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Still High Oil Temperature

L

Larry

Active Member
Flew again today. Outside air temperature was 69 deg F. I took off at 07:15 climbing at 100 MPH to 6500 ft. Started orbiting over the airport. Within 20 minutes my oil temperature rose to 240 deg F and stayed there unless I throttled back below 2000 RPM..

I have redone my baffling, no problem there. The sides of the turbulence reducers on the top inlet of the upper cowling are sealed. I have checked the calibration of the oil temperature gauge, within 5 degrees of actual. The oil pressure is 60 psi with 8 qts in the sump. Timing is correct and with the exception of the oil temperature the engine runs great. The oil cooler is a 7 tube Niagara Thermal supplied in the Van?s FWF kit. Mineral oil looks good and the plugs are not fouled. Looks like less than .5 qt burn per hour.

The engine is a Penn Yan O-320 and I only have 8.2 hours on it. This time in eight flights. Trying to break it in but do not want to exceed the oil temp limit for too long. I have not talked to Penn Yan yet, I will do that Tuesday. Penn Yan?s test shows an oil temp of 198 deg F after 30 min at 2700 RPM with OAT of 24 deg F. Yes they did the test in winter upper state NY.

What could be the problem? Incorrect setting of the oil thermostat? The oil cooler is hot but I have not checked to see if it is partially clogged. Oil cooler bypass valve malfunction? What else? I need help! :confused:
 
1. Confirm oil temp gauge accuracy
2. Confirm vernatherm is working
3. Confirm no blockage in hoses to/from oil cooler

It's likely to be one of the first two.
 
One thing that is suggested in the Sky Ranch book to help confirm that the temp guage is reading correctly, is to stick a long stem thermometer down the oil filler tube. You can buy these usually at hardware stores. As soon as you get the plane on the ground, check the oil temp in the sump and see if it matches your temp gauge.

steve ciha
 
The gauge is reading correct, I check it by lowering a thermometer into the dip stick area and the results matched the indicator in the cockpit. Where would I find info on checking out or lowering the setting of the vernatherm? How would I check for restriction in the oil cooler?
 
Larry said:
Where would I find info on checking out or lowering the setting of the vernatherm?
Click to expand...
The vernatherm is basically just an on/off thermostatic valve. It's not something that you'd adjust.

There's a great article on vernatherms in the latest issue of Kitplanes.

This page has a little discussion and some photos of Rosie's bum vernatherm that he replaced at my hangar one day... http://www.rvproject.com/20050409.html
 
Larry,

I have been working with my engine builder on a slightly elevated oil temp and can share some of the info they provided. My 0360 with 60 hrs has been running 205-210 in cruise (65% power)--I know that this is within spec from Lycoming but I am a fanatic.!!

Per the engine builder the oil temp taken at the standard oil temp probe location (close to the oil filter on the back of the engine) will be affected by the oil returning from the oil cooler so it will be cooler (not the same) as the oil in the case. They asked me to do the same thing you did--fly, note the oil temp on the gauge just before shut down, shut down and immediately check the oil temp through the oil filler tube--they said it should be about 20-25 degrees f (going on memory here) hotter than what the gauge indicated. Lyc uses vernathermn settings of 180-190 because they know the case temp is hotter and therefore sufficiant to boil off water from the oil (212 degrees f needed at sea level).

To test your oil temp probe accurately you need to remove it and submerge the sensor in boiling water or heated oil along with a thermo that you know is accurate. Many of the better multimeters have a digital thermo with a probe that you could use. If the water is boiling you should read 212 d f at sea level on the thermo and your gauge. For each 1000' above sea level you would deduct 1d f--mine checked at 209 in San Antonio, Texas.

To check the vernathermn follow the process Rosie used to check his--I think Dan C. has given you that link in a prior posting.

Best Wishes and Good Luck,

Cheers,

db
 
Firewall mount?

Ditto on above checks. It is a new engine and ambient 70F is not that cool.

Is the Niagara mounted on the firewall with Van's firewall mount kit?

OR is the oil cooler mounted in the typical postion #4 position?

Van's firewall kit is not very good. Nothing wrong with a firewall mount but the componets in Van's kit have poor details and are on the small size.

The Niagara cooler should be OK for a 320 Lycoming. For the record the best efficiency oil cooler (lower temp) is the Stewart Warner/South Wind or Harrison.

I am not saying the cooler itself is an issue, but check the part number, I think the latest Niagara should be a 20002a. I think Niagara went thru some part number / design change a few years back. I could be thinking of Aero-Classics or Posi-Tech brand of coolers. You can give Niagara a call on their 1-800 number. Just make sure you have the latest version of Niagara if that is the case.
 
