Raising the nose
I’ve never liked the low clearance between the prop and ground so while fitting the new engine I decided to fix this too. I just extended the down tube enough to raise the nose by about two inches.
I had to add a universal joint for the steering control since it was not possible to move the top of the steering shaft forward.
Instrument Upgrades
I started writing this post in 2021 and never got around to publishing it. Better late than never and I’ve even made a few improvements since then.
This all started when I tested the accuracy of the cylinder head temperature sensors. Apparently they read about 20-30F higher than reality explaining why I struggled so much with CHT on the Kawasaki. I’m sure the GRT EIS could have been calibrated or corrected to read correctly but that would not fix the most annoying fact that I cannot read the display if I am facing the sun! So I decided it was time to replace it.
Looking for options I decided to go with MGL Blaze series instruments for a few reasons. They are very bright, easy to see in the sun, affordable and full of features. When I discovered they also make an inexpensive RDAC that works with the Blaze series That sealed the deal. Not that I need the RDAC but I want to take advantage of it’s features for some other projects I also want to work on.
The RDAC provides a central location to connect sensors. It then transmits the collected data over a two wire CAN bus. This greatly simplifies wiring and will allow me to build a data recorder by collecting the data from the CAN bus.
I decided to get the MGL EMS-2 and put it in place of my altimeter. This will primarily display engine data replacing the GRT EIS. For airspeed and altimeter I got the MGL FLIGHT-3 that can display airspeed and altimeter along with fuel flow, fuel level, fuel endurance, fuel range, density altitude and more.
For the FLIGHT-3 to display fuel range it needs a serial GPS input so it knows the ground speed. Having already considered building a Stratux I thought this might be a perfect fit. The Stratux can provide ADS-B in, AHRS and GPS location on my tablet while also collecting data from the RDAC CAN bus and sending serial GPS data to the FLIGHT-3.
The main reason I had a small 7″ tablet is because a larger one blocked the GRT EIS so with the old EIS removed I can also fit a 10″ tablet!
After getting everything in place I now have a flight data recorder ‘black box’ along with ADS-B in, AHRS and much improved primary Instruments.
The only complaint so far is when ATC radar picks me up and my tablet alerts me to a ‘ghost’ aircraft on a collision course. This happens whenever a transponder aircraft is within 15nm and +-3500ft altitude of me and I am within range of a radar. The ghost will usually appear within +-100ft and within 2-3nm trailing me. The first couple times this happened I was quite concerned trying to avoid a mid-air collision from an aircraft that keeps following me and no matter where I look I see nothing. One time I was even flying in a circle like a dog chasing it’s own tail!
Had to do something about the giant hole where the GRT EIS was so I made a new dash panel. I moved the switches higher, lowered the choke and added a primer.
Engine Selected
My new Simonini Victor 1 Super engine has arrived just a couple weeks after ordering it! After looking over all the options the Simonini came out on top:
- Lightest option
- Most powerful at 54HP
- Water cooled
- Dual ignition
- Electric start
- No major modifications should be needed to install it
The dual Ducati ignition is a nice addition to have for some increased reliability. The wiring for that is already in place from when I had the Hirth F33 installed so hooking it up to the ignition switch will be easy. They even used high quality NGK racing wires and NGK BR9ES spark plugs.
The only things I don’t like about it is the fact it’s a single cylinder and a 2-cycle. That being said from all the information I could find it seems like when the carb is well tuned these do run pretty smooth which is the largest concern with a single cylinder.
The total installation, including the coolant should be about the same or less than the Kawasaki while making more horsepower. I’ll have improved climb rate and I also suspect less fuel consumption at cruise.
Water cooling is desirable to keep the engine at a steady temperature to avoid a cold seizure which seems to be the most common failure with 2-cycles on aircraft. For a radiator I decided to use the dual radiators from the Rotax 582. They are readily available and designed for this application. The fit is nearly perfect and fabricating mounting brackets should be rather simple. Routing the coolant lines will likely be the most difficult part of the installation. I expect they might be too much cooling, in the winter, but cable operated louvers are also available for these so that can be dealt with too. I’ll wait to install the louvers until I’m sure they are necessary.
