Jump Start Engines – part #4

Builders:

In this section, Lets look at two elements of the closed case, The Crank Group 1000 and the Weseman bearing Group 3000. There two parts make up the crank and 5th bearing arrangement, and are the fundamental components to the Jump Start Engines.

From background reading, you learned that the two places to have the stock GM 8409 crank processed are Moldex in MI and with Dan and Rachel Weseman in FL. There are a number of factors in which one you could choose, but my approach is to ask first: What 5th bearing are you using?

The most popular 5th bearing for Corvairs Is the Weseman Gen. 2. This is followed by their Gen. 1, and then Roy’s bearing. (The Jump Start Engines are being built around the Weseman Gen. 2 ) If you are going with a Gen. 2, then Dan and Rachel are going to process your crank in FL. If you are building a Gen.1 engine, you could go either way, but my preference is FL because the Dan replaces the gear on the crank with a new one and Moldex does not. (For builders interested in Roy bearings, Roy uses Moldex’s services, but he replaces the gear himself as part of his bearing design.)

You can take this link: http://flywithspa.com/corvaircomponents/new5thbearingcrankshaft.html directly to Dan and Rachel’s site for crankshaft rework information.  You can use this link to read about the Gen.2 5th bearing: http://flywithspa.com/fly5thbearingcom/5thbearingnewengine.html.  The total of these two parts is $2,200.

After we go all the way through this series and come up with exact totals for all the parts, assembly labor and the core, I am going to have all the builders interested in picking up a Jump Start Engine actually pay the $2,200 directly to the Wesemans as the ‘deposit’ on their engine. There are several reasons for this such as double record keeping, in state taxation, etc. But the most important one is that The four of us that I call “The Corvair all stars”, (Ourselves, the Wesemans, Roy’s Garage and Falcon Machine) have a long standing informal agreement that each company should get the regular price for his work, and the others support it, but don’t act as a paid dealer. There is a good reason for this. When a builder uses a part, he can rely on full support from not only us, but also the all star that made the specific part.  This has the effect of getting several experts into the builders corner, and incentivizing the others to show up at Corvair Colleges to directly work with builders. It is a cooperative relationship that primarily benefits the builders.

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Below are the numbers from the Group 1000:

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Crank group (1000)

1001(A)- Crank (8409 mark, GM)
1001(B)- Billet crank (Fly5thBearing.com)
1002- Crank gear
1003- Crank gear key
1004- Crank gear gasket
1005- Rear keys -2-
1006- Fuel pump eccentric
1007- Spacer
1008- Bronze distributor drive gear
1009- Oil slinger
1010- Main bearings
1011- Connecting rod bearings

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On the engine we will have 1001A cranks: the 1002 gear is replaced, along with 1003 and 1004; the two 1005 keys are #5858 from Clarks, 1006-1009 come on the core cranks, we just clean and inspect them carefully, but the ones on most core cranks are in good shape. We will be putting new main bearings, #1010 in the case when we assemble it.

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Weseman 5th bearing group (3000)

3001- Bearing kit (designed for short gold hub 2501B)
3002- Alteration to standard gold hub (2501A)
3003- Alteration to black hub (2501C)
NOTES: Selecting this bearing option allows deleting the 2300 group. Contact Dan Weseman directly at FlyWithSPA.com for more information.

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In a later part we will go over the 2501B hub, which is the correct one for the Weseman bearing, both Gen 2 and Gen 1. The two notes 3002 and 3003 relate to retrofitting a previously built engine with a Gen 1 bearing assembly. -ww.

 

 

Jump Start Engines – part#3

Builders,

In this part, let’s look at the sub-groups that will be in the assembled short block. One of the organizational tasks I put a huge amount to effort into in 2012-13 is our Group Numbering System, which logically breaks down your engine build into groups, and assigns every single part in the flight motor a number.

