OIL return for turbo

[Jaff.]

right this is the only thiong stopping me from sticking the engine in my car now so i need some help.

i need to construct some sort of oil return from turbo to the block/sump.

it needs to stay as close to the block as it can because the driveshaft is close so something like a 90deg bend out of the block will be needed.

i havent got any tapps or a drill bit big enough to tap a hole in the block so i need alternative ideas. can anyone help me?

my current idea is bolting this to the sump...
http://www.ebay.co.uk/itm/Turbo-Oil...arts_Vehicles_CarParts_SM&hash=item3f12e924be

then having a rubber pipe going to the turbo. will this work?

please help i need to get this engine in the car to stop me from loosing hope with the project

 

[scotty2hotty81]

Either way if you tap the sump or block, your still going to need a big drill and tap.

 

[Iceberg_172]

there isnt really any alternative to fitting a pipe to the sump. You will need to drill holes

not sure if there is one but is there a turbo/turbo diesel equivalent to the engine you are using, perhaps getting a sump from a turbo/turbo diesel lump that has the same stud pattern of sump as your current engine?

 

[Jaff.]

well with that fitting i just need to drill a hole. i can find a drill bit easy enough its the tap im struggling to get

 

[Cupman29]

You could remove the sump and get it drilled and tapped at a local machine shop for a few quid. If you were near me I could do it for you.

 

[Jaff.]

You could remove the sump and get it drilled and tapped at a local machine shop for a few quid. If you were near me I could do it for you.

thats a good idea! i didnt think of that, ive only been thinking about drilling and tapping the block which cant be done as its built.

might do it tomorrow! cheers. cant bilieve i hadnt thought of it before!

 

[Chip-mk1]

Taps are readily available, just buy one?

 

[Laine_16v]

Please correct me if im wrong, i know very little about turbo conversions but..

I was under the impression if the return is tapped into the sump it can get blocked because the oil level in the sump will sometimes be above the return, now i have heard this can cause blockage issues, stop oil free'ly returning to the sump is the level of the oil splashes around above the return level? could be complete BS but would like to actually know the truth on that one.

I do know there is a conviniently place flat tab at the rear of the block on an F7 that can be tapped for an oil return instead of the sump, however dont believe that part is there on the F4's.

 

[Jaff.]

Please correct me if im wrong, i know very little about turbo conversions but..

I was under the impression if the return is tapped into the sump it can get blocked because the oil level in the sump will sometimes be above the return, now i have heard this can cause blockage issues, stop oil free'ly returning to the sump is the level of the oil splashes around above the return level? could be complete BS but would like to actually know the truth on that one.

I do know there is a conviniently place flat tab at the rear of the block on an F7 that can be tapped for an oil return instead of the sump, however dont believe that part is there on the F4's.

you are right, but if its high enough i can see that being much of a problem...

i have an F7 but the engine has been built and run in so taking it apart to drill the block is a no go. hindsight tells me i should have drilled it before i built it but meh

 

[Chip-mk1]

Please correct me if im wrong, i know very little about turbo conversions but..

I was under the impression if the return is tapped into the sump it can get blocked because the oil level in the sump will sometimes be above the return, now i have heard this can cause blockage issues, stop oil free'ly returning to the sump is the level of the oil splashes around above the return level? could be complete BS but would like to actually know the truth on that one.

I do know there is a conviniently place flat tab at the rear of the block on an F7 that can be tapped for an oil return instead of the sump, however dont believe that part is there on the F4's.

Its not uncommon for cars to have an oil return under the level of the oil sitting in the sump, oil will still drain into it.

Suck some coke up a straw that is buried in the liquid still and the moment you stop sucking and take it out your mouth it will flow back down the straw again.
you just need a bigger straw for it to drain as quickly as it would into air thats all, there is resistance but not enough to actually stop flow, just to slow it down, but enlarging the tube size has the opposite effect and cancels this out.

 

[Iceberg_172]

when the engine is running all the oil wont be sitting in the sump anyway would it? most of it should be circulating round the engine. only time there will be a build up in the pipe is when the engine is off?

