Rb26 Operating Temps

[pnblight]

Hi Guys,

I recently finished a full rebuild on my Gtr R33 and during the process i installed a low temp nismo thermostat 64deg (std 72deg) and greddy radiator 48mm and am about to fit a 19 row oil cooler with relocator and thermostat 72deg Apexi, but i have found that my old 82 deg normal operating temp has drop remarkable to around 68deg with out the oil cooler fitted yet. I oil temp still seems to rise over 70 degs while the water stay in the high 60's. Even with a/c on cruising in mid 30's heat the water temp never exceed 72degs.

My question to you guys is this how cool is to cool oil and water temps. I'm currently not concern at the moment as oil temp is still quiet similar to before it's just water temp low but when the oil cooler goes on i dont want it running to cool and out of the working range of the oil. The reason for these changes are in track conditions oil temps can race sky would quiet quickly and i would the car to handle track work better and manage heat issues. I should also mention i am also running a 8.5 to 9 litre custom sump.

pete

[WetGTR]

Hi Pete,

I have a 48mm PWR radiator with a Nismo Thermostate & a N1 Water Pump. The cooler you have it the better unless its that cold that your ECU tries to richen it up which I doubt. The only thing I found is that the heater might not work as good during a cold night but thats about it. On the oil temp side, well as long as its in its operating temp range you won't have a problem. Its a good idea to have an oil temp thermostate to regulate that, you might have one already.

BTW I have a 9L custom sump with a HKS Oil Cooler that has a built in thermostate.

[pnblight]

Hi Pete,

I have a 48mm PWR radiator with a Nismo Thermostate & a N1 Water Pump. The cooler you have it the better unless its that cold that your ECU tries to richen it up which I doubt. The only thing I found is that the heater might not work as good during a cold night but thats about it. On the oil temp side, well as long as its in its operating temp range you won't have a problem. Its a good idea to have an oil temp thermostate to regulate that, you might have one already.

BTW I have a 9L custom sump with a HKS Oil Cooler that has a built in thermostate.

<{POST_SNAPBACK}>

yeah the oil cooler system has a 72 deg thermostat (apexi unit) which has not been fitted yet.

Does anyone know the std operating temp most oils work best with in?

eg(60-120deg?)

pete

[N1GTR]

90-110 for turbo motors is good i think

[Sydneykid]

Oil temperature, courtesy of Castrol......

In order for motor oil to perform its major function - lubrication - its viscosity (the measure of its thickness or resistance to flow) must be capable of holding up under your engine's extreme temperature conditions. Oil thins when heated and thickens when cooled. Choosing the proper viscosity grade for the ambient temperature of your geographic location becomes vitally important.

A monograde is an oil whose viscosity is defined at only one temperature, either high or low. A multigrade must meet both high and low temperature viscosity requirements simultaneously. This makes multigrades an easy and popular year-round choice for drivers who experience hot summers and harsh winters. They are easily recognized by the dual viscosity designation (i.e. 10W-30 where the 10W is the low temperature, or winter designation and the 30 is the high temperature designation). It is the viscosity modifier additive that produces a thickening effect at high temperatures but is dormant at low temperatures.

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I have never ever had a Castrol technician advise me that the oil temperature is too low in one of our engines. So we don't run oil thermostats, never have.

Water temperature There used to be a general rule that engines produce their maximum power with water temp around around 85 degrees. Run an engine at 95 degrees and 75 degrees and (without changing anything) it will produce more power at 85 degrees. Due to ideal vapourisation of fuel, metallurgy of components, combustion temperature etc.

More recently it has been found that lower temperatures (than 85 degrees) can in fact produce more power. The idea is, the resulting lower cylinder head temperatures allow more ignition advance (and/or compression) to be applied before detonation sets in. The advanced ignition produces more power than is lost by the lower combustion temperature.

This requires closer to the edge tuning than most road cars would tolerate, they have to survive in 45 degree heat, with the air con on, dawdling along in the traffic etc. In a race car this is not really an issue, so we can tune much tighter.

Having a 72 degree thermostat simplistically means that the thermostat opens fully at 72 degrees. If the cooling system is sufficiently large enough this means that the engine should never get over 72 degrees. If the engine does get over 72 degrees then having a 72 degree thermostat is pretty much a waste of time. Well, it is, until you get a cooling system that IS capable of keeping the temperature at 72 degrees.

Since it gets over 72 degrees, it isn't advisable to tune it (with ignition advance) for more power to take advantage of this lower temperature. Unless you have water temp compensation mapping that starts at 72 degrees.

Hope that was of some help

cheers

Edited January 10, 2006 by Sydneykid

[pnblight]

Since it gets over 72 degrees, it isn't advisable to tune it (with ignition advance) for more power to take advantage of this lower temperature. Unless you have water temp compensation mapping that starts at 72 degrees.

thanks gary

but i actual said it has Never gone or 72deg even on a really hot day with a/c on the works, so i guess that means like you stated the cooling system is now up to the upgrade for general surpose driving will have to see how it fairs on the track.

(so posible i might be able to tune it quiet hard)

Gary what oil temp would you consider safe to run and engine hard on 60deg up wards?

pete