oil temp

[Gareth Brandt]

HI
Any good ideas were to install oil temp sensor?
And how effective is a 13 row cooler?

Regards Gareth

[ianh1968]

This really depends on what oil temperature you want to know...

1) The temperature in the sump
2) The temperature of the oil going to the main bearings

Most temperature gauges read 40-140 DegC.
Only with NO cooler did I ever manage to get anywhere near the top end of this scale.
I got up to about 130 DegC, by which time the oil was so thin there was a serious pressure drop.

If you measure the sump, this will be before the cooler and you will obviously get a higher reading.
If you measure the temperature between the oil filter head and the block, which is effectively the
temperature going to the bearings, you will get a lesser reading if you have sent the oil to a cooler
first.

It all gets a bit messy in a Mini if you want a cooler, an oil-stat, and a gauge, but I have devised
a really neat solution...

What I use is a modified temperature gauge take-off that is for the BSP type fittings.
Normally, it has a 1/2" BSP inlet, a 1/2" BSP outlet and a 5/8" UNF hole for your temperature sender probe.

I take a hacksaw to either the inlet or the outlet, sawing the female BSP stub off flush with the main body.
This hole, I then bore out to take a 5/8" UNF thread. In the original 5/8" UNF thread, I put a straight
outlet for a 1/2" hose. For example, the type that is usually screwed into the block.

On the original inlet to the cylinder block, I put a 90 degree 1/2" hose to 1/2" BSP fitting.

Doing this, you can turn the oil flow through 90 degrees in close proximity to the distributor AND get
a temperature gauge facility at the same time. This setup does not foul up on the dizzy cap...

As regards the cooler, I use the thermostatic sandwich-plate for the take-off points.
On one car I have a standard width 10 row cooler, on the other I have a half-width 16 row cooler.
Both of these are sufficient. You most probably do not need a 13 row, but these are quite often
less expensive because they are a very popular fitment on other vehicles. The quality of oil
is also much better these days, so paranoia about excessive temperatures should no longer apply.

With very similar setups on both cars, the highest temperature I have seen is about 105 DegC.
This is after serious and prolonged thrashings.

Here are some photos:

dscf0004.jpg

dscf0005.jpg

dscf0007.jpg

dscf0009.jpg

dscf0008.jpg

If you are lucky enough to have one of the old 30-110 DegC temperature gauges then this
is ideal. I had one years ago and have recycled the face onto newer water temperature
gauges when necessary. If you are not overly fussed about a gauge saying "oil", by all
means use a "water" one - They are basically the same thing.

Ian

[Gareth Brandt]

Thanx Ian
Very informative. My problem is I don't get as higher reading as I would like to get, about 60 C on a hot day (road usage). But my sensor is after the cooler and filter.I know oil temp should be 100+ C but this is in the sump. Is 60 C too low?? Even after cooler? See pics The hose going in through the bulkhead is for my accusump.

Regards Gareth

[Spider]

Great posts and pics guys.

I made up an adaptor that fitted the bulb to the inlet side of the Oil Cooler (yonks ago when I had one). I feel measuring the temp where the sump plug is, or any low point in the sump, is not very indicative or helpful.

Ian, nice one mate, very ingenious and neat.

Gareth, nicely presented car! 60 is on the Low Side, tried blanking off the cooler? You don't need to blank all of it off.

[ianh1968]

Thanks, gents...

Gareth's photos have made mine look a bit scabby!


My modified sender was intended to be a prototype, a proof
of concept if you like. One day I'll make up a more discreet
sender unit, perhaps out a bit of hex-ally bar...

I can't see from Gareth's photos if there is a thermostat in the system?
Mine is supposedly set at 82 DegC and under normal "road-use" driving
in the south of the UK I am showing about 75 DegC.

Maybe the ambient temperature in Sweden is lower than here?
... or maybe a longer drive is needed to get the temperature up?

Wind the pace up a bit, and the oil temperature will soon go up.
As I said before, mine, up to a maximum of about 105 DegC. I have
often managed to get the oil about 20 DegC hotter than the water...

