Regular readers of this blog will know that I have been working at intervals over the last 2 years to try and reduce engine operating temperatures following a rebuild from 150bhp to 160bhp.
I had reached the point a few months back where I could run at around 350 degrees (using bottom bayonet CHT probes) in level flight on all cylinders except #3.
At the recent annual inspection, Jesse discovered that there was a crack in the rear baffling panel that hangs down underneath the rear of the engine casing. This baffle panel has to be able to move forward and aft in order to be able to rest against a flange on the lower cowling. This seals the lower rear of the engine compartment, preventing cooling air from exiting at the rear of the cowling. The air instead has to rise through the engine compartment.
This baffling is riveted to other baffling at the rear of the engine, but part of the aluminum has fractured, so the baffling is now able to float and drop when the lower cowling is in place. As a result the baffle "floats" backwards past the cowling flange once the plane is in the air and positive pressure is generated under the engine. After landing the other day on a local flight, I could see the baffling bent back at an angle.
The result of the displacement of the lower baffle is a 15 degree rise in CHTs across all cylinders, and a 10 degree rise in the oil temperature. This takes the average operating temperature of #3 cylinder up to (or above) 375 degrees) at which point I begin to get oil blow-by from that cylinder. I am still not sure (a) why #3 is always 15-20 degrees hotter than the other cylinders, (b) why the oil blow-by occurs. I suspect some issue with ring seating or sticking, but it would probably require a boreoscope exam of the cylinder to confirm or deny that suspicion. I have a medium-term plan to replace the current stock cylinders with Millenium cylinders in any case.
This weekend, the fractured baffling will be replaced with a new cut-to-measure piece of aluminum. This will ensure that the plane is truly ready for longer trips in September and October. I have a trip planned to New Mexico and then there is Rough River approaching soon.
After Rough River, I will fit and test Ed Spracker's modified carbureter venturi (see previous posting) and test it back-to-back against the standard one-piece venturi.

...and the plane is signed off for another year of flying. Tomorrow Jesse and I will complete a compression test on the engine in Cleburne.
Then it will be back to flying, until the Fall improvements take place (money permitting). On the list for Fall are:

1. Move battery to firewall
2. Install nose oil cooler/air heater
3. Fit gear leg fairings
4. Install baggage pods

I also want Santa Claus to send me a Garmin 496...

The nose wheel on a Long-EZE is a small-diameter wheel more usually used on taildraggers (which makes sense, since the Long-EZ is essentially a reverse tail-dragger with a castoring nosewheel).
This wheel is part of a more marginal part of the plane; the nosewheel assembly developed when Long-EZEs were using smaller engines and were being built with empty weights around 800 pounds. With the de facto standard powerplant for a Long-EZE these days being the Lycoming O-320, and with the addition of other gizmos to planes, many Long-EZEs weigh in at over 1000 pounds empty. This increases the loadings and stress on the nosegear significantly.
My primary nosewheel is a Gerdes wheel fitted with slick Cheng Shin tire and inner tube (courtesy of Ken Miller). I have a spare Brock nosewheel/bearing assembly fitted with a treaded tire and tube which is carried inside the nose of the plane attached to a bulkhead, for field use if I encounter nosewheel problems away from home. The nosewheel assembly can be swapped in 10-15 minutes in the field.
One issue noticed in the past by owners is that if the tire pressure drops significantly in the nosewheel, the tire can start to rotate on the rim. This abrades the inner tube, and can puncture it.
I had an example of this several years ago. I pulled out the plane, loaded it up, lowered the nosewheel and jumped in. I cycled through the internal pre-flight, fired up the engine, and went to move off.
The plane promptly dived to the right.
I tried again. The plane still wanted to dive to the right.
I suspected a sticking main brake. I pulled the plane back into the hangar, removed the wheelpants, and checked both brakes. No sign of wheel sticking or other brake issues. I replaced the wheelpants, pushed the plane outside, and got in again. Started the engine. Went to move off.
Now the plane dived to the left.
WTF?
Then...I did something rather sensible. I looked through the nosewheel inspection window.
The front tire was flat.
I did not notice this issue when I was about to get in the plane, becaause, with the nose gear extended, there is no weight on the nosewheeel, thus a flat tire will not compress. Once you are in the plane, and a significant portion of your body weight is on the nose gear, a flat tire is easily spotted.
I replaced the nosewheel with the spare (Brock) nosewheel, and went flying.
When I pulled apart the Gerdes wheel and removed the inner tube, I had suffered a classic abrasion puncture of the tube due to the tire rotating on the rim.
With such a small tire, loss of even a small amount of air has a significant impact on tire pressure. After this incident I began monitoring the nosewheel tire pressure every month. I usually find the pressure has dropped by 5-10 pounds in a month, requiring air to be added.
You should plan to monitor the nose tire pressure at least monthly to avoid the tire rotation/inner tube abrasion problem. I also added an item to the checklist to push down on the nose after lowering the gear and look at the nose tire to see if it has lost pressure, before getting into the plane.

