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Technical => Engine Tech Forum => Topic started by: Swartz on June 17, 2006, 01:45:36 PM

Title: Oil/head Temp.
Post by: Swartz on June 17, 2006, 01:45:36 PM

hey, just wondering what temp. my engine should be running at. I have head and oil temp guages. After about 5min of running the car, head temp. was aprox. 260 and oil barely went above 120 (the guage starts at 120 so it barely went up, but when i shut the car off it would go down a tiny bit. so it is working.) When should i start worrying? if it does get too hot should i just shut my car off, or keep it idling so the fan is still cooling the engine down....

Title: Oil/head Temp.
Post by: Bubba on June 17, 2006, 02:41:47 PM

Removed my .02 because Bruce is right...
Csaba

Title: Oil/head Temp.
Post by: Swartz on June 17, 2006, 02:50:23 PM

hey, thanks for the response. My oil temp is T'd in to my oil pressure sender, and the head temp is the ring style under the spark plug. Once i can get the car out and run it ill be able to get a better idea of my average temps.  

Title: Oil/head Temp.
Post by: Bruce on June 17, 2006, 08:48:09 PM

Quote

.... most of the commercial grade automotive gauges and senders are inaccurate.  That includes VDO gauges.
 

That statement is inaccurate.

The VDO gauges I tested were dead on, within one needle width.

Title: Oil/head Temp.
Post by: Bubba on June 17, 2006, 10:32:38 PM

Well. Bruce.  I guess I will have to chalk it up to bad luck all my life.

Title: Oil/head Temp.
Post by: Bruce on June 18, 2006, 12:29:00 PM

Must be.  
Gene Berg made that same blanket statement, that all gauges are way off.  That's why I tested mine.

Some guys test theirs by comparing the readings to other gauges.  This means nothing.  You must have a known standard.  For an oil temp gauge, dunk the sender in boiling water.  It is known that water will boil at 100

Title: Oil/head Temp.
Post by: Bubba on June 18, 2006, 01:19:42 PM

Removed because there is no point arguing with Bruce. ^_^  

Title: Oil/head Temp.
Post by: Bruce on June 18, 2006, 04:47:36 PM

How were your thermocouples calibrated?

The co I work for manufactures instrumentation for the oil and gas industry.  We make pressure sensors, temp sensors and flow meters.  Customers demand calibration traceability to known standards.  Last year we spent over $100k getting ONE of our flow meters calibrated at a testing lab in Colorado.  Now that it is calibrated and traceable, we can now use that as a standard reference for future manufactured flow meters.
We are also an ISO certified manufacturer.  One step to achieving that is that all of your measuring tools used in manufacturing must be calibrated bi-annually.  Last month the bill was $7k.  

If your thermocouples were not calibrated, the error could have been due to them.  Without a calibration certificate, you are just guessing.

Your calibrations showed that the CHT gauges were off.  If it is true, it does not necessarily mean that oil temp guages are also off.

Title: Oil/head Temp.
Post by: Bubba on June 18, 2006, 08:08:24 PM

Well, as usual, you are always right.

Title: Oil/head Temp.
Post by: Bruce on June 19, 2006, 03:26:40 AM

So I guess your thermocouples were NOT calibrated.

Title: Oil/head Temp.
Post by: Bubba on June 19, 2006, 05:24:30 PM

Quote

So I guess your thermocouples were NOT calibrated.

Your assumption is inaccurate.