Oil Temp Probe

PaulProe · #1 (**permalink**) 11-28-2011, 09:09 PM

I am using a Canton oil pan on my FE, the one most everyone uses on the typical FE engine build. On the wing of the pan, at the top drivers side is a threaded bung to put in the oil temp sensor.

I am using an Autometer Cobra Series mechanical gauge.

With the NPT adapter and the collet adapter, the probe is supposed to be suspended into the oil. But I am finding with the engine running, there is enough oil in the upper galleys that it doesn't touch the oil until the engine stops and the oil drains back to the pan.

Has anyone else run into this? Any suggestions on how to get the probe lower into the pan?

Paul

Rick Parker · #2 (**permalink**) 11-28-2011, 11:15 PM

Any way to run a tap into the bung to enlarge it slightly, allowing the NPT adapter to screw in further thus lowering the probe? There are different makes & designs of the same adapter, some are slightly different lengths, Autometer, Stewart Warner and others. Are you running the correct (for the pan) volume of oil??

Barnsnake · #3 (**permalink**) 11-28-2011, 11:32 PM

If that bung is on the top of the wing it sounds like it's for the dipstick. On my Canton pan the temperature bung is on the side of the wing about half-way down.

Tom Cimino · #4 (**permalink**) 11-29-2011, 06:34 AM

PaulProe is right. On my Canton oil pan there are two bungs. One on the top and in the front of the right wing for the dipstick, and one on the left, a little aft of center, on top of the wing, for the oil temp sending unit. I haven't installed my engine yet, but that is a question I have asked myself. I will probably weld a new bung on the back of the oil pan just to be sure the sender is in oil.

MaSnaka · #5 (**permalink**) 11-29-2011, 08:34 AM

You can install the sender probe in the drain hole with the proper adaptor fitting. Might be easier if the pan is installed already.

John

ERA Chas · #6 (**permalink**) 11-29-2011, 12:32 PM

Paul's question raises a good additional question; at what level is oil in the pan at idle and then at say 4000RPM?

I know at cold rest, my level is near the top of the cheek. How much gets pumped out of the pan (exposing the sensor) while running? We only need enough to keep the bottom of the pick up submerged-maybe 3/8 to 1/2 ".

And John makes a good point-maybe plugging the sensor bung and using the drain bung is a better idea?

RET_COP · #7 (**permalink**) 11-29-2011, 04:00 PM

Same problem with my Champs pan. By the time I finished adapting my sensor to the pan (top of a wing) it ended up higher then I wanted.I know the sensor is in the oil when the engine is off because the oil level it at the top of the wing, but with the engine running I wonder how low the oil level drops. my sensor will read 10*C hotter when I turn the car off than when running. I'm sure I get splash on the sensor when running because it does read temperature.
Lou

PaulProe · #8 (**permalink**) 11-29-2011, 05:19 PM

Last thing I want to do is drop the pan and weld a bung to it. Major pain plus it ruins the plated finish. Autometer says they can't change the probe and the probe compression fitting precludes you from threading it into the bung any further.

One option is to put the probe into the oil stream, between the block and the remote filter.

What are the advantages / disadvantages of sensing temperature of the oil as it comes out of the pump? Probably a shade higher in temp from the pump / pressure increase.

Not wild about putting the outlet into the oil drain hole.

Paul

ERA Chas · #9 (**permalink**) 11-29-2011, 05:32 PM

Quote:

Originally Posted by PaulProe

Not wild about putting the outlet into the oil drain hole.

Paul

Do you mean the sensor into the drain hole??
That's what John and I are referring to.

patrickt · #10 (**permalink**) 11-29-2011, 06:06 PM

Paul, FWIW, Canton Pan, 8.5 qts w/ cooler and remote filter, sensor on the top, NEVER a problem with the sensor being in the oil. Restrictors on the heads -- .060 in size.

PaulProe · #11 (**permalink**) 11-30-2011, 05:56 PM

Patrick
Mine is exactly like yours, except using Autometer gauge. I am guessing yours is another brand? Other than that, looks identical.

I am using the typical FL1 filter on a remote bracket. Determined the level by putting 7 quarts into the pan (Canton calls it an 8 qt system) and then marking the dipstick. I then added enough oil to fill the filter/lines/oil cooler to bring it up to that mark.

Guessing that is a little too low. Spoke to Canton today and they recommended adding a 1/2 Qt. of oil. They were guessing there is enough windage from the big block that it is sucking the oil away from the probe. I am using the Canton 20-938 screen type windage tray. Allows quick return of oil but they say it isn't as effective as their new louver type.