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When I wrote the getting started series, I introduced the numberings system with this story: Getting Started in 2013, Part #2, Group numbering system. It is a good, short, introduction, but I later changed the system slightly. In the first system (which was used in the getting started series) You had Group 1000, (the crank group) but you also had part# 1000 which was the crank. Shortly I saw this was a little ambiguous, and decided to make the crank part number 1001, and bump all the part numbers down one digit. Not a big deal, but it makes it easy to understand that when we are speaking of 1000, 1500 or 2000, we are speaking of the whole group, not an individual part. Our regular catalog page:

http://www.flycorvair.com/products.html

Has all the correct part numbers as they are after the revision. Read and understand the getting started articles, but the numbers we use in this series will be the final ones that appear on our catalog page.

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The catalog page has all groups, #1000 through #4300 on it. That may sound like a lot, but keep in mind that 3400 through 4300 deal with airframe installation components that you don’t need to get an engine running at a college. Also, there are a number of groups like the Front cover group 2300, that are deleted if you are building with a 5th bearing, There are two oil system groups, 2700 and the heavy duty 2800, and you only need one, and there are three 5th bearing groups, 3000 (Weseman), 3100 (Roy’s) and 3200 (mine) and you only need one. The numbering system has to cover a lot of options, but to build your engine you only need to use part of it. This series will guide you through with some examples.

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If you look at it for a minute, you will understand that the “Catalog page” is far more than a list of items for sale. only a small fraction of the part numbers are items we sell. The page has a larger function as a checklist for your engine build. Rather than flashing back to it, consider printing one out and getting a highlighter and checking the items off as you collect and prep them. Even though I have been building the engines for 25 years, I still like to use a checklist to get everything organized.

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I have a few hundred hours in Grace’s Taylorcraft. It is a very simple plane, but if you look in the glove box, it has a laminated, hand written pre-flight check list, and I still take it out and run through it and say the items aloud.  Make fun of that if you want, but I am never going to be the guy who took off with the fuel shut off, the plane radically out of trim, or the primer unlocked.  If you don’t want to be the guy who comes to a college to assemble and run his engine but doesn’t have lifters (#1105) or head gaskets. (#1403), use the checklist.

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OK, below are the Groups we will be dealing with to build the Jump Start closed cases.( Getting Started in 2013, Part #7, ‘Chas. Charlie’ Short Block ) after this we will break it down to the individual parts in each group.

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(1000) Crank group

(1100) Cam Group

(1200) Case Group

(2000) Rear oil case Group

(2400) Starter group

(2500) Hub Group

(3000) Weseman bearing Group

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Reading for background:

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To read about the Crank Group 1000

Getting Started in 2013, part #1, Crankshaft process options.

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To read about the Cam Group 1100:

Getting Started in 2013, Part #3, The Camshaft Group (1100)

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To read about the Case Group 1200:

Getting Started in 2013, Part #4, Case Group (1200)

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To read about the Rear oil case Group 2000:

High Volume Oil Pump

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“If two guys walk into my booth at an airshow and ask about engines, everyone should understand that I am going to be polite to the guy who wants to tell me about the 4 cylinder Corvair he had in high school, I am going to answer all the questions of the guy who has seen my website, but didn’t look enough to even hear about the number system, but I am going to invest as much of my time as possible with anyone who shows up with a printed numbers list, a highlighter, a pencil and a working knowledge of how we describe the engine now. There is only one of me, and there will be many people at an airshow as interested spectators. That’s good, but my mission is to teach builders, not entertain spectators. I am glad to talk to the later and do a little hangar flying if they are standing there, but mission #1 is to communicate with builders, and nothing says you’re a builder like having a written plan in your hand.” -ww

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( Our booth at Oshkosh 2014 is #616 across from Zenith aircraft)

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Jump Start Engines – part #2

Builders:

Here is part #2 of the Jump Start Engine series. This one will cover some background before we move onto details.

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18 months ago I wrote a 20 part series on “Getting Started.” The entire series can be found by clicking on this reference page: Getting Started Reference page.

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In that series, from part#5 to part #9 we looked at 5 different closed case options. The had alphabetized names, AA through EE. The Jump start engines I am proposing, with Gen II Weseman bearings, 8409 cranks and failsafe gears on OT-10 cams are most like the engine described as the third, or “Chas. Charlie” option. You can read about it at this link to part #7: Getting Started in 2013, Part #7, ‘Chas. Charlie’ Short Block.

