RV-6 normal CHTs

[britt fincher]

I've looked over numerous post on this subject and see a wide variation in opinions. I test flew a 6 with 455 since new O-360 hartzel CS prop. CHT on 110 knot climb 89 degree day got up to 428 by 2000 AGL. on # 3&4. They did come down at level off to 380 or so. I know this doesn't exceed Lycoming limits, but is this fairly normal or not.

[tracy]

428 is too high for me. My o360 hits about 390 on a steady 110 kt climb on a hot day. This only o occurs on the #3 cylinder. Once I level off, it goes down to about 340 with the rest of them. The other cylinders max out at about 370. I am swinging a c/s prop.

[Geico266]

Originally Posted by tracy

428 is too high for me. My o360 hits about 390 on a steady 110 kt climb on a hot day. This only o occurs on the #3 cylinder. Once I level off, it goes down to about 340 with the rest of them. The other cylinders max out at about 370. I am swinging a c/s prop.

Have you tried removing the cabin heat muff and blocking off the 2" vent hole over the number 3 cylinder?

[Snowflake]

Are your CHT probes the kind that are a ring that sits under the spark plugs, or the bayonet style that "plug in" to a hole in the cylinder?

Mine are the "ring" style, and I also can see just over 400 on climbout, but they drop to 350-380 (depending on power setting) once I level off.

[Kyle Boatright]

428 isn't horrible, but I generally climb at higher airspeeds unless I'm doing short field work or trying to clear an obstacle. Higher airspeeds = lower temperatures.

[RV10inOz]

428 is horrible. We know that from this point it is a launch pad for undesirable things if left unchecked or other variables get out of hand.

Accepting something like this, sort of like saying it is OK to steal from big corporations as they can afford it but not from a small private business.

Which cylinders? All or just one?

Fuel flow? Is it enough?

Spark timing?

Baffles or more importantly exit air?

[Kyle Boatright]

Originally Posted by RV10inOz

428 is horrible. We know that from this point it is a launch pad for undesirable things if left unchecked or other variables get out of hand.

Accepting something like this, sort of like saying it is OK to steal from big corporations as they can afford it but not from a small private business.

I submit this as an example of how not to respond on an internet forum.

If you want to disagree, fine.

But c'mon...

[RV10inOz]

So you think accepting 428dF in a climb is a good thing and normal?


I understand you and many folk in the US don't get the Aussie folk when it comes to a shot across the bow like that, and thats OK, I will take your criticism. Down here it would not get the raising of an eyebrow, but all that aside, back to the facts, do you think this is a good scenario?

I promise to try to keep analogies to a minimum.

[Rosie]

Originally Posted by Kyle Boatright

428 isn't horrible, but I generally climb at higher airspeeds unless I'm doing short field work or trying to clear an obstacle. Higher airspeeds = lower temperatures.

I'm with Kyle on this, and with everyone flying in all parts of the world, the definition of a 'hot' day will vary. Living here in here in the Mojave desert, I regularly see (on a climb) CHTs above 420°F on what I consider a 'hot day'; above 115°F. My field elevation is 2400' with the Sierra Mountains less than 8 minutes to the north, a generous climb rate is desirable and necessary.

On hot days, I will climb out at 430°F and will always level by 450°F to allow the O-360 engine to cool (#4 is my hottest); full throttle, full rich. All of my cylinder temps will settle below 400 in cruise.

As for engine data points, my first engine went 2501 hours with ZERO (Lycoming) cylinder issues, and I'm now almost 1400 hours into engine #2 with no issues (ECI cylinders).

Of course, your mileage will vary Rosie

[britt fincher]

Thank you for all the replies. I know this is a hot topic, haha,but not trying to start a fight here. Not sure what type probes it has. I think bayonet. It was not that hot of a day for Georgia 89 degrees F. What compounded my concern was it came back with a not so good of an oil sample from Blackstone. Twice the iron and aluminum. This engine may have been running warm a while. No visible metal in the filter though?