Checking temperature

[KrashnKraka]

<motoman> lost his way so I repost his latest info on the topic.
Following along no worries, just got nothing growing here, need rain ;-)))

KK


Hot day, hot oil

A couple of us were sharing heat readings , but I lost the thread location.
So here it is to find.
Last Sat 96F.
Mow weeds out chute 30 minutes.
Craftsman dyt4000 Intek 24.
*Oil cooler and fan fitted.
*Oil filter 117F
Cooler fitting 189F
Sump drain plug 183F
Rocker cover 210F
Exhaust header413F
Oil temp (liquid) 280-300F
From Beedee gauge . See pics Idling 5 minutes with fan on oil cooler
reduced oil temp 50 degrees F.

*Attached Images
*592.JPG*(103.9 KB, 1 views)
*594.JPG*(98.8 KB, 1 views)

 

[gainestruk]

Ok guys, here is my 4th run with different thickness oil (last time, will run this grade from now on)
Outside air temp 83* at start and 87* at finish which is about the same as I've been doing.
This run is with Rotella T6 5W40 full synthetic.

20 min oil filter=153.3*, block=158.0*, drives=119.8*
40 min = 149.7*, 159.2*, 120.2*
60 min = 176.3*, 171.5*, 140.1*
80 min = 173.4*, 181.9*, 130.2*
90 min = 186.9*, 196.8*, 130.6*

Here is a run down from lightest to heaviest weight oil

5W30 synthetic ----------------10W30 Dino---------------5W40 synthetic--------15W40 Dino (these were from memory)
20 min=160.0*,125.7*,100.7*/ 147.9*,151.1*,118.4*/147.9*,151.1*,118.4*/180.0*,142.0*,142.0*

40 min=166.6*,136.7*,114.0*/ 172.0*,146.6*,123.9*/172.0*,146.6*,123.9*/200.0*,155.0*,135.0*

60 min=174.5*,133.7*,117.6*/ 165.3*,141.1*,123.4*/165.3*,141.1*,123.4*/212.0*,168.0*,140.0*

80 min=178.1*,138.0*,121.2*/ 163.0*,144.6*,125.7*/163.0*,144.6*,125.7*/200.0*,150.0*,148.0*

90 min=178.0*,155.6*,128.1*/ 176.0*,170.4*,125.2*/176.0*,170.4*,125.2*/

Looks like 5w30 got hot faster and was hotter than 10w30 Dino and 5w40 synthetic.
The 15w40 Dino ran the hottest.
Now how about someone else trying it ?
I will show temps again with 5W40 synthetic, but I'm not planning to try any other weight.

 

[KrashnKraka]

Ok guys, here is my 4th run with different thickness oil (last time, will run this grade from now on)
Outside air temp 83* at start and 87* at finish which is about the same as I've been doing.
This run is with Rotella T6 5W40 full synthetic.

20 min oil filter=153.3*, block=158.0*, drives=119.8*
40 min = 149.7*, 159.2*, 120.2*
60 min = 176.3*, 171.5*, 140.1*
80 min = 173.4*, 181.9*, 130.2*
90 min = 186.9*, 196.8*, 130.6*

Here is a run down from lightest to heaviest weight oil

5W30 synthetic ----------------10W30 Dino---------------5W40 synthetic--------15W40 Dino (these were from memory)
20 min=160.0*,125.7*,100.7*/ 147.9*,151.1*,118.4*/147.9*,151.1*,118.4*/180.0*,142.0*,142.0*

40 min=166.6*,136.7*,114.0*/ 172.0*,146.6*,123.9*/172.0*,146.6*,123.9*/200.0*,155.0*,135.0*

60 min=174.5*,133.7*,117.6*/ 165.3*,141.1*,123.4*/165.3*,141.1*,123.4*/212.0*,168.0*,140.0*

80 min=178.1*,138.0*,121.2*/ 163.0*,144.6*,125.7*/163.0*,144.6*,125.7*/200.0*,150.0*,148.0*

90 min=178.0*,155.6*,128.1*/ 176.0*,170.4*,125.2*/176.0*,170.4*,125.2*/

Looks like 5w30 got hot faster and was hotter than 10w30 Dino and 5w40 synthetic.
The 15w40 Dino ran the hottest.
Now how about someone else trying it ?
I will show temps again with 5W40 synthetic, but I'm not planning to try any other weight.

W0W..!.. I saaaaaay W0W.
U set a high benchmark, brother!
It needs to rain here but meanwhile I am:ashamed:

 

[motoman]

Good work. The thinner oil circulates faster and (hopefully) unloads heat faster . But where it unloads, the question. Without an oil cooler it only unloads on cyl walls and sump casting. Casting sits on a big gauge steel platform (on al feet -at least on my Intek/Craftsman). Once heated this big slab of steel will not cool down quickly. Guess I should take a reading of the steel platform to compare with the sump.