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If a builder wasn’t to assemble his engine as a 3,000 cc Corvair, the case has to be machined to accept the larger cylinders. Specifically the six holes for the cylinder spigot bottoms have to be enlarged slightly. This need to be done with great precision.  There is an older description of it at this link: 3,000cc Case Modifications.

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If you are thinking about which displacement you would like for your plane, you can read the “Getting Started” links about pistons and displacement. They are here;

Getting Started in 2013, Part #12, Piston Choices

Getting Started in 2013, Part #13, Basic piston/rod/cylinder combo.

Getting Started in 2013, Part #14, 2,850 cc piston/rod/cyl. Kits

Getting Started in 2013, Part #16, 3,000 cc Piston/cylinder kits

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That should be enough reading for one night.  On to part #3 tomorrow. -ww.

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Above, a rear view of a 3,000 cc Corvair engine.

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Jump Start Engine project – Part #1

Builders;

Here is a new series on engine building. It will be a detailed look at getting started that will serve many builders. The focal point of this are 10 “Jump Start” engines that we will have in the works for the next months, but the info will apply to anyone building a Corvair.

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What is a “Jump Start” Engine? Basically it is a complete core engine, that has some of the difficult parts done for the builder, but still needs work from the builder and replacement and conversion parts to be completed.

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Picture a builder who wants to build an engine, but is having a bit of a time finding a good core. He wants to do some prep work, reading and learning at home, but his goal is to bring his project to a single college and finish and run the engine in 3 days. He is a candidate for a jump start motor.

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Here is the idea:

1) The engine starts as a complete core motor at my shop. From it I send the 8409 crank to Dan Weseman for processing and the installation of a Gen II 5th bearing. The case is cleaned, checked and assembled with a new set of main bearings, an OT-10 cam, and a new gear. We assemble the Weseman 5th bearing onto the case here. We also install a set of Hybrid Studs (2502), Safety Shaft (2503), a  starter ring gear (2408), and a Short gold hub on the engine (2501B), and a High volume rear oil case. (2000HV)

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This would effectively cover most of the parts in Groups 1000, 1100, 1200, 2000, 2500 and 3,000. (see http://www.flycorvair.com/products.html)

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2) I take the heads while they are here, machine the carb pads off and weld on a set of the aluminum intake tubes.  This is done after the heads get a rough cleaning and have all the old parts like valves and springs removed.

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3) the remaining engine parts are rough cleaned and inspected, inventoried and bagged. We also have a comprehensive list using our numbering system of all the other parts the builder will need to finish the engine

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4) We can crate and ship this to the builder. He can then get familiar with all the parts, and at his own pace complete the engine. We can send him the heads, or we can forward them to Falcon Machine for rebuild. After getting everything organized and prepped, the builder can bring the completed case, plus all the prepped parts to a college, and with steady work he can go home with a completed running engine.

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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 put together we sold at CC#24.

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Potential Questions:

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“Is this a Kit Engine?” No. It is called a Jump Start engine to differentiate it. Kit implies that every single part in the box. This has all the core parts, but still needs many items like pistons, the rods to be rebuilt, gaskets, rod bearings etc. Part of the goal here is to keep the thing affordable. If it was a kit with everything in the box, it would be a lot of money all at once. This will cost some money, but getting started with this is going to be less than 50% of the cost of building a motor.

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“Can I just get you to make me a kit motor, you know, with every single part in the box, carefully cleaned, and prepped and painted?” Sorry we don’t offer that. Here is why: If I did all that, and it had an assembled case, It would actually take me about the same man hours to assemble the engine as it would to carefully pack the individual parts in boxes to ship. The time in building an engine is the prep work, not the assembly. If I sold a kit engine it would have to be nearly the same price as a completed engine from us. Contrary to what some people think at first glance, engines like our $10,750 running 2,850 cc engine are mostly parts cost and only some labor.

