Engine Swap Time

Exploring the many different options.


The one thing that is usually on every aircraft owner’s mind is the health of the engine. It is usually the single biggest expense the owner will have, although the price of some new glass panels are easily double the cost of an engine. Many judicious owners and clubs will put away an hourly amount of cash in reserve for the engine so that it doesn’t sting quite so badly when the time is due. For those who haven’t, the aircraft classifieds are rife with aircraft that have run-out engines, some of which are really good deals.

For me, it is a matter of reliability. I’ve always prided myself with 100% dispatch in all of the airplanes I have built over the last 35 years. Reliability is even more important to me now that I am using the RV-10 primarily for DAR and prebuys. In fact, the personal flying for fun last year was almost nil. I do fly at night, on instruments, and we’ve gone to Alaska three times and hope to go at least a couple of more times.

Here are the parts being staged. I think Jeff Schans mentioned that he overheard the cylinders saying, “We’re going to be flying on an RV-10!”

Since my Mattituck engine was a little over mid-time with 1200 hours, I decided it was time to start thinking about my own engine replacement so that I could get it done at a time of my choosing, rather than having to rush into something or have an adverse impact upon the business. A mid-time engine is certainly worth a lot more than one that is run out, so I figured that would help with the expense—especially since this one had new Superior Millennium cylinders installed 300 hours ago. I also mentioned that at my age, I might only have time for one more new engine. At least that was the sales pitch to Carol and she bought it!

Of course, another option is to overhaul rather than replace, but I really couldn’t afford the downtime associated with an overhaul. Most of the shops were quoting four to six weeks, and one shop quoted me five weeks if I left the airplane with them so they could remove and replace. However, it just didn’t seem right to me to have someone else remove and replace my engine on the RV-10. I knew if I did it, I would also take the time to inspect all of the other components while it was off.

I’ve had a number of different engines in my airplanes throughout the years, with good experiences on all of them. That included everything from finding a “new” O-320-E2G in someone’s basement for $3000 in 1981 when I was building my RV-4. I certainly didn’t know anything about engines at that time, but when I asked Van if it was a good choice for the RV-4, and he replied by asking if there were any others, I knew I had a good deal. Of course, trying to explain to the Hewlett-Packard Credit Union why I needed a loan on an engine for an aircraft I was building was an interesting conversation. Building your own aircraft was not exactly mainstream then!

Vic Syracuse (center) sees his new engine for the first time in person. Bob Dukeman, supervisor of test cell operations, is on the left, and Jeff Schans is on the right.

Many years later when I built the RV-6, I took advantage of the new engine offering from Van’s, which also included LASAR ignition. That engine had still been going strong after 1600 hours until the current owner recently had a prop strike (great pilot with over 1000 hours in type—just shows what can happen at any time). For my first RV-10, I purchased an IO-540 from Performance Aircraft Engines in California, followed by my RV-7A with an engine from Barrett, then an engine from Mattituck for the current RV-10. All were great experiences, but all of the aftermarket shops have the same thing in common—the engines aren’t really new. I liked having the new engine from Van’s, but I really liked the performance enhancements that were done by the aftermarket shops, such as balancing all of the internal parts and flow matching the cylinders. They all seemed a little smoother than the factory-direct engine from Van’s.

I thoroughly enjoyed the time I spent with Mike Kraft (left), the GM of Lycoming at Williamsport. Notice the Thunderbolt logo in the background; Mike is a very sharp guy and very enthused about Amateur-Built aviation.

The Best of Both Worlds

This time I decided I wanted a new engine again, but I also wanted some of the tricks. A few years ago, Lycoming announced the Thunderbolt Division for custom-built engines, so I decided to take a chance and give them a call. I filled out the online form and left a voicemail for Thunderbolt Sales Manager Jeff Schans. What a surprise it was when I received a phone call back within a couple of hours. Over the course of the phone conversation, I picked up on the enthusiasm in Jeff’s voice. He really liked what he was doing. Over the next few days we agreed on an engine configuration and a delivery date, and I decided I wanted to meet Jeff as much as I wanted to get my engine. Jeff gave me a delivery date of six weeks, which was the same as one from Van’s, but this one would be handmade by a couple of guys in a really nice shop off to the side of the production line. As it turns out, the two guys are actually brothers! As we talked further and Jeff explained the build process, along with the test cell run, I asked if I could come up and see it run in the test cell. For me, to see my engine run in the test cell at Lycoming would be a real hoot. I was really going to get to go to the proverbial mountain and see how it all was done!