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George:

The cooler is mounted just above #4 cylinder. So far my oil temp is high (240+ degrees when running above 2200 RPM at 7000 feet density altitude), I am satified that the oil temperature measureing device is accurate to 5 degrees, I am only burning <.5 qt per hour, I have no plugs fowled, no oil on the belly, and the oil is so clean after 8 hours that I have difficulty seeing the level on the dip stick. My biggest concern at this time is not seating the rings in the CermiNil cylinders by flying in such a way that I do not exceed oil temperature limits. This gives me only 30 minutes of high RPM flight. I do not want to wait till winter to fly off my 40 hours. This week I will contact Penn Yan and talk to them, remove the vernathermn and check it for proper operation per Dan Cs suggestion, and remove the oil cooler and blow it out, Any more suggestions?

Larry

By the why thanks all for your inputs.
 
How large is the opening feeding air to your oil cooler? I enlarged mine several times before getting oil temperatures to a range I liked.
 
Oil cooler baffle opening...

Kyle,

I never considered NOT cutting the baffle behind #4 cylinder any smaller than the size of the oil cooler radiator. I also sealed the corners of the cutout to be sure that NO air flow could get past the oil cooler. The only time the oil temp on my Penn Yan/ECI (Cermanil) O-320 160 HP engine got above 200 degrees F was on the long slow arrival to Oshkosh this year. It got to 217F when I shut down the engine in homebuilt camping.

Jerry K. Thorne
RV-9A N2PZ
Hobbs = 207.3 hours
 
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How is your CHT and EGT? Did your engine come with the intercylinder baffles, the ones underneath between the cylinders? You might have some cooling issues that are causing the oil temp issue. Also, your oil consumption would be excessive if it gets anywhere near .5 qt per hour. You should probably be talking to PenYan before running that engine anymore. Check with them on proper break in procedures for their engine.

Good luck,

Roberta
 
Jerry

What do you mean by ?NOT cutting the opening?? My oil cooler is mounted on the baffling behind cylinder #4 with the opening equal to the size of the oil cooler surface. Just like Van's instructed. All openings are covered with RTV. Any slight hole is filled with RTV. The engine came from Penn Yan with the inter cylinder baffles. My baffling is tight.

Roberta:

Per a Lycoming web site the normal oil usage is calculated by the following equation: Oil Usage per Hr is .006XBHPX4/7.4 which equals .5 for my 160 HP engine. Did I interpret this incorrect? What can I expect after run in? Tuesday AM I will call Penn Yan and talk to them. I do not understand why I am having this problem. I hope they can help. 40 hours is a long way off at this rate.

Larry
 
Larry, you are correct in your calculation, but that is the maximum allowable oil consumption, and not a normal amount. I ran my new 0-360 with Shell Oil 80. I drained the preservation oil out, removed and changed the filter, added the new oil (8 qts), ran for 1 hour during initial ground testing and engine adjustments, drained the oil and replaced the filter again, added 8 qts of new Shell Oil 80, ran for 25 hours. I added 1 qt of Oil 80 during the first 25 hours.

I ran my engine at 2500 rpm for about two solid hours on the initial flight. After that, I pretty much ran it at 24 sq'd.

I then drained the oil, replaced the filter, and added 8 qts of Oil 80. I ran this for 25 hours. I then switched to Shell 15W50 and change it every 25-30 hrs. I use about 1 qt in 20 hrs. When I add oil after draining old oil out, I add 8 qts, plus a new filter. This usually leaves the engine oil level at about 7.25 qts. I do not top off the oil level. I add 1 qt when I get to the 6 qt level, then change it at 25-30 hrs.

This info isn't going to help your oil temp problems. I just wanted to give you an idea what to expect as far as oil consumption and how one builder broke their engine in. Cermichrome cylinders may be more touchy than standard Lycoming. If you read the lycoming trouble shooting guide (if you haven't already) they do list possible causes.

Are you experiencing high CHTs? This could relate to the high oil temps. High CHTs could be the result of too much cooling air leakage and not enough getting around the cylinders.

Good luck,

Roberta
 
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I think I have finally found something to help reduced the oil temperature. Yesterday I removed the oil filter extension I added to clear the oil filter from the motor mount. With the Penn Yan O-320 the oil filter was very close to the RV-9A motor mount. During construction I installed the ECI AEL106-1 extension filter adapter to increase the clearance between the filter and motor mount. After removable now my oil temperature stabilizes just below 230 deg F at 2500 RPM where before it would approach 250 after 15 min at 2500 RPM. I guess the extension has some effect on the way the vermathermal works. Now I can concentrate on running in the engine. :) Any comments?
 
Ramps on top cowl?

Larry,

Is there any chance that you didn't install the ramps on the top cowl at the front air inlets? This will certainly cause what you are experiencing. Ask me how I know.

Best,
 
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