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Why do many VW engines come as kits? How are they different? With Corvairs, we are investing sweat equity in the engines in order to rebuild a very high quality American engine with new parts that are also made in America. The great preponderance  of VW engines are made of all new parts….that come from the Peoples’ Republic of Red China.  Yes, they once came from Germany and Brazil, but that was long ago. Today, most VW parts, cranks, cases. heads, all come right from mainland China. My goal is to teach people how to build and operate a high quality American engine, not to compete with $2/hr. workers in a police state without civil rights.

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“What if I wanted a 3,000 cc engine?” In this series I am going to give sample builds of  2,700, 2,850 and 3,000 cc Jump Start engines, and I will give an exact break down of the costs for each.

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“Hey, I already have a core motor.” My first though is just follow along in the series and process your own stuff in parallel with the series. If you wanted to get in on the engine because you liked the closed case idea, or wanted to move up to a 3,000 cc engine (which requires the case to be bored out before any assembly work starts) we could always take your core as a trade in, but most likely we would just help you find another builder who wanted to buy your core from you.

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How much is this going to cost? I don’t have the exact number, because we have a few variables here like if the case needs to be bored for 3,000 cc cylinders, if a builder wants all new studs etc.  In this series we will look at a number of different variations and put exact numbers to each one

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“How quick could I get one?” The crank process takes time., as Dan sends the crank to several different shops for magna-fluxing, heat treating and grinding.  There is some calendar time involved here. Right now we are 100 days or so away from the next college. If we take 10 days to write up the series, and a builder wants in, there should be plenty of time to get the work ready for the college.

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You are a busy guy, isn’t this a big influx of work? No, not really. I already have the engines here. I picked up the 10 cores at the Corvair Ranch in PA on our trip last month. They are already disassembled and partially clean. The crank and 5th bearing part of this will be done by Dan’s experts, I am going to send the cases out for cleaning and boring, I have Vern to assist with welding the head pipes, and the small parts bagging is not a lot of work. What is left is the case assembly, building the rear oil case, and putting the gen II 5th bearing on.  That is work, but not an enormous amount. Again, if I was building “Kit” motors, and doing all the work on every part, this would take until the end of the year.

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What is the budget time line on this? Part of the idea here is to get to the exact numbers though this series. Once we know this, if a builder wants to get in, my idea was they directly pay for the crank processing and Gen II bearing to Dan and Rachel Weseman, which is $2,200. This would function as ‘the deposit’, the rest would not need to be paid until we were going to ship it of bring it to a college. If the builder wanted to get the heads for it sooner so he could get them in the works, we could arrange that they would leave before the case was done.

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That is all the preliminary questions I could think of. If you have more, tune in for part #2 tomorrow, or feel free to ask them in the comments section, I will address them in the next part. -ww.

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CHT info taken from test flight of 601XL

Builders,

Note: The columns in the chart are shifted over one heading, it is a discrepancy between how excel and the wordpress format here presents printed data, wordpress automatically tries to center it, look past this and understand the story, I will try to reformat this and get a link to the full sheet later today-ww

Below is a chart of CHT data taken from Ken Pavlou’s 2,700 cc 601XL, which now has about 20 flight hours on it. The layout of the data Ken gathered is particularly interesting. Ken’s engine and installation is nearly 100% done according to our manual. His data collection is fed through his Dynon panel. His data is a very good representation of what any builder can expect if he is willing to follow our recommendations.

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First let me say that Ken is a very experienced pilot and astoundingly talented electrical engineer who really understands computers and instrumentation, so that eliminates a lot of variables right there.  But keep in mind that Ken was no ‘motor head’ before building his Corvair. I am pretty sure it is the first engine he ever built, thus it also represents what anyone willing to follow the proven path can expect.

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I have long told builders that 1) CHT temps measured under the plugs read far higher than if they are measured in the stock GM location on the Bottom of the heads. That is counterintuitive because the cool air enters on the plug side, but it is reality because CHT measurement under plugs tends to measure the plug temp, not the head temp. (this is not just a Corvair thing all Lycomings have the CHT port on the bottom of the head also, they are not correctly measured under the plugs either) I have long pointed out also that 2) the baffling style that we recommend for Corvair planes, with aluminum baffles with a rubber strip sealing it to the cowl, just like 95% of certified planes use, works period.

