Viscosity calculator

[ICDEDPPL]

I oversized my oil coolers in the boat a bit and my temps hover around 140* .
I have 2 big blocks with loose bearing clearances for marine.
According to the calculator with red line 5w50 Im an 69cst.
That seems like the viscosity of a 30w oil.
Am I looking at that wrong?
I`m thinking my oil is too thin because of the 5w but then the higher the temp the thinner it is so Im confused..

 

[kschachn]

What calculator are you using?

You seem to have a problem with temperatures here. The winter rating is irrelevant for this purpose.

All oil thins as the temperature increases.

 

[tnt_motorsports]

I oversized my oil coolers in the boat a bit and my temps hover around 140* .
I have 2 big blocks with loose bearing clearances for marine.
According to the calculator with red line 5w50 Im an 69cst.
That seems like the viscosity of a 30w oil.
Am I looking at that wrong?
I`m thinking my oil is too thin because of the 5w but then the higher the temp the thinner it is so Im confused..

Maybe I don't understand your question but hopefully this will help you with your viscosity question... 69cst @ 40C is a 20 weight oil, are you sure it's not SUS @ 210F and therefore right at the bottom of a 40 weight oil?

Viscosity Charts - Bob is the Oil Guy

Viscosities can be related horizontally only Viscosities based on 96 VI single grade oils. ISO are specified at 40°C AGMA are specified at 40°C SAE 75w, 80w, 85, 5w, & 10w specified at low temperature. Equivalent viscosities for 100° & 210°F are shown SAE 90 to 250 and 20 to 50 specified at...

bobistheoilguy.com

Just my $0.02

 

[kschachn]

Perhaps the OP has just seen too many dead people and won't return.

 

[userfriendly]

With 2 1/2 mains & rods and HV oil pumps, 15W40 hasn’t failed me yet in BBCs.

If you’re worried that 15w40 is too thin, consider 15w50 M1.

 

[wpod]

Why the 5W oil do you start the engines when it is freezing? Is the oil temps 140 or the coolant temps? what is the oil pressure?

 

[wpod]

With 2 1/2 mains & rods and HV oil pumps, 15W40 hasn’t failed me yet in BBCs.

Those clearances seem pretty much like the common used clearances.

 

[JavierH19]

This?

Mixing viscosities | Widman International SRL

www.widman.biz

 

[RDMgr]

This?

Mixing viscosities | Widman International SRL

www.widman.biz

These are blend calculators. You want a viscosity at temperature calculator. Your oil seems to be about 62 KV60°C.

 

[Rand]

Maybe? looking at a viscosity at 140f and using the chart to compare it to viscosity at 40C. (user error?)
OP didnt really explain his problem very well.
Perhaps @ICDEDPPL was interrupted by a dead person before completing his thoughts?

 

[ICDEDPPL]

Maybe I don't understand your question but hopefully this will help you with your viscosity question... 69cst @ 40C is a 20 weight oil, are you sure it's not SUS @ 210F and therefore right at the bottom of a 40 weight oil?

Viscosity Charts - Bob is the Oil Guy

Viscosities can be related horizontally only Viscosities based on 96 VI single grade oils. ISO are specified at 40°C AGMA are specified at 40°C SAE 75w, 80w, 85, 5w, & 10w specified at low temperature. Equivalent viscosities for 100° & 210°F are shown SAE 90 to 250 and 20 to 50 specified at...

bobistheoilguy.com

Just my $0.02

Let me clarify, I used this calculator to figure out the viscosity at 140* , which is 69cst.. not at 40C

Calculate viscosity at given temperature | Nimac Great Britain

 

[ICDEDPPL]

Why the 5W oil do you start the engines when it is freezing? Is the oil temps 140 or the coolant temps? what is the oil pressure?

My Morel lifters require a thinner oil otherwise I would just run a 20w50.
oil temp is between 130-155F
Oil pressure is good at 60-80psi ... 20 after a run at idle

 

[ICDEDPPL]

I guess I don`t have an understanding of viscosity, 5w50 to me would mean it`s thinner at cold temps yet thicker at higher temps which doesnt make sense since the hotter the oil the thinner it is.

 

[ICDEDPPL]

Last set up I was getting up to 250F oil temps @WOT , added an inline 12" cooler , 3 stage water pump and I never thought the oil would stay so cold with spring and piston oilers. at cruise I went from 185F to 140F oil temps... coolant temps never get above 100*

 

[ammolab]

I guess I don`t have an understanding of viscosity, 5w50 to me would mean it`s thinner at cold temps yet thicker at higher temps which doesnt make sense since the hotter the oil the thinner it is.

Your 5W-50 oil doesn’t get “thinner” at cold temperatures it just doesn’t thicken up as a straight 50 weight does….or more properly think of it as a magic 5W oil that doesn’t THIN out when heated.

Thus you have a proper oil for a cold start That resists thinning out at higher temps.

 

[4WD]

I guess I don`t have an understanding of viscosity, 5w50 to me would mean it`s thinner at cold temps yet thicker at higher temps which doesnt make sense since the hotter the oil the thinner it is.

The 5 and 50 are not related … 50 at operating temps - what do those Morel lifter engineers call the high side viscosity ? …
Finding 5W40 on some of the “speed sites” for them …

 

[ICDEDPPL]

from Morel: (no explanation why )

Desc1	BBC .903D T/B (HI RPM) P/O HYD ROLLER +.300 O/C
Desc2	DO NOT USE OIL HEAVIER THAN 5W40

 

[Sonic]

People need to stop talking about oil using the term weight. That just confuses folks. I see it on here constantly. Someone writes about oil and says it’s a 30w. ? Um no. 0w, 5w, 10w 15 or 20w as the first number. The second number isn’t followed by any w. And w doesn’t stand for weight anyway. Engine oil comes in grades.

 

[4WD]

from Morel: (no explanation why )

So Morel recommend this - and your engines are running cool -
(you will maintain MOFT) - so, who recommended a 50 ?

 

[4WD]

There were several mentions of a 40 and hydraulic lifters - read one from Lake Speed but getting server error trying to post

Clip from article