notveryhappyjack

iTrader: (4)

my -10an oil return line for my Hitachi ht18 turbo doesn't work, the oil goes into the exhaust & doesn't drain back into the front cover.

What do I need to change on my set up to make this work?
I'm already thinking of having the adapter fitting machined down, this will give my line slightly more slope to drain. I'm also thinking I should use a 45* bend and not the 90* off the chra. Or I need to just go larger oil return all together? advice?

here is how the current not working oil line is set up


My feed line is -3an, the turbo has a oil restriction mod, 15w40 oil. roughly 75-80psi cold idle.

bumpstart

looks like s5 block. 12a timing cover , 4 x 1000 cc multech type injectors and V trim stock cover s5 highflow

a standard layout im very familiar with !

drain is where most of us have it.. looks good..

though over here we usually have the turbo more forward adjacent the front rotor to clear steering box on RHD vehicles
( on s5 stuff we flip the manifold upside down and a few other tricks .. or use custom exhaust manifolds )

i would think you have a problem with the turbo .. or the venting system for the crankcase

but you can try moving the entry point on the timing cover down onto the "leg" so it drains almost vertically there and not horizontally in the block

PS.. if this is for a beetle .. the issue may be the rear facing engine cant drain the turbo during wheelstands

notveryhappyjack

iTrader: (4)

Close,

S5 tii, hybrid s5 turbo, RC injectors, 5 letter front cover. Going in a fb.

With the previous return line it never acted this way. Do most people use a 90 bend out 45 off the turbo?

IRPerformance

iTrader: (41)

The less than ideal placement of the turbo is your issue. Looks like a stock manifold from the pic. The turbo should really be positioned higher and more forward. Otherwise it is very difficult to get a good return line path. You could try to run the line down a bit further before turning it into the front cover.

notveryhappyjack

iTrader: (4)

Thanks for the responses.

I'm aware that the factory manifold has a lot of limitations. But for the moment I'm going to keep it factory manifold.

How do the rest of you all do your return lines on a stock set up

bumpstart

same as you have done . although in oz the turbo is adjacent the front rotor
.. incidentally on installs where the motor leans back towards tailshaft this means that there always a slope down towards the timing cover entry point

it may just be that as a rear rotor install ... and installed with a lean,, then your total angle for the pipe is now nearly horizontal

note that the factory s4 drain point is pretty much where you have it
yet for s5s they are lower down on the the front of the timing cover
so perhaps the factory also considers the unflipped s5 manifold to s4 FC drain leg point has insufficient angle
( although you can argue it moved for the EOMP... it is likely the position of the s5 manifold was designed with the new drain point in mind )

in that boat .. then you can tap the entry point vertically down into the "leg" on the lower edge of the timing cover for some improvements


barring all that .. then you have an issue with crankcase venting.. something you are not sharing with us

notveryhappyjack

iTrader: (4)

Crankcase is vented to atmosphere on the center iron by a hose that is roughly the length from the top of the motor to the oil pan.