Been searching the FE Forum, trying to find a correct oil level. Wish someone could tell me the distance from the pan rail to the oil surface on a stock motor. By the number of threads regarding this, looks like I am not the only who would like to know this dimension. You'd think after five years, someone would post an answer.

Trying to avoid issues from Over-Filling

Paul

patrickt · #12 (**permalink**) 11-30-2011, 06:00 PM

Quote:

Originally Posted by PaulProe

Patrick
Mine is exactly like yours, except using Autometer gauge. I am guessing yours is another brand? Other than that, looks identical.

Mine is a Smiths mechanical. Do you have the oil feeds in the heads restricted? If not then you might be filling up up-top and that could be the whole problem.

PaulProe · #13 (**permalink**) 11-30-2011, 07:16 PM

Quote:

Originally Posted by patrickt

Mine is a Smiths mechanical. Do you have the oil feeds in the heads restricted? If not then you might be filling up up-top and that could be the whole problem.

Oops, meant to post that info: Heads are restricted to .060 on each side. Topside isn't filling up with oil, I have some cut-off valve covers and have observed oiling action at topend. Not an issue, it is draining down ok and not accumulating.

Paul

patrickt · #14 (**permalink**) 11-30-2011, 07:23 PM

Quote:

Originally Posted by PaulProe

Oops, meant to post that info: Heads are restricted to .060 on each side. Topside isn't filling up with oil, I have some cut-off valve covers and have observed oiling action at topend. Not an issue, it is draining down ok and not accumulating.

Paul

Huh. And the temp on your mechanical gauge goes up significantly in, say, 30 seconds after you shut the engine off and, presumably, the oil level in the pan has now risen up to touch the sensor? I would think the "hurricane" of oil around the sensor would be good enough to give it an accurate reading, but maybe not.

ERA Chas · #15 (**permalink**) 11-30-2011, 07:33 PM

Paul, as a test, I would: plug your current sensor location, drain oil into a clean pan, install the sensor (probably need an adapter-I forget the thread sizes) into the drain hole. Refill oil. That will tell you quickly if you're getting real temps up there.
FWIW, I fill mine with seven too and the cooler, filter and lines account for 1 1/2 more.

patrickt · #16 (**permalink**) 11-30-2011, 07:44 PM

I would do what Chas suggested... but only after I popped the sensor in to a pot of boiling water that I put under the car -- then check the gauge reading and see if it's 212f/100c. If it passes that test, proceed to his test.

ERA Chas · #17 (**permalink**) 11-30-2011, 07:52 PM

Eureka! Found my thread sizes notes;
MY temp sender is 5/8-18.
MY drain plug is 1/2-20.
YOURS may differ due to the age of my pan.

ERA Chas · #18 (**permalink**) 12-02-2011, 08:02 AM

Paul,
Where are you with this problem?

PaulProe · #19 (**permalink**) 12-02-2011, 03:42 PM

Quote:

Originally Posted by ERA Chas

Paul,
Where are you with this problem?

Chas,
Car is now on blocks for some winter Mod's so this has gone to the back burner for a month or two.

Since I know the gauge works and oil temp is indicated when the engine is off, I think it is a oil level issue. Still searching for a dimension from the pan rail to the oil surface but not having much luck

I do have a stock FE oil pan and came up with the idea of putting 4 qts and measure to flange, then add a quart and measure again. That should give me a reading that Ford originally designed into the vehicle. The four quarts should replicate a typical stock 390 FE and the 5 qts should replicate the Cobra Jet issue where Ford said "add a quart"

Once I have that number, I can compare it to what I am getting on my Canton Pan with the 7qts in it. The error should show if there is one.

Something to play with this weekend

Paul

ERA Chas · #20 (**permalink**) 12-02-2011, 04:08 PM

Quote:

Originally Posted by PaulProe

I do have a stock FE oil pan and came up with the idea of putting 4 qts and measure to flange, then add a quart and measure again. That should give me a reading that Ford originally designed into the vehicle.

You can forget the stock pan and all that work. I just found my notes from when I did an r & r on my pan in July (off the engine). All dimensions carefully measured. Here ya go:
Floor of pan to pan rail=6".
Six qts in pan to pan rail= 3 3/8"
Seven qts in pan to pan rail=2 7/8"
Straight edge across the pan rail. Don't measure to block rail-the windage tray and gaskets will add dimension.