My name is Jurgen Roeland, I live in Belgium and I'm very proud to call myself an aircraft builder. Wish you a warm welcome to my builders blog.
Some people called me nuttzzz. Some people buy a porche when they get into the mid life crisis age. Other people take a second wife. Others get depressed. I decided to start building an airplane. A what ???? Yes, an airplane ! I skipped the phase of building the small plastic versions with glue and paint and went right into the real thing. My time is precious now so let's cut the obvious questions upfront. I heared them too many times already so here is the -mandatory FAQ reading- if you plan to visit my workshop. "You're building an airplane?" : Yes, I am. "A REAL airplane?" : Yes", "In your garage?" : Yes. " "One you can actually fly in?" : Yes! "You can do that?" : Yes!!!
If you look at history, it's been thousands of years that people have dreamed about flight and it's only in the last 100 years that we have now the opportunity to build our own airplanes and fly. The current project work is the results of years of deliberation, evaluation and planning. I took the advice of fellow builders very seriously and so should you. The type I have decided to build is the Van's aircraft, RV-7. I will motivate my choice in one of the subsections of this site. I hope you enjoy following my building adventures and that you will return frequently to check on the progress. The latest activity will always be posted on the main page.
For people that live nearby, feel free to come and have a look. Don't forget to bring a six-pack. The most frequently used lubricant in my workshop is called "Jupiler", bring some as I'm frequently running out of stock.
28/03/26- Measuring top plenum spacing with top cowling - 7h30
I made some markings on the passenger side of the top plenum to indicate where the cut off would probably be based on the position of the front diffuser. The overlap between diffuser and plenum roof has to be 1 inch.
The front and back marking on the side indicate this position. In the image on the right, I have drawn the rough line across the top.
Next I wanted to start more accurate measuring on the spacing between the top cowling and the plenum top. An easy way to do this is by using play doh plasticine (modelling clay). The general idea here is to make small pyramids of the plasticine in various locations on the plenum, install the cowling top on the airplane. This will push the clay down. It you carefully remove the cowl afterwards, you end up with thick pancakes which will reveal the actual height that was left between the plenum and the cowling.
We are looking for a distance which is at least 3/8" up to 1/2" inch preferably to accomodate for engine shake within the cowling. Especially during startup there may be quite a bit of movement.
I put the cones on and wanted to give it an initial fit.
After installing the top cowl, this is what it looked like inside.
and after removing them, I was left with this scene. Enlarging, the image below, you can already clearly see that the spacing on the left side (white) if higher than the spacing on the right side (orange). The plenum is attached with cleco clamps so I'll have to lower both sides with the the right side needing most decrease in height I am using a small aluminum block as a spacer between the front of the engine and the plenum. The sides are not trimmed yet at this point.
I'm using some blue tape to indicated the height of the pancakes after measuring them with a caliper.
Next iteration was already a bit better but not satisfactionary. What I want to indicate by this is that this is a repeating process and you'll take of the plenum and cowling multiple time before you get close to the final positioning.
While doing this I also had an eye out for the opening in the back for the oil cooler. I want to keep it as high as possible The hole in the rear side baffle is a good place to use cleco clamps to hold the plenum in place. The height of the rivet row of the reinforcement angle on the side may give you an initial indication of how low the plenum comes with a Sam James top cowl. The positive news is: my injector lines and sparkplug with ignition wire will be well within the height limit inside the plenum. This was a big issue with my other SJ plenum.
In the front, I was drawing small sharpie marks as I repositioned to keep track of the modifications.
Additional attempts with more cones.
The spacing start looking more decent. The dashed line on the front is the trim line to keep 0.75" lip from the plenum top.
The numbers are getting way closer to where they should be. Pilot side a little over 0.500". I will continue this next session until it's perfect.
13/03/26 - Cutting diffusers and trim baffles - 6h
Continued on the outer angles from last session. match drilled them to the side and bottom baffle. These will get #6 screws so a #30 hole for initial fitting is good for now. It will be updrilled later when the diffusers are in place.
Time to start some epoxy work. The diffuser air intakes are too long as they come out of the mould. On the underside, the flat area has to lay flat on the upper surface of the front baffle.
This is the first critical fitting point. I measured generously for an initial cut and will sand back after test fitting it a couple of time on the structure.
I also cut the sides perpendicular with the amount trimmed at the bottom. On the top, I left the overhang. It's not bothering anything and will see with the plenum top in place how this turns out. I then reinstalled the lower SJ cowling and verified roughly how much I would have to cut from the front of the diffusere so that it would fit behind the aluminum intake rings of the cowling.
