Pit Bull

[quote author=Doug link=board=4;threadid=14777;start=15#142216 date=1053964466]<br><br>seems like the flash point is still a good indicator of oil breakdown at high temperatures -- with regards to bearing failure and coking. And the 30 degree differenece between Delo and Rotella, for the purpose of determining a shutdown temperature, seems like a difference worth noting. We're talking about a 350 degree shutdown temperature, post turbo, and Delo gives you an approximately 10% additional margin. <br>[/quote]<br><br>WOW, so this happens a lot with Rotella T users??? Their bearings fail from coking? I better switch to Amsoil synthetic Sorry I can't help myself

doug

it only happens to Amsoil users who don't realize that Delo has a higher flash point! Sorry I couldn't help myself ;D

doug

just kidding -- Amsoil has a higher flashpoint than Delo. a whole whopping 7 degrees.

Pit Bull

[quote author=Doug link=board=4;threadid=14777;start=30#142588 date=1054057725]<br>just kidding -- Amsoil has a higher flashpoint than Delo. a whole whopping 7 degrees.<br>[/quote]<br><br>If you want to see something with a low flashpoint you need to meet my wife.

KATOOM

cowpie, good point, but one thing I was still wondering is what is the difference between gas oil and diesel oil? If gas oil is allowed a 100* high shut down temp then it would seem that their oils are breaking down at a increased rate or are containing different additives to allow the additional heat. ???

HC

If you'll permit a wild guess, I'm thinking that it would be &quot;good&quot; to run a gasser down to 300 degrees before shut-off, same as a diesel, but maybe it's just not practical. The diesel idles pretty cool unless under load; the gasser puts out more heat at idle. I'm guessing that maybe a gasser doesn't really ever get down to 300 degrees, so you'd just be idling forever. So instead, you cool it as much as is practical (400 degrees), and then just don't expect your turbo to last 500k.<br>Also, someone correct me if I'm wrong, but don't a lot of high performance turbo gassers RECOMMEND synthetic oil? Could it be this is partially to compensate for the expected higher temperature turbo shutdowns?

BigBlue

Could be. Personally, if I had a turboed gasser, I'd run synthetic and let it idle as long as possible to cool it off. I'd like to see a turbo charged gasser last 100K in the first place though.

KATOOM

<br>Quite possible. I never did understand what oil companys mean when they state on the bottle that &quot;this&quot; oil is suitable for turboed motors. Whats that mean? Does it have a higher flash? Or is it marketing?

cowpie

KATOOM<br>Good question on the oils. I'm only speculating, but marketing issues aside, the oils may differ as a result of the higher rpms gassers run at. Concerning the turbo issue, virtually all combustion temps are the same, regardless of fuel or ignition source. It is only the heat flux, or rate of heat generation that changes. Therefore gassers produce very similar combustion chamber temps as us oil-burners. Also, the turbos don't care if they are compressing air for a gasser or diesel. I would think cool-down considerations would be about the same. But then, my opinion and 50 cents will buy you a cup of coffee. 8)

Pit Bull

Almost all gas turbo charged vehicles call for synthetic. I would think it is because of their non coking ability ???

Bearfoot2

[quote author=cowpie link=board=4;threadid=14777;start=30#143893 date=1054313658]
KATOOM
... But then, my opinion and 50 cents will buy you a cup of coffee. 8)
[/quote]

OK...so your opinion is worth a lot. : Takes much more than 50 cents to buy coffee around here.

emjay

I'd grow old and die waiting for 300* pre-turbo. I usually let it drop a little below 400* Guess I need one of those turbo-timer gizmos. Or maybe synthetic oil. Or a lot more patience!