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I can not spend a single day at an airshow with out having at least one person tell me that I am not right about both 1) and 2), and they are sure of this because they read it on a website somewhere. At least once a day a guy will tell me that he is going to build Jabaru 3300 style fiberglass ducts because “they will work better and cool evenly.” Below is data that refutes such internet lore. I am not sure why anyone would be tempted to copy a cooling design from an engine known for running hot, but my field of expertise is engines not psychology.

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Ken is not the first guy to perform this test. 601HDS-TD builder Rich Whittington was one of the first. Rich’s plane is a 3,000 cc Corvair fed by a Stromberg, a good but slightly off the mainstream combination. Ken’s 2,700 cc MA3-SPA tri-gear plane is more typical. Get a good look at the data and see that the CHT in the GM location is running 80 to 100 F cooler than the plug reading; Also note that the L-R cooling spread on the engine is about 5 degrees. Does that sound like a problem? I doubt that there is a single certified plane that can beat that, yet I have had an army of people eyeball the baffling we use and proclaim it a defective design.

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The data is taken from a large sample of a whole flight with a climb to 6500′ and a decent and landing. The sample here is typical of the climb data. In the decent phase the L-R temp difference went down to one degree F.

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Below, a revised chart I am having a hard time making bigger:

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Original chart with shifted column headings:

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Left Bank Stock CHT Location

Average Left Bank (2,4,6) Plug Temp

Average Right Bank (1,3,5) Plug Temp

Difference L vs R Bank Plug Temps

L Stock Location vs L Plug Temp

Average

277

365

369

-4

Min

241

272

270

-9

Max

302

406

405

7

288

376

372

4

-88

288

379

375

4

-91

288

383

379

4

-95

288

387

383

4

-99

290

391

385

5

-101

292

393

388

5

-101

293

395

390

5

-102

294

396

391

5

-102

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Great internet answers: I was looking for the make and  model of a specific truck that appeared in a movie from the 1980s. I Google searched the question, suspecting the truck to have been a 1960s Kenworth. There were about 6 answers, all of which I knew to be wrong, all posed by people who claimed they were experts, including one guy who said he worked on the assembly line. At the bottom, one guy who writes in saying it was an Autocar A64, like the one pictured below. The 5 experts jump on him and call him a fool, several people chime in to confirm this, one even questioning if there was such a thing as an “Autocar,” The guy writes back with pictures of the actual truck that was in the movie, it’s current location, the name of the owner, and a link to it being for sale on Ebay. Doesn’t matter, they still think he is wrong. The internet, an endless chance to wonder about the sanity of mankind.

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More stories on CHT

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Corvair CHT, letters and notes.

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CHT part #3, Letters, notes, sources and inlets.

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CHT Part #4 more notes

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CHT part #5, flight data from Zenith 750

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Measuring Cylinder Head Temps on Corvairs.

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Cowling Inlet Area, marketing, accident stats, Darwin where are you?

Youngest Builder with a running Corvair.

Builders:

At Corvair College #29, the high point of the event was the perfect engine test run of the 100 HP Corvair by 16 year old Pietenpol builder Joseph Jameson. We ran a number of engines for the first time at the College, but everyone present took notice of Joseph’s achievement.

Many Pietenpol builders saw the October ’13  newsletter, which carried a nice story about Dan Helsper taking Joseph aloft for his first flight in a Pietenpol. Doc and Dee Mosher, Dan and most everyone who has met Joseph comments that he is obviously a bright and thoughtful young man, blessed with a supportive family. A few minutes in his company is enough to make anyone say something positive about the future of aviation.

Joseph has a lot of his airframe built, and is closing in on his PP check ride, but opted to dig into his Corvair engine when Kevin Purtee and Shelley Tumino hosted Corvair College#28 in Texas. You can see Joseph and his father Kelley speaking with award winning Piet builder and flyer Hans Vandervort at the college in this link: Corvair College #28, San Marcos, Texas

Joseph got his Corvair underway at #28, but signed up for #29 in Florida to finish and test run it. The engine is a 100HP Corvair, with a Roy, 5th bearing and Falcon heads.  It is not a “spare no expense” engine, but it is an exceptionally high quality Corvair with electric start, dual ignition, stainless valves, HD oil cooler and filter and some weight reduction items like a flyweight welded deep sump pan. The engine is a bit lighter than a C-90 or an O-200.