OK, (choir disregard this old familiar theme)... The aluminum air cooled heads as critiqued by an airplane guru...(paraphrase): The aluminum heads have an extaordinary task. Before machining they are heat treated @ 1000F and quenched to T6 (hardness). During operation the exhaust side of the head is extremely hot while at intake fuel and cold air incoming create a huge temp difference. Heads are subject to cracking if cooled too rapidly . This is the cause of valve seat problems. Over temp problems start at around 325F and (other sources ) soften at 390F. This causes valve guide problems. On the subject of valve guide seals...while oil flow can aid cooling , seals may be necessay to stop excess oil at the valve and guide interface. The high temps can cause coking (deposits) which can cause sticking of the valve, bending the pushrods.

Ideas for owners manuals (in my dreams)..."CAUTION , if dash oil temp gauge is over 240F do not shut off tractor. Go to shade and idle until oil temp reaches 240F or below. Never wash or cool warm engine with water." I know, I know, owners don't always even keep oil level, much less watch a gauge. Maybe if they were flying. Fantasy time for longer tractor life.

Edit: Add to owners manual. "Avoid any grass bagger system. Added weight and engine load drives up engine temperature . Use a sweeper."

 

[gainestruk]

Yep paying attention to gauges would be a challenge for some owners, BUT it takes on a whole new meaning when you are 3000' above ground and your life depends on keeping track of how engine is doing

 

[Pumper54]

Adding my .02 cents to this.
Bride mowed the yard today and I recorded the following temps using a Cen-Tech model 96451 Infrared temp gun, I shot the temps from about 3 feet away from each point.
Air temp was about 65 F at time of mowing.
Before start after 10 minutes of mowing at shut down (20 minutes after start)
Oil Tank 79 F 147 F 156 F

Oil drain plug 78 F 162 F 198 F

Oil filter 78 F 164 F 190 F
(center of bottom)

small X is the aim point center of filter and the Hex bolt to the right of filter are the aim points



Don't know why the chart keeps collapsing on it self.

 

[gainestruk]

I pointed my gun at middle center of front of block and center of oil filter like you, looks like you are getting about the same readings as me.

I had same problem with charts, had to try a couple of times till I got it all to line up.

 

[motoman]

Thanks for the added data. I am using a KE thermometer which allows a person to place the little round bead pickup directly on the the metal. Seems like the one reading that is similar so far is the sump plugs @ 180-195F in outside temps of 60-90F + Keep it coming. Especially head temps if possible.

 

[bertsmobile1]

All interesting folks but do any of you actually know what the ideal operating temperature of the oil or the engine is ?
In general a thinner liquid will transfer heat a lot faster than a thick one which is why you quench alloy steels into oil or in some cases molten salt baths.
Far more important than the temperature of the oil is its film density and strength as the film between the rod & journal is all that stops the engine going bang, big time.
As an aside the local blue smoke mob down here uses a cast iron crank & barel on the Poewertorque engine.
Every time a revision is made, they remove remove cooling fins as better methods of thermal evaluation and in particular thermionics has revealed that the barrel had too much cooling which was causing local cold spots.

Way back when I was young & stupid but of course knew more than all the professional engine designers , I fitted oil coolers to all my bikes as that was very fashionable particularly if you thought you were a red hot rider ( wern't we all ? ).
Anyway as the years went on I found myself keeping company with some people who actually knew about oils and after a few visits to the test labs, all the oil coolers came off, and suprise , surprise, the bikes actually went better without them.

A big big problem with infrequently used engines is moisture condensation in the cases and your oil must get hot enough to evaporate this water.
A low viscosity oil oil will transfer heat fasther than a high viscosity oil but the lower oil has a substantially lower film strength so must be pumped a lot faster in order to maintain a boundry lubrication on moving parts.
One of the main reasons Honda small engine start so easily is the fact they use 10W 30 to 10W 50 oil and at ambient temperature the oil offern next to no resistance. It also has next to no lubrication.

So whole what you are doing is interesting, don't be fooled by the cooler must be better camp, often it is not.

 

[motoman]

Professionals who see scores and scores of damaged engines , please respond. From this home hobbyist it appears that the low end air cooled engines are most all on the edge of overheat. By that I mean driving the head into 390F + territory where the alloy softens. The liquid oil probe/gauge on my Intek will (too) quickly go to 290-300F, but the oil cooler pulls it down to about 240F if 5 minutes. Someone suggested months ago that factory reps do not want oil to exceed 270F . Seems to me it does in many cases.

Do commercial engines have oil coolers? Bert, how 'bout flashing the sump plugs on the units you see. So far the whopping big sample of ?3? which we have shows these plugs at around 180-195F. IF (big if) the difference is 50F for the liquid oil here is a rough approximation of oil temp for those who do not have oil temp gauges. How many forum inquiries per month on "overheating," valid or not? Will these "overheating" low end rigs last longer if heat and oil level is controlled? I think the answer is yes.