High oil Temperature

[WWhunter]

I purchased an RV-8 with an IO-360 (200HP) with Hartzel CS prop. New to injected and CS after nearly 40 years of flying lower powered fixed pitch planes.

I am trying to get initial practice, essentially doing takeoff and landings. Since I am staying in the pattern, the prop or mixture basically aren't touched. I can only get two circuits in before the oil temp starts getting over 200 degrees. Once it gets there it rises raather quickly. By my 3rd landing it is starting to get into the yellow. Basically done for the day. This are my reading:

Oil temperature 224.

EGT CHT
#1 1141 291
#2 1128 292
#3 1170 339
#4 1105 295

Number 3 cylinder is definitely hotter than the rest, but this seems to be my typical experience with several diferent planes that I have owned. Is this typically that big of a difference spread?

I removed the cowling and checked all the baffling, which looked good. No oil cooler blockage. The oil cooler is mounted at the rear of the baffling. The vernatherm being stuck, or the oil cooler might be restricted, is a possibility.

My thoughts are that flying at the slow speeds of pattern work are a contributing factor, but would like advice/comments on what else it could be. Ideas?

Thank you

 

[ryschneider]

I purchased an RV-8 with an IO-360 (200HP) with Hartzel CS prop. New to injected and CS after nearly 40 years of flying lower powered fixed pitch planes.

I am trying to get initial practice, essentially doing takeoff and landings. Since I am staying in the pattern, the prop or mixture basically aren't touched. I can only get two circuits in before the oil temp starts getting over 200 degrees. Once it gets there it rises raather quickly. By my 3rd landing it is starting to get into the yellow. Basically done for the day. This are my reading:

Oil temperature 224.

EGT CHT
#1 1141 291
#2 1128 292
#3 1170 339
#4 1105 295

Number 3 cylinder is definitely hotter than the rest, but this seems to be my typical experience with several diferent planes that I have owned. Is this typically that big of a difference spread?

I removed the cowling and checked all the baffling, which looked good. No oil cooler blockage. The oil cooler is mounted at the rear of the baffling. The vernatherm being stuck, or the oil cooler might be restricted, is a possibility.

My thoughts are that flying at the slow speeds of pattern work are a contributing factor, but would like advice/comments on what else it could be. Ideas?

Thank you

I have almost the same numbers in my IO-360 angle valve (200HP), #3 is 30-40 degrees hotter than the rest.
During the summer, I remove the air dams from the front of the engine. My oil temps can get in that range on a hot day and I have a 13-row oil cooler installed behind #3 using showplanes oil cooler mount.

 

[ryschneider]

I purchased an RV-8 with an IO-360 (200HP) with Hartzel CS prop. New to injected and CS after nearly 40 years of flying lower powered fixed pitch planes.

I am trying to get initial practice, essentially doing takeoff and landings. Since I am staying in the pattern, the prop or mixture basically aren't touched. I can only get two circuits in before the oil temp starts getting over 200 degrees. Once it gets there it rises raather quickly. By my 3rd landing it is starting to get into the yellow. Basically done for the day. This are my reading:

Oil temperature 224.

EGT CHT
#1 1141 291
#2 1128 292
#3 1170 339
#4 1105 295

Number 3 cylinder is definitely hotter than the rest, but this seems to be my typical experience with several diferent planes that I have owned. Is this typically that big of a difference spread?

I removed the cowling and checked all the baffling, which looked good. No oil cooler blockage. The oil cooler is mounted at the rear of the baffling. The vernatherm being stuck, or the oil cooler might be restricted, is a possibility.

My thoughts are that flying at the slow speeds of pattern work are a contributing factor, but would like advice/comments on what else it could be. Ideas?

Thank you

My numbers below are back in mid-June, the oil temp in this case is during cruise but during TnGos on a hot day I definitely see the high oil temps and have seen them in the 220s. I had the same concerns, that vernatherm may have been stuck but I tested and got some help from a local A&P to confirm that the vernatherm was good.

Alt 10700
MP 20.5
FF 7.6 GPH
Oil Temp 195

#1 1315 304
#2 1346 340
#3 1373 364
#4 1318 324
LOP

 

[GroundPointNiner]

What size oil cooler do you have?

I ran into this issue on my RV-7A, even in cruise. When I purchased it, wheel pants were removed… so less cooling airflow for a given airspeed. Installing them made a world of difference. But, still runs hotter than I’d like. I replaced vernatherm… no dice. In my case, the oil cooler is simply undersized. I have a 200hp IO-360 as well (IO360-C1C6), and the builder selected an 8-row P20004C.

I am in the process of upgrading to an Aero Classics 13-row, with the Showplanes mount and expect that to be the proper fix. Hoping to wrap up this week.

