Ch 23 Engine and Cowling
Engine Selection:
I've finally made my engine purchase but not received it yet. (March 2018) There's much debate in the Cozy community on the "best" solution for the power plant and there are successful builder/flyers with alternatives to the plans prescribed and most common Lycoming O-360. I've considered Subaru and UL Power options based on what others have done, and for a long time, kept my options open. However, when I entered the finishing stage with the turtleback, I began to take steps to incorporate downdraft cylinder cooling, which is particularly suited to the UL 520is engine. My thinking was that If I didn't go UL, I'll either use these scoops for something else, or re-finish the top of the TB without them later. WELL IT's LATER (Dec 2017) and I've reached pricing agreement with UL for the 520is. I'm quite excited to have taken this leap, knowing I'm going to have a fantastic engine. I know I'll have some adaptation hurtles but feel that as the 3rd Cozy and 4th canard owner (that I know of) to take this leap, we'll collectively make it work well. The biggest long term concern I have is fuel, as I'd like to run MOGAS with it, based on the much more positive experience Nate Mullins (Long EZ with UL 390is) has had with MOGAS over 100LL. We'll see. I'm glad I had built my strakes completely from EZPoxy with slow hardener. MOGAS can be harder to resist with the epoxies and this one has a good track record IF it's post cured.
I've finally made my engine purchase but not received it yet. (March 2018) There's much debate in the Cozy community on the "best" solution for the power plant and there are successful builder/flyers with alternatives to the plans prescribed and most common Lycoming O-360. I've considered Subaru and UL Power options based on what others have done, and for a long time, kept my options open. However, when I entered the finishing stage with the turtleback, I began to take steps to incorporate downdraft cylinder cooling, which is particularly suited to the UL 520is engine. My thinking was that If I didn't go UL, I'll either use these scoops for something else, or re-finish the top of the TB without them later. WELL IT's LATER (Dec 2017) and I've reached pricing agreement with UL for the 520is. I'm quite excited to have taken this leap, knowing I'm going to have a fantastic engine. I know I'll have some adaptation hurtles but feel that as the 3rd Cozy and 4th canard owner (that I know of) to take this leap, we'll collectively make it work well. The biggest long term concern I have is fuel, as I'd like to run MOGAS with it, based on the much more positive experience Nate Mullins (Long EZ with UL 390is) has had with MOGAS over 100LL. We'll see. I'm glad I had built my strakes completely from EZPoxy with slow hardener. MOGAS can be harder to resist with the epoxies and this one has a good track record IF it's post cured.
Fuel Supply from Sump through Firewall:
This subsection covers installation work for the fuel system components between the center sump and the firewall. When I changed plans from using the Lycoming to using the UL engine, I no longer need the airflow performance pump and sold it to Andrew Anunson who's already fitting out his Lycoming but had not yet purchased the fuel pump. I kept my airflow performance serviceable fuel filter (40 micro) as I'll use it with the dual UL electrical pumps that come with the engine. I arranged with UL to have some of these auxiliaries shipped to me early so I could work on positioning them on the firewall before the actual engine arrived. Ray Lawrence of UL was super helpful and sent the fuel pump bracket and pumps, pre-filters, the post pump fuel filter, the alternator power electronics module that mounts on firewall, a mockup of the ECU, and misc other things. What I don't need, or gets duplicated in the engine shipment, I'll return to Ray. I've mounted the firewall studs (Rotaloc brand ordered from McMasterCarr) but just haven't gotten back to actually getting everything mounted. I'm trying to figure out how much stuff I want to get mounted on the firewall, just to remove it all when I have to get the fiberfrax and SS sheet fitted. See below on Fiberfrax/SS fire shield section where I talk about my approach to minimizing engine mount/dismount/mount.
