Small Engine Oil Temps

[Pete591]

Briggs Vanguard 16 Hp V-Twin

Outdoor temps in low 80's for all/atleast one hour of cutting on lawntractor.

M-1 15W-50 281*F
Optimol Conventional 30wt 285*F
Briggs 30wt 283*F
Motul 300V 15W-50 255*F

20HP Intek Extended Life V-Twin

30WT factory fill...who knows what.. 287*F
Mobil-1 Motor Cycle Racing 4T 10W-40 290*F
Amsoil ASE 30WT/10W-30 246*F

FYI...I did read where synthetic oil has a better heat transfer ratio vs. conventional oil. My results also show Amsoil ASE to be the winner of my "crude" heat experiment. I used a "dial meat thermometer" that is about 11" inches long...right down the oil fill tube after the engine sat for 15 minutes in all cases. Best I can do without an inline thermometer.

Significance of results? Some choices are better than others.

...oh...get your thermometers...let's see more #'s..!

These are aircooled engines...heat (or the lack of it) matters I would think.

 

[doitmyself]

Pete, those numbers seem to be very high. Have you checked the calibration of your thermometer??

Interesting results. The Amsoil was significantly cooler.

 

[bepperb]

Those temps are high. If your livelyhood depends on them, buy good oil.

 

[duaneb9729]

what should the oil temp be?

 

[JTK]

Originally Posted By: Pete591

20HP Intek Extended Life V-Twin

30WT factory fill...who knows what.. 287*F
Mobil-1 Motor Cycle Racing 4T 10W-40 290*F
Amsoil ASE 30WT/10W-30 246*F


Pete once again you're breaking new records. A month of ownership and you've done 3 oil changes on it. Premium synthetics on top of that!

Joel

 

[Pete591]

Originally Posted By: doitmyself
Pete, those numbers seem to be very high. Have you checked the calibration of your thermometer??

Interesting results. The Amsoil was significantly cooler.


I did calibrate the thermometer to boiling water.

Also, oil temps went up quite a bit on average by letting the engine "sit" 15 minutes after shutdown. Maybe I should have done immediate shutdown temps or both?

 

[Oldwolf]

Maybe the higher temp is better?

Keeping more heat away from engine?

The heat is going somewhere in the cooler oils temps. Where? Maybe into the block?

 

[Pete591]

Originally Posted By: Oldwolf
Maybe the higher temp is better?

Keeping more heat away from engine?

The heat is going somewhere in the cooler oils temps. Where? Maybe into the block?


Using an infra-red heat detector.. usually the temps are about 20* lesser than actual oil temps after 15 minutes of shutdown. I guess my measurements are more representative of "core engine temperatures". They do show that some oils can play a role in regulating heat dissipation better than others.

One can definately see that when the cooling fins stop the heat from the internals transfer to the block and to the oil...temp goes up. No radiator here...

I looked up what the average automobile oil temp is and it showed the average oil temp is about 220-240*F .

 

[Mamala Bay]

Originally Posted By: Pete591
Originally Posted By: Oldwolf
Maybe the higher temp is better?

Keeping more heat away from engine?

The heat is going somewhere in the cooler oils temps. Where? Maybe into the block?


Using an infra-red heat detector.. usually the temps are about 20* lesser than actual oil temps after 15 minutes of shutdown. I guess my measurements are more representative of "core engine temperatures". They do show that some oils can play a role in regulating heat dissipation better than others.

One can definately see that when the cooling fins stop the heat from the internals transfer to the block and to the oil...temp goes up. No radiator here...

I looked up what the average automobile oil temp is and it showed the average oil temp is about 220-240*F .


I have a hard time believing this, on your actual test on these engines "HOW MANY SPARK PLUGS". You are going to create more heat with 8 spark plugs versus 1 on most small engines.

 

[JTK]

Pete it's interesting data for sure, but not accurate as it would be with a temperature well submerged into the depths of the engine oil sump. Shooting spots on the jugs or block of your 20hp does not represent the actual temp of the oil in the sump. If you had 285F oil in the sump, other areas of that engine would be smoking hot.

Joel

 

[Pete591]

https://bobistheoilguy.com/forums/posts/1514221/

This was posted recently.

 

[JTK]

That engine was being running w/ approximately half the oil in it's sump that it's spec'd to run with.

Joel

 

[Pete591]

Originally Posted By: JTK
That engine was being running w/ approximately half the oil in it's sump that it's spec'd to run with.

Joel


True...but it's also an 8 HP single pistone..mine is a V-Twin 20 HP...fyi..I am getting a new thermometer and will report back. This one is factory calibrated.

 

[pickled]

Very interesting study Pete. Now where are you going to use the leftover Franken-oil?