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theamsoilguy

oil weight affect on oil temp

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I searched but couldn't find, I thought I read a good article on how oil weight affects oil temp. I think it was by a sponsor, redline maybe and I think it was on the chumpcar forum.

We have trouble keeping temps down when we push our car. 1g DSM turbo with bigger aftermarket intercooler and upgraded rad. We are still working on the tune. Car does have the stock oil cooler and we might move it for better airflow. We have already upgraded the rad.

The stock spec for the car is a 30 weight oil. I sell amsoil and we are running 50 weight race oil. Amsoil doesn't make a 40 in a race blend, but I'm wondering if I should use the non race 40weight.. 

 

Anyone recall the oil temp thread and able to find it? I think it talked about how the oil weight can affect temp.

 

Thanks Al

Edited by theamsoilguy

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You could mix the 30 and 50 weight

 

Lowering the viscosity will reduce the shear forces which will reduce the temperature increase due to friction, assuming your engine will survive on the lower viscosity.

 

You will make more power too

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What type of oil cooler are you using and what temps are you seeing?

 

My peak temps at Castrol with a factory oil to water heat exchanger were about 240 F on my NA V6 with a coolant temp of 190-200 F, with other tracks usually about 10 degrees cooler on both.

 

 

 

Edited by mender

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7 minutes ago, Huggy said:

You could mix the 30 and 50 weight

 

Lowering the viscosity will reduce the shear forces which will reduce the temperature increase due to friction, assuming your engine will survive on the lower viscosity.

 

You will make more power too

This

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I don't have a oil temp guage, but the water guage gets to 220 and I back off which seems to help, we start to get some knock at 210/220.

 

Its the factory oil cooler sandwiched between the intercooler and the rad. I might move it to headlight bucket. I'm just thinking that the 50 weight oil is contributing to the problem. The problem might sort out if we can nail the tune which we have been chasing because of other mechanical issues which we have now sorted out. 

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4 minutes ago, theamsoilguy said:

I don't have a oil temp guage, but the water guage gets to 220 and I back off which seems to help, we start to get some knock at 210/220.

 

Its the factory oil cooler sandwiched between the intercooler and the rad. I might move it to headlight bucket. I'm just thinking that the 50 weight oil is contributing to the problem. The problem might sort out if we can nail the tune which we have been chasing because of other mechanical issues which we have now sorted out. 

Get an oil temp gauge beside your oil pressure gauge. What are you seeing for peak oil pressure and at what rpm?

 

Sounds like you need to upgrade your radiator first though. If you're getting into knock, your engine won't last very long even with the right oil temp and viscosity.

Edited by mender

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Can I turn your question around....

 

Based on high temps, what viscosity oil should you run....?

 

You will find the thicker oils generally have a higher max temp before you boil out all the magic. They also are harder to pump and that lost energy goes into the oil as heat. You still most likely end up with a net gain, but the factors do hurt each other. 

 

Thicker oils also protect better in high impact loading, but this is usually more of a concern with gears than plain bearings. 

 

Get the max temp specs for the oils you intend to run and see if there is much variation with viscosity. If not, then for all the other reasons people listed, you generally want the thinnest oil that has the same temp, impact loading and anti foam protection. 

 

Also think about oil control, the oil temp will get out of control when the oil starts sloshing or pooling in areas you don't want....

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And remember that an engine and a weekend are at stake if you choose poorly.

 

Being an engine builder and having seen what goes on inside competition engines, I err on the side of caution and am more than willing to give up a couple of hp in exchange for assurance that the engine will survive unplanned events. All it takes is a bit of grass-cutting and a reduction of air flow and cooling to eliminate any margin that a lighter oil might have.

 

We had to use a stock rad at ORP last fall after our race rad got crunched and ended up with oil hot enough to smoke on the dipstick. Oil pressure was down to about half of normal but went back to normal after cooling down. A check of the oil filter after showed no bearing material. Redline 40 wt.

Edited by mender

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Since DSM and turbo dodges are like brothers in some regards I might be able to help.

 

I am running the 2.4 turbo lite motor in my current car. I have went from a slightly bigger rad to a “biggest I could fit rad” to aid in cooling and we’re running lower than stock boost!  Went from a 10,000 btu oil cooler to a 28,000 btu oil cooler to aid in temps. as well.

 

I think i have it nailed down to running approx. 230-240 oil temps and 195-200 water temps in pretty hot weather with the upgrades now and running a euro Mobil 1 blend 5w-40 oil. 

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From what I have read the maximum temp that produces the designed oil flow for most engines is 302 F  , over that number  the viscosity  change will effect the flow to less than the designed ideal...so 240 at the gauge worries me ..oil temps are an average ..I am concerned that the hotter spots would exceed the 302 Degree  ideal...a lower measured temp would mean a lower average  and  lower hot spots temp.  

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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Amsoil? This stuff is $2 a quart - regular price. If you are an OE engine, why not run the oil suggest by the OEM? At least that is what I do. 

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10 hours ago, Mopar 4 Life said:

Since DSM and turbo dodges are like brothers in some regards I might be able to help.

 

I am running the 2.4 turbo lite motor in my current car. I have went from a slightly bigger rad to a “biggest I could fit rad” to aid in cooling and we’re running lower than stock boost!  Went from a 10,000 btu oil cooler to a 28,000 btu oil cooler to aid in temps. as well.

 

I think i have it nailed down to running approx. 230-240 oil temps and 195-200 water temps in pretty hot weather with the upgrades now and running a euro Mobil 1 blend 5w-40 oil. 

 

I also use the euro mobil 1 5w 40. For an oil you can buy in w mart....it's pretty good stuff.

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On 3/13/2019 at 8:29 AM, Black Magic said:

 

I also use the euro mobil 1 5w 40. For an oil you can buy in w mart....it's pretty good stuff.

 

That's what we use too.

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