Bob Dukeman (left) explains the final preservation process to me after the engines come out of the test cell. Basically the engine oil and fuel systems are completely pressurized with oil to prevent any corrosion.

With the prior engines that I had built by the aftermarket shops, we had always increased the compression to between 9:1 and 9.5:1. For this one, I wanted longevity more than anything else, so I decided to go with stock compression.

Jeff kept me updated weekly as to the progress, including pictures, and when they got within two weeks of completion, he let me know the scheduled test cell date, and I bought my airline tickets. I really wanted to fly the RV-10 up, but I didn’t want to take a chance on missing it due to weather; it was still April, and I think that is considered winter in Williamsport, Pennsylvania. As it turned out, it was a great decision, as the day of the trip the winds were howling above 40 knots on the surface, with low ceilings and rain. It’s definitely better and less stressful to let the professionals with two guys up front and heavier equipment tackle this kind of weather.

Visiting the Lycoming Factory

I met Jeff bright and early on the day. While I had seen pictures of my engine, actually seeing it in person was truly impressive. It was a work of art, but I was really having a hard time keeping my eyes on the engine, as there was so much other stuff to see at the factory as well. Yes, it is a typical factory production line, albeit without the robotics that you see in the automobile industry today. These engines are still all put together by hand along an assembly line, and the people really seem to enjoy their particular function. More than one person stopped us as we walked by to explain what they were doing, and it was clear that each of them took pride in their work. I was surprised to see that even some components with high critical tolerances, such as the crankshaft journals, were polished and measured by hand. Clearly some real artisans at work! As a matter of fact, Jeff mentioned that Lycoming works tirelessly to make sure that its workforce is one of the most highly skilled in the business. Lycoming Engines has been a great corporate citizen to Williamsport over the years, which leads to loyal, long-term employees. Many of those I spoke with had over 40 years of employment.

Terry Schmelzle carefully flow matches each of the cylinders before they are installed on the engine.

I really wanted to take pictures; there are a lot of exciting things going on at Lycoming, but I was not allowed to even have my cell phone while inside the premises. Suffice it to say, it is a fascinating operation, very clean and very well organized. Mike Kraft, the general manager, even took about an hour of his valuable time to have a conversation with me. We talked about the exciting things going on in Experimental aviation, and I assure you that Mike and Jeff are extremely interested. They realize that the growth in general aviation is definitely being led by Amateur-Built aviation, and they want to be involved in helping it grow even more.

Now, back to my engine. As per our plans, we arrived at the test cell in time to see it being connected and instrumented for the first run. Yep, I was there when it first turned over, and it did start within 3-4 blades. What amazed me after that was how much harder it is run in the test cell than we run it on our airplanes. They immediately go to 1500 rpm for two minutes! And I am always so careful to not go above 1200 rpm when I start it on the airplane. What also was impressive was to see the engine run flat out at 2700 rpm for a full 15 minutes. I have never run an engine that hard. Yes, I know others do, such as racers and aerobatic performers, but they usually are right over a runway. It’s when I am in the clouds or flying at night that I’m telling myself that I hope I’ve been good to the engine so it will be good to me. Mike Kraft reminded me that when Lycoming certifies an engine, they test it not just to the 150-hour mandatory minimum. Instead they run a 400-hour pressure cooker test defined by AC 33.19-1, most of which is conducted at red line conditions on everything. Wow! Not that I am going to change the way I treat my Lycoming engines, as they have always been good and reliable for me, but it sure put some more confidence in my mind.

I thoroughly enjoyed the time and experience at Lycoming, and couldn’t wait to receive my engine and get it installed. Lately, I have begun to understand the fable about the cobbler’s children, as I am finding it harder and harder to make time for my own airplanes due to business commitments. The engine wound up sitting in the corner of my hangar for about a month giving me the evil eye I’m sure.

Frank Follmer (left) and Doug Bubb making final hookups to the engine prior to the run in the test cell. The engines are somewhat manually controlled in the test cell, but connected to a computer that plots all values against programmed limits, indicating a pass or fail for each required test. It was impressive to see, but in reality I wanted to give them one of our EFIS engine monitoring systems.

Installing the New Engine

Finally, over a holiday weekend and into a couple of weekdays, I was able to make some time, and with about 50 hours of labor, I was able to get the engine swapped out. This is also where my decision to do it myself paid off. I took the time with a bright flashlight to thoroughly inspect everything on the firewall, and I did discover one of the heater bypass valves was cracked. I discovered that on Sunday night, and thought it was going to be a setback, as I was ready to reinstall the engine, but luckily Aircraft Spruce carried the part and Carol retrieved it early the next morning. No time was lost, and it was nice to the see that the manufacturer, Plane Innovations, had made improvements to the heater valves to prevent the cracking. I replaced both of them, as it is much easier with the engine off. I figured with 1200 hours on the EGT probes, it was probably a good time to replace them as well, so I did, along with the CHT probes. It was easier to get to them with the exhaust system off.

