Skye Racer Flies Again!

I have not been blogging for a while since my focus has been on getting it back in the air leaving little time for meaningful posts. After the Airventure Cup I will circle back and write up the completion process, but it did fly again this morning!

Last week, I took it out for a high speed taxi and a brief test hop down the runway. This test revealed that I needed to add heat protection to a few more areas of the cowl, mainly where I used vinyl ester resin. It does not hold up to heat like West Systems epoxy. Fortunately, there were only a few places I used it in the final cowl.

For the first test flight (since modifications), the weather was perfect. 56 degrees no wind and clear skies. I warmed it up until the oil temp came up over 100 degrees, took the runway, set the power to 31" and released the brakes. At that power setting, the rpms were still lower than they used to be at full power before the turbo but the timing is set very conservatively. Still, it accelerated well and climbed acceptably. The motor ran perfectly with the temps all in the green.

After completing a turn and gaining enough altitude to make it back to the runway in case of issues, I reduced the power to 27 inches climbing at about 500fpm. After reaching 1000' AGL I circled the airport at 24" to let the temps stabilize. Head temps were around 350 and the oil temp was 190.

I pushed the power back up to 27" and let it stabilize again. All temps stayed in the same range, but I could feel warmth on my arm that was pressed against the fabric on the left side. I took that as an omen that it was time to come down.

Ready for first test flight!

That "before test flight" scowl

Post flight "I did not die" smile ; )

For what its worth, the turbo is a draw through system which means that the carb is before the turbo. There is no wastegate. Power is managed with the throttle. I had been told that the power settings would be difficult to manage, but it was almost identical to managing a non boosted motor. No chasing the throttle, as rpm's come up, the manifold pressure comes up slightly.

Another thing of note is how quite it is. On the ground, its quieter than a muffled Rotax 912. In the air, its very quiet as well ; )

Post op inspection revealed that all of the bits and bobs were still where I put them.

But back to my warm arm... My concern was warranted. My exhaust stacks have always been flush with the cowl without issues in the past, but the heat was enough to bubble the paint on the cowl behind the exhaust this time. The heat I was feeling was the exhaust going past the fabric. Looks like I am going to have to extend the heat shielding further aft.

Next steps are to re torque the heads and case bolts and give it a thorough inspection, and of course extend the heat shielding behind the exhaust ; )

The End is in Sight!

Its been a while since I updated my progress, but progress is being made! After the trip to Mojave, I had lots of things to catch up on. I was very burned out on working on it and thought I had better take a break from it before I pushed it out on the ramp and set it on fire ; )

Work did not resume till mid June with the focus of getting it ready for the Airventure Cup race. Still, there was much to do. I had been flying the KR quite a bit and decided to race the KR instead and switched my efforts to getting it ready to race thinking that it would be a much easier project. That was not the case as I continually ran into issues with it and ultimately had to scratch when an oil change before the race revealed lots of shiny stuff floating around in the motor. Back to the Sonerai, the KR will have to wait until winter.

Seat Rework

The first thing that I needed to address was the seat. I was not able to get enough tension on the seat pan to keep it from hitting the torque tube beneath. I opted to use steel piano hinge to support it which worked out very nicely. It takes 30 seconds to get the seat out or in.

However, due to the close tolerance pillow blocks, the torque from the the rear attachment caused the rear pillow block to bind and I had to come up with a method of transferring the load elsewhere. I ended up making two adjustable pushrods and attached them to a ridged structure.

New Aux Fuel Tank

I was excited to run the AVC race, but to do so nonstop, I needed to get a little more fuel on board. I removed the 5 gallon tank from behind my head and was in search of a tank that would fit directly behind the seat. A 7 gallon spun aluminum tank would fit but I did not want to spend $185 for something that was going to be removed after the tip tanks were installed. I found a 7 gallon air tank aluminum air tank at Harbor Freight for $69 and began the process of mounting it.

Mixture Control System

The other project that would need completed was figuring out a way to adjust the mixture in flight. The Mikuni SBN has a thumb screw but I wanted to retain my regular mixture control. I ended up scrounging up some old lathe parts and built a rack and pinion system. The rotary motion from the setup connects to the carb via a modified speedometer cable.

