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Oil squirters

dmattmul

Well Known Member
Today I was involved in a discussion on the Lycoming IO390 having oil squirters and did not have a clue if they did or not. I thought the 390 did not but was told all 390's do. Can someone direct me to an article on what these actually do and which Lycoming's have oil squirters? I've known a few friends whose 360's had oil squirters. Thanks
 
Correct, all angle valve IO-360's and 390's have them. As well, any parallel valve 360's or 320's that were used in turbo charged applications have them as well.
Merry Christmas,
Mahlon
 
And to expand on this thread a little, my parallel valve 540 had provisions for them from the factory and I added them at overhaul. A very easy and relatively inexpensive upgrade.
 
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They spray oil on the under side of the piston to add additional piston cooling. Since there is more oil for the oil control rings to deal with, than there is without squirters, oil consumption increases.
 
I did not document an increase in oil consumption (before vs. after an overhaul is invalid anyway), but seems reasonable. I did expect and experience a noticable increase in oil temp, however. And considering I added the oil jets to pull heat from my piston crowns and thereby increase detonation margin for auto gas use, I considered the added oil temp a welcome data point.
 
I did expect and experience a noticable increase in oil temp, however. And considering I added the oil jets to pull heat from my piston crowns and thereby increase detonation margin for auto gas use, I considered the added oil temp a welcome data point.

The added oil cooling load is what drove my decision to go with the next size larger oil cooler on my -10. I'm not flying it yet, but something I'll definitely be tracking.
 
Yep. I went bigger too. That was before I tried the viscosity valve trick, but needless to say I have ample oil cooling now.
 
Building a IO-540-J4A5 for my RV10, which was turbo charged in its former life, with factory oil squirters. Like previous comments, I'm hoping the oil squirters will pull heat out of the pistons so I can run pump gas.
 
Piston cooling nozzle assembly

For those of you who want to see proof that you have piston squirters in your IO-390, check out Lycoming's IO-390-A Series Engine Illustrated Parts Catalog. Item 16 is "NOZZLE ASSEMBLY, Piston cooling" which is in all models of IO-390A engines.
 

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The old school method for dealing with coagulated oil in the cooler and the resultant oil pressure rise was a spring loaded piston in the accessory case. In normal ops, the oil flow goes 100% to the cooler, but in the case of a restriction, the piston will lift and bypass the cooler. The current vernatherm has this feature as well, but experience indicates the sealing capability of the cone seat is wildly variable and as a result, some engines do not see the cooling oil flow they need. The viscosity valve is VERY effective and can completely transform the oil cooling capability of a given engine. This valve is discussed at length in the threads dealing with a "ball valve" for controling oil flow in winter ops. A search should bring up many examples.
 
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