pre-heating engine oil

[noet]

Hi,

Not that I'm concerned about my oil temp. since I always let the engine run for a few minutes before take off. At This point the temp. is between 30-35C*. I will need approx 10 miles of normal road speed to bring the temp. up to steady 86-88C*.

Engine is Raceline dry sump 2.3 Duratec 303bhp. Peterson 8 litres dry sump system. Running on Castrol Edge 10/60.

If possible I would prefer a quicker rise of temp. and the question is if anyone have experience in using any pre-heating system connected to the dry sump tank?

 

Egil

[Pezky]

You need a Laminova linky

 

I run one on my Zetec, oil temp increases a lot faster and is pegged to water temperature.

 

Speak to Carl of Sevenspeed

[Johnty Lyons]

At This point the temp. is between 30-35C*. I will need approx 10 miles of normal road speed to bring the temp. up to steady 86-88C*.

Just where are you measuring that Temp and are you sure its the OIL Temp I can't believe that with only 10 miles of road driving and No laminova [even with one its a tall order] you have Oil temps [with 8ltr capacity] of 86-88 I seriously thing your dreaming. I run a dry sump with that capacity and a Laminove and struggle to get Oil Temp up to 60C even after 30 mins.

Course I hav'nt checked your location You may be on the Equator. 😬

 

[charlie_pank]

I've got an oil/water heat exchanger and everything's up to running temp within a couple of mins.

[Jason Plato]

is your tank in front of the engine JJ ?

 

My duratec raceline dry sump warms to about 80C after about 6/9 miles folowing 5 mins warm up on the driveway whilst I get in at ambient temps of circa 15c like today, my tank is where the passengers feet used to be and the sensor is in the bottom of this tank - the duratec is a very oil warming engine compared to the K.

[Jason Plato]

a heater pad has been used by several on here for d/s tanks

[john milner]

I thought warming an engine on the driveway was discredited as it takes too long to get the engine up to temperature.

[keybaud]

The oil gets more viscous (thicker) as it warms up, so pre-heating it will make it worse at lubricating a cold engine.

 

Edited by - keybaud on 17 May 2012 19:26:39

[Dr Slotter]

Eh? It's the other way round?

[Chris B.]

thicker ?

[dannylt]

I thought warming up on the driveway was bad for bore wear, because of the rich mixture washing the oil off. Better just to drive off and heat up quicker. My Duratec with about the same amount of oil in a front mounted tank also heats up pretty quickly, so it must be a Duratec thing.

 

I have a heater pad, but I only bother using it when it's really cold, or bored before a track day. It's 250W 12V and you need a power supply/spare battery/diesel towcar. I bought it from Canada, I can dig up the details if you like. It's intended for sumps/diesel tanks on heavy plant in winter, but fits perfectly on the dry sump tank.

 

Oil most definitely gets thinner as it warms up, which is why the pressure drops. Multigrade oils are an attempt to help it stay thinner at lower temp.

[keybaud]

OK, it's not that simple.

 

As oil heats up it gets runnier, but a thicker oil will get runnier slower at the same temperatures. A multi-grade oil changes character as it heats up. A 5W50 behaves like a 5 at 0 degrees F and a 50 at 212 degrees F (100 degrees C). Bigger number = thicker oil, so it gets thicker up to a point; however, it will then start to thin. Pre-heating the oil makes it thicker earlier, thus reducing the cold start lubrication qualities, which is why you use a 10W40 and not a 40 in the first place.

[noet]

Thank's guys, - I belive I have got the expected answers .

The sender is located in the bottom of the tank. I have no reason to question 86-88 degree reading on the Stack, unless a missreading sender, which I doubt. I will look into the "laminova route" and talk with Carl.

(Regarding location, - Norway is known to be closer to the polar circle than to equator 😬)

 

 

 

[keybaud]

If you live somewhere cold, please pre-heat the engine and not the oil, otherwise you'll just destroy the engine quicker than normal.

[Dr Slotter]

Quoting keybaud: 

Bigger number = thicker oil, so it gets thicker up to a point; however, it will then start to thin. Pre-heating the oil makes it thicker earlier, thus reducing the cold start lubrication qualities, which is why you use a 10W40 and not a 40 in the first place.

 

Hmmm... I don't think that's true. The point of multigrade is to extend the properties of an oil over a larger range of temperatures e.g.

 

http://www.realclassic.co.uk/techfiles/oil03031907.gif

[keybaud]

Quoting Dr Slotter: 

Quoting keybaud: 

Bigger number = thicker oil, so it gets thicker up to a point; however, it will then start to thin. Pre-heating the oil makes it thicker earlier, thus reducing the cold start lubrication qualities, which is why you use a 10W40 and not a 40 in the first place.

 

Hmmm... I don't think that's true. The point of multigrade is to extend the properties of an oil over a larger range of temperatures e.g.

 

http://www.realclassic.co.uk/techfiles/oil03031907.gif

 

Please read up on multigrade viscosity before telling me I'm wrong, otherwise we'd all just use a 40 rated oil. There's a reason we don't, but the reason is the opposite of what most people think.

 

Edited by - keybaud on 17 May 2012 22:07:30

[Jonathan Kay]

Multigrade oils still get thinner as temperature increases, just less than other oils, as in the picture.

