MA3-SPA Test Runs.

Builders,

In the last week I have been running several back to back test of two Marvel MA3-SPA carbs.  The Carbs are mechanically identical, but have two different histories.

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Above, two MA3-SPA carbs, perfect for Corvairs. To be correct, they must be, as specified in my manual, part number 10-4894, or the exact equivalent. And that doesn’t mean another MA3.

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If your aircraft plans say the spar is to be made of Aircraft Grade Sitka Spruce, you can’t use white pine from Home Depot; If you plans say the longerons in your plane are 6061T-6 Aluminum, you can’t replace them with screen door material from Ace Hardware; and if you are building a “WW Corvair” , you can’t just use any MA3 because you found out the right one cost more than wanted to pay.

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Good News: the 10-4894 is the most common of all MA-3’s accounting for 50% of total production.  Once set, they hold their adjustment and do their work  a very long time. Look at the two carbs above, the silver one has been used on my test stand nearly 20 years. It has run 100’s of engines, you have seen countless videos of it starting brand new motors in one or two seconds of cranking……I have never done any work to it, and it has never been overhauled, and the serial number indicates it is as old as I am.  This is an example of a well designed machine.

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The black carb pictured is from my personal aircraft. It was rebuilt by D&G fuel systems about 6-7 years ago, and I paid the same $600 every other builder pays. In very carefully instrumented test runs, this carb ran perfectly, even on Justin Peters’s 3.0L motor and on Mark Borden’s 3.3L . The carb does not have to be re-jetted to do this, it does it all on its own, because it is an excellent design.

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To learn more about carbs, look at this:Carburetor Reference page

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Justin Peters Starlet progress in one hangar visit.

Builders,

Here are a few pictures to wrap up Justin’s 2.5 day hangar visit. It is a story of good times and great progress.  As you read, make your own plan for progress this season.

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Above, the finished motor mount.  It was a lot of calculation, measurement and work, but we charged him the same price as one of our production mounts. I have always regarded Individual enthusiastic builders with unique projects as an opportunity to demonstrate my support of homebuilders. There are plenty of businesses which either ignore them or regard them as a deep pocket to be picked, but I have a very long track record of treating them more than fairly.  The flip side of the coin is such builders must understand, and be patient for when we can do such work in our schedule. Justin is such a builder.

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The intakes on the floor were test fit, the shiny one is a panther, the gray one is a Vagabond, a variant of a Zenith intake. Neither one fit, so we carefully measured for a custom one.

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Above, Sunday morning was foggy, but Justin’s 3.0L Corvair put down a perfect test run. It had no issues at all, we just did a fine adjustment on the E/P-X ignition and it was good.  The engine is built exclusively from parts from SPA and myself.  Justin got started in the fall, and had the engine 95% ready by the end of the Barnwell Corvair College last November.  Knowing we were going to build a mount, I asked him to bring the engine also. The engine turned 3,370 rpm on the test prop. We took an oil sample to send to Larry Nelson at Lab One, and after it cooled we used the engine to check for cowling options, intakes and exhausts.

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Above, Justin holds an MA3-SPA carb in place while we study the space between the engine and firewall for a carb installation on a custom intake. He is very skilled with tools, he works HVAC as a regular career.  That type of mechanical work makes for craftsmen who are good with hand tools, good at planning several steps ahead and good at diagnosing solutions, He is well suited to building a unique airframe. Most people new to homebuilding would be far better served by a more common airframe, but Justin’s skills and his willingness to enlist assistance, make his choice realistic.

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Above, Justin samples my backyard range and 60 year old Remington 513T “Rangemaster”. He is an experienced hunter and skilled marksman. He nailed the yellow steel plate dead center, hit the remains of the Chinese multimeter barely visible in red, and went on the shoot the 1/4″ edge of a steel plate laying on top of the backstop, all off-hand.

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Above, a smile while fitting a nose bowl and standard spinner. the mount looks low but it is taller than it appears, the crank is 45″ off the ground in wheel landing position. This will not be a clearance issue at all with a correct diameter prop. Notice how the gear and suspension angle was corrected since the first pictures 2 days ago.  This is the kind of thing we can rapidly correct in the hangar.

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Above, the satisfaction of progress, of having a plan come together. Later in the year, when the outcome of the Super Bowl has long faded, Justin will take his airplane out to the flight line for its first time. This will happen because he made a plan and decided he would work on his plane this day and spend the balance of it driving the 855 miles back home. He chose to do this rather than be a spectator today.  Nothing wrong with having fun, but make sure it isn’t a poor substitute for what you really wanted to do this year.

