Author Topic: Turbo Oil return scavenging pump (Read 6365 times)

haybayian · « **on:** February 06, 2008, 01:12:16 pm »

I am considering setting up an electric pump on my T3 turbo's oil return line. Do you have any advice for me? At this point all I know is that a gear pump is a must (as opposed to a diaphragm one) and that I should be prepared to pay between 175 $ (Summit) and 230$ elsewhere.

Haybayian

dillenger1 · « **Reply #1 on:** February 06, 2008, 05:23:50 pm »

Will it work when cooling down,or will it be cycling all the time?

burn_your_money · « **Reply #2 on:** February 06, 2008, 05:48:52 pm »

gear pumps are positive displacement which means whatever goes into them, has to come out. So if it fails your turbo is going to be junk.

Why are you wanting to add one?

jtanguay · « **Reply #3 on:** February 07, 2008, 05:15:45 am »

scavenge oil from the turbo return line? hmmm... hope it likes sucking in air once in a while :lol:

EMP was designing an electric oil pump a while ago.. never heard too much since (it was going to be a really durable oil pump... that could take over the job of the main oil pump... good for priming the engine before starts, turbo cooldown, etc :wink:)

haybayian · « **Reply #4 on:** February 07, 2008, 05:37:17 am »

Quote from: "dillenger1"

Will it work when cooling down,or will it be cycling all the time?

I was thinking full time use but mainly when the turbine is spooling on with little or no oil after the engine has been turned off.

Perhaps a rotodynamic pump (centrigugal for instance) instead of positive displacement, working only shortly before and after the engine has been turned off would be a better idea?

Haybayian

myke_w · « **Reply #5 on:** February 07, 2008, 06:39:59 am »

So, is the idea to promote turbo longevity?

One thing to keep in mind is that the return lines on these cars are large enough to handle the amount of oil coming into / out of the turbo. If you sludge it, thats a different story. Also, most of the factory turbos go for well over 100k miles with no problems when the right oil is used and OCI's are observed.

Point being - there really isn't a longevity issue with the turbos on these cars.. also they don't run near as hot as cars that eat turbos alot (ie. heavy passat / a4 1.8t)

In my experience heat and sludging are the ultimate turbo killers.

If you were pushing tons of boost the situation might vary a bit, but I think if you were running a high grade synthetic 5w40 oil like pentosin, elf, Rotella syn or the like.. I think you'd be fine.. There are plenty of folks around here running insane boost and pushing near meltdown egt's that have few turbo problems.

jimfoo · « **Reply #6 on:** February 07, 2008, 06:46:51 am »

Quote from: "haybayian"

Quote from: "dillenger1"
Will it work when cooling down,or will it be cycling all the time?

I was thinking full time use but mainly when the turbine is spooling on with little or no oil after the engine has been turned off.

Perhaps a rotodynamic pump (centrigugal for instance) instead of positive displacement, working only shortly before and after the engine has been turned off would be a better idea?

Haybayian

I'm thinking your theory may be flawed. You will be sucking out of the supply side of the engine. As soon as you suck the oil, you are draining the engine oil passages(engine off), and as soon as the head drains, you will be sucking air. You won't be sucking it out of the pan.

haybayian · « **Reply #7 on:** February 07, 2008, 08:01:53 am »

quote:I'm thinking your theory may be flawed. You will be sucking out of the supply side of the engine. As soon as you suck the oil, you are draining the engine oil passages(engine off), and as soon as the head drains, you will be sucking air. You won't be sucking it out of the pan.[/quote]

Not the right place to suck oil indeed. Or perhaps there should be a separate intake plumbing in the pan. VERYYYYYyyyyyy complicated!!! :lol:

Interestingly judging from the responses here VW diesels dont have turbo lubrication problems.

Thanks for all the contributions.
Haybayian

Vincent Waldon · « **Reply #8 on:** February 07, 2008, 08:54:46 am »

Quote from: "jimfoo"

You will be sucking out of the supply side of the engine. As soon as you suck the oil, you are draining the engine oil passages(engine off), and as soon as the head drains, you will be sucking air. You won't be sucking it out of the pan.

Good catch... this means your turbo will start the next time *without* oil because the line is empty. Ack !!

Haybayian: my guess is that your question is related to your other thread on oil filter relocation

jimfoo · « **Reply #9 on:** February 07, 2008, 09:04:28 am »

The only way I could see it working, which would require a remote filter, would be to put a check valve after the filter but before the engine, and have your pump suck from between the filter and check valve. I would then plumb it in PARALLEL to the turbo oil feed, probably as close to the turbo as possible. That way the pump wouldn't interfere with normal oiling if it failed, would possibly supplement normal oiling if it made enough pressure, and could be run before or after starting. It would probably send oil to the bearings as well, so would eliminate dry starts.

burn_your_money · « **Reply #10 on:** February 07, 2008, 09:10:15 am »

Some heavy equipment has 2 starters, the first one drives an oil pump and the second is not activated until an oil pressure sensor in the head indicates that there is oil pressure present. I was thinking of adapting something similar to my car but have not looked into it enough

jimfoo · « **Reply #11 on:** February 07, 2008, 09:19:11 am »

Then again, an accumulator or two, one for starts, one to oil at engine shutoff, might be a lot easier to install.
Here you go in fact. http://www.accusump.com/acc_products/acc_turboiler.htm

haybayian · « **Reply #12 on:** February 07, 2008, 09:40:31 am »

Haybayian: my guess is that your question is related to your other thread on oil filter relocation

[/quote]

Yes I am in oil things up to my neck.
Haybayian

Vincent Waldon · « **Reply #13 on:** February 07, 2008, 09:50:07 am »

Well come on... tell us the details... inquiring minds want to know !!!

haybayian · « **Reply #14 on:** February 07, 2008, 10:54:16 am »

Quote from: "Vincent Waldon"

Well come on... tell us the details... inquiring minds want to know !!!

Well not much to write home about!

I am building a sportscar (Lotus 7) from scratch and my choice of engine was the AAZ. I had the engine rebuilt (long block) by a shop in Toronto and the VE pump was rebuilt by Giles with performance mods. I did not ask what he was going to do. He got me a T3 Garrett and manif. I built my own exhaust line from the turbo to the muffler in 3 " pipes. The VW engine was bolted to a Suzuki Samurai 5 speed transmission which I owned through an adapter sold by ACME in the US .

Currently I am sweating the engine details. The oil filter ended up too close to my home made engine support bracket so I have bought a kit to relocate it. I am ignoring the VW water/oil cooler and setting up a larger air oil cooler. As my car will be a Summer car only I think that this will work. As I was ordering a T3 oil return line I read a bit about turbos and learned that the racing crowd often equip their turbos with oil pumps in an attempt to save their bearings from running too hot or dry in some circumstances. As you can gather from my questions there are still a few things that I don't quite understand but I will keep reading.

I am grateful for the advice that you guys are giving me on this forum.

Haybayian