Dedicated turbo oil supply

[mullett]

This could well be a very silly idea...but here it is anyways.

A seperate, closed-curcuit oil supply for the turbo, with a small reserve, and an electric pump.

So there's always clean oil for the turbo, you don't have to mess with the factory oiling system when turboing the car, don't have to cut oil returns into the sump etc etc...

And, as an added bonus, no need for a turbo timer! Just have a small controller which keeps the pump running for a few min after shutdown...

Ideas, suggestions?

RM.

[LeeRoy]

Sounds good but what if it fails? and it would also have to be the right pressure

- LeeRoy

[Vios-GT_07]

electric pump for the oil? genius...

looks like a similar idea for the electric water pump design..

however, is the electric motor going to be able to supply oil at high boost? and also withstand the high oil temps? a big motor would be bulky in weight and hard to fit. A small motor might not handle the load and suicide, then killing the turbo..

what is wrong with the way turbo is oiled? dirty oil, clean oil... does it make any difference to the turbo's running? dirty oil = service...

[thechuckster]

having a sump full of oil helps control the oil temps and cope with the aeriated slurry that ooozes out of turbine housings.

You'd need a significant volume of oil - plus attendant cooling, storage and pumping system... in effect, duplicating the engine oiling system.

If you're concerned about oil temps and condition - upgrade to remote filters, a cooler with inline thermostat and a low pressure alarm (or even high temp alarm) on the oil line going to the turbo. If you had big bucks to spend, go dry sump?

fwiw: billzilla had fabricated some kind of external oil pump (for dry sumping) out of external oil pumps - might be worth giving his site a quick search if you're thinking of budget dry-sump optoins.

[mullett]

It's not really about the quality of the oil, that was just something I added. More about supplying oil after shutdown, not messing with factory oiling system, and making the turbo setup a standalone unit.

I was going to make the pump, in effect a gear pump driven by a good electric motor of some sort. I don't think a normal electric fluid pump could handle the heat/pressure or even the viscosity of cold oil (although, 5w oil is pretty thin...)

RM.

[thechuckster]

i've seen electric pumps circulating oil in diffs and gearboxes (to coolers) - but they're probably not designed to see the temps that engine oil gets to. They looked much like bosch fuel pumps but i'd guess that internally they're a bit different. The racing fraternity here should know more

Most turbos have a significant restriction in the oil inlet - so resudual pressure in the oil-feed line will keep oil slowly flowing for a while after shutdown.

It's also important to have a decent oil filter that doesn't let oil flow back to the sump.

The killer for turbos is heat - if your cooling system is up to scratch, and your plumbing allows fluid to flow thru the bearing housing after engine-off, you should be safe

[nick.parker]

Hey Mullet,
This is a good idea. Where I work we use electric oil pumps on two stroke engines, and no oil in the fuel. Uses a tiny fraction of the oil a normal two stroke burns.The pump is a pulse type pump, very compact (much smaller than your fist) and volume is controlled by pulse rate - a single pulse delivers a shot of so many cc. Can follow that up if you want - I would certainly consider it for myself (if I ever add a Turbo to the AW11 ). The pumps are designed for an automotive environment.

With regard to shutdown, (I might be worng here) but I imagine that having the shaft spinning is an integral part of the 'cool' down process, and oil might not get everywhere as efficiently without the shaft spinning.


Cheers, Nick

[feral4mr2]

didnt porsche use a oil pump set-up with one of it's low mounted turbo designs?

i am sure i read up on it ages ago when i was having smoke issues with a too low mounted turbo.

[mrshin]

It's been done before, and does have potential benefits. There is an oil pump in the Goss catalogue that's meant for gearboxes, diffs, etc. that would *probably* do the job. Include a small cooler and you'd probably be just about set. The only ones I've actually seen in person have been for centrifugal superchargers, but I can't see why it should be any more of a problem for a turbo.

[thechuckster]

didnt porsche use a oil pump set-up with one of it's low mounted turbo designs?

i am sure i read up on it ages ago when i was having smoke issues with a too low mounted turbo.

i think they scavange the oil drain - not force-feed the oil inlet.

edit: seeing as they do that, they must be pretty robust pumps.

[mullett]

Hey Mullet,
This is a good idea. Where I work we use electric oil pumps on two stroke engines, and no oil in the fuel. Uses a tiny fraction of the oil a normal two stroke burns.The pump is a pulse type pump, very compact (much smaller than your fist) and volume is controlled by pulse rate - a single pulse delivers a shot of so many cc. Can follow that up if you want - I would certainly consider it for myself (if I ever add a Turbo to the AW11 ). The pumps are designed for an automotive environment.

With regard to shutdown, (I might be worng here) but I imagine that having the shaft spinning is an integral part of the 'cool' down process, and oil might not get everywhere as efficiently without the shaft spinning.


Cheers, Nick

Definitly, that sounds like a winner for sure. I was just going to machine up a little gear pump, but that sounds brilliant. As far as shaft spinning goes, AFAIK the cool-down time on the engine is simply while the turbo spins down from whatever stupid RPM it was doing on boost, as long as you supply oil to the turbo until it stops spinning you're set....

Feral: That is the same thing I'm coming up against, a low turbo (but it's far from the only reason )

RM.

[nick.parker]

As far as shaft spinning goes, AFAIK the cool-down time on the engine is simply while the turbo spins down from whatever stupid RPM it was doing on boost

A few people have said things like this, but it only takes a couple of seconds for the turbo to slow down after boost.

Cheers, Nick

[V-Na]

As far as shaft spinning goes, AFAIK the cool-down time on the engine is simply while the turbo spins down from whatever stupid RPM it was doing on boost, as long as you supply oil to the turbo until it stops spinning you're set....

Incorrect.

Stagnant oil surrounding a hot static turbine shaft will thicken and can cake up inside the turbo causing damage.

[mullett]

Of course, cheers for that. Sadly, my +rep didn't quite get you to 30

So if you've got a flow of oil through a hot but stationary turbine, will it still cake?

RM.

[LeeRoy]

Of course, cheers for that. Sadly, my +rep didn't quite get you to 30

So if you've got a flow of oil through a hot but stationary turbine, will it still cake?

RM.

No, it cakes because it stops flowing and sits there and just cooks. Think about how how a turbo gets. Like when you are making macaroni cheese and leave it to sit the cheese sauce goes really thick. Similar thing with oil. So by having a turbo timer or just not hammering your car then switching your car off both the gasses and the oil are alot cooler so the ability of the turbo to cook oil is alot lower.

Check wikipedia Here

I don't think that just running oil through a stationary turbo would be enough as the whole assembly would be quite hot. I've 'heard' of fins slowly being bent by gravity from the heat making the metal more maluable(correct spelling?), is there any truth to this?

- LeeRoy