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My car was completed in 2005 and I’ve only driven it 4500 miles, so with so few miles a year, I usually change oil about every other year. Perhaps I’ve been lucky, but knock on wood, it’s always run fine.
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Low oil temp in my engine
Running an 8 qt pan and cooler on my 514 CI beast. Oil passes thru twin oil filters on its way to the oil cooler. On a recent 90 degree F day, after some spirited driving, oil temp rose to about 150 F. That's as high as it has ever gone. Granted most of my limited miles have been 20 or less miles, but the temps concern me. I have even installed a metal shield over the cooler, but not sure that helps raise temp very much.
Am strongly considering removing the cooler, and AN lines, and mounting oil filter on the engine block rather than the current remote location. Next trip, I WILL shoot the pan with my IR thermometer, just to confirm what I fear - low oil temps. |
Funny I have never even thought about low oil temps and personally, I would welcome low oil temps. Just use the proper weight oil your builder recommends . It is my thought that you guys are being like women worrying about nothing.
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This morning I drained the oil and will send off a sample for analysis, hoping to learn if their is any unusual engine wear. The magnetic oil plug showed very minimal metal shavings. As for the new oil, I've been using Valvoline VR1 racing oil, but since I somehow misplaced one of the empty bottles, I don't know what weight I've been using. I believe it was 20w-50. The only other weight they make is 10w-30. Which would be best in the hot summer temperatures and mild winters of Savannah? I don't drive the car often and don't track the car.
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Oil has an operating range. The upper range is pretty well known. The lower range is not well known. Some say it's as high as 200* or so. But 180* seems to be about the minimum. Studies done in the arctic show that engines running less than 160* show accelerated cylinder wall wear. Remember that street oil has two viscosity ranges, like 5W-40. When the oil is cold, the viscosity is low and the oil is "thin". Do you really want to be driving around with an oil that thin? Unless you're making a qualifying run, you do not. Also, the additive packages are designed to operate at certain temperatures. If you're not in that range, the additives don't work like they're supposed to. Some people think that if the oil temp is <212*, the water collected in the engine will not evaporate. Which is ridiculous. If that were true, your kitchen floor would never be dry. Just remember that the lower the temps are, the longer it takes for that to happen. |
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The oil viscosity index of 5W40 indicates its 'weight' of '5' when cold (0°F), and its 'weight' of '40' when hot (212°F). Explanation from https://autosneed.com/oil-viscosity-and-weight/ The SAE classification for multi-viscosity oil consists of two viscosity grades, such as viscosity SAE 10W-30. The first part of the grade (10W) is the comparable grade of the single viscosity oil that features the oil’s weight at cold temperature. The second part of the grade (30) is the grade of the comparable single viscosity oil that defines its viscosity at 212 degrees Fahrenheit. You should note that both parts of the multi-grade SAE classification are not viscosity values but grades. Here is another interpretation of how to read oil viscosity (SAE 10W-30) SAE = Society of Automotive Engineers 10W = the viscosity of the oil when measured at 0 degrees Fahrenheit (the “W” means winter grade) 30 = the viscosity of the oil when measured at 212 degrees Fahrenheit In other words, SAE 10W-30 has a base rating of 10 when cold. Therefore, it will flow freely at temperatures as low as -20 degrees Fahrenheit. Usually, oil thins out when heated because it becomes thinner, its viscosity number becomes lower. https://www.kewengineering.co.uk/Aut...ison_chart.jpg If you look carefully at the above chart, you'll see 5W oil has a Kinematic Viscosity of about 20 at 40°C (104°F), while a 40 weight has a KV of about 13 at 100°C (212°F). A 5W40 oil is equivalent to a 5 weight oil when cold (0°F) and equivalent to a 40 weight oil when hot (212°F) - but it's still MUCH thicker when cold than it is when hot - at least 50% thicker at 40°C / 104°F, never mind the much greater difference at colder temperatures. A 5 weight oil, being much thinner when cold, will often do a FAR better job of flowing into thin spaces (e.g. bearings) and small orifices (e.g. hydraulic lifters). As such, a 5W40 oil is often a far better oil than 20W50 in order to properly lubricate an engine at startup - when most engine wear occurs. Here's a good chart, showing different multi-viscosity oils during warm-up: https://www.kewengineering.co.uk/Aut...comparison.jpg Note the difference at 20°C (68°F) is much less than it is at 0°C (32°F), and the differences between 5W30 and 20W50 aren't easily discernible at 100°C (212°F). https://www.kewengineering.co.uk/Aut..._explained.htm |
Don't get all wrapped up in charts, graphs and numbers. They can be deceiving, unless you look up the actual test parameters. It's not as simple as drawing a line across the chart. It's a lot more complicated than that.
