Oil temps on track?

[illwillem]

So I went to the track this last weekend for the first time since doing extensive work to the NSX. Among other things I put in a new oil cooler with ducting and sensors to read the temps so I was surprised when it was running higher than i thought it would

Trying to get a consensus from some NSX people with gages, What temps are you seeing when you are on the track? Im NA and my temps would pass 235* in the first half a lap then peak at 264* within a couple laps before I would shut it down and come back to the pits.


from what ive been reading people are running much higher temps consistently in other cars (280-300) and are not concerned, what is the typical specifically for the NSX? im taking the reading from the out flow port from the SOS sandwich adapter.

 

[nsxnut]

Yikes.

I think it depends on how much power you are making and also on your water temp as well.

I am making 440 at the wheels. My oil temps after a few laps can get up to 245F. If I back out of it for a 1/2 lap it come down quickly. My water temp never gets above 190F. I have a an aftermarket radiator and vented hood.

I still have the stock oil to water heat exchanger above the oil filter.
I also have a 13 row setrab oil cooler behind the passenger side vent.
I wish I could put a fan on the oil cooler but can't.
I did cut the fender liner to allow for better airflow. this improved things a few deg.

I would be concerned with anything over 250F

I am measuring the oil temp at the same location.

Later,
Don

 

[g3driver]

I measure my oil temp from the bottom of the pan and see 230 to 280 by the end of 20min. I have done tons of research and talked with engineers from mobile one and joe Gibbs they both agree that in a NA car you are good up to 320F with full synthetic oil. I have also done multiple oil analysis after races and see nothing to be alarmed about. Now with that being said I do want to get an external oil cooler installed to take the load of the radiator. My water temps are from 190-220.

http://www.outrageousracing.com/blog/2013/3/20/oil-analysis.html
http://www.outrageousracing.com/blog/2013/1/17/oil-after-race-still-good.html

 

[illwillem]

Thanks for the replys, guys. Great info in the links. My temps were taken on engine exit pre-19 row cooler. so the intake oil temps should be 20-25deg lower than i'm reading on the exit. I realized last night that I never resealed the duct>heat exchanger gap and left about a 1/4 to half inch gap. The lattice on the oil cooler is so dense the air was likely being sucked out the gap instead of ramming through and actually cooling. I can imagine that my cooling was compromised by up to 20%. yikes.

I'm going to seal everything and pyrometer both output and input feed tubes to find out the cooling delta then also build a pressure venturi and find out the actual flow through the ducting set up I have. I'll then see if it falls in line with what manufacture recommends and if Im seeing the drops that should be expected. At least that way I can rule out the new oil cooler ducting and placement and move onto looking at other areas.

Im also going to change the oil brand, something that ive not yet done out of convenience. That Joe Gibbs stuff look pretty slick, im going to do more reading. Either way its good to know what the oil engineers say is the upper limit and that I fall well outside of it even though I was running higher than I should have been.

 

[nsxnut]

My oil temp sender is on the oil filter housing. I thought this was post oil cooler? Maybe my oil temp is not that bad?

At the higher temperature the viscosity is the problem.

I believe I am using ams 20w40 oil to improve the viscosity at the higher temp.

 

[stuntman]

250-280 is common and yes modern synthetics are easily good to over 300*F but it's probably better to keep the oil temps below 275, afterall oil does help cool the engine.

William - you want to measure your temp in the sump. Measuring post-cooler isn't that helpful.

My oil temp sender is on the oil filter housing. I thought this was post oil cooler? Maybe my oil temp is not that bad?

At the higher temperature the viscosity is the problem.

I believe I am using ams 20w40 oil to improve the viscosity at the higher temp.

20W40 and 0W40 have the same viscosity at 100-150*C. 20W40 is very thick for cold starts which is where a lot of wear happens.

Shell Rotella T6 5W40 has a great low and high temp viscosities and additive packages.

 

[nsxnut]

I lied... I am using 10w40

My oil cooler is after the pump and is in between the main and the pump.
Wouldn't you want to measure the temperature the bearings are going to see?
I guess measuring the temp of the oil in the sump is a measure of how hot your motor is.

Later,
Don

 

[stuntman]

I lied... I am using 10w40

My oil cooler is after the pump and is in between the main and the pump.
Wouldn't you want to measure the temperature the bearings are going to see?
I guess measuring the temp of the oil in the sump is a measure of how hot your motor is.

Later,
Don

Yes. It's like measuring the coolant. You want to know what the temps ARE, not how cool your radiator is making the coolant. -Which is why water temps aren't taken post-cooler -in which case you'd see extremely low temps until the thermostat opened when first turning on your car.

 

[nsxnut]

I'm still not happy about the temp... Viscosity falls with higher temps.
The AMS oil I am using and the shell Rotellla have almost the same viscosity at 100c.
With the accusump my car hods almost 8 quarts may not be a bad idea to switch to the Rotella

Later,
Don

 

[stuntman]

All oils thin out as they get hotter and thicken as they cool. The difference between a 30 and 40 weight oil is very little. Looking at the High Temp Sheer (HTHS) of the oil is also a good indicator of the oil's performance at very high temps.

Some good article (same one but one's easier to read)

http://www.ferrarichat.com/forum/faq.php?faq=haas_articles

http://www.bobistheoilguy.com/motor-oil-101/

For track use, a 0 or 5W 30 or 40 is a good ballpark.

