By Vic Syracuse, EAA Lifetime 180848
This piece originally ran in Vic’s Checkpoints column in the January 2025 issue of EAA Sport Aviation magazine.
Over the years, I have written some product reviews in my columns, specifically regarding items I chose to install in my own aircraft. I don’t necessarily like to highlight a product for fear of missing someone else’s gadget, but I do get a lot of queries from builders looking for guidance or an opinion, as many of them are on their first kit aircraft.
The neat thing about the amateur-built aircraft industry is that there are so many cool add-ons to the kits from many suppliers. I would venture to say this is the reason for much of the success of some of the more popular kitbuilt aircraft. My wife, Carol, has learned that the price I show here for a kit is about one-third of the total finished cost. Some of the kits are an exception, such as the Hummingbird helicopter and a few others that I’m sure I will miss if I try to name more.
I will admit that I find it fun to walk through all the exhibits at EAA AirVenture Oshkosh looking at all the new add-on gadgets and finish items. As a designated airworthiness representative, I get to see many of them completely installed. I also might add that, for some of them, I feel a small tinge of jealousy. There seems to be so much progress on “new” things each year. The technological advances are giving us better products with more features and benefits. The glass panels installed in our amateur-built aircraft have amazing capabilities and add to the fun factor with all the audio and video input choices.
With many cockpits being all glass today, a solid electrical system with stout backup capability is important, especially for those who fly on instruments, at night, or out in the bush. At the same time, we must be careful to not build an overly complicated electrical system. My approach for many years and across multiple aircraft is to have one main battery with two sources of electrical energy, and one backup battery for the electronic flight instrument system. Changing the main battery every four years has also been a good practice.
The sources of electrical energy have been one main alternator and one backup alternator, and I have found the B&C brands to be the most reliable. They are both externally regulated by an adjustable regulator, which has allowed for optimum charging voltage adjustments across different styles of batteries. With more than 6,000 hours on this setup now, I have only ever had a failure of one voltage regulator. It just works. I am all about reliability.
Lately, I have seen a new style of backup generator on some of the aircraft I inspect. It is mounted on the same vacuum pump drive as the B&C standby alternator, yet it is about half the size and weight. I also discovered that it provides the same output as the model I had on my RV-10, which is about 30 amps.
In cruise flight, my RV-10 requires a steady 22 amps of electrical energy. This new generator piqued my interest, and recently I got a phone call from Bill Judge, EAA 601868, the founder of the company that produces it — Monkworkz. I was impressed with his engineering background and his whole approach to backup power. We agreed that I should try it on my RV-10. Bill has built an RV-8
Now, did I tell you that I am a little resistant to change? We were heading to Alaska in a couple of weeks, so I decided to play it safe and delayed the installation until our return. The package arrived before we left, and I was really impressed with the quality of the product. It basically fit in the palm of my hand and reminded me of the B&C SD-8 standby generator many of us installed so many years ago. The SD-8 was a permanent magnet type of generator, and so is the new Monkworkz. While the SD-8’s output is only about 8 amps at an engine rpm of more than 2,000, this new one can output 30 amps at the same rpm and also provides output at idle rpm. Isn’t technology wonderful?
The installation was straightforward but did require some modifications. The B&C standby alternator has a regulator that is behind the instrument panel and requires power to make it work. The Monkworkz generator requires no power but does require a switch that connects the new regulator circuit to ground. In my case, I just changed the wiring on the standby alternator switch, but the kit includes the necessary switch if needed. Also, the new regulator is mounted on the engine side of the firewall and has provisions for a cooling duct, which is mandatory and is provided in the kit. Both the generator and the regulator require ducting of cooling air to them.
There are three 10 AWG wires coming out of the generator that must be connected to the regulator, along with a couple of connectors that come prepopulated. Bill also gives you a configuration choice as to whether you want the generator to come on by itself after failure of the main alternator, or by switching it on yourself. I like to test the standby alternator/generator on at least every other flight for 20 minutes, so I used it in the standard configuration with the switch providing the activation.
I’m sure everyone who’s built an airplane or a glass panel can relate to the apprehension of throwing the switch for the first time and hoping there’s no smoke. In this case, it worked fine with the engine off. Activating it with the engine running lengthens that apprehension a little bit, as it takes about five seconds for it to come online after you switch it on, as it goes through some internal checks before it confirms all is okay. The B&C standby alternator is instantly activated when it is energized, so the delay takes some getting used to.
I have now put about 30 flight hours on the new setup, and I am happy. There is no whine in it at all, even at a load that exceeds 30 amps, and it holds steady at 14.3 volts or 14.6, depending upon whether it is used as a backup or primary generator. The whole setup certainly takes up a lot less room than the B&C did. One caveat is that the bell housing spins, so you want to be careful and make sure no wires, tubes, or hoses touch it. As I get more time on it, I will give an update.
Of course, I can’t leave without some comment on maintenance. This one has to do with TLC on our aircraft engines. Please don’t let them sit. They need to be flown weekly if possible. This past week, I performed a prebuy on an RV-10 that had an engine installed about five months after an IRAN (inspect and repair as necessary), and then had flown only six hours in the next six months after installation. During the hourlong demo flight with the seller and buyer, it burned a quart of oil.
My borescope inspection revealed some serious anomalies, with at least one cylinder showing severe and unexplained vertical scoring and substantial pooling of oil. There was pooling of oil in all remaining cylinders, and all lower spark plugs were dripping with oil when removed less than 12 hours after the flight. I downloaded the engine data. At least two of the cylinders had cylinder head temps more than 500 degrees on the previous flight. Unfortunately, something seems to be seriously wrong, and both the buyer and the seller were disappointed. Right now, it appears that at least two of the cylinders need to be removed, and potentially a complete engine teardown will be needed.
To say this put a damper on the fun factor is an understatement, but at least we caught it before the aircraft left for a new home halfway across the country. Now, go fly your airplane if you have one and keep the fun factor alive!
Vic Syracuse, EAA Lifetime 180848, is a commercial pilot, A&P/IA mechanic, designated airworthiness representative, and EAA flight advisor and technical counselor. He has built 11 aircraft and has logged more than 11,000 hours in 75 different types. Vic founded Base Leg Aviation, has authored books on maintenance and prebuy inspections, and posts videos weekly on his YouTube channel. He also volunteers as a Young Eagles pilot.