Bypass filter for the turbo oil line?

[Fysh Guide]

The local napa dealer offered me an Amsoil bypass filter kit at cost ($80 cdn). I currently have a small full flow filter and cooler plumbed between the block outlet and the turbo and was thinking about R&Ring the full flow filter with the bypass. The Amsoil website says the system can filter the full capacity (up to 8 quarts) in under 10 minutes. My question is if anyone knows what the flow rate of the turbo oil line is? I know the line is 6AN.
I figure that nice clean cool oil through the turbo can't hurt it and filtering it down to 2 microns or so is bonus. The concern is restricting flow too much. I also figure it would be better to try this on the original turbo before I order a new one.
Any thoughts before I jump in?

 

[Turbine Doc]

You know as critical as oil is to turbo, and as fast as it spins, I'm not sure I'd put filter there that could clog and starve the turbo of oil, there is a port above the factory oil cooler lines same as FS2500 kit uses IMO that would be better place to grab it, add in a boss to the oil fill neck for return oil and you would be back in business, without putting turbo at risk.

See here:http://www.dieseltowingresource.com/showthread.php?t=3431

 

[JMJNet]

My question is why only filter oil to the turbo? As TD said, it is better to filter the oil in the engine. If the engine oil is cleaner, the turbo oil is cleaner also.

 

[Fysh Guide]

My question is why only filter oil to the turbo? As TD said, it is better to filter the oil in the engine. If the engine oil is cleaner, the turbo oil is cleaner also.

The turbo oil does return to the engine. It is in essence a bypass circuit already. I figured filtering enroute to the turbo would be convenient for installation, location and maintenance of the filter, and as I said, nice clean cool oil to the hottest fastest moving part in the engine. The concern is as TurbineDoc points out, a lack of flow to the turbo. That is why I am trying to but can't seem to find the flow rate to the turbo.

 

[schiker]

Explain again you are adding an amsoil kit between block and turbo.

The amsoil kit does a bypass in described in kinda sorta series so you get most all same flow but approx 10% goes through the fine filter. You'd still get good flow through the regular filter on the amsoil kit but probably some overall restriction to flow from piping losses.

Be careful hose puts a lot of drag on oil flow especially small hose. Which is another discussion.

 

[Fysh Guide]

At this point I am contemplating the single filter kit between the block and the turbo. The website info claims that all the oil in the system is filtered in under 10 minutes but I may be misunderstanding this. I currently have a full flow filter and a setrab cooler plumbed into the turbo line. The filter is mounted on the fan shroud, pass. side, and the cooler is down in the pass. side bumper nostril. The braided line connecting this is 8AN to compensate for any pressure loss. Stock line is 6AN. I've had this setup in for over a year with no issues. Although I don't have hard data to support it, it does seem that the turbo runs a bit cooler. This claim is based on the age old seat o'the pants (palm o'the hand) test. Take it as you will, but I do beleive it.
I do want to install the bypass system when I R&R the cooler lines, but due to work I can never find the time. Installing a fine media filter in the turbo line would be very quick and easy alternative if it would allow adequate flow to the turbo. I am hestitant to do this unless I'm sure flow would be enough. That's why I'm looking for opinions, better yet, knowledge.....
Again TD, yours is respectfully appreciated... Thanks

 

[packratt]

Go to amsoil's web site and look at the installation instructions.

 

[Turbine Doc]

Flow is substantial from that line (I coated the side of the wifes red TDI bug with black oil in scant second, when I got in hurry and wanted to hear ATT spin and I in hurry forgot to tighten the line and it came off, she wasn't a happy camper.

The turbo is designed for unrestricted gravity free flow, oil outlet is about 3-4x larger than inlet so in order to keep the turbo free of accumulating oil and foaming in the bearing sump (I think), it is something aircraft engines design for, our trucks ain't jets but I know with lubrication a lot of time goes into design/study of the supply and drain paths.

I suspect oil in and out is expected to be fast as possible, slow the flow any and (this is conjecture) you may create enough hesitation in flow over time slight cooling of oil and in nooks and crannies it makes coke deposit, build enough coke deposit and you induce a fail item either plugging a oil port, or dislodging as a hard solid and going to the pan. It may be fine and dandy, but IMO with other proven safe locations to choose from I'd be hesitant to tap into that line.

 

[schiker]

As a rough comparison:
8 quarts in 10 minutes is 0.2 gpm.

A typical std oil filter is rated for about 11 gpm iirc and guestimate the full flow of the 6.5 is maybe about 6-8 ish gpm range at WOT.

But the turbo would only see a portion of the total flow so rough guestimate would be 0.1 - 2 gpm or more so 0.2 sounds too close for comfort.

Now if you open the port to atmosphere no restriction of turbo bearing it would probably spray out oil a little faster probably pump out 2-4 gpm or more at idle.


Then I guestion the 8 quarts at 10 minutes what differential pressure makes that flow. Its suppose to see oil gallery pressure feed side & zero pressure output side. And it might take 20-30 psi differential pressure to make that flow ie normal gasoline highway driving. But at idle when there is only 10-20 psi oil gallery pressure in a typical 6.5 the bypass filter might flow less oil.

Your full flow std filter probably works fine because the turbo restriction is larger than restriction across a full flow filter media. And thus the oil pressure is probably the same at the turbo inlet with or with out the full flow filter inline.


I have looked a bit but never found the gpm rating of the oil pump and all this is a guestimate but hopefully is kinda sorta close at least in the ball park.

I 'd like to see what others guesitmate. Based on what and see what we can come up with. I don't think hard numbers are easily obtainable and few know for sure.

 

[schiker]

I have read if you Tee into turbo feed line you will measure oil pressure of engine.

I have read the turbo bearing is a labyrith type seal and don't think it will support much pressure. SO while I said the restriction of the turbo bearing above not sure...

Now I question is there an orifice retriction in the turbo for oil flow. Such that it chokes down the flow enough that the spinning turbo "pumps" shears & foams the oil and sends it on down towards the oil pan at a rate equal or higher than the proposed orifice? Otherwise the turbo bearing would have to support some pressurization????

I'd think you would have to know what the output flow of the turbo drain is in operation then exceed that flowrate by something with any piping or filter inline between the block and the turbo. Otherwise you could starve the bearing.

Can you over feed the turbo with oil?

 

[DILA]

Since there at least 3 easily accessible points to hookup a bypass unit in the engine bay, why take a chance on killing your turbo. Look at a sandwich adapter on the oil filter, the plug on the block next to the cooler lines or add a tee at the OPS. Finish off with the nifty $12 amsoil fitting to return the oil to the oil filler cap.

 

[Slim Shady]

Flow is substantial from that line (I coated the side of the wifes red TDI bug with black oil in scant second, when I got in hurry and wanted to hear ATT spin and I in hurry forgot to tighten the line and it came off, she wasn't a happy camper.

The turbo is designed for unrestricted gravity free flow, oil outlet is about 3-4x larger than inlet so in order to keep the turbo free of accumulating oil and foaming in the bearing sump (I think), it is something aircraft engines design for, our trucks ain't jets but I know with lubrication a lot of time goes into design/study of the supply and drain paths.

I suspect oil in and out is expected to be fast as possible, slow the flow any and (this is conjecture) you may create enough hesitation in flow over time slight cooling of oil and in nooks and crannies it makes coke deposit, build enough coke deposit and you induce a fail item either plugging a oil port, or dislodging as a hard solid and going to the pan. It may be fine and dandy, but IMO with other proven safe locations to choose from I'd be hesitant to tap into that line.

The bearings in the turbo in essence float on a thin layer of oil. There is a bearing that rides inside a bore and inside the bearing the turbo shaft. The pressure to the turbo bearing make the shaft and bearing float. Any restriction in pressure and flow would have a long term detrimental effecy on the turbo shaft. I would find another place for the filter, take Turbine Doc's advice

 

[matuva]

x2 on what TD, Slim & dila say about location---, not worth the risk

 

[Matt Bachand]

If you want a cooler turbo, buy the A Team Turbo.

 

[Wrecker]

The bearings in the turbo in essence float on a thin layer of oil. There is a bearing that rides inside a bore and inside the bearing the turbo shaft. The pressure to the turbo bearing make the shaft and bearing float. Any restriction in pressure and flow would have a long term detrimental effecy on the turbo shaft. I would find another place for the filter, take Turbine Doc's advice

Absolutely correct, wrong place for that.

 

[Fysh Guide]

The bearings in the turbo in essence float on a thin layer of oil. There is a bearing that rides inside a bore and inside the bearing the turbo shaft. The pressure to the turbo bearing make the shaft and bearing float. Any restriction in pressure and flow would have a long term detrimental effecy on the turbo shaft. I would find another place for the filter, take Turbine Doc's advice

Not that I hadn't noted Turbine Docs advice, adding this clinches it. I actually knew and understood this but hadn't thought of the possible effects of a pressure drop.:idea:
Idea cancelled...
Thank you gentlemen.
By the way Slim. Does your new turbo kit have a floating bearing?onder:

 

[Slim Shady]

Not that I hadn't noted Turbine Docs advice, adding this clinches it. I actually knew and understood this but hadn't thought of the possible effects of a pressure drop.:idea:
Idea cancelled...
Thank you gentlemen.
By the way Slim. Does your new turbo kit have a floating bearing?onder:

That it does, this is the standard for most turbos except for the new ball bearing ones. The ball bearing is a little less friction but much more expensive and costly to replace.

 

[Missy Good Wench]

The turbo bearing is a hard bronze bushing set that presses into the housing.
The bearing has a flange on either end to take up end thrust.

The seals are like little piston rings with interlocking ends and these ride in a little machined area just outside the bearing area.
The seals just knock down the "fly off" oil that comes out the ends of the bushing.
There is an oil return groove between the bushing and the seal to allow the excess to drain away.
So there is not any oil pressure against the seal itself.

The oil is fed under pressure into the bearing and then leaks out and runs via gravity out the bottom of the housing and back to the pan.

Back a couple years ago when I rebuilt our 94 Burb I had reason to take the turbo apart.
The carbon buildup in the turbine side of the housing had expanded due to the antifreeze that puked out when the head gasket blew.

After 2 months the turbo was stuck TIGHT.
I took it apart to see why and the carbon was the only issue.

Easy fix with just some cleaning and reassembly. Just about as simple as it gets.

Unless the turbo is starved for oil, they will run for a very long time.
The other issue is if something goes through the blades.

I am thinking that the advise against adding a filter in the feed line is a good one.
Any reduction in oil flow to the turbo will result is catastrophic failure of the turbo.

Considering the nature of the turbo bearing (bronze) the extra filtering is of no real value.

If you wish to have a better filter on the engine, install a remote unit that replaces the factory filter base and then feeds the new filter via hoses to the remote location.

Best

MGW

 

[gmctd]

Functioning turbos for many years have used full-floating bushing-type bearings to achieve the 100k+ rpm required for higher than 2psia Boost pressures - pressurized engine oil enters the cartridge and splits into two galleries, one to each floating bearing bore - oil exits from the bushings and shaft into a central open mezzanine-type gallery - each bushing has at least two oil passages, most having 4, bored from outer to inner diameter - the floating bushing rotates @ ~1/2 shaft speed on a film of oil in the cartridge bore - the gas-turbine driven compressor drive-shaft rotates @ speed on the rotating film of oil inside the bushing - this action totally reduces oil pressure in the cartridge bore to almost nil, as the lubricating oil is thrashed into dense foam by the highly spinning bearings and shaft - thus, the steeply-angled oil-drain return-line is sized ~1" to accomodate the resultant foam, which gravity-drains from the central mezzanine area in the cartridge back down into the sump - engine oil pressure in top-side, gravity return out bottom-side - thus the importance of cartridge mounting orientation

Therein, the bushings rotate at ~50000rpm wrt the cartridge, the shaft rotates at ~50000rpm wrt the bushing, which is ~100000rpm wrt the cartridge - that method allowed the proliferation of inexpensive, functional, reliable turbochargers

Turbo compressor seals for Diesel service are labyrinthine\centrifugal, as Boost pressure prevents leaks, and Diesel engines do not develop significant vacuum levels in the intake system which would pull the oil past the shaft - the turbine seals are also labyrinthine\centrifugal, as Exhaust Gas Pressure prevents oil leaks - the turbine end also has a piston-ring type seal to prevent hot sooty exhaust gas under pressure from leaking in and carbonizing the lube oil, and the soot from contaminating the oil - reason the turbine shaft spins easy when hot, not so easy when cold, is partly because the oil film is denser when cool, providing increased resistance to shaft rotation - also, the shaft and bushings have gravity-settled on the bottom of their respective bores, which increases resistance to rotation

Some modern-tech turbos have returned to ball-bearing technology - early attempts were disastrous failures, as some were sealed\self-lubricated, said bearings soon self-destructing due to centrifugal forces slinging the lube out of the bearing races - others, lubed by pressurized engine oil, also failed where the oil was saturated with both filterable and unfilterable combustion byproducts, in addition to the primitive methods of crankcase ventilation, usually a vented brillo-filled cap on a valve-cover with an open-ended blow-by tube hanging down under the vehicle in the road-draft - that caused the wide black stain down the middle of all hiways, byways, and roadways in those eldritch times - also resulted in high silicates content in the sump oil supply - ball bearings are extremely allergic to silicates and other contaminate particles

 

[Bullseye240]

Ok...so I just learned more than I needed to know, but hey I did learn something!!