 

[illwillem]

The SOS cooler has 2 ports, one on the intake port side and the other on the output. im using the port on the output side so I am measuring the the temps as its coming out of the motor (or at least that what i think, correct me if im wrong). Im thinking about just tapping the oil pan and taking the temps from in there insted anyways. Also, Billy, When you say sump im assuming you mean the factory pickup location not at the accusump (which would be post cooler).

Hottest I mesured was 264, assuming i'm getting that reading from the correct location then changing the oil weight to a 5w30 and fixing the ducting should just be making positive changes.

 

[RYU]

When talking about the different locations for the oil temp sensor.. in terms of the actual variance in temps.. are we talking about a small variance or a big variance? Does anyone have any data on that?

I'd particularly like to know what the oil temp variance is if taken in the oil pan vs. on the oil filter sandwich plate. Hopefully it's not something crazy like +/- 30-50F and hopefully more like +/- 5-15F

 

[stuntman]

The SOS cooler has 2 ports, one on the intake port side and the other on the output. im using the port on the output side so I am measuring the the temps as its coming out of the motor (or at least that what i think, correct me if im wrong). Im thinking about just tapping the oil pan and taking the temps from in there insted anyways. Also, Billy, When you say sump im assuming you mean the factory pickup location not at the accusump (which would be post cooler).

Hottest I mesured was 264, assuming i'm getting that reading from the correct location then changing the oil weight to a 5w30 and fixing the ducting should just be making positive changes.

You should have fairly accurate readings if your sensor on the oil cooler is on the "Hot" side (shown where the red arrow enters the cooler on this diagram):

http://www.scienceofspeed.com/products/engine_performance_products/NSX/ScienceofSpeed/oil_cooler/

If your sensor is on the opposite side, then it's not very helpful. An easy fix would be to swap the lines so you're measuring the temps pre-cooler.

Measuring the temps in the oil filter sandwhich plate should also be a fairly accurate reading if you're reading the oil on the outside of the sandwhich plate which comes directly from the oil pan (the red lines on that SOS link).

Yes when I said "sump" I meant the oil pan. Measuring at the accusump would be even more useless since the valve opens and closes.

 

[illwillem]

Okay cool, thats the exact diagram I used when I was planning my set up so the temps should be fairly accurate. Ive just gotta get back under the car and make some adjustments and try again.

 

[stuntman]

So where is your temp sensor exactly? I see it on your other thread right next to the T-joint for the accusump. Which side of the oil cooler is that line? The hot side (going from the pan to the oil cooler) or the cold side (cooled by the heat exchanger then goes into the sandwhich plate where the oil is filtered then further cooled by the stock oil-water cooler?

 

[illwillem]

Thats is the pressure sender you see in those pictures and that line is post external cooler. It goes Oil temp probe>external oilcooler>checkvalve>accusump>pressure sender>OEMwater to oil cooler.

I read pressures after the accusump so I can and track of whats happening in the sump


So, Yes, correct. That temp probe is at the pan to cooler (hot) side, just before line that feeds the external oil cooler. And the 264 degrees is the temp coming out of the pan Before the external oil cooler and before the OEM oil-water cooler. I can imagine there is quite a drop in oil temps after it finally makes it through the accusump and the two cooling systems.

 

[stuntman]

Thats is the pressure sender you see in those pictures and that line is post external cooler. It goes Oil temp probe>external oilcooler>checkvalve>accusump>pressure sender>OEMwater to oil cooler.

I read pressures after the accusump so I can and track of whats happening in the sump


So, Yes, correct. That temp probe is at the pan to cooler (hot) side, just before line that feeds the external oil cooler. And the 264 degrees is the temp coming out of the pan Before the external oil cooler and before the OEM oil-water cooler. I can imagine there is quite a drop in oil temps after it finally makes it through the accusump and the two cooling systems.

Excellent. I would have been surprised if you were getting 264*F post cooler. Yes your motor should be seeing much lower oil temps but you are correctly measuring the proper hot oil -what's in the pan and what your oil temps are truly running.

 

[illwillem]

Cool, thanks for the input. Im going to make the adjustments to the ducting and oil weight.

 

[RYU]

Thats is the pressure sender you see in those pictures and that line is post external cooler. It goes Oil temp probe>external oilcooler>checkvalve>accusump>pressure sender>OEMwater to oil cooler.

I read pressures after the accusump so I can and track of whats happening in the sump


So, Yes, correct. That temp probe is at the pan to cooler (hot) side, just before line that feeds the external oil cooler. And the 264 degrees is the temp coming out of the pan Before the external oil cooler and before the OEM oil-water cooler. I can imagine there is quite a drop in oil temps after it finally makes it through the accusump and the two cooling systems.

Ding! I'm banking on this. In my case, I'm running a sensor before and after the air-to-oil cooler on my side mount 13row however, I don't have a sensor after the OEM water-to-oil unit

 

[stuntman]

Cool, thanks for the input. Im going to make the adjustments to the ducting and oil weight.

Do your homework since there's a lot of 5W30's with low Phosphorous and Zinc levels.

M1 0W40 has a lot of both and Shell Rotella T6 5W40 has a lot. Motul 300V 5W30 has a great additive package.