- Joined
- Mar 10, 2018
- Messages
- 165
- Reaction score
- 90
I'm looking for opinions on running LOP.
I have a '66 260B. IO540D4A5. I had it overhauled several years ago, and had them use new ECI cylinders, and flow-match them all. I do not have matched injectors.
I have a 6-cyl EGT with data recording. I did a series of tests in cruise, to see how well the cylinders line up when leaning. The bottom line is they're not perfect, but not too bad. I got a spread of about 1.5GPH from when the first one peaked to when the last one did.
Since the overhaul, I've been running LOP when I get to cruise. My protocol is to monitor the hottest two cylinders and get them over the hump to about 50LOP. The engine has been running perfectly like that for several hundred hours. But: I recently changed A&Ps, and the new guy is saying he recommends against LOP operation on these older engines, because the induction system isn't tuned for it, and you'll never really get it even enough. My previous A&P said he thought as long as there wasn't a big spread, and the CHTs were good (which they are) that it was fine.
So I'm looking for other opinions/experience. Do you run an injected 540, or similar engine, LOP? Without having done the whole 9 yards of tuning? Does what I'm doing sound like a good idea, or am I asking for trouble?
Thanks in advance for any wisdom.
I have a '66 260B. IO540D4A5. I had it overhauled several years ago, and had them use new ECI cylinders, and flow-match them all. I do not have matched injectors.
I have a 6-cyl EGT with data recording. I did a series of tests in cruise, to see how well the cylinders line up when leaning. The bottom line is they're not perfect, but not too bad. I got a spread of about 1.5GPH from when the first one peaked to when the last one did.
Since the overhaul, I've been running LOP when I get to cruise. My protocol is to monitor the hottest two cylinders and get them over the hump to about 50LOP. The engine has been running perfectly like that for several hundred hours. But: I recently changed A&Ps, and the new guy is saying he recommends against LOP operation on these older engines, because the induction system isn't tuned for it, and you'll never really get it even enough. My previous A&P said he thought as long as there wasn't a big spread, and the CHTs were good (which they are) that it was fine.
So I'm looking for other opinions/experience. Do you run an injected 540, or similar engine, LOP? Without having done the whole 9 yards of tuning? Does what I'm doing sound like a good idea, or am I asking for trouble?
Thanks in advance for any wisdom.