Both of these projects are currently on hold since I don't need them to get the thing back in the air before the snow flys.

Prop Finishing and Balancing

The day before I left for Mojave, I tried to remove a messed up decal from the prop. I tried a bunch of different things to get it off. I tried to remove it with some acetone... 2 hours later, all of the paint was off of the prop and the damn decal was still firmly in place ; ) It got a quick coat of flat black paint and went back on for the event.

The prop was way out of balance and needed to be finished properly. for paint, I used automotive sand able primer as a base and Krylon flat black and wet sanded it with 1500 grit paper keeping an eye on the static balance between coats.

The Cloudcars props have a 1/4" pilot hole in the center so I bought a perfectly straight piece of 1/4" stainless steel tube and put it on my Du-bro model helicopter rotor balancer. It is incredibly accurate, costs $27 and is more than the high dollar aviation balancer I usually use. If you are interested, check it out here: http://www3.towerhobbies.com/cgi-bin/wti0001p?&I=LXD712

Final static balance check

A tiny piece of 200 grit sand paper is enough to drop the blade to the base!

The final finish is an enamel clear coat wet sanded to 2000 grit for finish smoothness and a very cool flat black look!

Valve Train Geometry

Since there were so many changes to the top end of the motor (new Revmaster heads, thinner base shims to drop the compression and new cam), I needed to reset the valve train geometry. The basic idea is that you want to have the valve at its half lift point when the adjuster screw is in line with the valve stem. This is done by shimming the rocker shafts and making pushrods of the proper length. There is a ton of info out there on the process so I will skip the details. 

A custom bracket and a dial indicator is used to find the valve's half lift point

Cutting the new pushrods to length on a lathe. If you have access to one, its the best tool for making the pushrods length identical

Of course, after the valve train was set up properly, the back side of the adjuster screws was hitting the low height valve cover I had to use on one side to clear the cowl. Lots of grinding and filing on both the adjuster screws and inside of the covers solved the issue. One change always seems to lead to many others...

Fuel System Revision

As posted in the past, the fuel system is fairly complicated. 3 tanks, redundant pumps, a fuel flow gauge and a carb with a return line make for quite a puzzle. I love the flow gauge and wanted to retain it so I had the carb's return line plumbed in after the transduce but before the pumps. While all of the ground tests were performed with the system, there are a number of problems with the design. The most serious issue was that there was no way for air or vapor to get out of the system. The carb would just pass it back to the pumps and the pumps to the carb in an endless loop. To address the issue, I was going to install a vent line just before the pumps. While the solution would work, I started to consider why the carb had a return line to begin with. The belly of a jet ski is a hot place and I assume that the return line allows the fuel to cycle back to the tank for cooling. Kind of sounds like the cowl of a turbocharged Sonerai... For now, the return line feeds back to the main tank and I will test the other idea in the spring. 

Spar Taper Pins and Fuel Tank Revisions

The only way to gain easy access to the fuel system is to have the wings off of it and the main tank removed. Both of those items were not easy. 

The tank removal issue was because of the difficulty of making hard line aluminum fuel lines in an area you can't get to or see. While the wings were already off, I decided to just bite the bullet and get it done. 

The Sonerai's wings are held on by 6 taper pins, 4 in the main spar and 2 in the rear. The problem was that there is an aux fuel tank in the way of the nuts for the front taper pins. It took Tim and I 4 hours to get the wings off of it before Mojave and would have taken as much to get them back on. Again I opted to take the hard route and come up with a way to make the task easier. 

Since I can't get the spar box out of the plane easily, I opted to JB weld a set of modified nuts and taper pin washers to the back of the spar. However, as I looked closer, I found that the guy that built the wings and spar box drilled the holes at an angle. Lots of options were explored and I eventually was able to glue the nuts in place using the taper pins as guides. 

