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!

Skye Racer History Part 2 - Current Modifications Recap

Current Modifications

I had been looking at dyno charts from automotive engines that were almost identical to mine and noticed that they were making about 25hp more than I was at 4000 rpms. The only difference I could find was better induction and exhaust systems.

I started exploring the idea by removing the existing intake “U” tube and made two short manifolds that connected to the heads. Using these manifolds, I ground tested various dual carb setups, the largest set being a pair of Mikuni 41mm slide carbs. While I was not seeing any improvements at static rpms, I was able to confirm that it would idle just fine.

A new tuned intake manifold and exhaust system was designed using formulas derived from documentation on the subject, but there was simply not enough space under the cowl for them. Tuning for 4000 rpms, the four tubes that would run to each intake port would have been 16.4" long tapering from 1.7" at the plenum to to 1.5" at the head.  The plenum chamber required a volume of 1450cc's.

Turbocharger

Still wanting to improve fuel distribution and increase power, I continued to ponder the dilemma. Shortly after, I was speaking with Joe Horvath from Revmaster Aviation about using dual Revflow carbs mounted to two short runners when the subject of turbochargers came up. Joe mentioned that he thought he still had most of the parts to put a complete system together. We discussed it for a while and I ended up purchasing a Rayjay turbo and various other parts, most of which would not fit under the cowl and were ultimately not used.

The turbo is a Rayjay "B" flow 300 series that was used on the 150hp turbo Corvair cars. Its the smallest of the 300 series and weights about 12 pounds. The 300 series uses a positive (carbon) seal assembly enabling it to be used in a "draw through"configuration with the carb mounted before the turbo allowing the use of a carb without modifications.

Exhaust

The exhaust was constructed from 1.625" mild steel and welded with gas. I attempted to incorporate a small flex coupler in each primary pipe. I was not able to get them to seal after welding using gas or wire feed. 

Flex coupling installation which was ultimately removed. 

The flex couplings were abandoned and thick silicone exhaust gaskets were used at an intermediate point in each primary to allow for some movement of the pipes. 

After welding and cleanup, the pipes were coated inside and out with a 2000f ceramic coating to reduce heat within the cowl and prolong their life. Not counting the weight of the turbo, the exhaust weighs 16 lbs. 

Exhaust componants after ceramic coating

Completed and installed exhaust system

Since the system is a draw through, a waste gate is not required as power is controlled by the carb's butterfly. I have purchased an external waste gate and may use it in the future, but for now I want to see if I can avoid adding the extra weight and complexity.

Carburetor 

Many hours were burned searching for a carb that met my goals. The Mikuni SBN was selected because of its tuneability, performance, size, lack of a float bowl, capability of in flight mixture control and price. Details can be found on another blog post here: http://schmleff.blogspot.com/2013/04/alternative-carbs-mikuni-sbn.html 

Mikuni SBN and custom bracket to allow the use of a standard throttle cable and TPS sensor

Fuel System

Since the carb requires about 4 psi of fuel pressure, a redundant pump system was incorporated using two Facet fuel pumps plumbed in parallel. More details found here: Fuel System

Electrical System

Since the aircraft now requires electrical power to fly, A dual battery system with the ability to isolate each was used. The aircraft did not have a charging system so a 35a alternator was installed, as well as a starter for convince. 

Electrical system schematic

Since both batteries can be online at the same time, the use of newer lithium battery technology was not used. The batteries are high current uninterruptible power supply batteries, weigh 4.5 pounds each and cost $27 each. The batteries come with spade terminals so copper posts were potted to the top of each battery.

Converted UPS batteries provide 240 CCA

Ignition System

I have been flying for years with a single mag. It failed once during my flight testing phase, at about 45hrs total time on the mag. After that, I took it apart and performed a "factory" overhaul on it. I have never been worried about it failing in flight. 

A programable secondary ignition was installed for a number of reasons. With the ability to run the engine above sea level pressure, the ignition timing advance needs to be reduced as boost levels rise to prevent detonation. Being fully programable, the ignition system also allows for greater efficiency at lower power settings. A few added benefits are redundancy, data logging, electronic waste gate control and various GPIO functions. 