The exhaust looks great too! It looks like I’ll be able to make the exhaust work without any major modifications but won’t know until I get the engine mounted.
The engine simply looks amazing, every feature and contour exists because it’s needed and seems well thought out. It might be argued that for an aircraft engine some features might be overbuilt and could be lightened. But at the same time such features are also good because the parts are much less likely to fail. The exhaust header is a great example of this with it’s beefy construction, integrated loops for the ball joint springs and threaded tap for the EGT sensor. While an EGT sensor was not provided a coolant temperature sensor was included.
As seen on the EGT sensor tap copper washers are used throughout the engine. The cylinder head nuts, coolant temperature sensor and fuel pump pulse line tap all have copper washers. When copper washers are properly annealed they will disform and take on the shape of the surfaces they are compressed against making a great seal. Copper also expands more then steel when heated which should help to improve the seal as the engine is heated.
After reading the manual even the belt tension adjustment procedure is impressive. Like most belt drives the prop pulley is mounted on an eccentric. To tension the belt you rotate the eccentric with a torque wrench and lock the eccentric in place when you reach 2.4kgm (about 17.5 ft lbs). No guesswork or measuring belt deflection needed, just a simple repeatable method.
Getting the engine and radiators mounted should not be too difficult but will require fabrication of numerous brackets and supports. My plan is to get the engine mounted, add supports for the exhaust and then the radiators. It will likely be a few weeks before the first start.
Kawasaki let me down again!
On the evening of July 14th 2022 I was having a great time flying around and had just turned to head back to the airport when I hear a loud bang and instantly lost engine power. The only bean field I could make put me in a crosswind but still a better choice than corn! Made a soft landing with about 150ft ground roll. The only damage was a bent 1/2″ diameter aluminum strut on the nose wheel.
The wife, kids, brother and father all helped take the wings off and get it back to the airport on a trailer. A couple days ago I removed the engine and started taking it apart to find the problem expecting to find some messed up pistons or something. Totally shocked to see the Crankshaft snapped!
I’m just one guy who, for whatever reason, has had bad luck with Kawasaki 440A engines. I think both failures I’ve had are outliers and uncommon. It’s been a great engine for many people but for me, I’m done with it. I’d like just a bit more power anyway to improve climb rate and had such bad luck with them its time to move onto something else.
So I’ve spent many hours looking to see what engine options exist. My wishlist is 50HP, EFI, 4-cycle, water-cooled and around 80lbs. Every engine in the list below has electric start and alternator.
| Engine | Cost | Weight | HP | Type | Cooling | Pros | Cons |
|---|---|---|---|---|---|---|---|
| Half VW | $6000 | 84-102lbs | 45 | Two cylinder, 4-cycle | Air | Reliable, easy to find parts, Dual Ignition | Requires small wood prop |
| AERO1000 High Output | $9000 | 81lbs | 39 | Single cylinder, 4-cycle | Water | EFI | More Frequent maintenance and parts replacement, difficult to fit in cowl. |
| Simonini Victor 1 Plus/Super | Guessing $6k-$6.5k | 71lbs | 48/54 | single cylinder, 2-cycle | Water | Dual Ignition, very light | Only one source of parts in USA, single cylinders typically vibrate more |
| Hummel V-Twin | $5200 | 83lbs | 35-40 | two cylinder, 4-cycle | Air | Cost | Unknown TBO, newer design |
| Hirth F-23 | $10-12k | 78lbs | 50 | Two cylinder, 2-cycle | Air | EFI available, very smooth running engine | Cost |
The half VW is heavy and the limited prop selection will make it hard to improve the climb rate.
The AERO1000 H.O. his everything on my wishlist except the power. But it is a very high revving engine requiring more maintenance. It’s also quite expensive and will require some modification to fit in an attractive cowl such as modifying the exhaust and using two smaller radiators.