I received some messages from Bill Lane saying that the distance to aim for between the front of the diffuser and the inlet ring is about 3 to 4 mm.
Here is what Bill said: "First set the rings like SJ instructions, then when you are installing the inlets allow the excess on the front to extend into the hole on the cowl. Once the inlets are happy with sides and all, then trim the front to allow 3-4 mm of clearance to the rings. No more is needed, they won't hit with the engine running."
So i went ahead and drew a line couple of mm behind the inlet ring so that I could position the diffuser on the front baffle with the ring in place. Alignment between those 2 is critical. Esthetically as well as functionally. I t took me a couple of iterations sanding back the front more and more. I used a narrow hand held belt sander to gradually sand back at equal distances.
I read somewhere about a cowl height measuring trick with paperclips. I tried this to see how it works and will use this in a couple of days when cutting back the baffle wall heights.
more cutting back. It worries me a bit that the front flat section becomes quite short. I hope I will still be able to put a hardware clamp on there.
Started the same work on the pilot side diffuser. The cylinder is more backwards there so the front tube is a lot longer to start with
This is how it looks like with the ring installed.Still too tight in the front for now but I prefer to have some leeway once everything is in place. All I want for now is to align horizontally on the front baffle surface and in line horizontally with the inlet ring so that I can drill those bottom holes in the diffuser.
I cut out the left and right side paper templates for the front baffle. They will need minor modifications to follow the contour of the superior engine.
Did some initial fitting with the roof on and marked some trim lines on the baffle side and rear line. This is all very temporary in order to be able to fit the top cowling on and do the real measuring using the paperclip method. I'm always afraid to cut too much so I'm very conservative. It takes a lot more time but also gives peace of mind.
Drilled the initial holes in the diffuser floor. Key here is to make sure the diffuser bottom surface is truly flat on the surface of the front baffle. I drilled a holes #4 and then put #4 screws and nuts on to pull it together before drilling the next hole. Finally this will get #6 screws so it also allows for some minor repositioning while updrilling.
Then I have put the top cowling on for a first time. To my surprise, the baffles are still way too high.
You can see here in the rear corner how close this baffle is to the curve in the top cowling. You need 3/8 to 1/2" ideally under the top cowling to avoid rubbing by engine movement (especially during startup).
You can also see in the image below that the baffle walls from the standard vans kit are too high for the Sam James cowling. Not a big deal to cut back the baffles walls, the only issue that will show up is that the rear baffle wall support bracket will have to be modified the this also will be way too high. I have seen that modification also in the Bill Lane install manual so I'm not too worried about that.
08-12/03/26 - Making brackets and angles for plenum - 15h
I bundled the work of the last couple of days in one article. When installing the Bill Lane Plenum, you are required to fabricate some additional custom made angles which do not exist in the standard Vans baffle kit. The primary purpose of these angles is to prevent that the lower front baffle would rotate forward due to vibration. Especially on the passenger side where the propellor governor oil line passes, this could have disastrous consequences. In my case I have no such line as I have a fixed pitch propellor but nevertheless, I'm going by the plans and be a good boy.
On the passenger side, you have to make a bracket like the one below. The manual states you can also try to make this out of one piece but having them constructed out of 2 pieces rivetted together makes the fitting and tight fit on the engine much easier. Yes it's a couple of grams more weight but that's for the weight fetishists. I made the two parts below out of 0.063" sheet, bend the angle and then started grinding away material on the 3M deburr wheel until I got to the desired shape. Getting the holes for the engine bolt and the upper rivet holes in the right location was a bit tricky.
Here is what it looks like when it's installed on the engine. The front baffle will rest on top of this. As you can clearly see, the bottom angle hooks onto the cylinder base, preventing the whole structure from tilting forward.
Then I rivetted both parts together with 2 AN426AD4 rivets
Reinstalled it in assembly with the front baffle.
The inner corner of the front baffle also has to be re-shaped quite a bit. The inward notch is the provision for the prop governor oil line. As said, I don't have that but I'm making it anyway in case someone ever wants to convert it to a constant speed prop.The 2 cleco's in the center right will be the positions where 2 AN525-8R screws attache the front baffle to the lower baffle. That's what the nutplates will be for.
On the pilot side , this is what the Vans Baffle standard kit looks like. A single bracket attaches to the engine case.
The Bill Lane plenum installation wants you to keep that bracket and fabricate an additional bracket underneath which will make use of the forward engine attach hole as well. Again to prevent rotation. The rough shape can be seen below.
The little step up will hold an extra aluminum angle that will support the small section of intake ramp that will remain underneath the front baffle.
