The Panther’s engine, worlds strongest Corvair flight engine.


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.

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