College Tech


Here are some technical notes from the building at CC #22.


Above, Craig Anderson of South Dakota with his Weseman bearing equipped 2,850 cc Corvair in process. Greg’s engine is built around a Moldex nitrided crankshaft and a pair of Falcon heads. The engine will feature all of our Gold Systems. He installed the Weseman bearing at the College.

Old school EAA builder Byron Engle, at left above, and David Cain take apart a core engine on one of the 2′ x  4’ tables. About eight of the builders brought a core motor for disassembly or further inspection.

On the right is Gary Boothe, who was attending his fifth Corvair College. He is a Pietenpol builder from California. At left is Buddy Linder, Pietenpol builder from Texas.

Corvair Colleges are an unprecedented opportunity to exchange ideas and thoughts with other builders. This type of conversation is not really possible online. There is a whole social side to aviation that can only be served by in person events.

Above is another one of the Corvair cores that showed up being torn down. Although it was completely filled with leaves in the cooling shroud, it turned out to be a pretty good engine internally.

Eric Overton is in the gray sweatshirt. In the photo above we are going over the studs in his case to verify that they’re in good shape. Eric is a highly skilled Ivy League trained electrical engineer who is comfortable developing very high-end electronic systems. At the College he gave a very funny dissertation on America’s addiction to consumer electronics, and his role as a facilitator. He went on to humorously point out that he drives a 1963 Ford and is building a World War I replica aircraft because everyone knows successful pushers do not use their own addictive products, thus he steers clear of technology in his own life.

Above, I speak with Roger Grable, who came to the College with his wife Sarah. They’re building a Zenith 750 and making great progress on the airframe. Roger elected to purchase a complete 2,850cc engine equipped with a Weseman bearing and all the installation components from us. They came to the College to become much more educated about the engine they will be installing and operating on their aircraft. We personally produce about 15 engines in a busy year. Because they are a good value, we have never had any trouble selling every one we can make. This reality, and the fact that pre-built engines are not our primary mission, has allowed me to be selective in who we choose to build for. Believe it or not, I frequently get calls from people who will readily confess to not being interested in learning anything about engines, to the extent of being unwilling to read our Flight Ops Manual. From long experience, I know to politely decline to build engines for such people. Roger represents the polar opposite of this, a builder whose schedule puts a high premium on his time, but yet he is still willing to come to a College and take the time to learn many of the techniques that we have painstakingly developed which allow Corvair pilots to enjoy the engine’s excellent reputation. I am always glad to work with builders who possess Roger’s perspective and values.

Above, Norm Beauchamp’s 2,700cc Corvair engine destined for installation on his Kitfox Model V. A close look shows that the engine is equipped with Clark’s full fin heavy duty cylinders. The engine also sports a Weseman bearing. This is one of the Weseman’s earlier cast housings. The current series of production are all billet machined housings. The switch to billet housings has allowed Dan to mass-produce the bearing and have them available and on the shelf.

Sonny Webster of Texas with his core engine ready for disassembly. He is building a Zenith 650.

Ken Schmetter, at left above, watches Becky Shipman’s 2,700 cc engine coming off the stand. Becky’s engine is equipped with one of our Welded Aluminum Pans. Also visible is one of our new high-volume oil pumps. The black rubber hose shown in the view is a bypass for the high-volume oil cooler that is not installed yet. On the test stand I want the oil in the engine to come up to temperature fairly quickly. This is done by keeping the oil cooler outside the cooling baffle, or in the case of heavy duty oil coolers just running a hose as a replacement until after the engine is broken in. Corvair engines take a long time to develop high oil temperature on the test stand with cool air washing over all parts of the engine. During the initial break-in, there are a number of good reasons to have the oil temperature come up quickly.


Above, Brian Manlove, Zenith 650 builder from Texas, gives me a hand warming up connecting rods to be installed on 2,850 cc pistons. The gas we are using is map gas which burns a little bit hotter than propane. Visible on the right is my plastic jawed jig for holding 2850 pistons while the rods are installed. The small upright holds an adjustable stop that keeps the wristpin from traveling too far over during the installation. When the small end of the rod is heated to 400 Fahrenheit, you have about 2 seconds to install the wristpin before it becomes held fast in the connecting rod.

Above, Norm Beauchamp works on his engine with Ken Schmetter. In the photo, Norm is carefully going over the installation of a Clark’s high-volume oil pump. High-volume oil pumps are recommended on all engines that utilize Weseman bearings. The Clark’s pump comes complete with instructions on how to assemble it but it does take some trial and error to get it to set up smoothly.

The above photo is of a Weseman bearing coming out of its packaging. This is one of the new billet housings. Dan and his family have produced approximately 250 bearings, of which the last 50 or so have been billet units. The majority of these bearings are now on completed and running engines and dozens of them are out flying and logging lots of hours. The high time unit has now exceeded 400 hours. The bearing is retrofittable to a completely assembled engine, and it is affordably priced at $1050. The unit is completely compatible with all of our Gold System Parts. Going to a billet housing allowed Dan to shorten the manufacturing process from several facilities to one with a follow-on quality control check. This has gone a long way to allowing Dan to keep these bearings in stock and on the shelf available whenever builders need them.

Above, I carefully go over crankshafts with Jon Sanders. Jon had two different crankshafts on hand, both with new gears. Careful inspection revealed that one of the crankshafts was standard and was factory nitrided. This crankshaft can go directly into an engine after it has been threaded for a Safety Shaft. It does not need to be re-nitrided unless it is ground undersize. Jon’s plan is to build a 2,700 cc engine with a Weseman bearing and install it on his KR-2S.

Here is a movie:

From left above, Kendall Darder ready with a wrist pin, Gary Boothe, Brian Manlove on torch, Craig Anderson of the Documentation Department and myself installing pistons on rods. I did three sets while we were at the College and gave a number of people a firsthand look at the process.

The College is all about builders working together. Above, Jon Sanders lends some exacting assistance to Craig Anderson on the installation of the Weseman bearing on Craig’s 2850. Weseman bearings have a complementary installation kit that is available from Dan’s family. The price of the kit is refunded upon its return to the Wesemans.

Above, the dial indicator shows that the steel crankshaft hub that the Weseman bearing rides on is correctly installed. Barely visible are the three small Allen screws that are centered around the crank nub. By adjusting these screws and the tapered shims underneath them carefully, the steel crank hub can be zeroed to exact alignment with the crankshaft. The engine in the picture is Craig Anderson’s. The camshaft gear is a billet failsafe model from Clark’s.

This core looked absolutely terrible on the outside, but inside was hiding a viable engine. At first glance it does not look ready to actually be considered for rehabilitation into an aircraft powerplant, but first glances can be deceiving. Look closely and see that all the head studs are in excellent condition. Although I’m not a big fan of engines that have had water down in the bores like this one has, my major objection is based on the idea that they are more difficult to take apart than a core that rotates. An engine like this must have the valve seats carefully inspected because engines that had water in the combustion chamber for any length of time may have serious dissimilar metal corrosion between the seats and the aluminum cylinder heads. If you have a cylinder head that has had water in it, I would be very reluctant to utilize it on an airplane unless I sent it to Mark at Falcon and allowed him to completely reconditioned the head. If you’re planning on using the heads from your core motor with just a basic valve job, you need to have excellent condition heads to work with, not ones from a core like this. It seems counterintuitive but the most budget-minded engine build often starts with the most expensive core motor available. Conversely, expensive rebuilds can be done from any core because every single part including the valve seats themselves will be replaced in process.


More Running Engines coming in next posts.

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: