Turbo vs. high revs NA

tai

Messages
54
Location
Austin, TX
Just wondering, is turbo the hardest on oil, harder than high revving normally aspirated engines. I'm thinking if an oil can handle a turbo engine for a given mileage, then it should handle just about any engine (except for those Toyota Avalon engines [Smile] ). Agree? Thanks
 

Patman

Staff member
Messages
21,988
Location
Oakville, Ontario
I agree, if it can handle the abuse of a turbo car, it will really shine in a normally aspirated engine, even a high revving one. [ March 01, 2003, 05:13 AM: Message edited by: Patman ]
 
Messages
47,628
Location
Duvall WA - Pacific NW USA
Two things come to mind: 1) Owning a turbo I have seen it kill oil. Period. I would never put dino oil in my turbo unless it was a less than 500 mile flush or something. Dead dino oil not only dies in turbos if not changed spot on or preferrably less than 2XXX miles it will start to coke up and take the turbo oil lines/bearings out... 2) Amsoil as wild as they are with extended changes - says for example with my car 10,000 miles MAX. I have gone 10K, almost there again - and the oil is pretty well spent.
 
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47,628
Location
Duvall WA - Pacific NW USA
Yes my turbo is water cooled, but it has oil bearings. Do those huge turbos have oil bearings? And maybe they do a better job of getting/keeping the heat energy away from the bearings.
 
Messages
1,565
Location
palm beach
ok, first thing. i have seen numberous vw 1.8T's go 200K on dyno 3000-4000K changes. second thing, i have seen numerous vw 1.6T diesels go that far as well on dyno oil. its the same block (gas and diesel vw block is the same) so saying one engine is better designed would be irrelivant. and, diesels with turbos are harder on oil than gas engines. because as far as air flow through the exhaust is concerned, a diesel is at wot 100% of the time, this is harder on a turbo than a gas engine. not only that but diesels are harder on oil to begin with. if you want to resist coking, let your engine idle for a couple minutes before shutting down, this gives the turbo time to cool down.
 
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2,444
Location
Indiana
quote:
if you want to resist coking, let your engine idle for a couple minutes before shutting down, this gives the turbo time to cool down. [/QB]
Just outta curiousity, if one is running synthetic oil (which is more resistant to coking), is it still necessary to do the 2 minute cool down?
 
Messages
1,565
Location
palm beach
really, it cant hurt to have a 2 minute cool down, even with synthetic. so why not? i wont dispute the fact that synthetic is better for a turbo than dyno, heck, its better for non turbo applications too, but i will say i still think dyno is still good enough. you wont ruin ur engine or coke up your turbo if you were to change dyno at the specified intervals.
 
Messages
951
Location
Loveland, Colorado
Before they were water-cooled, Saab recommended a cool-down period for their turbos. Now, however, the minimum recommended oil type is 5W-30 semi syn (factory fill & "preferred" type is 0W-40 full syn) & they're water-cooled, so they no longer suggest any cool-down. Typically, you're not shutting the engine off immediately after an extended load on the turbo, but rather driving for some amount of "normal" load for at least a few minutes before turning everything off. If you're both water-cooled & running synthetic, this normal driving period should be enough without additional cool-down. [Edit:] Oh yeah, I almost forgot. Yes, I agree that any oil which can survive a turbo environment should shine in a NA engine (Toyota 3.0L V6s excepted). [ March 01, 2003, 06:33 PM: Message edited by: Greg Netzner ]
 
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6,388
Location
Washington St.
Pablo, Your reports of dino oil in turbochargers is interesting. Industrial turbochargers on diesels and most over-the-road trucks with turbos all use dino oil. What's different? Do automotive turbochargers skimp on internal oil reservoir capacity so the oil overheats more easily? I've changed the oil in a large turbocharger with its self-contained oil system...the turbocharger is six feet tall and uses an ISO 68 dino turbine oil. This particular diesel has four of these turbos, runs at near full power about 20 24-hour days a month, and the turbocharger bearings are good for at least five years with bi-monthly oil changes...and no pre- or post-lube pump. Most smaller sized diesel generator sets (below locomotive engine size) use dino oil with no pre- or post-lube and various shut down procedures. Is your Volvo turbo water cooled?...that makes a big difference, as does the size they allow for an oil reservoir inside the turbo. Ken
 
Messages
264
Location
High in the Rockies
Ken2, Most diesel or industrial turbochargers don't spin at the same RPM as auto turbos do. The redline for the twin turbo Audi that we drive is 6,500 rpm. I don't know what the turbo's rpm's are at that engine rpm but I know the turbos are small, spool up very quickly and virtually have no turbo lag so they must be spinning in excess of 100,000 rpm. Others may know for sure. (It's hard to get technical info on these Audi's for some reason). We obviously don't drive it there all the time but putting it there puts a lot of stress on the turbos and their oiling needs. Most over the road truck diesels rarely rev over 2,500 rpm, Huge diesel locomotives rarely run over 1,000 rpm. Besides, these industrial applications are designed for million mile (or more)applications. Not so with the automotive turbo designs. [ March 01, 2003, 12:57 PM: Message edited by: DEWFPO ]
 
Messages
333
Location
Detroit (Rock City)
FYI, the exhaust gas temps of most of the diesel rigs is A LOT lower than you'll see in a hipo gas turbo car. I see 1500F at the top of 4th gear, I think that diesel egts are 1100-1300F. Robert
 
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