced, and it goes right back into index. I have installed dozens of these on Corvair flight engines. They are readily available, in stock, on the shelf items available, along with matching cranks from the Weseman’s:

https://flywithspa.com/corvair/

.

——————————————————

.

Consider this: I have my own bearing design,  Group 3200;  It has been proven for almost ten years, it has flown hundreds of hours, I have one on my own plane. I could promote them and sell them for a profit, but I don’t. My motivation isn’t to just sell things and make money, it is to recommend the best parts and sources for builders, and this is more important that egotistically promoting something because I thought of it and made it, when there is something that when considered objectively, better serves builders. This is why all the production engines I build have Weseman bearings on them, and why strongly recommend them to every builder.

.

The bearing from Roy’s garage is Group 3100 in the manual.  It is a good design, and no one has done more than I have in the past to promote Roy’s work as an option. The limitation of the design is that each case and crank must be shipped to Roy, where the bottom end has to be hand machined by Roy. This is a labor intensive process, and if he was doing nothing else, he would be pressed to make 20 assemblies per year. In the past I have had Roy as a guest at many Colleges and for several years in my booth at Oshkosh. For a long time he has had a back order list well over a year. Instead of ‘sticking to the knitting’ and addressing this, he has spent hundred of hours on “R&D” goose chases. At the start of 2015, I quietly told him I was no longer comfortable promoting his work or having him come to colleges, as it didn’t seem he was serious about getting caught up. His response has been to spend his time developing a ‘secret’ modification to allegedly make 20% more power, telling builders that our CNC parts don’t fit Corvairs, and trying to promote the idea that he alone, a guy without a pilot’s nor A&P licenses, who has never owned any plane, somehow knows better than anyone else how to build and operate these engines. I have been working in experimental aviation for more than 25 years, and let me offer the observation that many people who started with a good basic product, but came to see themselves as more brilliant than everyone around them, didn’t last much longer.

.

Many builders understand that it will take several years, on average to build their plane. That is fine, but builders need to choose their sources carefully. and not start off by sending their case away for a year or two when a better option exists, when they can make immediate progress. A builder, signed up for a college, can simply call the Weseman’s and buy a bearing right off the shelf, we can bolt it together at the college, and with little effort head home with a closed case. That is getting a year head start on the process. It also costs less money. For anyone who might claim that my endorsement of the Weseman bearing is related to money, guess again. When I put one on an engine, I pay full price for it, and because I live in the same state, I pay tax on it. My promotion of it is simply because it is the best option for any builder who wants to make progress.

.

-ww.

.

.