Normal Oil Temperature Range

B

blanducci

Member
I'm doing break-in on a top-overhauled 165 in a 14-13-2 (that I've had for 3 years and flew only for the 3'rd time this New Year's day) and am curious what others see for normal oil temps. I've got an EI engine monitor and the oil temp 'yellow' indication is between 200F and a few degrees below the Franklin specified max oil temp of 230F. After an hour or so I'm seeing oil temps rise to around 205F to as high as 215F. Would prefer that the monitor wasn't flashing 'oil in the yellow' warning constantly if 205 to 215F is actually considered normal. OAT here in WI has been in the 20F to 30F range during the flights. If it makes sense I'd like to bump the engine monitor's 'in-the-green' range to include up to 215 or so. I assume the unusually high power settings associated with break-in are driving the oil temps higher than normal, but I don't have enough flight time in this plane under 'normal' conditions for reference.

Thanks,
Bill - N74424
 
Bill, that seems high to me. My 150 powered 14-13-2 ran around 80-85c (176-185f) on a really hot day climbing out of Oshkosh with all the camping gear I saw 95c so I put the nose down and quit climbing. I had the old three in one gage on mine.
 
Elevated oil temps are normal on a new engine.. a drop in temp is the classic indication that break-in has occured.
If your temp stabilizes below red line you're probably OK. Higher power levels and the blow-by normal with new rings are the culprits. Get a feel for what you're is running and watch for a drop but by all means, make it work! Babying a new engine often turns out bad.
Of course, someone always want to point out that you're measurement isn't calibrated.. that's not often the case, especially with EI stuff. But if you really want to, you can drop the thermocouple in boiling water and see if the EI says 212.
Long periods of non-use can cause some corrosion in cylinder walls (and other places).. best to change oil often for a bit and if you do analysis, expect higher-than-normal iron levels.

I left Dallas for San Diego with an IO-470 that only had 3 hours on it.. ran it at lowish RPM and Highish power setting - somewhere over Arizona the oil temp dropped. Now it one of the sweetest engines I've ever owned.
A friend installed a factory new O-470 in his skylane and despite my constant badgering refused to work it, worried about the high oil temp. you guessed it, ruined. On top of that, he provided Continental with engine telemetry data from his whiz-bang monitor. Continental refused to pay for an overhaul.. He could have bought another Skylane for what he put into that engine :)
 
That's good to hear. I'll keep an eye on the oil temp as break-in progresses. I feel we've been running it pretty hard - close to WOT for 2600 to 2700 rpm out of 2800. I knew to watch for a drop in CHT as the rings eventually seat, but makes sense the oil temp would do the same. CHT spread is about 65F with the right side cooler - and the front right the coolest.
 
Bill,
Make sure the ducting from the nosebowl to the oil cooler/carburetor is as airtight as possible.
You don't want any leakage.
The advise previously given is spot on. Your rings should seat in one or two flights. Leave the throttle
wide open for most of the flight, but vary it occasionally.
And yes, after break-in or 3-5 hours, drop the oil and check for debris...there should be some fine flakes
visable. Use mineral oil for the next couple oil changes.
Dan
 
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