 

Jonathan

[garybee]

All engine oil gets thinner as it gets hotter. I can see why you're getting confused though.

 

Of the two numbers that make up a basic oil grade, the 1st is the oil's cold rating and the 2nd is it's hot rating (which you clearly know). bigger numbers means thicker and the hot rating is always a bigger number so it would appear that the oil gets thicker as it heats up. The hot rating is measured in a completely different way however, so you can only compare hot ratings against other hot ratings and cold ratings against other cold ratings.

 

As Dr Slotter's graph shows, the purpose of a multigrade oil is to decrease the rate at which the oil gets thinner as it heats up.

[keybaud]

Apologies, having gone back to the books, my understanding of the behaviours of vicosity index improvers was slightly flawed. I was under the impression that the chemical changes they underwent that caused the effective 'weight' of the oil to increase with a rise in temperature could cause the effective 'thickness' of the oil to increase. I still haven't found any conclusive proof that it doesn't, but the consensus is that it only slows down the rate at which the oil thins.

 

I've only seen subjective graphs drawn with straight lines, not drawings of actual viscosity changes, so I'd be interested in any real data anyone can point me at.

 

/edit Found it at graph 4.

http://www.kewengineering.co.uk/Auto_oils/oil_viscosity_explained.htm

 

A 10W40 is a 10 oil with additives that slow down its rate of thinning so that at 100 degrees C it has dropped to the effective thickness of a 40. It is not a 10 oil at a low temperature that changes its character to become a 40 oil at 100 degrees.

 

Edited by - keybaud on 18 May 2012 00:08:00

[garybee]

To summarise all this for the person who started the thread...

 

The 1st answer you got was right, an oil/water heat exchanger will bring your oil up to temp quicker. The Laminova heat exchangers are very nice bits of kit if a little pricey. With the spec. of your car though I'm guessing the £200-£300 they cost isn't too much of an issue.

 

For those that don't want to fork out that ammount there are plenty of mass produced cars with oil/water heat exchangers fitted as standard. Most of them are sandwiched between the oil filter and housing (fine if you have a take-off/remote filter, probably no good otherwise) but some are completely remote mountable units (I will point out one after the auction is finished on ebay so I don't have another 50 people bidding against me 😬).

[Gridgway]

Quoting keybaud: 

Please read up on multigrade viscosity before telling me I'm wrong, otherwise we'd all just use a 40 rated oil. There's a reason we don't, but the reason is the opposite of what most people think.

 

The reason you are wrong is that a multi-grade oil works when it is cold and hot. Otherwise by your argument the hot oil in your engine will not lubricate it. If you had a single weight oil, you'd only be able to use it at one temperature.

 

Also why is it common practice in race engines to pre-heat the oil if it's so bad for the engine?

 

Graham

[keybaud]

Quoting Gridgway: 

Quoting keybaud: 

Please read up on multigrade viscosity before telling me I'm wrong, otherwise we'd all just use a 40 rated oil. There's a reason we don't, but the reason is the opposite of what most people think.

 

The reason you are wrong is that a multi-grade oil works when it is cold and hot. Otherwise by your argument the hot oil in your engine will not lubricate it. If you had a single weight oil, you'd only be able to use it at one temperature.

 

Also why is it common practice in race engines to pre-heat the oil if it's so bad for the engine?

 

Graham

 

Out of interest, did you read my follow up post, or just poke sticks at the one you quoted?

 

p.s. If race engines pre-heat an oil, do they even use a multi-grade? Why would they use a multigrade such as 10W40 if you're going to heat it up to behave like a 40 before it gets used? Surely, it would make more sense to just use a 40 weight?

 

Edited by - keybaud on 19 May 2012 17:18:46

[Gridgway]

Quoting keybaud: 

Out of interest, did you read my follow up post, or just poke sticks at the one you quoted?

 

p.s. If race engines pre-heat an oil, do they even use a multi-grade? Why would they use a multigrade such as 10W40 if you're going to heat it up to behave like a 40 before it gets used? Surely, it would make more sense to just use a 40 weight?

Apologies, I missed that there was a second page.

Re race engines, we pre-heat the oil for my race engine and do use a multi-grade.

[john milner]

The pre-heating of engines problem is with cars on driveways. As I understand it most engine damage occurs when the engine is cold so leaving it on tickover is worse than driving off at a moderate rate. Race engines may be different as they are unlikely to have to do 100,000+ miles.

[Roger King]

Yes, warming the engine by leaving it idling before you drive off is bad practice because you are extending the time spent in the high wear zone. Likewise, driving off and thrashing it to get the temperature up as quickly as possible is also bad because the thicker (cold) oil won't protect surfaces properly and all the running clearances will be wrong until the engine is hot.

 

The best and simplest practice is to start the engine and drive off with modest restraint, but not too gently. This is simply the least worst option available to most people.

 

Interesting point from Keybaud about pre-warming race engines and why would they need multigrade. I don't know the answer because I've been out of touch, but it may be that F1 and the like use unique lubricants to suit the specific application. For more prosaic machinery that pre-heats its oil, I suppose you could argue that modern synthetic multigrades are so good that they are still preferable even though the multigrade part isn't really needed.