[BlackHemi41]

So I just got back from a track day at Gimli Motorsports park in Manitoba. It was my first time out there and I had an absolute blast. My 2016 392 Scat Pack performed great. The 6 piston Brembos got hot enough to smell them, but no fade whatsoever. Good predictable handling, transmission and diff worked great, all went well except for one minor issue: High oil temp.

To be fair, it was pretty hot at the track, about 28 C on the hottest session, and I was pushing the car pretty hard. Sessions are 20 mins, and I was near the end of it. I checked the performance pages display and my engine oil temp had got up to 137 C, or about 278 Fahrenheit. At that point, I backed off and did a cooldown lap. The car had no warning lights or limp modes or anything like that, still had plenty of power, but that scared me a little. The coolant temp stayed pretty normal, I don't think it exceeded 105 C.

I don't think I hurt the engine (I hope not anyway), and still runs perfect as far as I can tell. I checked the oil level between sessions (I accidently overfilled it a little bit) but it was never low. I am wondering if that's normal for a 392 with the factory oil/coolant heat exchanger to get that high? Should I change the oil now after getting it that hot?

 

[Nuke]

Check out this thread for some back and forth on this very subject:

6.4L Temperature Maximums

I occasionally do HPDE road course track events at Road Atlanta. Last time I went, I noticed my oil temp got up into the 270's (approx as I'm going off of memory). I run Amsoil synthetic and change it before my events. However, it concerns me a bit that it got that high. We run 20 minute...

www.challengertalk.com

 

[BlackHemi41]

I feel kinda dumb, I forgot all about that thread. Thanks Nuke. Pretty much answers my questions.

 

[Nuke]

Did you take part in it? I didnt remember who all partook, just remembered discussing the track effects on oil temp.

 

[Rockster]

So I just got back from a track day at Gimli Motorsports park in Manitoba. It was my first time out there and I had an absolute blast. My 2016 392 Scat Pack performed great. The 6 piston Brembos got hot enough to smell them, but no fade whatsoever. Good predictable handling, transmission and diff worked great, all went well except for one minor issue: High oil temp.

To be fair, it was pretty hot at the track, about 28 C on the hottest session, and I was pushing the car pretty hard. Sessions are 20 mins, and I was near the end of it. I checked the performance pages display and my engine oil temp had got up to 137 C, or about 278 Fahrenheit. At that point, I backed off and did a cooldown lap. The car had no warning lights or limp modes or anything like that, still had plenty of power, but that scared me a little. The coolant temp stayed pretty normal, I don't think it exceeded 105 C.

I don't think I hurt the engine (I hope not anyway), and still runs perfect as far as I can tell. I checked the oil level between sessions (I accidently overfilled it a little bit) but it was never low. I am wondering if that's normal for a 392 with the factory oil/coolant heat exchanger to get that high? Should I change the oil now after getting it that hot?

Apparently these cars: Hellcats and the 6.4l models; get the oil plenty hot on a road course track. It is hard to know what's too hot and what's not. Maybe one can gain some insight if he had access to the various technical data.

Or rather than taking a stab at analyzing this data and coming up with an intelligent "guess" it occurs to me that maybe contacting the manufacturer of the oil asking specifically what is the upper "safe" operating temperature is might be worth the effort.

My reference regarding oil temperature comes from a book on Porsche engines and the author states 250F on the track is too damn hot. Thus I would at strive to keep the oil below that temperature.

This requires monitoring the oil temperature while on the track and backing off -- if safe to do so on the track -- even "pitting" while letting the engine idle while the oil temperature gets reasonable. Not sure how this works. I know from just driving my Hellcat on the street and when the oil temperature reaches 230F it takes some time on the freeway to get the oil temperature down. I've never really bothered to see how quickly it drops just idling.

If the oil temperature brings you in too soon you need to consider better oil cooling. This brings with it its own set of problems that have to be dealt with. Pressure and volume drop. T-stat control to avoid over cooling the oil. A bypass in case the oil T-stat fails in a closed position. (There may be a T-stat solution that fails "safe", AKA open.) Mounting the oil cooler where it is effective but not subject to rocks/road debris that can hole the unit.

Maybe a bypass type cooler that is fed by a separate oil pump (electric) which could be controlled by a temperature sensor is a viable solution? Kind of an auxiliary cooler to supplement the factory installed cooler.

Regardless, show up at the track with fresh oil. You want the engine full but not overfilled. Be sure you have some extra oil just in case level drops. Check the oil level before going out for a session.

Afterwards given how hot the oil gets and who knows what level of breakdown (granted possibly none) it has experienced it might be prudent to change the oil after a track session. "Racing" is not an enterprise to run on a limited budget.

 

[Nuke]

I don't know the specific oil you are using, but as long as it is an SN rated synthetic, you are likely okay. If it's an SN Plus rated synthetic, even better! It's been tested to run at 300F for 90 hours straight (on the venerable Pentastar of all engines):

https://www.swri.org/sites/default/files/sequence-iiih-test.pdf

source for that test doc: https://www.swri.org/passenger-car-lubricant-testing

 

[BlackHemi41]

I don't think I did take part, but I did read through it at some point.