When I first started transition training on the plane in August 2000, we suffered a brake failure on the ramp at Marco Island. This was caused by a caliper piston o-ring failure. The failed o-ring was replaced.
Since both o-rings had originally been installed in the braking system in 1995, it was likely that the other o-ring would also need replacement.
The day before a scheduled flight to Taos, I found that the other o-ring was indeed starting to fail. I found that the brake dust around the caliper was wet, and removal of the caliper showed a leaking o-ring.
I removed the piston, and replaced the o-ring. I replaced the piston (note this for future reference) and then re-assembled the brakes to the wheel and bled the brake. I tried the pedal and all seemed well.
The next morning, Marsha and I loaded up the plane and prepared to depart. While sitting in the plane, I pressed both brake pedals several times to make sure that all was well. On the third press, the brake pedal on the right sank to the floor. That was the brake that was repaired...yesterday. Fluid was all over the ramp under the wheelpant.
How had this happened? Quite clearly something was not right, and since I was the person who had performed the repair, it seemed that I had done something wrong.
I found a mechanic on the other side of the field, and he agreed to come and look at the brake. We removed the caliper from the wheel, and pulled the assembly apart.
The mechanic smiled. It was a "d'oh!" moment (aka Graham You Idiot).
The o-ring rides in a groove in the piston. This groove is machined near the bottom of the piston, so that the piston can project a long way from the caliper base surface. However...I had replaced the caliper piston in the caliper bore upside-down. Now the o-ring was only 1-2 mm below the "top" of the piston. As soon as I pressed the pedal enough to move the piston that 1-2 mm in its bore, the o-ring was exposed and the piston partially popped out of the bore. When we took the caliper apart, the piston was partially out of the bore at an angle.
Well, no real harm. We cleaned up the fluid leakage, replaced the piston the right way up, bled the brake, and we were on our way 2 hours later.
After this, the checklist was amended to include a brake pedal function test before moving the plane under its own power.
Make sure that you check your brakes carefully as part of preventitive maintenance and as part of the pre-flight. On these planes, the brakes not only stop the plane, they are the steering system. Brake failure on landing or rollout will leave you with limited or no steering, and that could easily ruin your day.

This occurred while I was performing transition training in the Long-EZ, with Jesse in the back.
We took off from VandenBergh in Tampa to fly South to Marco Island. No special reason, it was a reasonably short flight and we could practice landings.
We landed at Marco Island, but as I taxiied in to park, I could feel that the left brake was not as effective as normal.
We took a break, then got back in the plane to take off. When I started the taxi, I discovered that the left brake was no longer working - the pedal kept on going down to the floor.
With only 1 functioning brake, if you use the other brake, you can perform a neat 360 degree turn and park right back where you started from. Which is what we did. On getting out of the plane, we could see brake fluid dripping on the tarmac from inside the wheelpant.
We were able to move the plane to a temporarily open hangar. Removing the wheelpant and the caliper unit showed fluid leaking from a defective o-ring. The o-rings on the brakes had not been replaced since the plane had flown 5 years previously (the plane at the time had just over 170 total hours).
We had no equipment to bleed the brakes, and no mechanics were available on the field.
We therefore hired a car locally, left the plane, and drove back to Tampa. The next day we returned, bringing new o-rings, DoT 5 and a brake bleed kit. We replaced the o-ring, cleaned up the brake caliper and brake pads, and bled the brakes.
I then performed ground testing, and, satisfied that the plane was operational, we handed back the rental car, and flew back to Tampa.
This was a useful incident, since it helped me to get used to performing maintenance on the plane as part of my transition training. The incident also helped me to rapidly become familiar with the braking system, which was good, since the brakes on Long-EZEs do require frequent monitoring; the braking system is also the steering system, so if you lose a brake on landing or takeoff, you can easily execute an unplanned agricultural excursion. I now monitor the brakes on my plane frequently for any signs of performance deterioration or malfunctions.