 

[Dan519]

Please correct me if im wrong, i know very little about turbo conversions but..

I was under the impression if the return is tapped into the sump it can get blocked because the oil level in the sump will sometimes be above the return, now i have heard this can cause blockage issues, stop oil free'ly returning to the sump is the level of the oil splashes around above the return level? could be complete BS but would like to actually know the truth on that one.

I do know there is a conviniently place flat tab at the rear of the block on an F7 that can be tapped for an oil return instead of the sump, however dont believe that part is there on the F4's.

you're absolutely right, it can be a bit marginal having the return in the sump. Not allowing oil to flow away from the bearing core can cause an issue with excess pressure, which can lead to oil breaching the seals. I've seen people fit return pipes that drop down from the turbo then loop back up to a return hole in the block. Smokes like Lily Savage first time it's driven usually as the oil can't get out so back up to the core.

Into the block would be best, removing the sump would allow you to drill and tap the block and not fill the engine with swarf. You'll have to be exceptionally careful to make sure there's nothing gets into the bearings/oil pump etc

 

[Jaff.]

you're absolutely right, it can be a bit marginal having the return in the sump. Not allowing oil to flow away from the bearing core can cause an issue with excess pressure, which can lead to oil breaching the seals. I've seen people fit return pipes that drop down from the turbo then loop back up to a return hole in the block. Smokes like Lily Savage first time it's driven usually as the oil can't get out so back up to the core.

Into the block would be best, removing the sump would allow you to drill and tap the block and not fill the engine with swarf. You'll have to be exceptionally careful to make sure there's nothing gets into the bearings/oil pump etc

as above mate i havent got a drill or tapp big enough to drill the block. the sump i can take into work and drill it on the pillar drill then just take it to a machine shop with the correct tapp

 

[Dan519]

well if you must fit it to the sump, do it as high as you can so it stays above the oil level

just buy a drill and tap though IMO

 

[Chip-mk1]

when the engine is running all the oil wont be sitting in the sump anyway would it? most of it should be circulating round the engine. only time there will be a build up in the pipe is when the engine is off?

I'm not sure on the exact percentage of oil that will be in the sump at any given time (interesting question actually!) but I would hazzard a guess its upwards of 50%.

All that matters to the turbo core is that the oil has somewhere to go that takes less pressure to get to than past the seals, so like I said, if its into the sump make it a lot bigger than you would if it was into "fresh air" (in quotes cause actually you have positive crankcase pressure even into the air not just into the oil when the engine is running!)

Running it back round and into the dipstick tube pipe is another option ive seen people use.

 

[wag1]

Considering mine is an F7R too

That last picture, I mocked that up ad a template and took it to pirtek to make a proper one. As long as it falls and theres no where for oil to collect then thats all that matters...

Oil return was a pig for me too

It is shaped like that because I have a williams box so it had to be like that to pass the williams starter motoir

 

[Jaff.]

my F7R looks diffrent to that...

taps the size i need are fooking expensive! for somethign ill never use again it seems a bit of a waste. i cant see it being a problem right at the top of the sump? theres only about an inch diffrent to wag1's above then...

 

[Chip-mk1]

my F7R looks diffrent to that...

taps the size i need are fooking expensive! for somethign ill never use again it seems a bit of a waste. i cant see it being a problem right at the top of the sump? theres only about an inch diffrent to wag1's above then...

Right at the top of the sump seems the easiest option.
you could always just drill through and use a bulkhead type fitting rather than tap it too of course.

 

[wag1]

I would be happy to put mine into the sump. If you think about it the oil will just sit at the bootom of the sump, its not going to prevent oil returning from the turbo is it.

 

[Jaff.]

Right at the top of the sump seems the easiest option.
you could always just drill through and use a bulkhead type fitting rather than tap it too of course.

like the one ive linked in the OP?

 

[Dan519]

I would be happy to put mine into the sump. If you think about it the oil will just sit at the bootom of the sump, its not going to prevent oil returning from the turbo is it.

the key is the fitting into the sump not sitting below the oil line

 

[Andyman]

Top of the sump is fine.