Rivetted both together with 3 AN426AD4 rivets
Some rivetting on the front baffle after closer trimming of the front diffuser fitting line.
Another modification from the Vans Baffle kit. Vans has a small angle on the intersection of the lower front baffle and the side baffle to connect the corner. As the Bill Lane plenum has an epoxy diffuser in that location, you cannot use that angle. Instead, you fabricate a larger angler that will sit on the outside of the corner. I roughly cut the angle in the image below and placed it next to the small angle from Vans for comparison.
13/08/25 - Test hanging catto prop first time - 1h
A big day again in my project. Nothing substantially done but I have hung the propellor on the engine prop hub for the first time. I kind of wanted an idea how everything would fit together and what is delivered by Catto with the propellor, spinner and saber extention.
I have a 4 inch Saber extention, spool type. This is required for the Sam James cowling installation. It took a couple of tries to find the way to do this but it's pretty self explanatory once you understand things. The spinner is predrilled and cut and the holes in the spinner plate are also made with nutplates installed. This makes it pretty simple.
Short bolts hang the spool to the prop hub behind the starter flywheel. You bolt these in in a star pattern. I am just doing this temporarily so there is no torqueing involved yet. This will come of a zillion of times. The long bolts holding the propellor and everything forward of the spool extentions are very long. The threads also extend quite far through the extension. This is probably for having enough space if an additional weight plate has to be added up front.
Here is a view with the prop bolted on. This is pretty damned cool seeing this a first time.
Milestone day ! This is one of those days that you know mark the timeline of building your airplane. The moment you hang the engine in the engine mount. After many days of thinking about missing any things on the firewall, I came to the conclusion that this is the right moment to hang the engine and move on to the firewall forward work. There are some more things I need to do on the firewall, but it's not possible to be sure about the exact location to drill large holes in the firewall until I can actually evaluate the position with the engine in place. i'm thinking of the mixture and throttle cable and alternate air cable. Other than those, I'm pretty sure everything on the firewall is in place.
The same thinking goes for the rear of the engine case. Make sure the 45° restrictor fitting for the oil pressure is mounted in the engine case prior to hanging the engine. It's almost impossible to install this once the engine is on the engine mount. Mine was already installed by PMM during engine assembly. While you are at it, also install the other oil cooler fittings in the engine case (in and out). These can also be done later but it's easier now.
First step was to remove the safety straps that held the engine to the wood pallet that was used for transport. I want to keep track of how this was done as this engine is a brand new engine that has not yet been on the test bench. When all is ready, I will need to unhook the engine and bring it to PMM Wingservice to have it running on the test bench for a first time. This has the disadvantage of extra work on removing the engine and all connections again and having to do it again after it has been run. On the other hand, the major advantage is that I do not have to worry about corrosion and idle time of the engine as it has not yet been running. The cylinders are as if they would be in a stock location on a bench waiting for an engine. There has been no movement of the cylinder heads on the cylinder walls and everything has an oil film on it as delivered from Superior Air Parts. Whether building takes me another 3 years or just 1, it won't matter. I'm gladly willing to take that extra work knowing there is no pressure.
The engine was protected well on the front and rear crankcase and supported in the front under the front with some wood block supports. I'll have to keep all this in stock so that I can re use it in the same way when I bring the engine back to PMM.
Using the engine hoist, we pulled it up, removed the pallet and moved it over to the front of the airplane. Alain helped me on this task to keep the engine in position. It's best having some extra hands around when you do this as the engine is heavy and the bolts are not always willing to go in as easy as you think it would.
The last part of the moving is the most critical as you don't want your magneto's or fuel pump to bump into the engine mount. Having one person moving and another one guiding the engine is no luxury.
Also notice I leveled the airplane in flight mode. This is much easier to position the engine than if it would be sitting on all tyres which would require you to position the engine at an angle. This leveled way makes it much easier.
I found some documentation online from someone who did this before and described the process. I studied this carefully and upfront, had a close look at the barry mounts and dyna bolt set. You can read it following this link https://www.myrv14.com/buildlog/20150917/Engine_Hanging.pdf. Vans Aircraft also has some drawings available which are not part of the standard plan set that you receive with the kit.
Study the plans carefully, the barry mounts have to be positioned so that the engine rests on the compression side in the bottom and the compression side in the back on the top mounts. The compression barry mounts are the ones that have a step in the rubber. The non compression ones don't have the ribble on it and look like plain rubber. If I remember well, the non compression ones also are a little larger. Also take care that the washers are in the correct locations. The barry mounts come with one big washer in the box. It's good to assemble the order of all this before starting to move the engine and have thing prepared well. I colored the position of the large washer red in the picture above.
