patterson

patterson

Well Known Member
Patron
Hello,
I just installed a late model Lycoming with "piston oil squirters" and am seeing 205+ oil temperatures despite using a slightly larger than normal oil cooler. These temperatures are recorded at an outside temp of 30 degrees at 7,000 feet. Cruise at 10K feet / 21 degrees OAT yeilds 190 degrees:eek:
My cylinders are a bit cold at 250 - 290 degrees but my oil is just too hot. I'm worried about trying to fly in warm weather with these winter numbers. The engine I replaced was too cold in winter and had to be shuttered.

Someone mentioned that using the oil squirters case changes the motor from "air cooled to oil cooled".

Any ideas/suggestions would be appreciated.
Ron
RV-4
N8ZD
 
check the archives for ideas

There are lots of discussions of this. If you search on 'oil cooler' or 'oil temp', you will find several.

Where is your cooler? Are you SURE you have the side edges of the cooler sealed to the mount so that all the air goes through the cooler?

I thought mine was sealed and when I finally put some orange RTV around the perimeter, my oil temps went down some. I have some pictures posted in old threads showing my cooler install.

I have IO-360-A1A angle-valve, oil-squirters, and it does seem to be true, the cylinders run cooler, the oil runs hotter. With a big cooler, well installed, the problem is solvable.

For comparison, last week, cruising 7000 ft, OAT of 30F, I had 165F oil. I have a butterfly valve to restrict cooler flow to help it stay warm in winter. In summer, 90F days, climb straight to 10,000 ft at 110 kts and I see peak 215F oil, 365F cylinders.
 
Last edited:
Calibrate"

Step 1 square 1 calibrate the OT gauge. Until you do that your just guessing.
But these are not bad temps anyway.
Good luck
 
With piston squirters, you'll definitely need a big oil cooler. We learned that lesson the hard way on my friend's RV-8. A standard Vans-supplied NDM 7-row cooler will never be able to cool such an engine. A cooler like a SW-10599R, SW-8432R, or a 10-row Aero Classics cooler has been known to work pretty well with a piston-squirter IO-360. If you can find room to fit one, the larger 13-row coolers can definitely get the job done in hot summer temps, but you'll also need to rig up an airflow control valve on that large of a cooler for flying in cooler weather since it'll cool too much then.
 
Factory suggestions

From Lycoming's Operating Tips handbook -

8. For maximum service life, maintain the following recommended limits for continuous cruise operation:
a. Engine power setting ? 65% of rated or less.
b. Cylinder head temperatures ? 400˚ F. or below.
c. Oil temperature ? 165˚ F. ? 220˚ F.

http://www.lycoming.com/support/tips-advice/key-reprints/pdfs/Key Operations.pdf

Is 190F is cruise a bad number?

Even 205F is OK by lycoming if it is a climb number...
 
These are in very cold winter air

Gil, I think the OP's concern is that these numbers were observed when it was below freezing outside. What will it be like in the heat of summer?

Steve.

az_gila said:
From Lycoming's Operating Tips handbook -

8. For maximum service life, maintain the following recommended limits for continuous cruise operation:
a. Engine power setting ? 65% of rated or less.
b. Cylinder head temperatures ? 400˚ F. or below.
c. Oil temperature ? 165˚ F. ? 220˚ F.

http://www.lycoming.com/support/tips-advice/key-reprints/pdfs/Key Operations.pdf

Is 190F is cruise a bad number?

Even 205F is OK by lycoming if it is a climb number...
Click to expand...
 
scsmith said:
Gil, I think the OP's concern is that these numbers were observed when it was below freezing outside. What will it be like in the heat of summer?

Steve.
Click to expand...

Yes... but there is a Vernatherm in the equation altering the numbers somewhat...
 
Can't tell where the OP is - if in warmer states, the temps will definitely go up in summer. I'm in the great lakes area and I have to keep speed up in the climb and watch temps to make sure they stay within range.

You are probably going to want a bigger cooler, make sure all the gaps in the baffles are sealed & the seal around the cooler is solid. You may want to find a way to get more air to the cooler (ie., a 4" feed up from 3" - that makes about a 75% increase in the cross section in square inches).

Dan
 
You must log in or register to reply here.