No need to pay silly money on the fittings either.

Go to a engineering place rather than searching anything ''car'' based. I got mine for about £1.50 - Equivalent ones on ebay are a tenner for exactly the same thing

 

[Chip-mk1]

I was thinking more like this:
http://www.ebay.co.uk/itm/3-AN3-BUL...arts_Vehicles_CarParts_SM&hash=item3f079cac0b

Not that specific size, but along those lines where it passes right through and is secured with a nut on the other side and a sealing washer under each side.

 

[Chip-mk1]

Top of the sump is fine.


No need to pay silly money on the fittings either.

Go to a engineering place rather than searching anything ''car'' based. I got mine for about £1.50 - Equivalent ones on ebay are a tenner for exactly the same thing

Agreed, local hydaulics company is the way to go!

 

[Cupman29]

Mine just goes into the sump at the highest point.

 

[Jaff.]

I was thinking more like this:
http://www.ebay.co.uk/itm/3-AN3-BUL...arts_Vehicles_CarParts_SM&hash=item3f079cac0b

Not that specific size, but along those lines where it passes right through and is secured with a nut on the other side and a sealing washer under each side.

I have plenty of similar fittings but I had reservations of having a nut inside the engine that has potential to fall off

 

[Cupman29]

I have plenty of similar fittings but I had reservations of having a nut inside the engine that has potential to fall off

Agreed, I would be happier with a tapped hole on my engine.

Nice manifold by the way!

 

[Andyman]

I have plenty of similar fittings but I had reservations of having a nut inside the engine that has potential to fall off

You don't have a nut inside the sump. Tap the sump, screw the fitting in and locked / sealed in.

If it was to fall off which it wouldn't, it would fall out the way

 

[Jaff.]

You don't have a nut inside the sump. Tap the sump, screw the fitting in and locked / sealed in.

If it was to fall off which it wouldn't, it would fall out the way

Chip mentioned the nut on the back of the fitting

 

[Andyman]

Just for reference only:

http://www.ebay.co.uk/itm/VW-BUG-BU...ccessories&hash=item45ee53ee36#ht_1008wt_1163


Ones i used on my Zetec are like the above.

All i did was drill the hole, thread it, put Loctite on the fitting and screw it in to the sump but not right the way in so to get a seal.

Should screw in very very tight if your using the right tap and drill bits etc

 

[Jaff.]

Right I need some clarification here now then. How big does this return have to be?

 

[Andyman]

Match it to the size of the pipe of the return.

No idea if their all roughly the same from turbo to turbo but the one i used on a T34 was a 3/4''

 

[Chip-mk1]

Cant really see that would be an issue at all TBH

Even if the nut did fall off (why would it if its tightened? none of the other bolts fall out of the engine) it would just sit in the bottom of the sump, its not like its going to fit through the mesh on the pickup.

 

[Jaff.]

That's a good point but I like to worry lol. I have a good fitting that I could use that requires it to be "nutted" on the other side. I may use that

 

[scotty2hotty81]

I wouldn't do that, what If the nut falls off? Mine is tapped and lock tighted been fine for the last 4k miles and that's with only 2 threads in the sump.

 

[Tutuur]

I have the same fitting as Andy used. In my built willy engine it's drilled into the flat spot but i have a LC meg. F7r too.
On the bottom off the block there is a hollow piece (dent/dimple). With the sump off i felt thats exactly where a bridge for the crank support bearing is. But just next to that dent on the right ive had enough room for 3 fingers before the crankshaft hit it.

So that would be the ideal place imo, enough room to use a nut on the inside!
Good luck!

 

[Dan519]

TBH, if you really want to do it right, have a piece welded into the sump. Easy with the sump off

 

[Jaff.]

I know I should weld it but the guy who does my welding for me has welded the back of my car and a new manifold for me and I promised to leave him alone now lol. I will post a couple of pictures up later of what I plan to do and see what you guys think. I double checked the clearance I have with the driveshaft yesterday and it is not a lot! So it's joking to be very tight