The pins are now screwed in from the cockpit side using holes that are cross drilled into the pins and a punch. To keep them from backing out, the cross drilled holes are safety wired. It now takes about 10 minutes to get the wings on and off ; )

Taper pins awaiting safety wire

Controlling Heat

One of my primary concerns for the turbo project is all of the heat that its going to be dumped into a tightly fit cowl. As mentioned previously, the exhaust is ceramic coated inside and out and the hot side of the turbo has a blanket on it, but the starter, coil pack, mag and carb sits just above the exhaust collector. The first project was to make an enclosure for the coil pack. Its in the picture, but its hidden behind everything else back there. It's fed by 1/2" tube from the baffles. What is visible is the heat shield on the rear left cylinder's exhaust pipe. It runs within an inch of both the oil cooler and starter. the heat shield is a split tube over two small wraps of header wrap to prevent scuffing. The hose clamps keep everything in place. 

To deal with the heat from the collector, I built a box around it that has a sealed top and an open bottom. A 1" tube from the baffles feeds cool air into the narrower top section and exhausts it directly in front of the cooling exit. Its a simple shape, but making anything on this thing serviceable is a nightmare. Its basically a clamshell of aluminum and stainless held together by piano hinges.

Closeup of the collector baffle and a glimpse of the coil shroud

Timing Table Modifications

During recent test runs, the engine would not idle on the secondary ignition alone. I had the prop off of the airplane anyway so I verified that the digital ignition was firing when told to using a timing light. It checked out nicely but the problem was still there. I had the timing at idle set to 15 degrees BTDC. That may work well in a car that idles without any load, but this engine was not happy about it. With the engine running and the computer hooked up to the ignition, I increased the advance until it was happy. It needs at least 20 degrees of advance to idle smoothly. 

Dynamic Prop Balancing

The difference between a dynamically balanced prop and static only balanced one is usually dramatic. All of the roughly 2 dozen prop variations that have been on it were both statically and dynamically balanced before flight. Its a process that usually takes a few hours but its worth it. After its complete, there is virtually zero engine vibration decreeable by the pilot.

This time around, I installed the probes and did the first calibration run and it was at .06 IPS.  That is usually the kind of number you would hope to see after the balance job! That was easy...

The End is in Sight!

To date, it's been 26 months since its been apart. Its taken thousands of hours of research and work to get to this point, but the point of the project was to learn new things. I don't want to learn any more new things for a while ; )

The only thing standing between now and a test flight is the cooling baffles. The left side is 95% complete and the right side is at about 65%. Another side project that has to be completed before test flying is the completion of my helmet/mask conversion. Its a $50 ebay Chinese fighter helmet and a $19 military surplus mask. Neither comes with any electronics but you can still put together a good helmet and mask for under $200. For now, the mask is being fed by air outside of the prop arc just in case I end up with smoke in the cockpit. More on this in the future.

A full review and "how to" of the helmet and mask conversion will be posted in the future. 

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KR2S Landing With Full Flaps and Belly Board Deployed

Well, the Sonerai is not quite ready, so I have been working on getting the KR ready to race. Most KR's either have flaps or a belly board to aid in landing, but this one has both. Here is a quick video of what it looks like from the cockpit with both deployed at the same time.

Jeff and Tim's Mojave Adventure Part 1

The Mojave Fly-in is over and the plane is loaded and ready for the road. We are taking a day to get some rest before headed home. Here is a recap of the trip so far.

The Mojave Fly-in is focused on innovation. Its the kind of fly-in that even if I had not been nominated for an award, I would have made a commercial flight to be there anyway. Lots of very cool aircraft and people who are thinking outside of the box and developing new ideas.

I had originally planned on flying the Sonerai to the event, but as the event got closer, it was apparent that I was not going to be able to complete the work and flight test it in time. The amount of work to be completed was overwhelming and I did not want to cut corners just to make it to the fly-in. I did my best to get it ready for flight before I left. The week preceding the event I got a total of 17 hours of sleep and lots of help from a few friends, but there were just to many things to do.

The day before we were going to leave, we got 4" of snow, 16 degree temps and 30 mph winds.

The plan was to load the trailer up Monday night and leave early Tuesday morning. We did not end up loading the plane until Tuesday morning and left at 2pm.

Getting the cowl installed for the trip

Getting ready to load up

Loaded up and ready to rock!

We made it as far as Des Moines Iowa the first day. We were concerned that the truck's starter was going to completely give up, but it started the next morning so we headed out for Hammon Oklahoma with the plan to stop at Tim's friend Jeff's shop to change the starter.

