need help locating secondary oil temp port on O-235-L2C

IowaRV9Dreamer · #1 10-20-2008, 02:43 PM

Hi - to all you knowledgable Lycoming experts - is there a place on a Lycoming O-235-L2C to install a secondary oil temperature probe? If so, where? The engine has the Lycoming spin-on filter adapter (which houses the primary probe and the Ventratherm) and is also set up for an oil cooler.

I've looked thru the Lycoming data with no success.

Thanks for any info,

mahlon_r · #2 10-21-2008, 08:38 AM

There really isn't a good place that will give you the same temp reading as the normal oil temp location. Some use a 1/8 pipe style probe on the front end of the lifter galleries but the oil tends to be hotter there, then where you take it normally. The specs you are given are for the standard location which is about the coolest the oil ever is. So if you use a different location, the oil temp is going to be higher then what you would see at the standard location. I suppose, once you get the error factor down from normal use, you could use either place, correcting the front lifter galley location back to standard location specifications.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."

IowaRV9Dreamer · #3 10-21-2008, 11:49 AM

Thanks Mahlon - I'll check out the front of the engine. What about the location shown below? After reading the Lycoming oil filter adapter information, I think this is just a plug where the ventratherm used to be. I think it has been relocated to the oil filter adapter. Do I have this right?

Thanks for your help

mahlon_r · #4 10-22-2008, 07:21 AM

You could use that port; however there is no flow through it when the vernatherm is closed. So it would be relying on convection when the vernatherm was closed. Might indicate the same temp and might not. There was a certified engine installation that used it, with a really long oil temp sensor probe. Never understood how it could be used as a primary location but it was. I never tested to see if there was a delta with the standard location. I suppose if there was a very little leakage past the closed vernatherm, it would have flow past it and that might make it accurate to the standard location.
Good Luck,
Mahlon
?The opinions and information provided in this and all of my posts are hopefully helpful to you. Please use the information provided responsibly and at your own risk."