Considering Switching to different Oil

[AvB]

First of all, cheers to all my friends here at the forum !! So ... to the point .

Im currently using Castrol SAE 20W50 Oil for more than 2 years, everything its ok so far, but recently here in Havana temps are going very high, during daytime it reaches 34`C , its incredible hot and this coming summer it will surely brake all local records (last August the record was 37`C) , so i don't want to stress the engine and decrease its lifetime, i was thinking to switch, on my next oil change, to Castrol SAE 15W40 , due to its viscosity ..

Also, i will receive in the coming months ,an Alloy Oil Pan and Valve cover  both of them GIANNINI... surely this will help with the excessive heat.

Any thoughts friends?? What do you think i should do

[Da Londo]

What year is your 126? 15W40 is recommended oil. The temps you got there are not too high for the car as it is the same as in Italy, bigger oil pan can be okay but you need to make sure the oil gets up to working temperature. Don't fit a 4.5 L oil pan if you're running a standard engine. Oil temp gauge would be ideal to keep an eye on your oil.

[AvB]

What year is your 126? 15W40 is recommended oil. The temps you got there are not too high for the car as it is the same as in Italy, bigger oil pan can be okay but you need to make sure the oil gets up to working temperature. Don't fit a 4.5 L oil pan if you're running a standard engine. Oil temp gauge would be ideal to keep an eye on your oil.

My 126 its from 1986. The oil pan is 3.5L and its from Giannini. Ive ordered this because of fear of the engine getting extremelly hot. With this oil pan do i have to use a less viscosity oil?? or shall i continue to use 20W50 ?

Thanks for replying

[Da Londo]

In my opinion the difference between the two is not big enough to change it. But I wonder if your engine is actually suffering from the heat, I'd recommend installing an oil temp gauge before the you put in the oil pan, I believe running temp is around 100 to 110 deg C but I'll need a quote on that.

[drcdb15]

In a typical petrol engine, the temperature in the combustion chamber is around 800-850 deg C. The temperature under the piston crown is in the region of 350-400 deg C.

As Da Londo said, the temperature of the oil in the sump is around 100 degC. So the oil is experiencing thermal gradients of around 250-300 C degrees between the top of the engine and the sump.

Against this, the difference in cooling effect that the external air has between say 20 degC and 37 degC is barely measurable. To the human eye and hand things may seem very hot in a hot summer, but in the range of temperatures routinely encountered in a combustion engine this change is minuscule.  To an engine, 37 deg C is not "hot", it is just a slightly warmer "cold".

[AvB]

In my opinion the difference between the two is not big enough to change it. But I wonder if your engine is actually suffering from the heat, I'd recommend installing an oil temp gauge before the you put in the oil pan, I believe running temp is around 100 to 110 deg C but I'll need a quote on that.

Ok, will do that when i receive the new oil pan in 30-40 days. Thanks

[AvB]

In a typical petrol engine, the temperature in the combustion chamber is around 800-850 deg C. The temperature under the piston crown is in the region of 350-400 deg C.

As Da Londo said, the temperature of the oil in the sump is around 100 degC. So the oil is experiencing thermal gradients of around 250-300 C degrees between the top of the engine and the sump.

Against this, the difference in cooling effect that the external air has between say 20 degC and 37 degC is barely measurable. To the human eye and hand things may seem very hot in a hot summer, but in the range of temperatures routinely encountered in a combustion engine this change is minuscule.  To an engine, 37 deg C is not "hot", it is just a slightly warmer "cold".

Ok , thanks for the info , as i said in the message above to @Da Londo ill put a oil temp gauge just to know what is the temp ... and i surely hope that the alloy oil pan (which es 3.5L by the way) and the alloy valve cover will help on decreasing the general temp of the engine..

Thank you both for replying

[1973/126]

 I know this is not directly answering your oil question, but this little gadget helps to keep the engine much cooler.
 http://www.ebay.co.uk/itm/282042587876?_trksid=p2060353.m1438.l2649&ssPageName=STRK%3AMEBIDX%3AIT
 I`ve got one on our car and it works a treat.

[AvB]

I used to have one and i removed 2 years ago