I agree with Spider - Certainly if there's no 'stat, try blanking the
cooler off. Try blanking it off totally at first to see if that makes a
difference.

Ian

[Gareth Brandt]

Just might try covering it up What's the down side, running too cool (except frequent oil changes) ? And yes, no stat

[Spider]

If the Oil runs to cold, it doesn't lubricate as well as it should, that would be my biggest concern. There's also increased fuel consumption and the engine not getting all it's horses out. In some oils, the detergents don't work as well at lower temps and this can lead to sludging, but regular (very regular) changes will go a long way to helping in that dept.

Another big factor that affects oil temp is bearing clearances and the oil pressure.

Also, don't forget that the viscosity grade that should be used is also ambient temp based.

<Edit: I should have added to my first post that I measured the Oil Temp at the inlet to the Cooler as I was concerned with looking at Maximum Oil Temp for the worry of exceeding the Oil's maximum rated temp and thus loosing it's lubricating qualities, it not like coolant where pulling over and letting the temp come down will make everything 'alright'. It you wanted to get a more accurate idea of running temps, you'd most like measure the temp as you have done (on the cooler outlet).>

[Gareth Brandt]

Hi again
Completely covered oil cooler today, and 25 C ambient temp, but still not more than 78 C oil temp after a long motorway run (110 km). The 78 C is measured after cooler and filter. Water temp at steady 78 C. When driving along small streets it dropped to 64 C. Am I measuring at the wrong point? Should I be looking at sump temp?

[smithyrc30]

Hi again
Completely covered oil cooler today, and 25 C ambient temp, but still not more than 78 C oil temp after a long motorway run (110 km). The 78 C is measured after cooler and filter. Water temp at steady 78 C. When driving along small streets it dropped to 64 C. Am I measuring at the wrong point? Should I be looking at sump temp?

If the engine water temperature is a steady 78C why would you expect the oil temperature to be significantly different to that please?
Most of the temperature in the oil comes from the 'work' being put into it and the great contributor to that is crank bearing speed in the engine. High revs. will equal higher oil temperatures. In the gear box, high speed and load adds temperature.
It would seem to me that the oil temperature is responding to the manner in which it is driven. Highway speeds about engine water temperature, city driving lower because all the loads and speeds are lower.
Does the engine have a thermostat fitted please?

[Spider]

Hi again
Completely covered oil cooler today, and 25 C ambient temp, but still not more than 78 C oil temp after a long motorway run (110 km). The 78 C is measured after cooler and filter. Water temp at steady 78 C. When driving along small streets it dropped to 64 C. Am I measuring at the wrong point? Should I be looking at sump temp?

Yeah, that's about what I would expect to see. I've found that for road use, the Oil and Water Temps closely follow, though the Oil Temp lags the Water Temp in regards to the amount of time it takes to change.

Certainly, the 78 deg. sounds much better that the 60 you have been seeing.

[Gareth Brandt]

Thanx for the answers So 75 C + is ok when motorway used? And yes, I also have asked myself why the oil temp should be much higher than the water temp, but friends of mine (with minis) have water temp of about 85 C but read an oil temp of about 100 C (measured before the cooler) going down the motorway. I measure after cooler and remote filter, but I still can't see how a oil cooler can be so effective....lowering temp by some 30-40 degrees... and no, I don't use an oil thermostat

Gareth

[Spider]

75 deg is on the cooler end of acceptable, I'd rather see 80 - 85, but also depends too on what Oil you are running.

Another big factor that affects oil temp is bearing clearances and the oil pressure.

Yet another factor is engine tune and how hard you are running it as the Oil also cools the underside of the Piston Crowns (which adds to Oil Temp), so, for example, lean running can raise Oil Temp, as can just thrashing it about. It's not straight forward to compare one engine to the next, but for Motorway running, I would expect to see the Oil temp around that of the coolant.

One other thing to consider is gauge accuracy, I've seen many, some name brand ones, being out as much as 12 degrees right out of the box.