When Joseph was done, we pre-oiled it and put it on our test stand. It started in less than 2 seconds of cranking. We put down a 30 minute run to break in the cam and lifters, followed by a second run. I have run several hundred Corvairs on the stand in the last decade, and Joseph’s engine ran as well as any of them. It was smooth, didn’t leak a drop of oil, and his adjustment of the hydraulic lifters was perfect. A visitor to the college asked what this young man’s ‘secret of success’ was. I said “He actually read the book and he follows the instructions.”

Hats off to Joseph for his achievement in learning and building, and special thanks to everyone in the Pietenpol community that played a positive role in assisting him. Joseph and his Dad are planning on attending Brodhead this year, if you have not met them, take a moment to do so, they are outstanding people. -ww

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Father/son team the Jamesons from TX, stand beside their newly run engine. The engine is destined for a Piet that is mostly done. Dad (Kelly) is clear that the plane and engine are really the handiwork of his son, Joseph. A very bright and skilled young man.

Myths about propeller efficency

Builders,

On the Pietenpol discussion group, a well meaning guy reposted a story from the 1996 Pietenpol newsletter. The subject was on prop efficiency. It included the comment:

The Corvair engine is another compromise. They have a loss of efficiency due to the small diameter propeller and accelerate poorly (due to the tall gear effect) but produces good power. ” 

The guy who posted this probably didn’t know it, but I know that the comment is without merit, and no one who actually conducted a test, or understood propellers would make such a comment. Yet, here we are, 18 years later, in the information age, following the same myths that have been floating around for decades.

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The above comment has no educational value. Take it line by line: All engines, not just a Corvair are a compromise, period. Testing shows that a 100HP engine climbing at 60 mph with a 66″ prop may be close to 95% as efficient as one with a 72″ prop; Ask any tester you like, there is no such thing as an engine that produces good power but accelerates poorly. This only happens when it has a bad prop on it.

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OK, the whole point of having a dialog, reading thoughts or communicating about the building of planes is to learn something and use this knowledge to improve the plane you are building. The comment above serves none of these functions. It is only valuable to people who which to reinforce false realities they believe in. You can divide almost every story you read that allegedly shares information on airplane building into to camps: Valid testing that supports learning, and opinion or out of context stories that support myths. Only one of these will make your plane better.

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This division cleaves all discussion, any story can be put in one pile or the other.  What always gets me is this simple fact: Less than 20% of homebuilts are completed. I have been around Pietenpols a long time, and I would guess that their completion rate is far below 10%. What no industry magazine or salesman is going to tell you is that the completion rate, as a whole for our branch of aviation is actually dropping. Yes more planes get completed, but the sell many more these days. Given this fact, you would think that builders would all recognize that to personally beat the poor average, they have to make some smart choices, and a critical one is learn from valid tests, and don’t waste time listening to the same myths and old wives tales that lead 80% of previous builders to failure. But, for some reason, the myth mill still works every day, and people participate in it, directly sabotaging their own chances of learning and success

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It is somewhat frustrating to conduct a mountain of public tests, but they are cited less often than dubious sources from decades-old news letters. For people who wish to see real side by side thrust tests and dyno runs, get a look at this link to our testing page: Testing and Data Collection reference page. For Pietenpol builders who want to see that a 72″ prop doesn’t hold a candle to a 66″ one bolted to a powerful engine, look at: Pietenpol Power: 100 hp Corvair vs 65 hp Lycoming. If you would like to read about how most of the things said about “prop efficiency” are myths, get a look at this:The case of the Murphy Rebel, “eyeball vs. testing” I would hope that the next time the myth machine goes to work, someone will share a link to these pages, or even this story.

