Shop Time w/T.W. Friends

How can 5 thin to 30? In 5W-30, I thought the smaller the number the thinner the oil is; so 5 was as thin as it got and 30 was as thick as it got.

 

Correct - 30W is its rest state and 5W is its most viscous state. There are other properties, but those are based on design, makeup and additives. My only fear with “old” lubricants is the breakdown of any such additives. They may drop from suspension and with exposure change state (crystallize, decompose, separate). I’d certainly still use it, but would not pour out the “bottom”.

 

i've done this more times than i should probably admit to. about 2 years worth.

a. it was all free yard equipment.
b. it dilutes into the gas quite well.
c. nothing blew up, but i also didn't care about any of it because the lawn mower and snow blower were resurrected garbage-pile pulls.

like was said, i seem to always end up with random 1/2 quarts lying around after oil changes. they worked quite nicely for that purpose.

 

Waste not, want not.

 

Grab a coffee, this will take a minute...

You are correct:
Lower viscosity grade numbers EX: 0, 5, 10 are thinner
Higher viscosity grade numbers EX: 30, 40, 50 are thicker
All oils thicken when cold and thin when heated to normal operating temperature

5W-30 Let's take it apart:
5 = 5 grade base stock, it will always be 5 grade - this is the cold viscosity
W = indicates the oil has a pour point depressant additive that helps the oil to not thicken (as much) in extreme cold
30 = is the engineered hot viscosity

We need a thin oil for reliable cold starts and fast flow after starting as well as cold pumping - too heavy of an oil might not allow the engine to spin fast enough to start, would take a long time to get to the valve train and might break the oil pump drive.

We need a heavier oil at operating temperature for good lubrication under load.
Sounds like a paradox doesn't it...

Enter the magic of chemistry - polymers.
As used in engine oils, polymers can be thought of as molecules that resemble a chain - a temperature sensitive chain.

When cold the chains are all balled up and allow the low viscosity oil to flow freely.

At operating temperature the polymer chain stretches out binding the oil together making it more resistant to thinning.

Chemists calculate the amount of polymer needed to give the viscosity spread required, this is part of the "V I pack" - viscosity improvers.

A 10W-40 oil will require more polymer to achieve the 30 point spread than a 20W-50 because the 20 grade base stock is thicker to begin with.

So if you got this far here is the take away:
5W-30 oil is a 5 grade oil that will thin no more than a straight 30 grade when at operating temperature.

 

My luck would never be that good!

 

Yall get on up and get with it. Let's make a difference today.

 

We have a small, rural hospital about .2 miles away from our home.. Complete with helipad. Sometimes it sounds like the helicopter’s gonna fly right into my home when it comes in. Like it did a few minutes ago…

No ambulance siren before (that would’ve woke me too) so I wonder what the emergency was. I always wonder…


@RustyGreen , thanks for the primer on oil viscosities. . Timely as I spent yesterday changing the oil in the summer toy- 10 quarts of full synth 5W-50 (GT350).

Good morning all . I hope you have terrific Monday.

 

Gt350 you say? Lets see the ol voodoo girl Jim.

 

Morning all back to work today then cot to scout a beehive removal at one of our stations. Will see what going on you all have a great day

 

From Google Maps:

 

GT350!

This is a pictures required situation!

 

My neighbor across the street has a blue stripes on white Gt350 and it brings a smile to my face every time he gets it above 3500 rpm. It's his baby and he drives it like a grandma.

 

A fellow across the street at one of the downtown properties was washing one in his driveway, naturally I was over there quick. It has a setting on the head unit to modify the exhaust sound from mild to wild - electric cut outs I guess, no way I could get down to look under.

BTW: The car belongs to his brother, he can borrow it whenever he wants...

 

The key here is "small rural hospital" where anything more than a stubbed toe is a real emergency for the care givers in that facility. Because of the state of the world, ground ambulances are rarely staffed and a ground transport to another city, county or state is nearly impossible, helicopters are called in to save the day. It's not a very economical solution for the patient and isn't required for most transports but it has now be come the new normal.

 

Good morning guys Hope it was a good weekend for you.

 

New week, new broken boats. Perhaps parts will be plentiful this week and I'll make service bounty.. one can hope

 

My first pic! (12/5/15) At the dealership, they kept it on display through the winter.




And one for posterity


Man would I love to have one of them now!

 

I used to think anyone who worked on engines knew all this because if I understood everyone else would find it simple.