I think with these kinda gauges, you're probably better off noting what is normal rather than taking any specific number is may show as gospel.

[carbon]

To get oil really hot just fit a sumpguard!

Just don't make my mistake of fitting a sumpguard, and not fitting an oil cooler. This give the main bearings a really hard time when I took it for a 300 mile run down the motorway... that nice copper finish on the mains.

I was lucky there was no damage to the crank, a new set of mains and full oil pressure restored.

[Vegard]

Oil should be 100 degrees to "cook" the water.
If you're seeing 75 degrees, remove the cooler.

Oh. Please don't use jubilee clips on oil hoses. Please!!!

[surf-blue-850]

Surely it's better to have the oil at the coolest temp possible? Or am I missing the point somewhere?

[Gareth Brandt]

No jubilee clips......and the engine oil needs to be above 80 C to get rid of water but needs to be as high as 95-100 C for it to lubricate correctly. Getting a stat!!

[ianh1968]

Oh. Please don't use jubilee clips on oil hoses. Please!!!

... Care to expand?


Some types of hose do not require clips, The fittings are "Fir Tree" type
Some types of hose have swagged fittings,
Some types of hose do NEED CLIPS. (Don't they???)

I am sure that if I did not put clips on my hoses, the oil would piss out all over the place...
(and so would the water, and that's at only about 15PSI maximum...)

Or do you mean "Don't use Jubilee BRANDED clips?"
MY OPINION: The JCS HiGrip Stainless ones are the best quality.

Ian

[Spider]

Oh. Please don't use jubilee clips on oil hoses. Please!!!

... Care to expand?


Some types of hose do not require clips, The fittings are "Fir Tree" type
Some types of hose have swagged fittings,
Some types of hose do NEED CLIPS. (Don't they???)

I am sure that if I did not put clips on my hoses, the oil would piss out all over the place...
(and so would the water, and that's at only about 15PSI maximum...)

Or do you mean "Don't use Jubilee BRANDED clips?"
MY OPINION: The JCS HiGrip Stainless ones are the best quality.

Ian

Sorry, did someone say RACK or are my glasses crook?

[ianh1968]

Sorry, did someone say RACK or are my glasses crook?

I don't know about your glasses, but I only tend to remember things
if I am told the reason why...

For example #1:

Racks - I will always remember that you can't put a LHD rack in a RHD car
because it will end in tears. Turn the wheel left, it will steer right, and vice
versa. Just saying - "You need to change the rack" relegates this information
to the back of my very small brain, where eventually, it will slip down my
back and disappear out through my arse-hole.... As has been proven
recently, the time taken for the "fart" to emerge can be very short indeed...

(I will also always remember that Spider has a fantastic collection of
appropriate photographs which he will share with us at any opportunity...).

For example #2:

No clips on oil pipes - I will never remember this or even consider doing
it either unless someone tells me a logical reason why clips should not be
used. Just saying - "Don't use clips" relegates this piece of information to
the "Trash Bin" as it does not have any explanation to back it up...

For example #3:

I have worked on the railway for 6 years and only just found out recently
why "they" say that we should wear our Hi-Viz jackets with the zip done up.

Before, I did NOT wear my jacket with the zip done up, purely because I
was told "do-it-up-because-I-tell-you-to".

The reason is that on the front of the jacket, there is a reflective 'V' shape,
and on the back, a reflective 'H' shape. In the dark, track-side, someone
can see which way you are facing which could be very important if I am
about to get run over by a train. If I am facing away from an oncoming train,
the driver will more than likely sound the horn to alert me of his presence.

I am now more concious of having my jacket done up. I don't have to
remember "why" anymore as I have been provided with a logical explanation.

The moral of this tale is this:
A few extra words go a hell of a long way towards helping people retain
useful information.

Ian

[Spider]

Ian, very true.

Thought association.

Excellent explanation and examples.

I'd just add that most people think in 'pictures' so I find it helpful to try to talk and write in 'pictures'.