Cowl flaps?

[aaronk25]

Dave I live in mn and close my cowl flaps to flush when closed in winter and in summer set closed position to 3/4 inch open. Mine runs 415 rop at 75%. 360-380 at 75% lop. That's why lop is the way to go if you want to take the best care of the power plant..

[Marauder]

I went flying today. Due to wx it was brief but gave me the information I needed. I can't get it to stay cool ROP. It just won't work. I had it doing 12.5gph at 5500' WOT 2500 RPM and it was still getting very close to redline. When I tried doing LOP I got it down to about 9.0 gph and it was quite smooth, using my egt I figured I was about 25-50 degrees LOP. 10 knot speed penalty though, but I could close the cowl flaps! I'm having my avionics guy quote me a price for a new JPI when I get my work done.

Something just doesn't sound right. I will interested to see what you come up with after the engine analyzer installation. On my F, the factory installed probe is on the 3 cylinder (might be standard for all Mooneys for all I know). When I had my GEM installed years ago, I found that my number 2 cylinder was actually the one that peaked first and always ran the hottest.

I am wondering if you might have a flaky probe. I don't know your history (relatively new to the site), but at that fuel flow, I wouldn't expect the high temp you are seeing. Keep us posted!

[Marauder]

Right after I posted my message, I remembered I did have a high cylinder temp once. It was related to a problematic fuel injector. Not sure it is related, but another possible cause.

[David White]

Something just doesn't sound right. I will interested to see what you come up with after the engine analyzer installation. On my F, the factory installed probe is on the 3 cylinder (might be standard for all Mooneys for all I know). When I had my GEM installed years ago, I found that my number 2 cylinder was actually the one that peaked first and always ran the hottest.

I am wondering if you might have a flaky probe. I don't know your history (relatively new to the site), but at that fuel flow, I wouldn't expect the high temp you are seeing. Keep us posted!

I'm relatively low time (600 hours) and all of my experience is with carburetors, so fuel injectors are new territory for me.

[OR75]

just wondering.... have you tried a setting as per the POH ?

for example .... 2400rpm , 23 in at 6000.

if the CHT does not go down , at least the noise level will go down ...

[jetdriven]

You can also use th Twin Bonanza LOP method. Simply lean for a 3-5 KIAS drop in airspeed in cruise.

I think I am gonna start a new trend, climb to 60 degrees F, set prop to hear Bob Segar over the cockpit noise, and lean for a 3 KIAS speed loss!

[Hank]

I think I am gonna start a new trend, climb to 60 degrees F. . .

Just don't try that around here! Pretty soon, high temps will fall below that and stay there for a few months. When it's 10Fthe on the ground, how high must you climb to reach 60F? :-)

[Marauder]

I'm relatively low time (600 hours) and all of my experience is with carburetors, so fuel injectors are new territory for me.

Issues with the fuel injection system can cause differences in fuel flow to the cylinders resulting in high/low CHTs. If an injector is partially clogged, you would be running less fuel into that cylinder and changing the temp it is running at relative to the other cylinders. Ideally, fuel flow through the injectors are the same. I remember years ago doing an owner assisted annual where I measured fuel flow out of the 4 injectors and was amazed at how much difference there was. I think this is the logic behind the GAMI injectors (http://www.gami.com/gamijectors/gamijectors.php).

If I recall correctly, there was also either a SB or AD for crimped injector lines. Without a way to look at all 4 cylinder temps at once, you may be experiencing a problem only with that one cylinder.

Not saying this is your problem, but just another data point as you go through the troubleshooting.

[jetdriven]

Right after I posted my message, I remembered I did have a high cylinder temp once. It was related to a problematic fuel injector. Not sure it is related, but another possible cause.

If you are a ROP operator, a clogged or dirty fuel injector will make that cylinder run leaner. At takeoff power it can run dangerously hot. At your 50 or 100 ROP setting, it can run at peak and overheat,and in both cases with no indication to the pilot if you don't have an engine monitor. After 50-100 hours of this, the cylinder is ruined, with an admonishment from the mechanic for running "too lean", and a promise to run another gallon per hour to save cylinders. So 100 ROP and 13 GPH for your IO-360 engine. (LOP is ten or less)

LOP operators discover this by the inability of the engine to run smooth LOP. It will being to run rough because the cylinder with a dirty injector will be far leaner than the others, and will misfire much sooner than them.

So, for your own health and for the sake of your engine, if you are a ROP operator, occasionally do the GAMI spread test, or simply lean until your EGT shows 50 LOP at 23" and 2500 RPM at 7000'. If it won't run smoothly, investigate why. Our new factory engine would not run smooth LOP. This test won't hurt your engine, and will uncover a dirty injector. Clean them and enjoy a happy engine. A lot of "hot cylinders" are simply dirty injectors.

[201er]

just wondering.... have you tried a setting as per the POH ?

for example .... 2400rpm , 23 in at 6000.

if the CHT does not go down , at least the noise level will go down ...

And so will the speed...