Club 80-90 Forums

im halfway through a 1.6d to 1.9 aaz conversion but having read through loads of threads concerning use of jx parts it seems if i use aaz manifolds and turbo im going to kill the engine because of the oil return from the turbo being at wrong angle causing engine to run partly on waste oil. Is this right and is there any way round it?
If not will my cs manifolds fit as a temporary measure while i find some jx bits if so any idea what it will run like

plenty running standard AAZ set up , search on BY aswell . ive blanked the block where oil return line connects and have run mine into the sump a la JX . done 1k miles and no probs so far !

causing engine to run partly on waste oil.

There are some issues with both setups but don't recognise waste oil as one... are you an engine oil recycler?

phil , you might be thinking of engine running off oil coming from rocker cover into inlet tract/breather , never happened to me but believe it has come up in convo before

Thats reassuring did i read somewhere you used a k+n filter?
That oil return pipe, did you make one up cos BW do one but only fits jx manifold apparantly.

yep , i used the whole AAZ set up ie didnt use JX mnaifolds/turbo etc . had to ditch airbox as the AAZ manifold/turbo sit higher and would foul got some silicone hoses and a big filter behid rear light.
local 'pirtek' (yellow pages - hydraulic fittings + hoses) will make you a return line up . i made my own using a 45' fitting into sump and a length of hose going to turbo from 'outlet' end near turbo .

copied from one of Baxters posts -

"AAZ's, if plumbed up with breather into turbo inlet start injesting their own oil on right hand bends, they then tend to set off at an alarming rate of knots, smoke and make nasty noises.

Few things that can combat this.

1 Sort turbo oil return line so it's as close to the vertical as possible.
2 Use a windage tray sump gasket, but that means bellhousing mods.
3 Divery oil breather into a ctach tank so it doesn't blow directly into the air inlet for the turbo.
4 Only add 4.5 litlres of oil to an empty engine then remark the dipstick.

if you drive steady then you will never notice it, if you hoon around it becomes a problem."

hence me putting oil return to sump to give more of a factory/vertical 'drop':D

http://www.brick-yard.co.uk/forum/forum ... p?TID=9812

The first paragraph after 'notes' is what worried me!

I bought a sump a few weeks ago to replace my leaky one ( split by drain hole, it has metal filler around it but still dripped everywhere. will bin it cos i dont think its repairable.) luckily the one i bought is a TD one with drain for turbo so just need longer return pipe.

Not sure if its necessary but im renewing the oil and water pumps ( probably not changed in its llifetime )

If it helps, Im runnning my 1.9mTDI with the stock Golf MK3 oil return set up....now done over 15,000 miles......no problems........
Think about it, turbo is spinning in excces of 50,000 rpm, oil is being pressure fed at full pump pressure, do you really think the oil relies on gravity feed back to the block.......

The 'oil surge' problem is caused by too much oil in the sump.......often a result of folks not fitting the correct lenght dipstip as part of the conversion. Then to make problems worse, they use a golf oil filter which is too small and does not hold as much oil as the correct 1.6d T25 oil filter which is much bigger............
Also, many 2nd hand 1.9 engines have already done 100,000+ miles before they are fitted to a T25, so the turbo/seals are normaly due for referb. Many over look this.
Gav

do you really think the oil relies on gravity feed back to the block.......

Yes, I do, and it does...

Turbo speed has nothing to do with oil drain, the oil does not experience the turbo revs, it all flows around the CHRA assembly and out, pressure only building up when it can't drain naturally back to sump, otherwsie outlet pressure is zero, free fall back to sump...

Nearly all turbos on all vehciles work on this principle and the common law is this... '..ensure adequate vertical drop for oil feed back to sump, sound advice in any book on trubo vehcile design!'

Agree that worn turbo seals and high oil levels are mainly the problem

I agree HarryMan, but the gravity is mainly to stop oil 'pooling' when the engine is switched off.

I dont recommend you do this but....
If you remove the oil return pipe from the turbo, then start the engine....you willlsee what I mean, thats more than gravity making the oil spray!!!

Anyhow, like I said, never had a problem......

GaV