(They have proven that the earth is nearly round - it is just a bit flatter at the poles and a bit wider at the equator).

https://www.scientificamerican.com/article/earth-is-not-round/



batman wrote on 06/12/19 at 19:44:26:

Do you have any kind of recent research or data to back this statement up?  Something from somebody with the tools and equipment to support this legend?

batman wrote on 06/12/19 at 19:44:26:

You have repeated this several times on the forum, and I did an internet search to find out where this "belief" come from.  The only references I could find was for folks working on V-8 engines used in cars.  That 10 psi might be the ticket for an engine with hydraulic lifters and plain bearings - but I still don't believe it is applicable to a single cylinder engine with roller and ball bearings.  From what little measuring I can see has been done on the Savage engine......it doesn't provide anywhere near the kind of pressures you are quoting.

https://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1118629

batman wrote on 06/13/19 at 07:48:27:


All oil is thick when it is cold....and thins when it gets warm....and thinner when it is hot.

The viscosity ratings of oil are tested 100 degrees centigrade for the upper rating.  The oils are heated and then allowed to flow through an orifice....the rate for flow is established using straight grade oils (SAE 20, 30, 40, 50, etc).  A multi viscosity oil that is rated at 40 flows through the orifice at the same rate the straight weight oil does at that temperature.  This means that at 100 degrees temperature....an SAE 40 oil and a 15W-40 flow at the same rate.

The cold weather rating at 0 degrees Centigrade is not so easily defined, as it is a combination of tests.  Not only do they test the flow rate of the multi grade oil and compare it to the flow rate of the straight weight oil - but they also compare the oil resistance to shear.

https://wiki.anton-paar.com/en/sae-viscosity-grades/

https://wiki.anton-paar.com/en/viscosity-index/


batman wrote on 06/13/19 at 07:48:27:


The viscosity of an oil at operating temperature is approximated by the upper number of the multi viscosity rating at 100 degrees centigrade - which is 212 degrees......what they consider as an operating temperature for water cooled engines.  To say that a 40 weight oil at 100 degrees has a viscosity of 10-14 at this temperature is misleading - as you have not stated what temperature the 10-14 weight oil is at (I understand you are implying the 40 weight oil is thin when hot....I get that).  However the engines are designed to run with the engine oil being thin when hot.

I also understand that oil is thick when cold, and it does not flow was well when cold.  However the difference in thickness between a 5W, 10W, 15W and 20W oil is not significant at summer temperatures, and really isn't a contributing factor in which motor oil to buy for summer use......however some folks argue that more additives are used to lower the winter use rating, and those additives take up space that would normally be occupied by oil molecules - thereby reducing the lubricating value of the oil (Theory is a 15W-40 oil will have more oil and less additive than a 5W oil and provide better lubrication).

So that is how I feel and what my beliefs are based on - I am using Rotella  a T4 15W-40 in my tractor, and T6 5W-40 in my cars and motorcycles.  If somebody wants to use a 20W-50 in the Savage in the summer...I am OK with that as the factory says it is OK in the owners manual - they may want to consider a thinner oil if they ride in cool temperatures.

Here is a video to satisfy your interest in what motor oil looks like at -30 degrees.......not a good day for riding your motorcycle, and definitely the kind of weather that requires a block heater or warm garage.

https://www.youtube.com/watch?v=MVn5OzuHtjg


 

Around 1966 I was a student in a automotive trade-high school in the Bronx NY. We had a old shop teacher who was very smart and had seen it all.  One day he took a hand held oil gun , walked over to the window and squeezed out about one ounce of oil onto the glass and told us not to touch it. The next day he had us wipe our finger across the glass.  A film of oil could clearly be felt. He then went on to tell us that this is how it works in a engine, and all the talk about oil starvation, and wear during start up was BS. That made sense to me.

HOTROD, you wiped your fingers across it the next day , I put my bike away for six months(4,380 hrs) , not 24 hours . That's a whole different ball game.

How much later ? Pressure is there by rotation of the crankshaft, at times before ignition. At this point there is no load on the engine anyway.