 

[eaglen92ce]

Most (mine included) angle valve (200hp) powered RVs are not good at tolerating touch and go opearations in the summer. Your numbers are not really pointing to abnormal operation to me. Your CHTs are actually cooler than optimum. Remember these engines are air and fuel cooled. In a touch and go we ask full power (full fuel, not much airspeed) for a short period to get to pattern altitude and then we remove most of the fuel (cooling) and stay at a low airspeed (not much air for cooling). This cycle does not last long before oil temps rise. Does your aircraft do fine on cooling in a cruise mode?

 

[Quotafiller]

your cht/egt as mentioned is totally fine (or even low). what is the OAT ? oil temp in the 220's is not ideal but totally fine. if it goes down in cruise i wouldnt worry about it too much. in the long term maybe a larger oil cooler as mentioned. i think i went from a 9 row to a 12 row in my rv6. helped for sure.

 

[RNB]

My ideas:
Find the manual for your engine.
Read it.
Make note of redline oil temps. What is ideal? What is maximum?
If you are in the ideal range OR not at maximum- chill out!!!
What is your oil level and what is maximum? Oil serves as a coolant.

While you are at it, make note of cht and egt limits.

Good that you looked at baffling.

 

[Carl Froehlich]

Remember the Harzell BA CS prop starts to mimic a flat disc at low pitch (high RPM). Oil temps will be higher as there is less engine cooling air getting to the oil cooler.

When I replaced the baseball bat FP Sensenich prop on my first build with the nice Hartzell BA prop I noted two things on first flight:
- The acceleration on takeoff was amazing
- Oil temp was much higher than normal after landing

It took me awhile to figure it out. Let the engine breath some between landings by going to a high pitch (lower RPM).

I’ll note that your EGTs show a lot of fuel going into your engine. I suggest a few GAMI data runs to see what is going on. At first blush on your numbers #3 looks leaner than the rest. Do the GAMI data runs after you check for intake leaks. See Vic’s latest video on how to check for induction leaks:

Carl

 

[RV8Squaz]

I purchased an RV-8 with an IO-360 (200HP) with Hartzel CS prop. New to injected and CS after nearly 40 years of flying lower powered fixed pitch planes.

I am trying to get initial practice, essentially doing takeoff and landings. Since I am staying in the pattern, the prop or mixture basically aren't touched. I can only get two circuits in before the oil temp starts getting over 200 degrees. Once it gets there it rises raather quickly. By my 3rd landing it is starting to get into the yellow. Basically done for the day. This are my reading:

Oil temperature 224.

EGT CHT
#1 1141 291
#2 1128 292
#3 1170 339
#4 1105 295

Number 3 cylinder is definitely hotter than the rest, but this seems to be my typical experience with several diferent planes that I have owned. Is this typically that big of a difference spread?

I removed the cowling and checked all the baffling, which looked good. No oil cooler blockage. The oil cooler is mounted at the rear of the baffling. The vernatherm being stuck, or the oil cooler might be restricted, is a possibility.

My thoughts are that flying at the slow speeds of pattern work are a contributing factor, but would like advice/comments on what else it could be. Ideas?

Thank you

Define yellow. Lycoming only publishes

I purchased an RV-8 with an IO-360 (200HP) with Hartzel CS prop. New to injected and CS after nearly 40 years of flying lower powered fixed pitch planes.

I am trying to get initial practice, essentially doing takeoff and landings. Since I am staying in the pattern, the prop or mixture basically aren't touched. I can only get two circuits in before the oil temp starts getting over 200 degrees. Once it gets there it rises raather quickly. By my 3rd landing it is starting to get into the yellow. Basically done for the day. This are my reading:

Oil temperature 224.

EGT CHT
#1 1141 291
#2 1128 292
#3 1170 339
#4 1105 295

Number 3 cylinder is definitely hotter than the rest, but this seems to be my typical experience with several diferent planes that I have owned. Is this typically that big of a difference spread?

I removed the cowling and checked all the baffling, which looked good. No oil cooler blockage. The oil cooler is mounted at the rear of the baffling. The vernatherm being stuck, or the oil cooler might be restricted, is a possibility.

My thoughts are that flying at the slow speeds of pattern work are a contributing factor, but would like advice/comments on what else it could be. Ideas?

Thank you

Define yellow. The Lycoming Operator’s manual only defines a desired temp of 180° and a maximum temp of 245° at ambient temp above 80°. Your numbers seem fine to me. I wouldn’t worry about it unless you’re getting close. FWIW, I have a 4” SCAT feeding a plenum attached to a large Stuart Warner oil cooler. My temps rarely get above 190°.

 

[eaglen92ce]

If you need/want to practice takeoffs and landing with high OAT just insert a short 10 or 15 minute flight leg between landings. During that delay time get the airspeed up, power down (maybe 65% or so) and lower the RPM as Carl suggests. Lowering the power and RPM while maintaining higher airspeed will keep the engine happy and you can then go shoot another landing. Now you are practicing engine management in addition to the patten work.