Grabbing a nice dinner with Jeff and Tim

While Tim and Jeff worked on the truck, I finished up a few things on the plane. 

 We finally rolled into Mojave on Friday at about 3pm with lots of things to tidy up on the plane.

A quick picture stop as we arrived

We unloaded the plane and got to work tidying up a few details. It took until about 10:10am the next day to get everything put together and ready to taxi to the event. I had hoped to get some flight testing in once we got to Mojave, but I was unable to finish the right side cooling baffle in time. Soooo close, but no cigar. I decided to leave both baffles off of the engine for the event and temporarily tied up the wires.

Not much room remains!

Ready to taxi to the event

I had hoped to have more time to look at all of the other aircraft on the flight line, but I ended up spending most of the day talking to people about it.

Waiting for the judges to take a look

Ended up having to install the old wheel pants since the new Sam James pants required significant modifications to install

Lots of great company on the flight line!

 

 After the event, we tucked the airplane back into the hanger for the night.

The awards dinner that evening was fun as well. It was in a large hall with about half of it being used for tables and seating. The other half was filled with people flying electric model aircraft ; )

Record Attempts

Below are the results of the record attempts that took place during the preceding week:

The Awards

Four awards were up for grabs:

Best Design 2014:

This award is for the best technical mod of the year, corresponding to the technical (aerodynamic, mechanical, structural) nature of the mod.

Best Build 2014:

This award is for the best craftsmanship mod of the year, corresponding to the build quality (aesthetics, schedule, build difficulty) of the mod.

Best Test 2014:

This award is for the best test series related to a mod of the year, corresponding to the testing (documentation, scope, difficulty) done associated with a mod.

Experimenter of the year 2014:

This award is for the best overall mod of the year.  Best combination of design, build, and test.

Mojave Experimental Fly-in Awards, left to right, Kevin Eldredge Best Build, Zach Reeder, Scaled Composites Catbird Pilot won Best Test for his 5000 KM Speed Record, Mike Patey, won Experimenter of the Year for his Highly modified Lancair Legacy, Jeff Lange for his highly modified Sonerai I. In the Yellow Jacket is Tom Aberle, who got the award for Best Failed Record Attempt. (caption courtesy of Eric Whyte)

I was honored to have even been nominated for an award, but to win one was the icing on the cake. The modifications I had done stretched my knowledge and abilities well beyond where I was when I started them. Many of the parts were made two or three times before I was satisfied with the results. Once again this little airplane has taught me new skills that will surely come in handy when building my next project.

Without the help and sacrifice of a bunch of people I would have not even been able to get the plane far enough along to take it to Mojave.

In no particular order, I want to say thank you to everyone that helped with the plane!

Tim Kline, for helping me get the thing out there behind his truck and lots of hours helping me tie up details.

Scott Severson, for helping me get paint back on it (which was shot the day before we left).

Ed Fisher, for countless hours of advice.

Eric Whyte, for his "gophering" for supplies and making my ass happy (he helped make the seat pan and cushion).

Mark Hegy, for helping me get the new spinner cut and fit.

Mat Klatt, for helping me with lots of little details.

Michael Long, for helping with the seat cushion and other details.

Tracy Buttles, for helping me with the firewall forward fuel lines.

John Lange, for helping with various projects.

Joe Corragio, for being a great sounding board for ideas and many valuable suggestions.

Brian Long, for plasma cutting a number of parts for me and keeping me company late into the night.

Joe Horvath, for lots of advice and guidance, as well as sponsoring me with a set of Revmaster's awesome 049 cylinder heads.

Dick Keyt, for heling me sort out my oil cooler ducting design.

Jeffery Boal, for the use of his shop along the way.

Jeff Barnes, for helping offset the fuel costs for the trip.

Elliot Seguin, for putting on a great event and nominating me for an award.

Packing up and heading home

Before we took the plane apart, I asked Tim if he wanted to see if he fit into it. Wellllll, no ; )

Tim trying to squish himself in under the canopy ; )

We loaded the plane up on Sunday and took the rest of the day to relax at Tim's friend Art's house. 

Part 2 to follow with the rest of the trip home!