So Just think about it for a minute. A multi-weight oil is designed for a specific purpose. The "5W" part is thin, so it flows easily when it's cold. The "40" part is a bit thicker, so it supports the bearings, rollers, and such when the engine is hot. It's not logical for it to be the other way around. You wouldn't want something that's molasses when cold, and baby oil when hot. Would you want to be driving around all the time with a 10W oil? Certainly not. If that were good for engines, we'd all run a straight 5W oil and be done with it. |
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Gary |
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https://www.youtube.com/watch?v=8cyzRwlzHRc https://www.youtube.com/watch?v=21iYS-vaCQU Quote:
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What you're obviously missing - or choosing to ignore - is how temperature affects viscosity. 5 weight oil has a viscosity of 161 at 20°C / 68°F, while 40 weight oil has a viscosity of 16 at 100°C / 212°F - that means the 5 weight is 10 times thicker at 20°C / 68°F than the 40 weight oil is at 100°C / 212°F. BTW, I've poured multi-viscosity oil in a Canadian winter - and I have personal experience that 5W30 is like corn syrup or liquid honey when it's cold. Believe what you want, but facts don't lie. |
I said don't get wrapped around the axle about all the charts and graphs. Not because the science doesn't matter, but because there's more to it than that. If studied those charts (and more). If all you look at is a couple of charts, you'll miss the big picture.
But, back to the main point. There is a minimum operating temp for engine oil. I have searched for what that is, exactly, but the answer seems to be variable. Some engineers say it's 180*. And some say it's 220*. So I'm not sure. But it certainly seems to be no less than 180*. |
Initial comment:
Remember that street oil has two viscosity ranges, like 5W-40. When the oil is cold, the viscosity is low and the oil is "thin". Do you really want to be driving around with an oil that thin? Unless you're making a qualifying run, you do not. Questioning of initial comment: Perhaps it's the way I'm reading this, but you seem to imply that 5W40 is thinner when cold than it is when hot. Hopefully that's not what you mean. Questioning of initial comment: Here's an admittedly unscientific experiment conducted by a father and his sons that clearly shows 5W-40 oil is significantly thicker at 0 degrees celsius than it is when it's approximately 100 degrees celsius. -------- It seems the challenge side here is out to prove that oil is thinner when hot than cold. I ‘assume’ the initial comment was, made loosely, in relative terms, intended to mean the same, as follows. That is, in general, given the two numbers in a multi-viscosity oil, when oil/temp is cold, an oil with the lower grade number would be thinner at that same lower temperature than would an oil with the higher grade number. More specifically, I think he was referring to the 5W grade, and its properties, a ‘thinner’ starting/cold temp grade compared to other grade options on the grade scale, and so even thinner (too thin) when it heats up. I don’t know that he spoke to the protection to the 40 grade at higher temps, rather was just making a point about the 5W cold/starting oil temp grade itself. Maybe both sides are actually on the same page, stated in vastly different ways, on that point anyway! Just a thought…Brent |
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I put a Mocal which is period correct
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Cooler and thermostat
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I have a cooler and the canton thermostat, and the oil ALWAYS marches right up to 100 c and stays there unless I put the leather to it then it goes as high as maybe 105 or so...the rate at which it goes to 100 is pretty much independent of ambient temps...of course I’m in CA (not proud) so the block never gets very cold when cold...could be different in really cold climates I guess. Cheers Steve H SPF 1764 |
Taking Bobcowan’s suggestion, I tried the infa red thermometer and yes, my oil pan temp is 175+/- degrees so either my gauge or sender is bad. My sender is mounted on top of remote mounted oil filter. In removing it, it appears to be perhaps too short to protrude directly into oil flow. Also, reading Stewart Warner gauge installation info, the say not to use sealer tape in mounting sender because the contact with motor is the ground. My sender is mounted into a threaded reducer fitting, allowing the smaller diameter sender to fit into the larger diameter opening in filter bracket. The reducer fitting appears to have had some tape in the threads. Perhaps that’s the problem.
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Edit: Updated link https://photos.app.goo.gl/64HC5yV31a8VMi977 |
Couldn’t get the link to open, but my oil pan appears to have an extra plug, presumably threaded through which I might could use my existing sender. Before I try that, I may try running a ground wire from my sender.
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read my entire post
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