Can an engine run TOO cold

Maybe worth noting is that water starts to boil at 212F at sea level. It vaporizes at a lower temp (notice steam coming off the pot prior to boil). However, at 13,000ft, water boils between 185-190F. Therefore oil temps in that range would be sufficient to remove water by vaporization.
 
hotprops said:
ok what is the oil temp ? if it is on the cool side as well might want to check vernatherm and seat
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Did not think this was on continentals until I looked in the Engine manual. Looks like I have a Vernathem to control oil temp.

Will need to investigate this.
 

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Trailboss said:
Maybe worth noting is that water starts to boil at 212F at sea level. It vaporizes at a lower temp (notice steam coming off the pot prior to boil). However, at 13,000ft, water boils between 185-190F. Therefore oil temps in that range would be sufficient to remove water by vaporization.
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There is a change in the boil off temp when emulsified in oil.
 
Yes, Continentals have a vernatherm. Problems can include carbon that keep the valve from seating all the way, improperly set, etc.

Of course, I just have stock gauges for oil temp, so it's entirely possible I'm running too warm (or too cold).
 
your oil is way to cold at 130. and the temp sensor is located after the last rear crank journal the hottest place. it will show you in the engine manual . take the wire off the sending unit and read the ohms cold than do the same hot. the manufacturer of said sending unit will have the values to see if it is the gauge .sending units rarely go bad until they leak .
 
Thought I would post the solution to my oil temp problem.

I got a hold of D'Shannon folks and they were extremely helpful and confirmed this was a common problem with the efficiency of their baffles being run in the colder areas of the country.

He mentioned they have a bolt on solution in the works and it is going through the FAA approval process so its not available. But the common fix is to cover up 1/4-1/2 of the oil cooler with aluminum and gorilla tape it to keep it in place.

He mentioned changing out the vernatherm valve but then if I flew to someplace warm I cannot change it to cool things down, but you can just remove the cover plate if things get warm.

So I played with different coverage and finally settled on all but a 1" slot that puts my oil temp at 85 DEG C with OAT at 30 DEG F and my oil pressure now runs in the green (barley) and it used to run near 75 PSI (now its 60 PSI).

:thumbsup:
 
MyassisDragon said:
Dumb question here but after changing my spark plugs from Massives to Fine wires I noticed she can run LOP with less fuel and smoother so now my EGTs are the same (1300-1350F) but my CHTs are 250-260F and dont even show up on the JPI anymore.

This is on a Continental IO-550B with Deshannon baffles and GAMI's

Conditions for flight yesterday:
40F OAT
7000FT ALT
2300-2350 MP
2350-2400 RPM
12.5 GPH
168 TAS (152CAS)

I can also lean further by almost 1GPH but the engine doesn't feel as smooth (still smooth though) and my speed drops a few knots. but the CHTS drop into the low 240F range.
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What is your oil temp? If over 170 you are fine. If not, you need to get the oil temp up. Tape off part of your oil cooler. If 170 or over, don't worry. Fly the wings off her.
 
GLMS_NC said:
What is your oil temp? If over 170 you are fine. If not, you need to get the oil temp up. Tape off part of your oil cooler. If 170 or over, don't worry. Fly the wings off her.
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I believe that is way too broad of a statement and it depends on which engine and where the oil temperature is being measured.
 
timwinters said:
I believe that is way too broad of a statement and it depends on which engine and where the oil temperature is being measured.
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Really? He said he has an io550. RTM - it has required oil temp readings clearly documented.

On a Coni oil is measured in front of crank or at base of cooler. Manual doesn't differentiate temp for different locations.

From the manual...
Oil Temperature Limits
Minimum for Take-Off......................................................... 24°C/75°F
Maximum Allowable............................................... 115.6°C/240°F
Recommended Flight Operation...................................................170° F.


From the oil filter discharge port, oil is directed through a crankcase passage to the oil cooler. In addition to facilities for oil cooling, the oil cooler incorporates an oil temperature control valve. Oil passing by the oil temperature control valve cavity directs oil either through the oil cooler core and or through the oil cooler bypass to the crankcase passage at the rear depending on the oil temperature. If engine oil temperature is above 180°F, all oil is directed through the oil cooler.
 
timwinters said:
Fair enough!:redface:
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Not trying to give you a hard time, but I encourage every pilot to read the manual for your engine and airframe carefully. The answers to most questions are answered there. CMI wants oil temp at 170 for a reason. Notice CMI doesn't publish specific EGT numbers, but they do publish specific CHT numbers. Knowing this will help you get max life from, and you will protect, your motor.

Related, CMI also says they want continuous cruise of certain motors above 2300 RPM to get the counterweights working. Below 2300RPM's the counterweights don't come out and that causes additional issues. Again, the manual does a great job explaining all this.

I hear all the arguments LOP vs ROP. Guess what - CMI says running LOP if done right is fine. But I have heard countless hangar rats tell me I am destroying my motor running LOP. None of that is based on any science.

Manufacturers give us these manuals for free and many offer toll free support. I only wish Honda published all their manuals for free and gave toll free technical support.
 
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