Race Prep Miata race-only chat.
Sponsored by:
Sponsored by:

Oil cooler tech

Old 09-10-2015, 09:08 PM
  #201  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,645
Total Cats: 3,009
Default Oil cooler tech

Is that measured on the pre or post cooler part of the sandwich?
sixshooter is online now  
Old 09-10-2015, 09:18 PM
  #202  
Elite Member
iTrader: (4)
 
hornetball's Avatar
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,301
Total Cats: 696
Default

It would have to be pre, because the post cooler route goes through the filter and then into the block through the central pipe.

250 pre-cooler is nothing to worry about.
hornetball is offline  
Old 09-10-2015, 09:28 PM
  #203  
Boost Pope
iTrader: (8)
 
Joe Perez's Avatar
 
Join Date: Sep 2005
Location: Chicago. (The less-murder part.)
Posts: 33,017
Total Cats: 6,587
Default

Originally Posted by hornetball
It would have to be pre, because the post cooler route goes through the filter and then into the block through the central pipe.


Depending on the design of the plate, and its orientation, it's possible to take a measurement either pre or post-cooler.

This one, for instance, has ports on both sides:

Attached Thumbnails Oil cooler tech-80-dyidu_1c6cc459d5029a76f71e74cc32252194daec52bf.png   Oil cooler tech-1.0x0.jpg  
Joe Perez is offline  
Old 09-10-2015, 09:29 PM
  #204  
Elite Member
iTrader: (4)
 
hornetball's Avatar
 
Join Date: Mar 2008
Location: Granbury, TX
Posts: 6,301
Total Cats: 696
Default

Brainfart.
hornetball is offline  
Old 09-10-2015, 09:32 PM
  #205  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,645
Total Cats: 3,009
Default Oil cooler tech

Yep, that's like mine and why I asked.
sixshooter is online now  
Old 09-10-2015, 09:37 PM
  #206  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

Mine is just a sandwich plate. Just for gauges/spacing.<br />
<br /><br />What temp should I be worried?
<br />Rotella T6
aidandj is offline  
Old 09-11-2015, 12:52 AM
  #207  
Elite Member
iTrader: (2)
 
Arca_ex's Avatar
 
Join Date: Jan 2013
Location: Chandler, AZ
Posts: 1,628
Total Cats: 427
Default

Originally Posted by aidandj
Mine is just a sandwich plate. Just for gauges/spacing.<br />
<br /><br />What temp should I be worried?
<br />Rotella T6
I'd start thinking of pulling off or doing cool down laps at like 240... running a boosted Miata with no oil cooler is kind of asking for trouble.
Arca_ex is offline  
Old 09-11-2015, 12:54 AM
  #208  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

Originally Posted by Arca_ex
I'd start thinking of pulling off or doing cool down laps at like 240... running a boosted Miata with no oil cooler is kind of asking for trouble.
<br />
<br /><br />
<br />I have a 25 row setrab.
<br />I was refering to where the temp was taken.
aidandj is offline  
Old 09-11-2015, 01:30 AM
  #209  
Elite Member
iTrader: (2)
 
Arca_ex's Avatar
 
Join Date: Jan 2013
Location: Chandler, AZ
Posts: 1,628
Total Cats: 427
Default

Oh. I'm assuming that temp is before the oil cooler so then that means I have no clue for your scenario.
Arca_ex is offline  
Old 09-11-2015, 03:27 AM
  #210  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,292
Total Cats: 475
Default

Originally Posted by aidandj
Oil temp question.<br />
<br /><br />At the track today, I'm seeing 250 indicated in my sandwich plate. I know 250 is getting hot when its in the pan but my sensor is in the plate. What temp should I start doing cool down laps?
Not miata obviously, but a lot of high performance german cars go into limp mode in the 270's *F (dropped rev limit to about 1/2 of normal, HP down to ~25% of normal_ and stays there until oil is in the 250ish range. My C63 shuts the party down at 275, drops revs to 3,500 max, upshifts to highest gear, will remove your control to manually downshift it, power drops to about 100hp.

Given the fact that many of them shut it down around 270, I would think beating on it all the time near say 250 is probably a bad idea. If you did it, I'd swap the oil afterwards.
patsmx5 is offline  
Old 09-11-2015, 07:47 AM
  #211  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

Isn't oil at the filter 10-20* hotter than the oan?
aidandj is offline  
Old 09-11-2015, 08:06 AM
  #212  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,645
Total Cats: 3,009
Default

The question remains, is this oil temp prior to the oil cooler? If yes, and the oil is then being dropped to 220-230 in the cooler then it is in the acceptable operating range for T6 synthetic on the track. I would back off at about 260-265F. Racers often run higher in the heat of battle if they must, but they rebuild engines more often.

