This website details the building of a Van’s Aircraft RV-8, a single engine, two seat, tail-wheel, fully aerobatic, and cross country capable plane that strives to achieve “Total Performance.” This blog exists as a way to share the experience with friends, family, and other builders. Building a plane is a huge undertaking, and this site is my opportunity to pass it forward.
Posts
Maintenance and Tuning – First report Recently updated !
I’ve completed 7.3 hours now in N22UP since June 13th. And during that time there has been a number of maintenance issues dealt with, and general tweaks. We’ll try to hit them one by one.
After the first flight it was readily apparent that I had three noticeable issues. First, there was an oil leak off the accessory case. Exactly where, was hard to tell – as the oil goes everywhere. I wrapped a bit of paper towel around a couple suspect areas, and determined it was likely the o-ring on the prop gov oil line. Additionally, the nose seal was weeping some oil, and the horizontal induction snorkel was rubbing the cowl. None were going to cause me to fall out of the sky, but all would be dealt with. After a couple more flights, I decided it was time to deal with them immediately to save the alternator etc from getting drenched in oil.
Nose seal.
Here you can see some photos of the mess the nose seal is making spraying oil everywhere.
Replacing the nose seal means pulling the prop and the flywheel. And in my case, it also means the crankshaft timing wheel for the ElectroAir ignition also must be removed… and then retimed.
Here you can see the old nose seal as we’ve gotten it out before we cut it off. After we cut it off it took quite a bit of time to get the old bonding agent cleaned out.
Then the new nose seal goes into hot water, and then is stretched over top using a special tool.
Unfortunately, after returning the airplane to service, the latest flight shows that the nose seal – or something in its immediate vicinity is still leaking. So I’ve ordered a new nose-seal, and we’ll start chasing this down again.
Breather tube.
I don’t have a picture of this at the moment. But basically I relocated the tube further aft for its exit above the exhaust.
Prop Oil Line O-Ring.
Here’s the o-ring fitting in question. A bit of a pain in the butt to reach. After replacing this o-ring,
Here are a few pictures of the old o-ring after removal. It looks like it got mangled in the threads.
After replacing the o-ring, there is still a leak in the vicinity. Using some paper towel testing shows the leak appears to be the oil cooler bypass valve. I have a new gasket for that already enroute.
Induction snorkel rubbing cowl.
When the rubbing was first discovered, I placed some 3M double sided tape in the area to protect the parts temporarily. I cut a section out and fiberglassed in a new section with about 1/4 of relief. 
Unfortunately, that was not enough. As you can see, I now have two new areas that are rubbing. (Little black rubbing points). So, I’ll have to provide even more relief.
My approach to each point is to get a straight edge and mark a circle around each that represents about 1/4 of fall from the high point. You can see this resultant circles here.
I then cut an even larger section out than previously. I glassed over this today, and will get a photo next time I am at the hangar. 
Broken wheel pant.
Turns out I didn’t trim my wheel pant to tire clearance far enough. The tire rubbed the pant enough on the first flight landing that it cracked the wheel pant and took a chunk out. I used some flox to get the cracks and removed chunk back in place. 
Then i used my thicker glass weave on the inside, and my fine weave on the outside. 
Lastly, I trimmed both wheel pants further, and re-installed.
Scat tube rubbing oil dipstick.
The scat tube that runs from the baffle to the oil cooler, was being problematic. It was rubbing the oil dipstick tube, and potentially the engine mount. I tried one fix – shortening the scat tube, but unfortunately I did one trim too many and lost the appropriate amount of flex needed for engine movement. So a new bit of scat was installed. This time, I decided to go dirt simple. Zip-tie plus rubber tubing offset and some silicone tape.
Oil and filter change.
I did an oil change at 6.4 hours. Since I had to pull the prop for the nose seal, I figured I might as well do it. Here you can see my methods using my awesome quick drain.
As well as my form-a-funnel for the oil filter.
I cut open the oil filter.
Mike Rollison showed me a neat trick to remove the oil filter pleats and then squeeze the oil out with a vice. Here are photos of the cleaned up oil filter pleats.
Some small bits of metal were evident. None were ferrous. Mike said this is 100% in line with what he would expect for an engine during break in. I kept the pleats so that they can be compared to the next oil change.
I also sent my oil to Blackstone Labs for oil analysis. Yes, its a bit early, but nows the time where there could be trouble. So lets see what the oil has to say.
New seats and stick boots.
I bought nice stick boots from Oregon Aero. These will protect from foreign objects getting lodged and give the cockpit a good aesthetic. I was also able to grab a set of used Classic Aero cloth seats off Van’s. The trim is blue, which doesn’t work exactly for my plane, but these will do perfectly for now. They even came with extra material and booster seats!
Brake line length reduction.
I forgot to take any before photos, but basically the low pressure brake oil lines were too long. They needed about 4″ per side removed. I also needed to then add some new protections against rubbing in place. Here is the result.
Also, a bonus photo of Squire. Because he’s awesome.
Flying & Performance – First report Recently updated !
As of today, I’ve logged 7.3 hours in the aircraft. The airplane is flying well, but there have been some maintenance issues. So lots, to cover. We’ll cover things one topic at a time. First, lets take a look at engine performance so far.
