Bike/car oils. An interesting read

[2wdrift]

I won’t trust a 10W40 oil to protect my engine when I’m doing a slow technical trail in 40+degrees heat. Motorex 10W60 is cheap insurance.

Does the operating temperature of the engine differ that much?

Yes, and with an aircooled engine it will be quite a bit more so.

You are wrong. The temperature differential between ambient temperature and heat sink temperature affects the efficiency of the heat sink.

In plain English: The hotter your air cooled engine gets the more efficient the heat transfer from engine casing to the surrounding air becomes.
The same works for a radiator and a liquid cooled engine.
The air cooled engine will run a little bit hotter on a hot day. You will anyway not need another oil just because your sump oil temperature goes from 110°C to 120°C.
In a modern liquid cooled engine the engine temperature fluctuations caused by an increase in ambient temperature are hardly noticeable as they will be levelled out by the coolant thermostat and the radiator fan.

Last but not least:
The differences in performance of a 40 vs. a 50 vs. a 60 oil at the oil temperatures encountered in a naturally aspirated petrol engine are marginal. Please note we do NOT talk turbo charged Diesel, your bakkie might be better off running on a 50 oil vs. a 40!
The huge difference lies in the cold viscosity: A 5W will perform considerably better on cold start than a 20W

I agree with your statement, but while going really slow I have seen aircooled bikes, some of them mine, starting to sound very different to normal. They tend to get a more metallic clicking noise and they seem to lose a bit of power.  I am not arguing about your theory, but when struggling on a sand dune liquid cooled bikes with electric fans seem to be slightly more stable temp wise.

[Black_Hawk]

 

[Regis Laconi]

Ek het met my XR 650L deer die Richtersfeld gery, die temp van die dag was 56 grade celsius.  Vanaf Vioolsdrif tot in Sendelingsdrif en oor die pond na Rosh Pinah.  Die bike het partykeer so warm geraak dat ek die motor kon ryk...maar soos n Honda het hy aanhou loop.  Hy het op Actevo geloop.  Hy loop nou nog in Rosh Pinah en hy gebruik nogsteeds Actevo.  Nog nie n dag se kak gehaad nie.

Laas jaar toe doen ek dieselfde trip met my 690.  Met die wete dat dit bliksems warm daar word vervang ek my standaard coolant met n Motorex coolant.  Die fiets loop ook op Motorex 10W 60.  Ek moes seker 20 keer stop in 189 km om die bike te laat af koel.  Dit was net so onder 50 grade en die bike se fan kon net nie by bly nie.  Ek het seker 3 keer n warning light gekry vir temp.

Ek dink regtig nie engine olie sou n verskil gemaak het nie.  Warm is warm.

Gebruik warmee jy veilig voel en kan bekostig.  My 929 Fireblade het 14 jaar lank gehaardloop met 136 000 km op, ek het Shell Helix 20W 50 in hom gegooi.  Ook net omdat ek dit verniet gekry het.

[TheBear]

Ek het met my XR 650L deer die Richtersfeld gery, die temp van die dag was 56 grade celsius.

Bliksem!   At those temps how did you survive?   Do we humans get 5W-80 blood or something? Just reading that temp caused show dehydration symptoms! 

[Regis Laconi]

Ons het diere langs die pad gekry ( boer bokke ) wat net dood neer geslaan het.  Van hulle het nog gelewe.  Ons het hulle na koelte gedra en vir hulle probeer water ingee, maar niks het gehelp nie.  Ons het ongelukkig nie genoeg water saam gedra om hulle nat te gooi nie.

Die bok wagter was geen plek te sien nie.  Dit was hartseer.  Ons het seker meer as 10 bokke langs die pad gekry.  Wil nie weet hoeveel het gevrek oppad rivier toe nie.

[2wdrift]

Ek het met my XR 650L deer die Richtersfeld gery, die temp van die dag was 56 grade celsius.  Vanaf Vioolsdrif tot in Sendelingsdrif en oor die pond na Rosh Pinah.  Die bike het partykeer so warm geraak dat ek die motor kon ryk...maar soos n Honda het hy aanhou loop.  Hy het op Actevo geloop.  Hy loop nou nog in Rosh Pinah en hy gebruik nogsteeds Actevo.  Nog nie n dag se kak gehaad nie.

Laas jaar toe doen ek dieselfde trip met my 690.  Met die wete dat dit bliksems warm daar word vervang ek my standaard coolant met n Motorex coolant.  Die fiets loop ook op Motorex 10W 60.  Ek moes seker 20 keer stop in 189 km om die bike te laat af koel.  Dit was net so onder 50 grade en die bike se fan kon net nie by bly nie.  Ek het seker 3 keer n warning light gekry vir temp.

Ek dink regtig nie engine olie sou n verskil gemaak het nie.  Warm is warm.

Gebruik warmee jy veilig voel en kan bekostig.  My 929 Fireblade het 14 jaar lank gehaardloop met 136 000 km op, ek het Shell Helix 20W 50 in hom gegooi.  Ook net omdat ek dit verniet gekry het.

Dis net omdat die XR nie warning liggies het nie...



Sent from my LG-D855 using Tapatalk

[lecap]

I won’t trust a 10W40 oil to protect my engine when I’m doing a slow technical trail in 40+degrees heat. Motorex 10W60 is cheap insurance.

Does the operating temperature of the engine differ that much?

Yes, and with an aircooled engine it will be quite a bit more so.

You are wrong. The temperature differential between ambient temperature and heat sink temperature affects the efficiency of the heat sink.

In plain English: The hotter your air cooled engine gets the more efficient the heat transfer from engine casing to the surrounding air becomes.
The same works for a radiator and a liquid cooled engine.
The air cooled engine will run a little bit hotter on a hot day. You will anyway not need another oil just because your sump oil temperature goes from 110°C to 120°C.
In a modern liquid cooled engine the engine temperature fluctuations caused by an increase in ambient temperature are hardly noticeable as they will be levelled out by the coolant thermostat and the radiator fan.

Last but not least:
The differences in performance of a 40 vs. a 50 vs. a 60 oil at the oil temperatures encountered in a naturally aspirated petrol engine are marginal. Please note we do NOT talk turbo charged Diesel, your bakkie might be better off running on a 50 oil vs. a 40!
The huge difference lies in the cold viscosity: A 5W will perform considerably better on cold start than a 20W

I agree with your statement, but while going really slow I have seen aircooled bikes, some of them mine, starting to sound very different to normal. They tend to get a more metallic clicking noise and they seem to lose a bit of power.  I am not arguing about your theory, but when struggling on a sand dune liquid cooled bikes with electric fans seem to be slightly more stable temp wise.

That's called detonation or knocking it has something to do with the engine over heating but nothing at all with the oil or lubrication. Since the knocking can be very destructive you should either ride at lower power setting and good speed and preferably not with the wind or stop and switch off and allow the engine to cool down.
If the problem occurs a lot you should change the jetting (go richer).

[TheBear]

Ons het diere langs die pad gekry ( boer bokke ) wat net dood neer geslaan het.  Van hulle het nog gelewe.  Ons het hulle na koelte gedra en vir hulle probeer water ingee, maar niks het gehelp nie.  Ons het ongelukkig nie genoeg water saam gedra om hulle nat te gooi nie.

Die bok wagter was geen plek te sien nie.  Dit was hartseer.  Ons het seker meer as 10 bokke langs die pad gekry.  Wil nie weet hoeveel het gevrek oppad rivier toe nie.

Ek kan dink.   Die warmste wat ek ooit ervaar het was 46 en dit was alreeds onuithoubaar.