View Full Version : Oil Temp Gauge Reads Lower with Extension Rod on 351W
Those that have experience with oil temp gauges on extension rods … did you find the oil temp reading lower than it actually is because of the extension rod?
I have the below extender on my 351W with a speedhut temp sensor at the end. Rod has a very small passage for oil and the rod is fairly long so I assume I should discount the temp reading. Curious if I should discount the temp at all and, if so, by roughly how much. I couldn’t find much info using google or searching the forum so any experience you guys have is great to hear.
https://www.summitracing.com/parts/SDK-C2OZ9B339DP
Jim1855
06-27-2022, 06:17 PM
Wouldn't be my choice of ways to measure temps. I would expect that the oil will cool in that tube and then there's the limited circulation to the sender, so you are not reading hot oil.
Short of the oil at the bearings I believe that the hottest oil is in the pan as it drains back from the heads and lifter valley. Some pans have the bung in place but often these need to be added, usually by drilling and welding.
The Summit extension tube is indicated for pressure, didn't see anything indicating a suitability for temps.
Jim
Yea, I noticed it was labeled as oil pressure but has two outlets. Blueprint suggested I get that specific rod in order to have both oil pressure and temp. Pressure seems to work great. Temp is generally pretty low and didn’t know how low exactly, I might ditch the rod and figure out an alternative for temp.
Bob Cowan
06-27-2022, 07:34 PM
The extension is a poor place for the temp sensor. Oil doesn't flow through there; it's a dead end. It's never going to be accurate or repeatable. You need to put it in the pan, or somewhere in the oil flow.
rich grsc
06-27-2022, 07:53 PM
Bob is correct. The sensor must be in flowing oil or the pan.
Jeff Kleiner
06-27-2022, 08:48 PM
X3. Oil is dead headed in that extension. Fine for reading pressure but useless for temperature. Best to be in the sump, or if you happen to have a cooler or remote filter in the flow exiting the engine.
Jeff
MB750
06-28-2022, 06:55 AM
Just curious, but why are you interested in oil temperature? Back in my Harley days it made more sense because the engines were oil cooled, but not a Windsor.
CraigS
06-28-2022, 07:04 AM
I like it so I have an idea if it is warm enough to go full throttle yet. I started paying attention to that after I sheared off the pin that locates the gear on the distributer shaft. It was a cool day at an autocross and I had made sure the coolant temp was up to normal but got to coast off the course when the engine stopped.
GoDadGo
06-28-2022, 07:52 AM
I opened up a CVR oil cooler sandwich adapter with a little strategic drilling (I'm Not Running A Cooler) and it made an excellent location for an oil cooler sending unit and an oil pressure safety switch. If you have the room it might be an option worth looking at.
The link shown below for the Ford Version of the adapter that I'm running:
https://www.summitracing.com/parts/cvs-ocs64
Good Luck & I Hope This Helps!
Verdict is in that the method with the extension rod is not optimal. I’ll relocate the oil temp directly to the pan.
Thanks guys!
Jim1855
06-28-2022, 09:07 AM
Oil temps? All depends on what you are doing with the car.
Water temps are important if in an event like Woodward Dream Cruise or heavy summer traffic. Oil temps become important if running road track sessions for 20 minutes and more. I ran a larger than normal oil cooler and regularly saw temps of 250-260f during sessions. Never saw this during more normal street driving no matter how hard I tried.
On the street I watched water temp and oil pressure, at the track it was oil temp and pressure. Always watched the tach.
Jim
Hoooper
06-29-2022, 02:33 PM
Just curious, but why are you interested in oil temperature? Back in my Harley days it made more sense because the engines were oil cooled, but not a Windsor.
On the street my water gets to 203 max, oil max 208 (this is with a thermostat controlled cooler bypass to get it that high). On track, water temp max 205, oil max 260, and that is with a big 14"x13"x2" stacked plate oil cooler. Oil temp shouldnt be an issue on the street but if the car gets run on the track and either doesnt have a cooler or has a cute little street size one youre gonna want to have a temp sensor to let you know when to slow down so you dont trash the engine.
Avalanche325
06-29-2022, 03:49 PM
Two ports is so you can have a pressure gauge and an idiot light. I have that for autocross where you don't have time to look a gauges.
As stated, temp sensor needs to be in the flow.
Two ports is so you can have a pressure gauge and an idiot light. I have that for autocross where you don't have time to look a gauges.
As stated, temp sensor needs to be in the flow.
That is a great idea for the idiot light, how low does the oil pressure need to get before triggering the light? You have me thinking I might add this for a winter project this year. It would really be a nice option to have even for street driving.