Anyway, the summary I get is:
250 F or less = optimal
250-260 F = normal on track
260-280 F = Somewhat normal on a hot day/pushing hard
280-300 F = repeatedly is too high
300 F or up = oil breaks down/excessive wear/ engine damage

If this is the case, it would seem there is nothing wrong with my car, though I am pushing it on the edge a bit on hot days. I haven't tried removing the lower grille as recommended in the manual. That might be worth a shot.

For the record, I am using the Pennzoil SRT spec 0W-40.

 

[Nuke]

I don't think I did take part, but I did read through it at some point.

Anyway, the summary I get is:
250 F or less = optimal
250-260 F = normal on track
260-280 F = Somewhat normal on a hot day/pushing hard
280-300 F = repeatedly is too high
300 F or up = oil breaks down/excessive wear/ engine damage

If this is the case, it would seem there is nothing wrong with my car, though I am pushing it on the edge a bit on hot days. I haven't tried removing the lower grille as recommended in the manual. That might be worth a shot.

For the record, I am using the Pennzoil SRT spec 0W-40.

You're good then. That's an SN rated oil, and that means it can do 290F for 40 hours straight without shearing down to a point it cannot lubricate effectively anymore.

source: https://www.swri.org/sites/default/files/sequence-viii-test.pdf

 

[Rockster]

You're good then. That's an SN rated oil, and that means it can do 290F for 40 hours straight without shearing down to a point it cannot lubricate effectively anymore.

source: https://www.swri.org/sites/default/files/sequence-viii-test.pdf

Uh, test platform: .7 L carbureted, single-cylinder, spark ignition, CLR lubricant test engine operated with an external lubricant heater circuit.

I hardly think a 0.7l carb'd single cylinder engine limited to 3150 RPM is enough like for instance my Hellcat's engine to rely upon this test for running my Hellcat engine oil at 290F for any length of time.

 

[Hal H]

all of the 392 / 6.4 and Hellcat engines have water-to-oil coolers as OEM.

I've seen mine get into the 255-260 range on roads like Tail of the Dragon / Diamondback Loop in my area.

the oil life calculation will count down oil life a bit faster if the oil is running at hotter temps - even then, the max oil change interval on these SRT engines is 6,000 miles which is pretty conservative

 

[Rockster]

all of the 392 / 6.4 and Hellcat engines have water-to-oil coolers as OEM.

I've seen mine get into the 255-260 range on roads like Tail of the Dragon / Diamondback Loop in my area.

the oil life calculation will count down oil life a bit faster if the oil is running at hotter temps - even then, the max oil change interval on these SRT engines is 6,000 miles which is pretty conservative

The water to oil coolers are not so much to keep oil temperatures in check but to provide a quicker warm up for the oil. That the oil temperatures hit such high temperatures is some proof of that.

This has come up before with other cars have I owned that were fitted with water to oil coolers. Engine specialists have posted data that shows the cooling benefit of these is minimal.

The oil change interval of 6K miles does not take into track usage and the resulting elevated oil temperature as this usage is not supported/condoned by Dodge. I have no qualms about my Hellcat's oil temperature reaching 230F for a few minutes after some few (or a bit more) minutes of stop and go driving. But I would not feel comfortable if the oil temperature exceeded 250F and climbed up to 260F or 270F or even higher.

 

[Decay]

Didn't I see Luke(from Steve White's) post some oil cooler info on this subject?

 

[BlackHemi41]

This has come up before with other cars have I owned that were fitted with water to oil coolers. Engine specialists have posted data that shows the cooling benefit of these is minimal.

I believe it. Heat always wants to spread to whatever is cooler around it, and more-so if there is a significant difference in temperature. In the oil to coolant heat exchanger, the 270 degrees in the oil is only transferring to the 220 ish degree coolant. It's not as significant of a drop as an oil to air cooler, where the air is ambient (85 or whatever), and also being forced into the grille opening at high speed.

That's why I want to try removing the belly pan next. Some air going by the oil pan might do good. I also wonder if the Hellcat (Now GT or 2019 Scat Pack) style hood would give better ventilation than my standard hood.

 

[Slidd]

In the SRT owners manual FCA says to remove belly pans for track use to improve cooling.

all of the 392 / 6.4 and Hellcat engines have water-to-oil coolers as OEM.

Hellcat cooler is oil to air and totally different than the 392 / 6.4L system and way better for track use.




Sent from my SM-N960U using Tapatalk

 

[BlackHemi41]

Unfortunately the Hellcat oil cooler won't simply add on to a 392 car. Aside from eliminating the coolant passages from the thermostat housing and the lower rad hose, the hellcat cooler doesn't fit behind the fascia according to Steve White parts. The foglight takes that space also.

If you have a 2019 392 widebody, it would probably be a much easier upgrade to add.

 

[Rockster]

I believe it. Heat always wants to spread to whatever is cooler around it, and more-so if there is a significant difference in temperature. In the oil to coolant heat exchanger, the 270 degrees in the oil is only transferring to the 220 ish degree coolant. It's not as significant of a drop as an oil to air cooler, where the air is ambient (85 or whatever), and also being forced into the grille opening at high speed.