The Simonini Victor 1 Super is attractive having the highest power output, least weight and is water cooled. But it’s a single cylinder and a 2-cycle. I’ve had a hard time finding videos/blog of others talking about it but I did find one builder who reported that it runs smoother than a Rotax 447 so that is encouraging!
The Hummel V-Twin looks great but is less power than I want. I think making a cowl for this or the Simonini would be equally challenging with the Simonini also requiring the radiator mounting. Deciding between those two boils down to more power or 4-cycle… Not sure what one is more important to me. If I found a v-twin that’s about 80lbs and 45HP I think I’d go for it.
The Hirth F-23 is a great engine, very smoothing running, reliable and lots of power. But it’s a 2-cycle and costly.
Right now I’m undecided but leaning towards the Simonini Victor 1 Super or the AERO 1000. If you have a suggestion please make a comment below.
Nose wheel steering failure
I’ve got about 150 hours on the airframe now and the left rudder pedal bracket that moves the nose wheel fractured. After taking a closer look it’s been cracked for while and finally failed.
The hole, where it cracked, was for the hinge pin. So I decided to shorten the hinge enough that this hole is no longer needed.
I modified both hinges but only replaced the cracket bracket at the moment. I need to order some material to replace the other one. Once it arrives I can fabricate it and install it with little issue.
New Project
I just started building a Fisher Dakota Hawk! It’s a two place side by side high wing. I’m planning to keep my MiniMax so will likely make a post here from time to time but mostly I will be making posts on the new blog for the Dakota Hawk.
Follow along with the Hawk build here: https://dakotatrihawk.wordpress.com
New Spinner
After changing the engine I need to fabricate a new fiberglass cowl. But before I can make a cowl I need to pick a spinner so I can match the cowl to it.
After much searching I decided to get the Wag-Aero Homebuilders Spinner. It is aluminum, about the size and shape I wanted but it does have a couple of issues. The first issue is that it’s made for a larger more standard sizes prop with a 3″ thick hub. My hub is only 2.25″ thick so I’ll need a spacer. The 2nd issue is that it has a 3 5/8″ center hole where my prop and drive is 1″ center.
I also need a spacer between the engine and propeller to make room for the spinner bulkhead flange. So I designed the two spacers in CAD. Each one has a small lip to accommodate the large center hole on the spinner bulkhead and 1″ centers to ensure alignment.
Once I had a design a CNC shop cut them out of delrin at a cost of about $80 each. Combining the cost of the spacers and the spinner maybe I should have just got a more expensive custom spinner…. The way I see it it, some day the spinner will get damaged and need replaced. I can call up Wag-Aero and get another one, and if they don’t make it anymore any number of other off the shelf spinners will work fine with my prop and spacers.
The spacers arrived coming in at a weight off 7oz and 7.25oz. the bulkhead fit well and the 1″ centers matched the prop hub too.
At the airport I removed the UltraProp and disassembled it. The first thing I need to do is drill holes in the rear bulkhead for the propeller blade bolts. To do this I put prop bolts through the rear spacer, then rear bulkhead, rear prop hub and finally the front spacer. With everything held in alignment I drilled the six 1/4″ holes in the rear bulkhead. Before disassembly I marked the orientation of all parts with a paint marker to ensure it can be reassembled exactly in the future.
Next the propeller was assembled along with the rear and front bulkheads. I cut a cardboard template for the prop cutouts that was close but not perfect. Using that template and a small cardboard tick stick I located the edge of the prop.
Using the template and tick stick I copied the shape of the prop onto a new template.
I enlarged the line by 1/8″ then cut out the new template and verified that it for well.
Next I printed a circle template on 11×17 paper with 120° marks and transferred the marks to the dome. Using the cut line on the template as the reference I transferred the cutout shape from the template to the dome.
I cut the bulk of the opening out using a nibbler tool. Then spent a few hours with files to open the holes up to the template lines. After I was satisfied with the openings I attached the prop to my old F33 redrive with the belt removed so I could verify that the dome is tracking on center using a sharpie held from the ceiling.
