Lycoming Versatherm

[marshmaster pat]

What is the use of the versatherm in a Lycoming engine? I know basically what it is supposed to do, but is it needed.

We were changing the temperature gauge from the oil pan to the Versatherm housing on a friend's newly rebuild motor. Switched the housing out with one with a temperature mount and there was no versatherm inside the housing. Screen was there.

Anyone know if it is ok to run the motor without one?

 

[jim]

Pat,

I spoke to Jr Jurnigan about that. He does not run the vernatherm. He runs a restrictor and has some good reasons for that. I don't know what size. Give him a call.

Jim

 

[cowboy]

http://www.avweb.com/news/maint/182617-1.html

Marshmaster,
Looks like the screen housing you installed may be for an engine that would have the vernatherm located elswhere, but all the lycomings should have one, or a different device that seves the same function.

I think they are used to by-pass the cooler when the engine is cold, and then send it through the cooler when the oil gets hot.

The article linked above does not say that specifically, but it suggests that an overheating problem may be caused by a leaking vernatherm allowing significant ammounts of oil to by-pass at all times. Seems to me that it would have to be a huge leak to allow all the oil to by-pass.

Shoot you may have run your boat already, and not had a problem.
I know you watch your oil temp close, as you frequently advise folks on your normal operating temps.

I never researched the vernatherm before, so I was interested to find out what there function was supposed to be.

 

[TerriABW]

spelling-(vernatherm) Not all Lycoming engines have a vernatherm valve and those that do are not all located in the same spot on the engine. If the engine has an oil filter then it has a vernatherm valve. Usually this valve is on the oil filter adapter. On some engines the vernatherm is on the accessory case.

 

[TerriABW]

Engines without a vernatherm valve have an oil cooler bypass valve (viscosity valve). The viscosity valve allows oil to bypass the oil cooler if oil pressure is too high. This valve has a spring, plunger valve, and a plug. The viscosity valve is usually located on the accessory case just under the tachometer drive.