This subsection covers installation work for the fuel system components between the center sump and the firewall. When I changed plans from using the Lycoming to using the UL engine, I no longer need the airflow performance pump and sold it to Andrew Anunson who's already fitting out his Lycoming but had not yet purchased the fuel pump. I kept my airflow performance serviceable fuel filter (40 micro) as I'll use it with the dual UL electrical pumps that come with the engine. I arranged with UL to have some of these auxiliaries shipped to me early so I could work on positioning them on the firewall before the actual engine arrived. Ray Lawrence of UL was super helpful and sent the fuel pump bracket and pumps, pre-filters, the post pump fuel filter, the alternator power electronics module that mounts on firewall, a mockup of the ECU, and misc other things. What I don't need, or gets duplicated in the engine shipment, I'll return to Ray. I've mounted the firewall studs (Rotaloc brand ordered from McMasterCarr) but just haven't gotten back to actually getting everything mounted. I'm trying to figure out how much stuff I want to get mounted on the firewall, just to remove it all when I have to get the fiberfrax and SS sheet fitted. See below on Fiberfrax/SS fire shield section where I talk about my approach to minimizing engine mount/dismount/mount.
Things to Consider if Buying a UL Engine:
So here I want to get some upfront information for new canard buyers (particularly in the US) for minimizing the effort of getting this engine integrated and flying. I'm building this list before I'm flying, so I expect it to grow, and will note when I'm flying.
Prop Flange Type:
One thing I didn't do well was know what my prop hole pattern was, and expected that UL reps would help me pick the right flange for this. That's too much to ask. Talk to your expected propeller manufacturer and make sure you know what the bolt pattern is and specify that to UL when you buy. For me it was not the standard UL 520is flange, but the SAE V-C flange. Removing the prop flange is not easy as it's tightened to apparently 300 ftlbs. I have to make a counter torque bar that will bolt to the flange, in addition to borrowing a really big torque wrench to get the bolt off. Nate had similar experience. Oh, and you need a 40mm socket (not very common, but but I got one through Home Depot so I didn't have to pay shipping.
Have a plan for air handling and the cooling: (I did and so far am happy with what I'm doing in this area)
- I followed Ryley Karl's approach of using NACA's in the top/back of the TB to feed the cylinder cooling
- I modified Nate Mullins approach by using a portion (don't think I need all) of the belly NACA in the Cozy to feed the oil cooler
- I used a portion of the air from the TB NACA's to blow across the rectifier cooling fins
- I also used a portion of the air from the TB NACA's to feed the airbox with the engine air filter.
All of the above ductwork was custom, and I spent a lot of time working on the design and prototyping of it. You will find more on this on the engine integration page. If you don't like custom work like this, talk to one or more of us specifically and see how much of our designs you might be able to use. If that's not enough, consider using a Lycoming and more closely following the plans.
So here I want to get some upfront information for new canard buyers (particularly in the US) for minimizing the effort of getting this engine integrated and flying. I'm building this list before I'm flying, so I expect it to grow, and will note when I'm flying.
Prop Flange Type:
One thing I didn't do well was know what my prop hole pattern was, and expected that UL reps would help me pick the right flange for this. That's too much to ask. Talk to your expected propeller manufacturer and make sure you know what the bolt pattern is and specify that to UL when you buy. For me it was not the standard UL 520is flange, but the SAE V-C flange. Removing the prop flange is not easy as it's tightened to apparently 300 ftlbs. I have to make a counter torque bar that will bolt to the flange, in addition to borrowing a really big torque wrench to get the bolt off. Nate had similar experience. Oh, and you need a 40mm socket (not very common, but but I got one through Home Depot so I didn't have to pay shipping.
Have a plan for air handling and the cooling: (I did and so far am happy with what I'm doing in this area)
- I followed Ryley Karl's approach of using NACA's in the top/back of the TB to feed the cylinder cooling
- I modified Nate Mullins approach by using a portion (don't think I need all) of the belly NACA in the Cozy to feed the oil cooler
- I used a portion of the air from the TB NACA's to blow across the rectifier cooling fins
- I also used a portion of the air from the TB NACA's to feed the airbox with the engine air filter.
All of the above ductwork was custom, and I spent a lot of time working on the design and prototyping of it. You will find more on this on the engine integration page. If you don't like custom work like this, talk to one or more of us specifically and see how much of our designs you might be able to use. If that's not enough, consider using a Lycoming and more closely following the plans.
More on the Engine and Cowlings can be found in the following pages:
Firewall and Mount
UL520is Installation
Cowling
Firewall and Mount
UL520is Installation
Cowling