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Wewjr.

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Traditional Homebuilding, Into the night.

Builders,

8:30 PM here in Florida, Saturday night and 65F out. We are closing in on completing Justin’s custom mount. Another hour at the weld bench and Vern will have it polished off. Over the years I figure we have made nearly 50 one of a kind mounts, this is the first Starlet mount, but not the last custom one. I have long said, if the only impediment to a builder using a Corvair is the mount for his plane of choice doesn’t yet exist, I will make it.

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Earlier today Justin and I stopped by the SPA shop where Dan and Rachel were working on a Saturday afternoon, as many small business owners do. They also have plans for this years flying season. The offered to let Justin try a Panther cowl, exhaust and intake, to check their fit to see if making custom items was avoidable. It was the kind of things old school homebuilders always did for each other.

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People have said some nice things about the work we do supporting builders. My actions here are not original ideas. they are patterned after how the best of homebuilders I met decades ago treated the ‘new to building’ me.

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I was fortunate enough to know the EAA’s founder Paul Poberezney. I exchanged letters with him, wrote for his personal magazine, was the first guest speaker at his SAA flyin. He was human, not perfect, but he really did understand how to treat people and look for their better side. Even if aviation really wasn’t a ‘brotherhood’ he believed it could be, and went about proving this one day at a time. His reward was largely the same one I’m after: getting to spend your days in the company of better people.  You can’t pay the bills with it, but it goes a long way toward having a satisfying life.

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Above, Vern putting the last of the Tig weld beads on the mount. This is where skill and experience come into play. We built the ‘tray’ in my fixture, welded some of the bottom elements complete, tacked all the tubes with it fixtured to the firewall, but all the finishing welds are done with the mount free on the bench. If you weld too much in one spot it will badly warp without a fixture. By considering the duration, sequence and angle of the beads, the welds can be done with almost no distortion.  Knowing just how much duration, which sequence and what angle comes from a few decades of mounts.

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Stolp Starlet Corvair Mount in progress.

Builders,

Below is a look at making a one of a kind Corvair mount.

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The elevation of the engine in the airframe is set by several factors like specified thrust line. On some designs you can alter this with caution, ie, my Pietenpol mount as 3.5″ higher than BHP’s because I deleted the cooling fan. But I wouldn’t try that trick on a tandem wing plane like a Dragonfly, because it has no elevator to counter act the potential pitch change.

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A very important cosmetic issue: The cowl must slope down from the base of the windscreen to the spinner. May sound dumb, but Dan Weseman and I have discussed countless times that an upslope there is a mortal design sin. Along with this, the tops of the main gear tires must point outboard slightly, otherwise the plane looks stupidly heavy. (there are also important dynamic reasons for this) Dan always adds that all fixed gear planes must also have wheel pants, but I don’t agree, but he is too big to argue with.

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Above, down slope to the spinner being assured. This give about a plans height thrust line anyway. The distance from the firewall to the motor is set by CG calculation. This plane had previously been finished and briefly flown on a C-90-12 by a meticulous builder……who made a colossally stupid error on his CG, weighing the plane in a 3 point attitude... it took me 5 minutes looking at his numbers to spot this, his main gear moments were in the wrong place by 1.5″,  but his DAR never saw this. Lesson: Trust your own training, don’t assume another homebuilder got anything right. 

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If you compare this picture with the previous one, we spent 3 hours yesterday correcting the sag in the main gear which gave the wrong camber to the wheels. The rubber bushings in the Starlet’s suspension design were motor mounts from a popular 1960s car……..The Chevy Corvair.

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Justin Peters: 855 miles to a custom mount and a 3.0L test run.

Builders:

Last night at midnight I waited outside our airpark entrance for a truck trailer, plane and a builder at the end of a full day drive. Out of the dark, it was Justin Peters, he just logged 855 miles driving down from Ohio. He come on a mission of productivity, as he intends to fly a very special bird on Corvair power this season.

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Above, A very tired Justin pulls in at midnight. It was 55 degrees warmer here than Ohio. His plane came down for a custom one of a kind mount in a 8X16 enclosed trailer.

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Above, Justin came very close to finishing his 3.0L Corvair at the last Barnwell College. I liked his attitude and suggested a combo visit where we could knock out his mount and test run his engine. This weekend is that plan coming together.  Justin’s engine is a 3,000cc Corvair with all the catalog parts that SPA and myself offer. In the above photo, Justin, Vern and Kitty work on setting the motor up for a run later today.

