I have a new rebuilt 13Bt that seems to be leaking oil from the inside. The irons are resurfaced along with new seals all the way around. I removed the turbo and manifold to find the inside of the manifold coated with oil from both housings. I'm at a loss and cant seem to figure out why. It seems like the oil is coming through the oil control rings. Anyone else experience this problem on a fresh build?

 

Who put the motor together? Were new oil control o-rings used? Were the springs installed correctly?

 

If it was ported its possible it was ported into the oil control ring sealing area.

 

I put the motor together myself and everything in the motor is new, the spings and rings are in the correct positions and seated properly.

A little update, after inspecting the rotor housings with a probe camera I noticed there is no oil buildup inside at all. Most of the oil seems to be coming from the back side of the turbo outlet as the entire housing is coated with a lot of fresh oil on the inside. One thing I just realized is the Oil filler neck im using does not have a breather for the crank case and is actually seals with an o-ring under the cap. I'm going to put everything back together and check for pressure coming from the crank case.

 

The port is a pineapple racing street port and I checked the sweep area of the rings before finishing the port so it should be good there.

 

Was that your first rebuilt you have done ?

 

Sounds like the turbo is the problem.

As you mention, with no vents on the crankcase, you will pressurize it and without question that will cause the turbo to bypass oil.

At the very least set up a catch can. Or do it properly with a PCV valve (as it's set up stock).

 

Aaron your right on the money. vented the crank case and it stopped leaking from the turbo.

 

Well, it did stop leaking from the turbo but was still smoking way too much so I went ahead and pulled the motor to check it out. Before I continue , I had the irons lapped and re-nitrated by chip, the housings are refinished by Goopy. I used a master rebuild kit for the rebuild so the rotors are completely rebuilt with new bearings, new oil control rings and o-rings, new side and corner seals with springs and Goopy 2mm apex seals with springs. The front and rear stationary gears are new Rx8 gears/w new bearings. So the motor is completely rebuilt.

E85 Premixed with Maxima Castor 927
End play is set to 0.0020

* note pictures posted show results of only about 5-10 min of idle time

When I removed the rear iron I could immediately tell there was a clearance problem with the side seals as there was clear signs of blow-by at the corner seals.


Checked the rear iron port to see if the oil ring was sweeping oil into the port. The ring rides right on the curve of the port so it should be fine. The mid and front irons were fine as well.


There is a build up of burnt oil on the side seals and the apex seals


This has to be a oil control ring issue but why would it be doing this with brand new rings and resurfaced irons in both housings? Is it possible the side seal blow by could be getting past the rings?

 

that actually looks like the nitriding as it scrapes away the surface layer to smooth out the finish. the grit should eventually sweep off the rotors(remember that air and fuel still hit the sides of the rotors). nitriding is a rather dirty process and it simply appears they didn't cut down the surface layer, which isn't necessarily a problem but it will show if you immediately tear the engine back apart. be sure to change the oil after about a hundred miles and flush the coolant after it is broken in.

i would check the side seal clearances, they are either too sloppy or too tight and binding up allowing compression into the inner area.

as for the smoking issue, 15 minutes on freshly nitrided irons is not long enough. expect the engine to smoke somewhat heavily for 15 minutes and nearly stop after an hour, it will still smoke on startup for a chunk of the remaining break in period. this can be bypassed by repolishing the friction faces but it is a labor intensive step. seeing the nitride on the irons may may you feel warm inside but it isn't exactly easy on the break in process.

IMO, unless it was really bad i think you jumped the gun and chip should have told you what to expect.

 

Hey I never thought about that being the cause of all that grime in there. I think im gonna go ahead and buy a new set of side seals to make the clearance a little tighter. As of right now Im getting around .005 - .006 which I think is way loose for a boosted block. The issue with the oil leaking is still a problem. At first it seemed the oil was coming from the turbo because the down pipe was soaked. I vented the crankcase by removing the filler cap and checked for any kind of pressure build up but there was none. So with the cap removed there was a significant change in the amount of oil that was leaking yet it still continued to leak . Im running a -4an feed to this S366 with a larger return line. I am using a modified oil pressure regulator and shimmed the front cover regulator as well.

 

S366 Application Notes:

3AN oil feed line is recommended. If -4AN or larger is used, an oil restrictor is required (just like GT turbos).



smh probably too much oil pressure on this poor turbo

 

if it is soaking all the way to the downpipe then yes i would probably say that is excessive even for the nitriding still lapping into the engine.

vent the crankcase
tighten the side seal gaps
make sure the oil seals aren't ripped from the installation and spring out freely and the springs are pointing the right direction(rear of rotors should lock if spun clockwise, fronts lock when spun counterclockwise)
check the oil seal track wear just to be sure it isn't wearing excessively quickly indicating an improper treatment

you already have a few of those addressed so just pay attention to the others.

keep in mind fresh irons will be porous, they will allow oil to slide past into the chambers so the crankcase must be well vented. lighter oils aid in the break in process, try a 10W30 and not a heavy oil like 20W50 to start with.