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Here is a simple example of testing and common sense from the last story link:

“Props with diameters of 74″ are only efficient on engines like the
Continental 65 with a low red line of 2300 rpm. Low rpm isn’t efficient in itself. A 65 Continental becomes a 75 continental with respect to power output by just a jet change and an RPM increase to 2600.  If turning the prop 300 rpm faster and using one with less diameter actually made less low speed thrust, than no one would have ever converted a 65 to a 75.”

Some pretty basic logic. I only ask people to believe what I can show them with tests and common sense like the point above. To counter this, the myth makers only have old newsletters and stories like “I heard a guy tried that once but it didn’t work.” Occasionally there will be input from a guy who touts a long dusty engineering degree as some credential as credibility for his favorite myth. If that is more valid than a specific test done in public, then I have a Unicorn to sell you.

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If you would like a simple example to destroy the myth that low speed aircraft have to have large slow turning props to have performance, let us take a look at some work from a man who only valued one thing in planes: Performance. This man was the greatest air racer who ever lived, and almost all of his work was done on planes that could be well powered by a Corvair. The Mans name was Steve Wittman.

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Let’s look at the plane below and the prop on it. It is Wittman’s “Big X”. It is a 4 seater powered by a 150HP Franklin. It was noted for having a very wide speed envelope.  Did Wittman use a big slow turning prop said to be efficient? No, he used a high rpm, smaller scimitar prop. This plane climbed at 70 mph, it had to have good low speed thrust, and it did. How long have people known that the only thing slow props have going for them is sound suppression? Well the photo here is from 1947.

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Below, the Buttercup. The photo is from the EAA museum where the plane was retired to after flying for 60 years. It is reported to have 3,000 hours on it. The prop is not the correct one, it is just for display. This plane will fly and climb at speeds well below the stall speed of a Pietenpol. it will also do 145 mph on the top end. How does it cover such a wide envelope with a C-85? Simple, it has a smaller diameter prop that it spins faster. For people who claim that high rpm props don’t make thrust, please explain what was making the thrust that drove the plane forward at 145 mph when the engine was turning 3,400 rpm. Again the ideas are not new, the buttercup was built in 1937.

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How about a slightly faster example? Below is a youtube link to Steve flying his Tailwind N-37SW, powered by a direct drive inverted Olds 215 V-8, bored and stroked to 262 cid. It has a 62″ diameter prop on it. It was cut down from a Cessna 150 aluminum prop. It climbed very strong and topped out at 3,600 rpm and 195 mph with out wheel pants. How do I know this? Because I flew in the airplane with him for a very vigorous flight in 1993. Notice that people who present myths always have a mysterious “guy who tried it”. I am essentially doing the same thing here, with the exception that I was there, my “guy” actually existed and was one of the greatest builders and pilots of all time, and, conversely, it worked for him. Other than those details, my story is just the same as any other internet myth.

http://www.youtube.com/watch?v=WsH-j4pF4fE

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Something I wrote about real aviators at the core of flight:

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“If you look at their lives close enough, all of the greats offer something to guide us in pursuit of the timeless truth of flying. Pietenpol teaches that we are more likely to find it in the simplest of planes; Lindbergh knew that you started your search inside yourself; Gann said that we will not see the truth directly, but you can watch it at work in the actions of airmen; and Wittman showed that if you flew fast enough, for long enough, you just might catch it. These men, and many others, spent the better part of their lives looking for this very illusive ghost. Some of them paid a high price, but you get the impression they all thought it was worth it.

While it is possible that someone who rents a 172 or even a person who reads Fate is the Hunter has some access, I honestly think that the homebuilder who dreams, plans, builds and eventually flys his own plane is infinitely more likely to experience the timeless truth of man’s quest for flight. All of the aviators who had some insight to guide you found it while they were in action, in the arena. If you inherently feel that you want to build a plane, you feel just like Pietenpol did. When you’re building it, you will find out how determined you are and what kind of perseverance you have. Lindbergh evaluated these qualities in himself every day. As you finish and prepare to fly, you will find others of enormous qualities and flaws, and you will learn to sort them and their counsel, as Gann always did. And when you fly your plane, and come to trust it because it is your creation, and you cut no corners, you will never want to stop, the way Wittman never did.” -ww-(2008)

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