How hot is hot

[motormayhem]

My cb360 has stock jets and pods, but with the float level set a little lower than stock (slightly more fuel in bowls). It runs great and doesn't pop or sputter at WOT at 8k (just richens up at idle). Looking at the plugs they look pretty good around 5k and maybe just a hair lean at 8k. What is a good way to tell how hot shes getting. I put about 250 miles on it this week and it ran great the whole time. I checked the oil temperature a few times and it was running about 210*F in traffic around town and about 245*F after a couple mile highway stint at 55-60. I'm running rotella synthetic. Those numbers seem reasonable to me for a 95*F day outside or am I way off?

 

[alzcbz]

How are you checking the oil temp?

 

[motormayhem]

How are you checking the oil temp?

Pull over abs stick a digital meat thermometer stuck where the dipstick goes.

 

[Tim]

I'm not an authority on this bit those temps dont seem high.

If the plugs look good and its running well ride the crap out of it.

 

[cklamer]

If you are really worried about it go grab yourself an infrared thermometer.
Just put that little red dot on the engine and it will tell you the temp.

Harbor Freight has one for about $36.00.

http://www.harborfreight.com/non-contact-infrared-thermometer-with-laser-targeting-69465-8905.html

 

[SONICJK]

Low to mid 200's is pretty standard oil temp for most any internal combustion gas engine.
There's really nothing to worry about up to about 250 with conventional oils, especially when the change interval is so short on motorcycles. You're using synthetic which holds up to heat better so I'd say you're golden.

I believe the flash point for rotella T6 is around 445 degrees, so you've got a good buffer there.

 

[SONICJK]

I might do a plug chop at your hwy cruise speed and see where you are there, I'd wager you're a little lean after the pods and thats why you're getting the temp spike on the hwy when there is more airflow to cool the engine. My bikes run hotter in town than on the hwy. (unless you're at high rpm, don't know your gearing or speed)

 

[mydlyfkryzis]

Those temps are typical for an aircooled engine. At those temps, all moisture is boiled off. Above 250 is where oil starts breaking down, 300 deg. is too much.

After a highway run, the oil temp will spike as the engine is still hot, but you are not getting the airflow over the engine like you were at speed.

250 degrees is the limit in general. Synthetic handles it better.

The high temps are why air-cooled engines have a lower miles change out requirement than aircooled.

Many new bikes (and my CB360 has an aftermarket) have oil coolers to maintain the under 250 oil temps.

 

[Sonreir]

My aircooled Duc has a temp sensor for the oil. A couple of weeks ago I took a 90 mile freeway ride in 90° weather. Oil temp peaked at 272°. Low 200s is normal for highway speeds or mid 200s for around town.

 

[xb33bsa]

i will test my 350 soon after a long mountain climb i have a remote proab dijitil meet thermometer 8)

 

[mydlyfkryzis]

Here's a good read on engine oils used for the military for gas and diesel engines:

http://www.dtic.mil/dtic/tr/fulltext/u2/a282838.pdf

While MIL-Spec, the military uses pretty much the same oils as civilians.

Here's an excerpt from the executive summary:

 

[motormayhem]

Cool, ya I figured the synthetic oil could probably take it for at least a little while. I was more worried if the rest of the engine likes those temps. Sounds like its pretty normal though. It will be interesting to see how it runs in the winter too.