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Constant oil cooling good or bad idea?
bi22le - 26/8/10 at 06:16 PM

Hi all,

Following on from a few track days (and general driving) done this year I have noticed the oil temp is alittle high for my liking (between 110 deg and 120 deg). Current cooling is done via a ford diesel oil to water converter sandwich between the block and oil filter.

I run some vent tube from under the car to the oil filter and that dropped it alittle.

I was thinking of getting one of those CBS oil filter fin heat sink things. Also make up some extra fins for the oil to water exchanger and use the duct to get good air flow across all fins.

My concern is there is no on or off its just cooling. I read somewhere about somebody fitting an oil cooler and getting a thermostatic valve for it so the oil gets warm (protecting the engine) and then gets cooled.

I never rag the engine when cold anyway so I was thinking it should be ok. Whats peoples thoughts.

Car is used for road mainly but hopefully about 5 track days a year.


r1_pete - 26/8/10 at 06:18 PM

You really should use an oil thermostat, running with the oil too cool will not protect your engine properly.

Think automotive do the stats.


turbodisplay - 26/8/10 at 07:12 PM

The oil cooler will have a thermostat built in, whether it still works is another question.
You could put anther sandwich block to double the cooling capacity.
Darren


britishtrident - 26/8/10 at 07:58 PM

The type of heat exchanger you have is designed to get the oil within 10 degrees or so of the coolant temperature, it also warms the oil on start up. You don't say what kind engine you have but if you want to lower the oil temperature lower the coolant temperature.
Personally I don't see 110c as anything to get uncomfortable about.


Rocket_Rabbit - 26/8/10 at 08:22 PM

quote:
Originally posted by britishtrident

Personally I don't see 110c as anything to get uncomfortable about.

I agree.

unless you are using somesort of pants mineral oil, 110-120 is well within optimum operating parameters.

If you are pushing 135 deg C, then perhaps it is adviseable.


Antnicuk - 26/8/10 at 09:05 PM

im surprised at the temps you guys are happy to run at. Mine was getting up to 120 on track days so i changed my stock (quite large) oil cooler for a Mocal one. The stock mazda cooler has a built in stat so i fitted a mocal in line one which prevents the oil going to cooler until it reaches temp. It now doesnt go over 95 on very hot days so im happy. Maybe rotaries are different......

[Edited on 26-8-10 by Antnicuk]


BenB - 26/8/10 at 09:56 PM

My ST engine has an oil / water heat exchanger as standard. Obviously it only kicks in once the water thermostat opens.


loggyboy - 26/8/10 at 10:10 PM

quote:
Originally posted by Antnicuk
It now doesnt go over 95 on very hot days so im happy. Maybe rotaries are different......



I have read that keeping temperatures over water boiling point aids in keeping water out the system (that inevetibly gets in to the oil system via cumbustion and condensation). By turning it to its gaseus state it purges the system of water everytime you warm it up.


02GF74 - 27/8/10 at 07:18 AM

From the peplle who should know:

quote:
Every en gine will have a dif fer ent oil temperature re -
quirement but, as a gen eral rule temperatures in excess of 110oC
should be avoided.


.... but then they have a vested interest in order to sell oil coolers!!


britishtrident - 27/8/10 at 07:30 AM

The oil and water temps should never be too far apart, modern engines are designed to run at 93 to 108c if you have an oil temperature within 10 to 12 degrees of that all all is well.

[Edited on 27/8/10 by britishtrident]


Antnicuk - 27/8/10 at 08:14 PM

quote:
Originally posted by loggyboy
quote:
Originally posted by Antnicuk
It now doesnt go over 95 on very hot days so im happy. Maybe rotaries are different......



I have read that keeping temperatures over water boiling point aids in keeping water out the system (that inevetibly gets in to the oil system via cumbustion and condensation). By turning it to its gaseus state it purges the system of water everytime you warm it up.



That makes sense but i think you have to bear in mind that the oil will be getting hotter than that in certain parts of the engine. In a rotary, the oil is injected in to the rotors to cool them so the general temperature at the point of the sensor (under the oil filter) is below 95 but it will be well over that in certain places.