Almost a Rotella user

Status
Not open for further replies.
Joined
Jul 22, 2007
Messages
674
Location
Nebraska
I would like to use Rotella T in my hard riden air cooled Vtwin bike, air cooled atv and a liquid cooled ATV. Everything looks good.. but what is is with these ---- poor flash points? The syn is @ 405-410 and the dino is @ 415. These are off of virgin OA's. Whats up with that? Whould I have any cause for concern?
 
no, but I'm no expert. Think trying to compare oils based on FP is kind of meaningless, unless your trying sell the oil and have one with a high fp, LOL. It may give hint of the basetsock used but isn't evidence that the finished product will perform better, IMHO. The oil is going to run at 220f maybe up to 300f on your air cooled v twin. The hottest spots in the motor, like under the upper ring lands and under the piston crown may get 800-1200f, don't think it's going to make much difference whether the oil has a 400f or 490f FP exposed to those temps.
 
I saw that too and was a little disappointed. It's interesting to note that I have an older writing (The Motor Oil Bible) that showed that when tested in 2002 Rotella T Synth had a FP of 475. Wonder what they did to change the formula? ...or perhaps it was just bad data.

I've started using the Rotella synth in my FJR but compared to your V-Twin, my water cooler is probably a lot easier on the oil...
 
"Engine oils that run at @ 212° are ideal in that moisture is allowed to
evaporate out of the oil. Above 260°F every 10 degrees increase halves the
oil’s useful life. Over 350° presents serious problems and engine oil
should be changed immediately. An oil cooler would be appropriate for
these elevated temperatures." Taken from Spectro oils.

Here is an excerpt from an email I received last year on this subject. I do not want to publish or quote the whole message without permission.

"Air cooled engines can suffer from inconsistent cooling and are designed to
run satisfactorily in the most difficult conditions without overheating.
Of course this means that they are overcooled under most conditions which
is a more common problem than overheating and is why oil coolers generally
do more harm than good. Ideally the oil temperature should be maintained
around 200 - 250F.
In liquid cooled engines the temperature is much more closely controlled
which gives the engine designer more freedom to use higher compression
ratios and higher power outputs without the risk of overheating.
The highest temperatures are usually attained in the region of the exhaust
valves and piston ring grooves but vary considerably depending on engine
design. 400f is about as high as it gets without causing trouble but there's
not a great deal we can do about it apart from using the best oil for the
job."

In an earlier article I was able to find, it was common for some aircooled engines to reach 350 F in the piston to cylinder area.

I would not discount Flashpoint as irrelevant. Hths numbers are important too. Take an oil with a starting FP of 415 F, run it for awhile and the FP could drop significantly possibly due to fuel diluition as one of the motorcycle UOA show.

I'm certainly no expert but I have spent considerable time searching and corresponding on this issue. I have nothing against Rotella but I, personally, would never run it in my aircooled babies to save a few bucks.

You can't beat a good 20/50.
 
The Harley Davidson 360 oil at last check didn't look any better on the FP than the Rotella.

I think you're good to go with anything over 375 degrees. Once you've gotten hotter than that, your engine is probably toast anyway.

Rotella is an excellent oil. We once ran it for 35,000 miles in a Caterpillar C-13 truck engine and the UOA came out looking fantastic.
smile.gif


Dan
 
Flash point is when the vapor from the most volatile part of the oil package first ignites. If there is any fuel dilution, you can bet the most volatile part of the oil is the vapor coming from the fuel.

There are also differing methods of determining flash point, (closed cup, open cup, etc..) and there may well be some different numbers resulting...as other oil tests net slightly differing numbers.

Anything close to 400degF should be fine, IMO.
 
Status
Not open for further replies.
Back
Top Bottom