Current Corvair Installation in a Pietenpol, Part 2

Builders,

Here is a look at the second part of Kevin Purtee’s Corvair installation, these photos were taken in his shop, the day after CC #32. This is a follow on to the previous story: Current Corvair Installation in a Pietenpol, part #1. If you follow all the way down, you will gain some insight to the type of characters that inhabit the Corvair/Pietenpol branch of the Corvair Movement.

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Above, an overhead shot of the engine. The Corvair is only 28″ wide, about four inches narrower than a small Continental. Kevin’s motor is set up with a stock Corvair oil system. In the manual, this is Group 2700. If he was using a HD oil system, he would follow Group 2800 in the manual. Any engine can be ‘upgraded’ later, but it is easier to build it in the HD configuration if you know that you will eventually do it. On Pietenpols, you can use either system, on planes like Zenith 750s, we always set them up as Group 2800 motors.

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The Gold oil filter housing is at the back of the motor, it is part #2601-S. This is the ‘standard’ housing, we also make a #2601-R ‘reverse’ housing where the filter is over the engine. The “-R” is only used on Sonex and Waiex airframes and a handful of applications that are very tight on space. The iol feed line for the 5th bearing comes off the housing. The line itself is part # 3051-S. It is an AN-6 braided line, but Kevin has covered it in a sleeve. The silver part on the firewall behind the housing is the Aircraft Spruce air oil separator. It works well and is less than $50. You can fly some Corvair installations without one, but most planes use one. It weighs only a few ounces.

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Pietenpols use our standard intake manifold, part #3601-S. In the photos above, the rubber mounting boots are not in place, but it is a good view of how the intake lines up with the head pipes we weld on heads. Note that the pipes on the heads are leaning inboard 20 degrees. This is required to get the most compact installation. We have fixtures that bolt to the head that hold the pipes in the right place during welding.  On the internet there are countless discussions about trying to make some bolt on arrangement that works as well as welded on pipes. If you want to make progress, make it look like this, it has worked for hundreds of other builders in the last decade.

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Above, a look from the bottom of the engine. The exhaust is #3901-E.  The camera is distorting the amount to ‘splay in the exhaust tubes. in reality the miss the corners of the fuselage by just 2″.  The high thrust line mount is #4201-C.

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Above, the close exhaust pipe is in perspective, and can be seen to hug the fuselage. The far side has the illusion of sticking out. The Corvairs exhaust is held in place by 6 clamps that look like distributor clamps. They are made from 316 stainless. I have tried making mounting points at the ends of the pipes, but these were prone to cracks. After more than 10 years of these systems flying, I can say they have a perfect crack free record, as long as you just clamp them only at the top where they bolt to the heads. Kevin’s  plane is being covered with the Stewart System. He chose this because he dosent tolerate the MEK element in Poly-Fiber covering systems.

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Notice that every engine we build at colleges has white painted or powdercoated push rod tubes. This is an importiant element in protecting the pushrod O-rings, (#1603) from heat damage.

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Above, Kevin and I speaking at Corvair College #32. Although we look very different, we have a lot of things in Common: We are both the same age; We are both Embry-Riddle graduates from the same Degree Program; we have both worked in aviation every day since we were 26; we have very similar perspectives on risk management.  Read: Thought for the Day: Two paths in managing risk.

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It was really cold at CC #32. When you see photos, notice how well everyone is dressed it never came out of the 30s for a temp. Builders had a good time, but we have already discussed moving next years Texas college to April to avoid a repeat.  That is good for next year, but while at the college, Kevin wanted to demonstrate that being cold is all in your head if you are having a good time. He is the unofficial leader of the Corvair/Pietenpol branch of the movement, and as such, builders have come to expect that he will likely set the positive attitude at any gathering of Pietenpol people. We have many ‘characters’ in the Corvair movement, and the bar for setting the pace is high. Other engines tend to attract people less comfortable with strong choices, we get the fun loving, independent types.

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Above, Pietenpol builder, Mark Chouinard’s engine on the run stand at CC #32. Mark is the 6’5″ cat in the cammo jacket. Note that everyone is wearing hats, and several people are wearing snow mobile suits. It was about 35 degrees, raining and windy out when we ran Mark’s engine. Mark spent a number of years in the Infantry, and as a fellow warrior, Kevin thought the occasion called for something memorable, something that would be a reminder that the Corvair Pietenpol builders are just a different breed….

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Kevin’s idea was that he and Mark should stand shirtless in the prop blast. Mark bowed out, but Kevin wanted everyone to know that it wasn’t really that cold. Note the rain drops  on the lens. Someone figured out that the wind chill in the prop blast was 90 below, even without the water cooling effect. He next time anyone asks if a Corvair college is a typical technical seminar, with power point presentations in the Holiday Inn banquet room, I will pull out this picture, it should cover the difference pretty well. -ww.