glennhake
New member
Well, I missed a summer of fly-ins while overhauling my engine. The reason I overhauled it was because it had been 35 yrs since the last overhaul and Continental recommends 11 years. I had over 1800 hrs on the 1500 recommended TBO engine. This annual I had 3 cylinders with low compression, 2 cylinders were due to worn valve guides, and one was through the rings. With my luck, if I repaired the cylinders, something would go wrong with the bottom end the next year, so after 20 years of trouble free operation I decided to bite the bullet and overhaul the thing with a local reputable overhaul shop. I also overhauled all the components firewall forward. Some stuff I learned.
1. You can stand a lot of gaging as you write checks
2. I've attended seminars by this guy:
http://www.avweb.com/news/maint/182849-1.html
One thing he said was don't go into the bottom end for a top end problem. There should be some indication the bottom end is deteriorating before going into it. Turns out he was right on my engine. The bottom end was close to new tolerances, I could have gotten away with just repairing the cylinders with 20/20 hindsight. I just ran out of guts.
3. I bought a wiz bang JPI EDM 700 engine analyzer so I could monitor cylinder head temps and lean to perfection. So far that's been a waste. Cylinder temp have been 350+/- 20 degrees. When I lean by ear or use the EDM 700 I get there same results. I figure the thing might pay for its self if a cylinder starts to act up however, and thought that might be a possibility during break-in. The EDM 700 includes a voltage read out which is nice. The component shop set voltage regulator/generator to 14.2 volts. It's running between 14.1 and 14.4 volts on the plane according to theEDM 700, more info than I want to know. I also bought the fuel flow option. When I first ran the engine there was quite a bit of air in the line. Fuel flow was unreadable. As the system purged itself fuel flow settled down quite a bit. Now it varies +/- .3 lbs per hour. I've never gotten rock solid indications like I'd expect. Fuel pressure is rock solid. The system also has a computer to enter total fuel, it then tracks fuel used and remaining. That part of the system has been accurate to .1 gallons/40 gallons consumed. Wiz bang!
4. I initially decided to go with Continental cylinders because the shop had no preference and I figured Continental ought to have cylinders figured out by now. Lynn suggested I go with ECI cylinders because he had good luck with them on his plane. His experience with oil consumption has been good since his top. After asking lots of questions I stumble across a few people that said Continental cylinders have steel barrels which are slightly prone to corrosion if the engine sits around a bit. The Nickel coating on the ECI Titan cylinders won't rust. The last 2 winters we've been snowed in forcing a 3 month period of no flying. For that reason and Lynn’s recommendation I decided to go with ECI. I burned almost quart the first flight hour. The next 8 hours I've burned .2 quarts on the dip stick. It looks like the engine won't require any oil between oil changes. That'll be a new experience after burning a qt every 3.5 hours the last 20 years.
5. The last 20+ years my engine has started reliably with the starter rocking through one compression stroke at a time. Cleaned all the contacts, overhauled the start with minimal change. A couple of years ago change from the G-35 to a C-35 battery. According to the specs the Concord has more cranking power. That helped some. I figured that on an engine with good compression I'd probably be lucky to start it. Change to the latest version of the sky-tec starter. The engine spins like normal. I still have the original aluminum rod as a cable.
6. There are a lot of hoses, wires, fuel lines, and cables in close proximity under that firewall. From the last time I had the engine off I knew there was a chance stuff could rub and if not found potentially cause bad things. Hopefully, with 2 sets of eyes we've found everything by now. All minor things, but we missed stuff or found things shifted and settle to new places the first 2 or 3 runs when we looked the installation over.
7. According to the electronic through the windshield tach, I’ve been running the engine 130 RPM faster than I thought the last 20 years. That tach error made already scary fuel flows scarier during initial engine runs. Who knows how accurate the MP gage is.
I’m sure the group would be interested if you have comment, opinions, thoughts or questions.
1. You can stand a lot of gaging as you write checks
2. I've attended seminars by this guy:
http://www.avweb.com/news/maint/182849-1.html
One thing he said was don't go into the bottom end for a top end problem. There should be some indication the bottom end is deteriorating before going into it. Turns out he was right on my engine. The bottom end was close to new tolerances, I could have gotten away with just repairing the cylinders with 20/20 hindsight. I just ran out of guts.
3. I bought a wiz bang JPI EDM 700 engine analyzer so I could monitor cylinder head temps and lean to perfection. So far that's been a waste. Cylinder temp have been 350+/- 20 degrees. When I lean by ear or use the EDM 700 I get there same results. I figure the thing might pay for its self if a cylinder starts to act up however, and thought that might be a possibility during break-in. The EDM 700 includes a voltage read out which is nice. The component shop set voltage regulator/generator to 14.2 volts. It's running between 14.1 and 14.4 volts on the plane according to theEDM 700, more info than I want to know. I also bought the fuel flow option. When I first ran the engine there was quite a bit of air in the line. Fuel flow was unreadable. As the system purged itself fuel flow settled down quite a bit. Now it varies +/- .3 lbs per hour. I've never gotten rock solid indications like I'd expect. Fuel pressure is rock solid. The system also has a computer to enter total fuel, it then tracks fuel used and remaining. That part of the system has been accurate to .1 gallons/40 gallons consumed. Wiz bang!
4. I initially decided to go with Continental cylinders because the shop had no preference and I figured Continental ought to have cylinders figured out by now. Lynn suggested I go with ECI cylinders because he had good luck with them on his plane. His experience with oil consumption has been good since his top. After asking lots of questions I stumble across a few people that said Continental cylinders have steel barrels which are slightly prone to corrosion if the engine sits around a bit. The Nickel coating on the ECI Titan cylinders won't rust. The last 2 winters we've been snowed in forcing a 3 month period of no flying. For that reason and Lynn’s recommendation I decided to go with ECI. I burned almost quart the first flight hour. The next 8 hours I've burned .2 quarts on the dip stick. It looks like the engine won't require any oil between oil changes. That'll be a new experience after burning a qt every 3.5 hours the last 20 years.
5. The last 20+ years my engine has started reliably with the starter rocking through one compression stroke at a time. Cleaned all the contacts, overhauled the start with minimal change. A couple of years ago change from the G-35 to a C-35 battery. According to the specs the Concord has more cranking power. That helped some. I figured that on an engine with good compression I'd probably be lucky to start it. Change to the latest version of the sky-tec starter. The engine spins like normal. I still have the original aluminum rod as a cable.
6. There are a lot of hoses, wires, fuel lines, and cables in close proximity under that firewall. From the last time I had the engine off I knew there was a chance stuff could rub and if not found potentially cause bad things. Hopefully, with 2 sets of eyes we've found everything by now. All minor things, but we missed stuff or found things shifted and settle to new places the first 2 or 3 runs when we looked the installation over.
7. According to the electronic through the windshield tach, I’ve been running the engine 130 RPM faster than I thought the last 20 years. That tach error made already scary fuel flows scarier during initial engine runs. Who knows how accurate the MP gage is.
I’m sure the group would be interested if you have comment, opinions, thoughts or questions.