Next it was time to drill nine 3/32″ holes in the dome. After all the holes were drilled the spinner was placed into the rear bulkhead and the holes drilled into the bulkhead. I used clecos to hold the bulkhead and dome together to keep things aligned.
Next I removed one cleco at a time and enlarged the holes for a #8-32 screw. After enlarging the hole I installed a screw and attached it to a MS21047-L08K nut plate on the back side.
Once all the holes were enlarged I removed the dome and attached the nut plate to the rear bulkhead with the screws. Then used the nut plate as a guide to drill the 3/32″ holes for the rivets.
All the nut plates were then removed, holes deburred and the rivet holes dimpled. Then the nut plates were riveted using Cherry CCC-32 countersunk rivets
The last step was to make some pieces to fill in the gap under the propeller blade. I attached each of these to the rear bulkhead using three CCC-32 countersunk rivets. I also attached a small piece of aluminum behind the parts using countersunk rivets to hold a nut plate for attaching the dome to these as well.
Installed it looks great
Engine Failure Update
Sorry for the delayed update, life has been busy lately.
Before installing the new engine I removed the exhaust so I could shake out any bits of metal that might have ended up in there. To my surprise a piece of the piston ring fell out.
This piece of ring looks like it broke off before the meltdown occurred. It is not discolored or heat damaged like the part of the ring that remained in the piston. When looking over previous photos it is also clear that the melting happened only in the area where the ring is missing.
The piston also has been damage where the ring retaining pin is located. With that pin dislodged the ring gap could rotate into the exhaust opening and break off.
After looking over all the evidence it quite clearly tells us a story detailing the sequence of events.
The front crank bearing cage broke and small pieces of the broken bearing made their way from the crankcase into the combustion chamber causing all of the damage seen on the cylinder heads and pistons.
One of these pieces made their way into the rear cylinder damaging the piston allowing the ring retaining pin to become dislodged.
Once the retaining pin was lost the ring gap was allowed to rotate into the exhaust opening where the ring caught on the exhaust port and snapped off.
With the top ring partially missing, at the exhaust port opening, the blow-by caused excessive heat to build up causing the piston to melt.
Once the piston melted compression was lost and the engine stopped producing power.
This piece of ring found in the exhaust was extremely helpful in telling us the whole story. I now feel confident that I fully understand what happened.
From my research crank bearing failed like this are uncommon with this engine so I think it is quite unlikely to ever happen again. So I’m flying around with the replacement Kawasaki 440a confident that it won’t have a catastrophic failure like this one but I have to admit I am a little paranoid now.
Engine Failure – Root Cause
I noticed that both the front and rear cylinders had signs of debris bouncing around in the combustion chambers. The front piston also had some scoring on the sides above the top ring.
I removed the cylinders and inside the front crankcase I found many chunks of metal.
I also noticed that when turning the crank I could hear a ball bearing fall and bounce.
https://soundcloud.com/eric-blevins-807713708/motor2-mp3
Starting to look and sound like maybe a crank bearing feel apart.
I shipped the motor to J-Bird and when they disabled it they confirmed that the front crank bearing was destroyed.
So it looks like the front crank bearing cage broke, pieces of that cage made their way into both combustion chambers. I think one of those chunks damaged the rear piston breaking the top. The blowby from the broken ring resulted in excessive heat buildup causing the rear piston to melt.
Unfortunately most of the engine is destroyed beyond repair. Basically only the ignition and intake are reusable. I’m happy with how J-Bird is handling the situation and I should have a new engine in about a week or so. Looking forward to getting back in the air!
Catastrophic Engine Failure in Flight
The Kawasaki 440A suffered a catastrophic failure in flight January 9th 2021. Once the engine is torn down and repaired I’ll post an update with more information and probable cause. What I do know is the rear piston has extensive damage as can be seen in the pictures below. In the meantime, enjoy the video of the emergency landing!
Ultralight Builder 