That's why I want to try removing the belly pan next. Some air going by the oil pan might do good. I also wonder if the Hellcat (Now GT or 2019 Scat Pack) style hood would give better ventilation than my standard hood.

There's a concern in adding a hood that directs air into the engine compartment. This air and the resulting increase in air pressure can interfere with air flow through the radiator. Engine cooling is primarily by coolant which if of course cooled by air flowing through the radiator. You want to do nothing to impede this air flow.

Leave the belly under body panels in place. Any air going by the oil pan will have minimal (probably no measurable) benefit on oil temperature.

For tracking I believe Dodge (or SRT) recommends (or at least used to) removing the front fascia to I guess allow more air to enter the radiator.

If you really want to do something about oil temperature you are going to have to look into an engine oil cooler.

 

[Hal H]

The water to oil coolers are not so much to keep oil temperatures in check but to provide a quicker warm up for the oil. That the oil temperatures hit such high temperatures is some proof of that.

This has come up before with other cars have I owned that were fitted with water to oil coolers. Engine specialists have posted data that shows the cooling benefit of these is minimal.

The oil change interval of 6K miles does not take into track usage and the resulting elevated oil temperature as this usage is not supported/condoned by Dodge. I have no qualms about my Hellcat's oil temperature reaching 230F for a few minutes after some few (or a bit more) minutes of stop and go driving. But I would not feel comfortable if the oil temperature exceeded 250F and climbed up to 260F or 270F or even higher.

yes - the oil cooler can help warm the oil up faster - but I'll point this out

I had an '09 5.7 / M6 R/T - modded this by adding the 392 cam & tuning - saw a big increase in oil temps. Added the 392 oil cooler. My '09 used to run ~ 209-211* temps stock. When driving in the mountains / grades it would climb to 221* and stay there. The oil life monitor was consistent in 5.5 - 5.7k intervals.

After the mods (before the cooler was installed) oil temps ran higher in the 219* range and running it hard / hills / grades would push the temps up to 225-230* and it would stay there even when driving more moderately. I saw the oil changes trip off anywhere from 1.85k to 3.6k intervals (the system saw higher average / peak temps and triggered shorter oil life calculations)

After installing the oil cooler it typically averaged 215-217* consistently, just as it does in my (stock) '16 392 / M6. Run either of those hard and the temps climb, but once back to 'normal' driving the oil temps fall back to the normal range within a couple of miles.

My coolant temps even on hot days (95*F +) are consistently 208*F - always cooler than the oil temperature, so it does have the effect of getting the excess heat out of the oil.

 

[stevewhite]

keep an eye on your oil temps, in my opinion stay below 270, anything above is too much, we were seeing temps in the upper 280's low 290's, and we would shut down and let it cool off

should no longer be an issue in the new set up, two oil coolers and two heat exchangers

 

[Rockster]

No doubt the oil cooler helps some but it is still not that effective when for example I observe that while the coolant temperature is in the 200F to 210F range the engine oil temperature is 230F. This in town driving. Once on the freeway/highway moving at a steady highway speed the oil temperature drops but it is a slow process relatively speaking.

Even though the oil temperature gets to 230F that doesn't concern me.

However, were I to track my car, I'd be concerned if the oil temperature got any higher. And really I'd want it lower than 230F. Ideally for track use the oil should be in the 212F range. The oil is up to its operating temperature and yet not at an elevated temperature. But even 230F would be preferrable to something higher. 250F or above I believe (channeling Bruce Anderson) is "too damn hot". Thus I would have to find something that would keep the oil temperature under better control, keep it from going too high while on the track.

I'm thinking an air oil cooler would be more effective at controlling oil temperature and in especially extreme usage scenarios: Road course driving. Given this type of usage I would consider it a must have -- or some oil cooler setup that has shown it can keep peak oil temperatures down to safe limits while the car is being driven on the track.

 

[stevewhite]

No doubt the oil cooler helps some but it is still not that effective when for example I observe that while the coolant temperature is in the 200F to 210F range the engine oil temperature is 230F. This in town driving. Once on the freeway/highway moving at a steady highway speed the oil temperature drops but it is a slow process relatively speaking.

Even though the oil temperature gets to 230F that doesn't concern me.

However, were I to track my car, I'd be concerned if the oil temperature got any higher. And really I'd want it lower than 230F. Ideally for track use the oil should be in the 212F range. The oil is up to its operating temperature and yet not at an elevated temperature. But even 230F would be preferrable to something higher. 250F or above I believe (channeling Bruce Anderson) is "too damn hot". Thus I would have to find something that would keep the oil temperature under better control, keep it from going too high while on the track.

I'm thinking an air oil cooler would be more effective at controlling oil temperature and in especially extreme usage scenarios: Road course driving. Given this type of usage I would consider it a must have -- or some oil cooler setup that has shown it can keep peak oil temperatures down to safe limits while the car is being driven on the track.

not sure I understand, oil cooler such as the following will help greatly in lowering oil temps