There are 2 lengths in the dyna bolt kit. 2 x AN7-43A and 2 x AN7-44A. The longer ones go on the bottom side, the shorter ones go on the top. The difference is not much more than the length of one of the washers.
Start with the 2 top bolts. The first one is very easy... tighten the bolt but don't torque it yet, you'll probably have to loosen them again working on the bottom bolts. You do need to tighten the first so that the barry mounts compress allowing the other hole to come in line with the engine case. Remember this is a dynafocal mount, the bolts point inwards. If the bolt is not tightened enough on one side, it's impossible to insert the second one. As you tighten the bolts, the barry mounts compress and also position themselves in the engine mount. That's important.
What I found very annoying is that you can't put a socket on the bolt head as the engine mount is in the way. I used an extension on the wrench but that didn't make it easier.
The engine sometimes needs a bit of persuasion to get it in position :) Although I don't think this did much. Found out later it's more important to tigthen the other side and use the engine hoist to lower or lift the engine a bit in order to get a bolt in.
The large washer goes between the compression mount and the crankcase as a spacer for the bottom mounts. On the top mounts, I have put that washer on the compression mounts under the bolt head as you can see in the image below. The image has both top bolts in place and tightened.
From there on, things went less smooth and it took about an hour or 2 before I got the last bolt in so I did not take any more pictures until it was done.
I'll try to describe the further process I took.
As both top bolts were tightened, I lifted the engine a bit using the engine hoist. This allowed me to slip the barry mounts between the case and the engine mount. Don't forget the large washer between the barry cookie and the engine case. Don't forget the compression side of the barry mounts is against the engine for the bottom mounts. Then I lowered the engine again and after some wiggling I was able to put the 3rd bolt in. I did have to loosen the top bolts a bit though.
The fourth bolt is the most difficult one. Looking with a mirror through the hole there was no way the bolt would go in. After a lot of moving up and down, I finally discovered my problem : the washer between the barry mount and the engine case was not aligned and the pressure on it is high enough that it makes it hard to move it. After lifting the engine a bit and tapping on it, I could get it more or less into place. A second trick I used was to take an old bolt which was smaller in size and grind down into a guide pin. Once I could slide that smaller bolt in, I was able to wiggle it around in order to get that washer and the engine hole into alignment. I put some grease on the final bolt shank and finally was able to put it in with only very light tapping of a rubber hammer.
I was feeling relieved as I bolted the final nut on that fourth bolt.
As final step, I torqued the bolts. These are AN7 which take 450 - 500 inch/lbs. I used the middle value of 480 inch/lbs. The engine will still need to come off as mentioned earlier but the position of the engine is very important when installing the cowling so I torqued it to the final value.
Took some pictures of the plane with the engine in place. This surely is a big milestone and is a "feel good" moment during the build.
Happy camper...
As I had some time left, I took out the fuel throttle body. This comes with a plastic spacer.
The orientation of the throttle body was a bit of a mystery at first but soon figured out what side was the throttle lever and which side the mixture. In the image below I installed it on the forward horizontal induction air intake at the cold sump of the engine. In the image below, the throttle lever is the gold colored arm.
Finally I covered the intake with some paper and masking tape in order not to get foreign objects entering the engine.
End of a productive day was off course celebrated with Alain with a good strong Belgian HQ beer.
Some advice on reading my log for fellow builders !
In some articles, I made corrections at later date on the original article to rectify my own stupidities or faults. Read through the entire article if you intend to use my findings/experiences on your own project !
At the Oshkosh airventure 2013, I took this cool shot with Richard VanGrunsven, founder and CEO of Van's aircraft. We had a short chat after he came out of a presentation where he attended putting the young eagles project in the spotlights.
Richard -usually known as "Dick" or "Van" was born in 1939 and became an American aircraft designer and kitplane manufacturer. These days his kits are so popular that the number of VanGrunsven-designed homebuilt aircraft produced each year in North America exceeds the combined production of all commercial general aviation companies.
Oshkosh is to you like Mekka is for a Muslim. If you haven't been there at least once in your life, you will NOT go to aviation heaven !
From Belgium, it's quite a trip but in the last five years of building, we managed to go twice to Oshkosh.
Nothing beats the experience of Oshkosh air venture in Oshkosh Wisconsin.
The first time we went, I visted sun'n fun in spring and decided to also visit Oshkosh. On sun'n fun there were rv's but the experimental parking there is kind of isolated and more difficult to make contact. So my idea before arriving in Oshkosh was, 'wel I hope there will be some RV's'.