First up, CHTs. Unfortunately, I did forget an SD card on a couple of my flights, so they are not all represented here. But we’ll start with first flight on June 13. You can see the maximum CHT reached is 383 after takeoff. The spread between highest and lowest is 52 degrees. Cylinder 3 is running the hottest – with the cylinder directly in front of it, running the codes. There is only 9 degrees between the two cylinders (2 & 4) on the left side of the engine.
I missed logging the date from a 1.1 hour flight on the 16th. So the next flight shows the engine after it has 2.2 hours on it. I have also added some metal foil tape to cylinder 1 to try to decrease its airflow, and increase airflow to cylinder 3. The CHT spread is now 41 degrees but between cylinder 3, and cylinder 4. The spread between 1 & 3 has dropped to 23 degrees. I also added some tape to cylinder 2, which was a mistake. All in all these numbers are really really good for an engine during break in!
I did two flights on the 18th, and you can see the CHT trend remains the same.
I missed the SD card again for a flight on the 19th. I did do a compression test after the flights on June 18th. Cylinders 1, 3, & 4 got 78/80. And cylinder 2 scored a 76/80. Removing all the bottom plugs showed them to be mostly dry, with cylinder #2, showing a little bit wet.
Now the plane went into a maintenance phase to correct several issues, that I will cover later.
Here is the CHT data from today, July 2nd. CHT max is 353. The maximum delta is 35 degrees. Cylinder 1 to 3 is now 17, and Cylinder 2 to 4 is 5 degrees. The numbers are all trending in the right direction. I’d like to get CHT 3 a bit lower, so I’ll play with that. Either way, what I take from these numbers are 2 things. First, this engine is cooling very well. Every flight has been maximum power for takeoff and initial climb, followed by periods of 25 squared or 24 squared. The engine has been run hard, and she’s running very cool! Second, as the CHTs are coming down, this is a good indication that proper break-in is occurring.
Now lets take a look at oil temps. I’m not going to do as many graphs for this one, as oil temps have remained solid, and are not indicative of break-in. Here is the latest flight. Oil temp basically between 176 and 189. 180 is optimum, so oil temps are right where I want them. Angle valve engines are known for running cooler CHTs and hotter oil temps. For this reason, I installed the bigger oil cooler, and so far that decision seems to be good all around. This baby shouldn’t have any problems with temperatures!!!
I have some preliminary speed data, but all the while I’m screaming around rich of peak for engine break-in, they should be taken with a grain of salt. Here are the speeds from a flight where I did the airspeed box.
At 25 squared I was getting about 181 to 184 KTAS, and at 24 squared I was getting right around 170 KTAS.
I have done a couple of stalls, and collected that data. Here you can see a stall series I did on June 18th. Stall with full flaps was at 53 KTAS, and 48.5 KIAS. I’ve only done a couple stalls, really just to establish safety of flight for the landing pattern. I will return to much more in-depth stall testing, when I’m comfortable that the majority of engine break-in is complete, and going to lower power settings will not harm break-in.
Ok. Now some fun photos and reports.
Some views from the cockpit on June 18th. It is such an absolute thrill to have my own airplane in the air!
And from today, July 2nd.
Last note on in-flight performance. Between the last flight on June 19th, and today’s flight on July 2nd. I did a lot of maintenance items, which I will cover in a subsequent post. I did do the on-ground configuration of the auto-pilot. So today was a good opportunity to give that an initial test. There are some procedures for doing in-air setup. Mainly centered around gains and torques. Today’s testing seemed to show everything working perfectly. I did heading and altitude holds, as well as turns, climbs, descents and even let the flight director pick up navigation to a direct waypoint. I don’t think much, if anything, will need to be tweaked in terms of gains, or torques. Auto-trim is currently turned off, so we’ll circle back to that at a later time too.
First Flight!!!! Recently updated !
The first flight of N22UP was on the evening of June 13th out of KDMW in Westminster, Maryland. My planned flight was 45 min of basically engine break-in. I was fortunate enough to be assisted by Mike Bullock flying his RV-7 as a chase plane, and Mike Rollison running a ground safety vehicle.
I spent the day replacing access panels and doing another final inspection on the aircraft. I fueled up with 13 gallons per side and did some basic flight planning. My intent was to take off, climb to 4 or 5000 feet and basically orbit the airport at 25 squared for engine break-in. My transition training instructor, Bruce Bohannon, had really focused my attention on oil pressure and CHTs – so my goals was to make sure I had the former, and I managed the latter. I was expecting high CHTs due to initial engine break-in. Mike Bullock and I did a final walk around of the airplane, then we took a flight around the pattern in his plane to recon potential off field landing locations in the event of a low altitude engine failure. Once back on the ground, it was time to jump in the plane and take it flying.
I was cautious on takeoff – easing the power forward I kept it nice and straight. She shot down the runway and was airborne in no time. I pulled power back quite quickly and was in a rapid climb in no time. My engine temperatures stayed excellent throughout the flight. I did a little slow flight, a full flap power off stall, and then returned to the airport for a low pass followed by a long wheel landing.
Afterwards, review of the airplane reviewed the following squawks. There was some oil in the cowl. Some we suspect from the breather tube, but there also might be some leaking from the prop oil return line. The nose seal also might have a small leak. The propellor governor maximum rpm will need to be adjusted down. There is some rubbing of the cowl on the horizontal induction snorkel. All in all – a great first flight!
I will post more with engine data analysis later!
