engine oils

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mickrach

Guest
:doh: hi there, iv just read about what engine oil to use and im using castrol edge racing 0w40 and this site says 10w 60. should i change it?. i thought it would be better all round?.anyone in the know?.
 
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Odin

Guest
0w40 is way to thin and will find it's way past the turbo seals in no time at all, I'd change it to 10w60 as is recomended by the oilman.


Rob
 
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Odin

Guest
He told me 10w50 or 10w60 is fine but 0w50 is way to thin.

I think I will use 10w50 on my new engine once its ran in, But if I had an older standard engine then it would be 10w60, Thats just my own opinion from what I've noticed over the many years and different types of cars though, I ran 10w60 for 3 years on my old engine and that stayed together even at 8000 rpm and 1.5bar of boost.


Rob
 
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campbellju

Moderators
Staff member
Silkolene R&D are recommeding 5W/40 ;-)

Spanner/works... Can/Worms etc.

Stumo did the investigation.
 
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Odin

Guest
Well I stand corrected, But all the same my engine ran fine for 3 years with 10w60and had very good oil pressure for an old hard used 65k engine, Another point was when it did let go in the end it was still in a very good condition for rebuilding with very little bore ware, So I don't think any of these oil will be wrong to use apart from the 0w50 which I hope we all agree on ;-) .

I think 5w40 is a bit thin myself and wont be using it.

Rob
 

oilman

Member
We do recomend the Silkolene Pro S 10w-50, you can use a 10w-60 but we feel the SAE60 is just too thick when hot.

If you speak to Silkolene they would suggest a 5w-40 but this is based on a stock car used for normal use, we havent come accross many stock GTIRs that have normal use and have found the 10w-50 to be that much better when pushed and is also fine for year round use.

Cheers

Guy.
 

campbellju

Moderators
Staff member
I'm just reviving an old thread as I was looking for the answer from 15 years ago but it was all posted on the tech forum which sadly is no more.

To fill in the gaps.

Stumo spoke to Silkolene R&D about the most appropriate oil for our cars.

Nissan recommend a semi-synth 10W30 for our cars in UK in the 90's but time and technology has obviously moved on.

The Silkolene team knew our SR20 engines as they were brought in to solve an issue with the Primera used in touring cars that was occasionally spitting bearing above 7000rpm. After testing they found the thicker oil of 60 was causing inadequate flow at high rpm and they switched the touring cars to thinner oils. As the bearing gaps on the touring car are similar to the GtiR, the conclusion was running too thick an oil is a risk at high rpm. Their advice was fit an oil cooler and run a 5w40 oil for a road/track car.

Another 15 years on I was wondering if a 5w30 would be feasible for a street car as lots of modern turbo cars use it now from the factory. Reading around I'm going to keep the safety margin of the thicker oil and stick to the Silkolene team's advice of 5w40.
 

Eng1

Member
Fitting an oil cooler pretty much negates any viscosity issue and a constant max sump oil temp .
With an oil cooler the sump temp is around 100 c max .
The main engine bearings are not in a “hot oil “ area , by that I mean where the oil sees highest temps , these are near the combustion area : lower piston and rings where the oil temps are over 200 c higher . To blame too thick oil is odd at the main bearings as the film is not that effected (less variation in viscosity)
If oil was “too thick “ and not enough flow , the oil pressure would be higher at that rpm compared with a thinner oil .
IF you don’t run an oil cooler then the real danger is oil that is too thin at high rpm thus losing its film strength - high rpm gives more heat cycles per min and thus much higher total heat for the oil to absorb . More power from the engine = higher heat produced for the oil to absorb and move
Higher rpm should produce more flow as long as the pump can keep up .
I prefer engines with super efficient oil pumps and high output pressure as they push more flow
- GTIR = 4,5 bar
- 2JZ = 6 bar
Both at similar rpms ,
the lower W winter number makes little difference , the engine is in a low /idle power and flow is less critical , the difference in viscosity is only a couple of points between a 10 shift in w number .
The oil cooler is the major thing rather than the viscosity number difference
 
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