The leaking Lord mount I discovered on the lower left mount position. I decided to proactively replace all four.

One other discovery was that one of the LORD mounts was leaking. That was a real disappointment, as I had replaced them less than 500 hours ago when I had the engine off to repair a cracked nosegear weldment on the engine mount. These guys aren’t cheap, at $250 each! I did replace all four again, and I got the engine hung pretty quickly all by myself. Having done many engines by now, I find that using an engine hoist with adjustable straps allows you to adjust the angle of the engine into the mount very quickly, making the bolt insertion a lot easier. I also think the dynafocal IO-540s go on much easier than the dynafocal O-360s and O-320s.

As we all know, things come apart much faster than they go together, and it is certainly important to make sure that all fasteners are torqued properly and safety-wired where necessary. I make good use of Torque Seal here to verify the particular item has been properly secured. It makes visual inspections after the first and subsequent flights much easier. Another set of eyes is always welcome, and Carol did her usual visual inspection and found a fuel line that hadn’t been connected. I stated that obviously I hadn’t finished it because there wasn’t any Torque Seal on it! Truth be told, she was my hero. I would have found it when I turned the fuel pump on to flush the system, but then I would have had to clean up a mess. I think a bouquet of roses is in order here!

A fixed-pitch prop is used in the test cell, and Lycoming has the pitch setting pretty well figured out for each engine. I was jealous of their stand for mounting the prop, as I always do it by hand, suffering through the commensurate back pain that follows. This stand made it a piece of cake to pull the prop off the wall and roll it over to the engine to install it.

After ensuring everything else really was connected, I turned the engine over with the starter to clean all of the residual oil out of the cylinders and pre-oil the engine. I had completely cleaned out all oil line hoses and the cooler, and prefilled them, as well as turned the engine through by hand with the prop to verify no hydraulic locks. I was amazed at how much preservation oil was in the engine from Lycoming. It seemed like every plug and cover that I removed was followed by gushing oil! Now, with the spark plugs removed and the starter engaged, I had indicated oil pressure rather quickly. It was time to install the plugs and run it. The first engine start was rather anticlimactic, although Carol said it smoked a little at first from the exhaust. No surprise there, given all of the oil that was probably still covering the cylinder walls. I checked all systems as fast as I could (both ignitions, both alternators for proper operation, cycled prop, checked mixture control) and shut down before the CHTs hit 300 F.

I have discovered that by using three attach points to a Lycoming engine, along with an adjustable strap on the front side, I can adjust the angle of the engine very easily and hang it pretty quickly by myself.

Test Flights

So now it was time to put the cowling back on. I really wish someone could 3D print a clear cowling as that engine is just too beautiful to cover up! Later that same day, I made two totally uneventful flights on it, with the first flight lasting about 1.3 hours. The highest CHT on climb-out was around 430. I leveled off at 2500 feet, keeping the power above 75%, all the while running almost full rich. Within 30 minutes all temps were below 400, and by the time I pulled the power back to land, the highest temp was 388 and the lowest was 357. Since I had moved the weights from the previous propeller balance onto the new flywheel, it was really smooth, too!

Engine temps after 15 minutes on the first flight. I couldn’t be happier with them. The CHTs continued to decrease until I pulled the power back, and maintaining the oil temp above 180 F required blocking the cooler with the valve. That was with an OAT of 70.

So far, with about four hours on it, I am super pleased. Basically, the experience with Jeff Schans and the team at Lycoming was a real pleasure, and the engine has performed really well. I plan to keep this engine for a really long time. Since it is made from all new parts, I’m thinking I will have it rebuilt the next time rather than replacing it. I am also very anxious to increase my flying time in the RV-10 again, as once I made a deal for the Mattituck engine, I agreed to limit the flying. For someone who regularly flies 20-30 hours per month, flying only 10 hours in 2 months has been tough.

Back to having some more fun again!

I really like using the hold function of the Avidyne IFD 540 when doing engine testing, as it allows me to keep my head up for traffic, all the while monitoring the engine parameters and knowing exactly where I am in relation to the field in case of a needed turn-back. I set it up to stay away from neighborhoods so I can be a good neighbor, too.


Please enter your comment!
Please enter your name here

This site uses Akismet to reduce spam. Learn how your comment data is processed.