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Above, the bird: This is a Stolp Starlet, a very rare traditional homebuilt. It is a very stylish parasol with a tapered and swept elliptical wing. It was designed by Lou Stolp in the early 1970s. He is the same person who designed the Starduster series of biplanes. Any ‘normal’ businessman would not assist in such a project, it doesn’t make sense. But I’m not a businessman, I’m a homebuilder who has a business for homebuilders. I understand why a 37 year old guy from Ohio might choose such a plane to express his ideas in flying. Supporting such builders has always been, and will remain, a pillar of my work.

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Justin will take this plane to the flight line this season for one reason: He has a plan, and he has put it in gear. If you have dreams of progress, they become reality only through a plan. If you need assistance, parts, support, encouragement and expertise, Call SPA at 904-626-7777 or myself at 904-806-8143. You can put it off if you like, but remember, time waits for no one.

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Wewjr.

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Kitty’s Back!

Builders,

Kitty, the junior welder in the Vern-William-Kitty trio, spent the day working with us  in my hangar. It has been a long time since she was a shop regular, almost a year since we have seen her. Kitty lives over on beachside, but is planning on working with us some this spring. A welcome boost in productivity and good company. We spent the day welding motor mounts and eating the wild hog ribs Vern BBQ’ed.

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Above, a chilly day outside my hangar.  Smiles reflect a good mood; a positive tone for a really good spring.  If you recognized the title of this story as a 1973 Bruce Springsteen song, you are either old or from New Jersey, or like me, both.

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Wewjr.

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Mark Borden takes the output record and sets down a wicked CMP.

Builders,

The last 48 hours were a blur of fun and productivity at my hangar, as Zenith 750 builder Mark Borden of MT, came to town, finished and ran his 3.3L engine in a box kit from SPA.  This morning it cranked for less than 2 seconds from dead cold to put down a very smooth break in run.

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Above, Mark’s  engine running. After a 30 minute run, I took the engine to full power for 10 seconds to check its output. It turned my test prop 3,440 rpm, a record, even factoring in the 45F OAT.  The 3.3 is one serious power producer. All 3.3L engines are based on the SPA Billet stroker, Made in the USA crankshaft. It’s 10% edge in displacement isn’t the whole story as 2016 professional computer dyno tests showed it actually has a slight volumetric efficiency edge and the output is 12% higher than a 3.0L Corvair. For Comparison my personal 3.0L Corvair turned the same test prop 3,340 rom just before Mark’s engine. 100 static RPM doesn’t sound like much if you are not familiar with tests, but it is a seat of your pants flying difference you can feel in your plane.

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Above, a quick look at a future story: It is 45F in the photo, the engine is at 1,500 rpm and the humidity is near 70%. This is prime icing conditions, yet there is no frost on the manifold nor carb; This is simple, I have the test stand’s rudimentary carb heat on, and it is not an issue at all. Carb heat works best if you actually use it. It is like giving to charities, seriously thinking of doing it counts exactly the same as not doing it at all. Carb heat is always to be used as anti-ice, not de-ice.

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All visitors at my place are welcome to use my range. Serious fans of shooting bring their own tools. In between build sessions Mark and I tried his Ruger New Frontier in .45LC. It was great. I used it to deal with an insolent, cheap multi meter which would not read ohms. The remains of the meter are red and hanging from the backstop.

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Mark was here for two days and blended right in to our community, meeting neighbors and sampling cultural highlights like ‘Ronnies’ the local bar and grill.  Mark is a really good guy, an airline pilot with a lot of interesting experiences like entering Cold War Albania just for a bit of adventure. He is a family man who chooses to live both physically and mentally far from the consumer world. Building his own engine fits with this.

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Above, a fun picture: Mark sets his “Captain Morgan Pose” with his running engine. complete with torque wrench sword and actual product (which neither he nor I drink) but it was all part of a very good time. Captain Morgan probably would find the ‘product placement’ humorous, but I’m guessing that Flight Safety would rather not have their jacket in there. Too bad for them, we were having a day Pappy Boyington would have found fun.

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Read this related story about meeting Mark 18 years ago: 2018 Zenith Open House -The long run.

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2019 is already 1/12th gone. What are you going to accomplish this flying season? It’s all up to you, man a plan today, don’t let this year escape. For more info on the ‘engine in a box’ program call SPA at 904-626-7777 and ask for Rachel, for more information about scheduling a build or run session at my hangar call my cell 904-806-8143.

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Read :“Captain Morgan” Contest at #39

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Wewjr.

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