I dug around and priced dozens of systems and settled on the CB Performance Magnaspark crank fired ignition kit. For $559, its not much more than a fixed ignition secondary and can do a whole lot more: http://www.cbperformance.com/ProductDetails.asp?ProductCode=2094 (for what its worth, don't tell them that its for an airplane ; )

The ignition system ties into many parts of the other systems

Magna Spark crank fired digital ignition

The 36-1 crank wheel that comes with the kit was not usable with an aircraft conversion and one that would sandwich between the prop flange and extension was designed and laser cut. 

Custom crank wheel 

When it came time to build a timing table for the system, I found little guidance as to what an aircraft ignition table look like. To get my head around what is happening in different phased of a typical flight, I built color coded (by phase of flight) spreadsheet and filled in the manifold pressure and RPM's I expected to see. 

Timing table exercise

Using the CAFE foundation's papers on ignition and many automotive air-cooled VW timing tables, I eventually settled on a conservative table using the latest advance of 30 degrees under full power. 

Initial timing table

The ignition logs various parameters for later analysis. It has been very useful in the testing process.

Log file from a high power test run

Turbo Scavenging Pump

After multiple test runs with various fixes, it became obvious that a gravity drain from the turbo was just not going to work. I already had a 4 gear dry sump oil pump but was not ready to invest the time to dry sump the entire oil system. What I did was convert the pump to use the larger set of gears to feed oil to the engine and the smaller set to pull oil from the turbo. This video gives an overview of the pump and covers what is required to convert the pump.

Engine Build

After the initial testing of the engine and systems were completed, the engine was torn down for inspection and modification. 

• Changed cylinder heads to Revmaster Aviation's 049 heads with hemispherical combustion chambers and evenly spaced dual spark plugs
• Changed the camshaft from an Engle-100 to an Engle TCS-10 turbo grind
• Installed Total Seal gapless rings
• Revised dipstick and tube to allow for better cooling baffle shape
• Removed unnecessary protrusions from the sides of the engine case to allow for better cooling baffle sealing
• Reduced the compression ratio to 7.5:1

Large valves and hemispherical combustion chambers are used in the Revmaster 049 heads

Induction System

This is one of the systems that I will likely redo in the future. Space and time were getting tight while I was trying to get the airplane ready for the 2013 Airventure Cup race. It is functional, but not as efficient as I would like. 

The induction system incorporating both filtered cool air and carb heat

Cowl Modifications

The cowl was revised and extended forward to reduce drag, allow space for the ignition's VR sensor's and to allow for better cooling baffle diffusers. These topics are covered in detail starting at this link (and newer posts): Cowl Mods

Using splines, sheetrock tape and lightweight filler to make a plug

Cooling System

As mentioned, the longer cowl provided more room for divergent ducts to feed the cooling baffles. More information about the baffles can be found here: Cooling Baffle Design and Construction

Preparing to make the left side cooling inlet flange

With no remaining space for a divergent duct for the oil cooler, the lower cowl was reshaped. More details can be found here (and in later posts): Lower Cowl Work

Glass over foam was used to make room for the oil cooler and ductwork

The oil cooler duct was built using a similar process. More information can be found here (and in newer posts): Oil Cooler Duct

Foam blocks being glued between the oil cooler and the inlet area

Completed oil cooler duct

The interface ring for the oil cooler duct was made out of solid aluminum using a drill press and various mill and wood router bits. For details click this link:Inlet Ring

Removable oil cooler inlet rings

Seat and Control System Redesign

With the sheer number of new modifications with a number of them having not been tried before (like the use of a Mikuni SBN on a 4-stroke airplane engine), I decided to make space to fit a helmet on while testing. Doing so required that the seat and control system be revised. More information about these modifications can be found here: Revised Control System

Old (top) and new control system functional drawings

Single piece pillow blocks getting a grease groove cut

Completed control system before installation

What's Left?

My goal was to have all of these modifications completed and test flown before the Mojave Fly-in, but I simply ran of out time. The right side cooling baffle and baffle seals and a few cleanup details remain. After the last few months of little sleep, its time for a break. Work should resume soon and it should be back in the air shortly!