It typically gets slightly more difficult to get hotter as the temp increases (unless you have real shortcomings in the cooling system) because as the difference between ambient and the oil temp continues to grow the cooler actually cools a little better, all things considered. Don't cook your engine.
sixshooter is online now  
Old 09-11-2015, 10:16 AM
  #213  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

Is pre cooler.
<br />I will be changing the oil and sending a bit to Blackstone.
aidandj is offline  
Old 09-11-2015, 02:00 PM
  #214  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,292
Total Cats: 475
Default

Originally Posted by aidandj
Isn't oil at the filter 10-20* hotter than the oan?
Dunno. The main source of heat into the oil is from being sheared in the bearings, then it gravity drains into the pan. If you could measure the oil temperature going into the oil pump, whatever temp the oil is once it's in the pickup tube, it's not going to get any cooler unless there's an oil cooler it's pumped through. Oil pump will heat it some, resistance flowing through oil passages, filter restriction, heat from surround engine components/block, etc.

I read online that the "normal" spot to measure oil temps is in the oil pan sump, so that's where I put my sensor. I wonder where the germans put theirs? I'll look for it on my mercedes next time I change the oil.
patsmx5 is offline  
Old 09-11-2015, 02:05 PM
  #215  
Moderator
iTrader: (12)
 
sixshooter's Avatar
 
Join Date: Nov 2008
Location: Tampa, Florida
Posts: 20,645
Total Cats: 3,009
Default

I would think the hottest oil would be coming from the bottom sides of the pistons and the oil control rings since that's where the fire is.
sixshooter is online now  
Old 09-11-2015, 07:29 PM
  #216  
Junior Member
iTrader: (1)
 
GraemeD's Avatar
 
Join Date: Sep 2009
Location: Colorado
Posts: 166
Total Cats: 6
Default

Originally Posted by sixshooter
I would think the hottest oil would be coming from the bottom sides of the pistons and the oil control rings since that's where the fire is.
iMO you are correct, but then you take that hot oil and compress it, compressing anything makes it hotter.
GraemeD is offline  
Old 09-11-2015, 07:35 PM
  #217  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

<p>Wouldn't the best place for a temp sensor to be post cooler, so you know the actual temp of the oil going into your bearings?</p><p>Then you can look at the properties of your oil and see when you should shut down.</p><p>I also have the issue of not trusting my oil temp gauge, because my coolant gauge wasn't exact out of the box.</p><p>Oh well. Good thing its a 1.6</p>
aidandj is offline  
Old 09-11-2015, 07:42 PM
  #218  
Elite Member
iTrader: (16)
 
patsmx5's Avatar
 
Join Date: Aug 2007
Location: Houston, TX
Posts: 9,292
Total Cats: 475
Default

Originally Posted by GraemeD
iMO you are correct, but then you take that hot oil and compress it, compressing anything makes it hotter.
Hottest oil and "most heat added" are not the same. I agree hottest oil is probably the oil stuck to the cylinder walls and pistons.

Originally Posted by aidandj
<p>Wouldn't the best place for a temp sensor to be post cooler, so you know the actual temp of the oil going into your bearings?</p><p>Then you can look at the properties of your oil and see when you should shut down.</p><p>I also have the issue of not trusting my oil temp gauge, because my coolant gauge wasn't exact out of the box.</p><p>Oh well. Good thing its a 1.6</p>
Best depends on what you want to know. If you want to know how well your cooler works, then a sensor after the cooler is probably best. If you want to know how hot the oil is right after it just cooled the bearings, then short of having a thermocouple installed on the crankshaft, the sump is the next best place to measure it.
patsmx5 is offline  
Old 09-11-2015, 07:43 PM
  #219  
SADFab Destructive Testing Engineer
iTrader: (5)
 
aidandj's Avatar
 
Join Date: Apr 2014
Location: Beaverton, USA
Posts: 18,642
Total Cats: 1,866
Default

<p>But why do I care how hot the oil that just cooled my bearings is? Don't I want to know how hot the oil that is about to cool my bearings is?</p>
aidandj is offline  
Old 09-11-2015, 07:50 PM
  #220  
Elite Member
 
codrus's Avatar
 
Join Date: Mar 2007
Location: Santa Clara, CA
Posts: 5,165
Total Cats: 855
Default

Originally Posted by GraemeD
iMO you are correct, but then you take that hot oil and compress it, compressing anything makes it hotter.
Oil is a liquid, not a gas, you're not compressing it.

Oil will get a bit warmer when pumped due to friction, but that's pretty low (low friction is, after all, the main point to having oil).

I suspect it doesn't really matter all that much where you measure it. Personally I change the oil before every track day, because the cost just isn't significant compared to everything else.

--Ian
codrus is offline  

Thread Tools
Search this Thread
Quick Reply: Oil cooler tech



All times are GMT -4. The time now is 03:12 PM.