Saratoga II TC Operating Questions
All.
I recently purchased a 2002 Piper Saratoga TC. It had around 1300 Hours total time. Prebuy came back great all compressions in mid 70's. and airplane has been very well maintained. It has been a few years since i have flown pistons and Never fooled with GAMI injectors and have a few questions. Thanks in advance
Here is how i run it. after start I lean it out on the ground for smooth engine operation. Climb out: 35 in after 1000 feet, everything else full foward. Cruise: 30in/2300rpm/1550 TIT, 375 on the CHT, #2 Cyl the hottest at around 400. Descent start pulling an inch a minute until 17 inches (typically in the pattern at this point) dirty it up and land. I have not tried lean of peak however i am in the process of researching it and want to (know what i am doing first)
Question: During Taxi out I am having trouble making the engine idle smoothly. It seems to have a sporatic miss (especially when cold). I have been running fine wire spark plugs and were told they are easily fouled. Has anyone else had this problem? I am thinking about going back to normal plugs and seeing if the problem will go away. Upon runup i aggressivley lean it out to clean the plugs however after a minute or two at idle the problem comes right back. this goes away of course as soon as power is applied at take off. After landing on taxi in it usually runs pretty smoothly until the next startup and taxi out. JPI Engine moniter shows nothing abnormal (occasionally on runup it will lose a cyl on the mag check until I lean it to clear the plug. Any and all advice is greatly appreciated! thank you
I recently purchased a 2002 Piper Saratoga TC. It had around 1300 Hours total time. Prebuy came back great all compressions in mid 70's. and airplane has been very well maintained. It has been a few years since i have flown pistons and Never fooled with GAMI injectors and have a few questions. Thanks in advance
Here is how i run it. after start I lean it out on the ground for smooth engine operation. Climb out: 35 in after 1000 feet, everything else full foward. Cruise: 30in/2300rpm/1550 TIT, 375 on the CHT, #2 Cyl the hottest at around 400. Descent start pulling an inch a minute until 17 inches (typically in the pattern at this point) dirty it up and land. I have not tried lean of peak however i am in the process of researching it and want to (know what i am doing first)
Question: During Taxi out I am having trouble making the engine idle smoothly. It seems to have a sporatic miss (especially when cold). I have been running fine wire spark plugs and were told they are easily fouled. Has anyone else had this problem? I am thinking about going back to normal plugs and seeing if the problem will go away. Upon runup i aggressivley lean it out to clean the plugs however after a minute or two at idle the problem comes right back. this goes away of course as soon as power is applied at take off. After landing on taxi in it usually runs pretty smoothly until the next startup and taxi out. JPI Engine moniter shows nothing abnormal (occasionally on runup it will lose a cyl on the mag check until I lean it to clear the plug. Any and all advice is greatly appreciated! thank you
Comments
Fouled plugs are a common problem, always the plugs associated with the right magneto switch, probably the plugs that are in the lower position. My theory is that they foul after landing, I try to turn off fuel pump and lean the mixture as soon as possible after I land. (This also prevents stalling the plane on high altitude runways). If the engine runs rough after power-up, usually means you have fouled plugs. Just turn on the electric fuel pump while you are taxing to "fix" the problem. During run-up, the first thing I test are the magnetos for fouled plugs, if fouled just raise the MP up a bit higher, and run lean as you can for about 30 seconds. Retest mags, complete rest of run-up, then turn off electrical fuel pump and run lean until you are cleared for takeoff.
I have GAMI's installed, and can run LOP if required. Pretty easy to do, has never caused any problems. Do not use it that often, too slow. But you will learn a lot about how the engine works in the process of learning how to fly LOP.
#2 cyl hottest in cruise by design. The air cooling venting is optimized for climb, nothing you can do about it. You will find that optimal fuel, as determined by optimal optimal temps, is very dependent on altitude and OAT. Basically, the higher you fly and the hotter it gets, the higher the fuel flow needs to be.
Eric
N392HP
I appreciate the reply. Since that post I have found a couple of issues that compounded the problem. For one The ceramic had been cracked on a couple of the spark plugs. I believe they had been mishandled during the prebuy. There were also a couple of induction leaks (the primary one being from a broken drain valve that allows excess fuel to dump if overprimed) When the turbo was doing its job at high power settings it would force this valve closed. However at low power settings the valve would "float" causing air to leak out. I am assuming this would result in a rich fuel air mixture and foul the plugs regardless of mixture setting on the ground. It was truly amazing how much replacing that valve completely changed the idle. She runs like a top now (knock on wood). That number 2 cyl seems to hover around 410 degrees at 7 to 10 thousand feet. It seems like there is not much I can do to change that. Again I appreciate the reply. It is nice to hear what other operators are experiencing. Any other tips are welcomed!
Being a normally aspirated kind of guy I'll stay out of this thread except to say that if LOP slows you down anywhere below critical altitude you're probably doing it wrong. One of the key's to LOP is understanding that once LOP you throw out the factory power tables based on RPM and MP and look at the FF gauge. When LOP horsepower is a direct function of fuel flow. In a turbo HP = 13.75 * GPH. If you want to run, say, 70% power leave the thottle wide open and set the fuel flow to 15.3 gph. Well, WOT might overboost you in a turbo - but at least open the throttle enough to make sure that at 15.3gph you're well on the lean side. You'll go just as fast as 70% power ROP. Your engine settings are just different.
Sorry for the diversion. Happy to take this up in a different thread if this is too far off-topic.
Title
Send any photos or resistance readings to the author at Platinum. They are collecting the information for a possible AD, in conjunction with Tornado Alley Turbos.
Spark plugs with missing ceramics are suspected in at least four engine failures in the last two years, due to pre-ignition.
Thanks guys for the reply. The saratoga is running great. I still havent really fooled with LOP operations yet. I think i have come to the conclusions that a gallon or two more per hour is worth the extra insurance in keeping the CHT''s under control. Especially on the Turbo ones. I do have another question:
I have noticed a ring of oil coating the exhaust. Its always on the first flight of the day. It is burning around 1 qt every 5 hours or so. Is this excessive and is that oil coating around the exhaust normal. It really isn't much and It appears that the exhaust is right next to the overflow drain on the motor.
Thanks in advance