Help! Turbo build problem!

LCkoolJ · 05-20-07, 07:09 PM

I'm wondering if anyone can help me out - I just finished putting a turbo on my BJ40, and just fired her up tonight. I haven't taken it out on the road yet, but standing still I have very little boost and there's oil coming from somewhere. I have checked all my fittings and they're all good - it looks like its coming from the exhaust. Does this mean that there's a cooked seal in the turbo? I have the oil into the turbo tee'd into the oil supply line right from the oil pump, and the return line to the return line on the oil pump. Please tell me its something simpleand not a problem with the turbo! Its a big job getting it on and off...

cruiser_guy · 05-20-07, 07:40 PM

There is always little boost unless the truck is working.

Is oil leaking or is burnt oil coming out the tailpipe?

I'll be in Abbotsford on Wednesday. If you want, PM me and I'll give you the contact info. As you can see in my signature, I've done a turbo on a couple of 3B's.

LCkoolJ · 05-20-07, 09:16 PM

I actually took it for a little burn down the road, and I still get hardly any boost - the best I can get on my guage is about 4 or 5 psi. There's no oil coming out of the tailpipe, but where my downpipe joins to the exhaust (I have an exhaust clamp there) there's oil spewing out of the joint. Its a significant amount of oil, and its getting everywhere. Could it be that my oil return line is too small and its backing up and blowing past the seals? I'll pm you - if you're willing to have a look, I would be very grateful!

seapotato · 05-20-07, 11:11 PM

when I first did my turbo on my bj40, I did the same thing, plummed it into the the alt. fittings, and it backed up and spewed oil.

I put a bung in the oil pan and it solved the problem, guess it needed more flow...

as for boost, they hardly show any when it's just sitting, but once youre driving it comes up.

can you adjust the wastegate?

redstang410 · 05-20-07, 11:16 PM

Sounds like a cooked seal. It happened to a turbo we installed, but that one was leaking into the intake side. Is the turbo used? Was it rebuilt?

Try adjusting the wastegate more and disconnect the line going to the wastegate actuator and try to see if boost increases.
If it does, then you have to put more tension on the wastegate rod.
If that doesn't help, then theres a problem with your turbo, or it could be sized wrong for your engine.

Tapage · 05-21-07, 10:54 AM

I have no boost in my setup if I put no load on my engine .. at least on the city I get no more than 10 PSI no matter what much rpm I try to reach. Under load in the HW another history.

LCkoolJ · 05-21-07, 11:35 AM

I was wondering about the return line thing - I think I'll try plumbing it to the oil pan before I rip the whole works off again!

LCkoolJ · 05-21-07, 11:40 AM

Quote:

Originally Posted by redstang410

Sounds like a cooked seal. It happened to a turbo we installed, but that one was leaking into the intake side. Is the turbo used? Was it rebuilt?

Try adjusting the wastegate more and disconnect the line going to the wastegate actuator and try to see if boost increases.
If it does, then you have to put more tension on the wastegate rod.
If that doesn't help, then theres a problem with your turbo, or it could be sized wrong for your engine.

It is a used turbo, yes. How do adjust the wastegate? Its hard mounted and just has the line going back to the intake side... I gotta get this oil problem solved first anyway, then I'll worry about the boost. I suspect if there's a bunch of oil flowing through the turbo and into the intake, its going to seriously mess up airflow and probably clog the line going to my boost controller/guage anyway, so there won't be any accurate readings!

LCkoolJ · 05-21-07, 11:44 AM

Quote:

Originally Posted by seapotato

when I first did my turbo on my bj40, I did the same thing, plummed it into the the alt. fittings, and it backed up and spewed oil.

I put a bung in the oil pan and it solved the problem, guess it needed more flow...

as for boost, they hardly show any when it's just sitting, but once youre driving it comes up.

can you adjust the wastegate?

Quick question - how big of a return line did you use? The pressure lines I got from Mopac are about the size of a brake line (apparently sufficient according to a turbo guy that works there), and then my return line is 1/4 inch ID. I would say it probably would allow for 3 or 4 times the amount of flow that the pressure line would - that should be fine, right? Or should I be going with something much larger?

cruiser_guy · 05-21-07, 11:56 AM

The return line on both of my completed turbos (piped into the vacuum pump oil return and NOT spewing oil) are 1/2" I.D. Any smaller and you'll be asking for trouble.
I'll see you later this week!

jus cruzin · 05-21-07, 04:43 PM

if you have a non-adjustable waste gate you can fit an adjustable valve (like a gate valve)into the hose that goes from the compressor housing to the waste gate valve. When you close the valve slightly it will give you more boost. This is not recomended unless you have a boost gague to keep tabs on the pressure. Also I would get everything working properly before you do this mod

seapotato · 05-21-07, 05:21 PM

yep, half inch ID or thereabouts...was so p.o'd at the mess I went big.

LCkoolJ · 05-22-07, 11:18 AM

Quote:

Originally Posted by jus cruzin

if you have a non-adjustable waste gate you can fit an adjustable valve (like a gate valve)into the hose that goes from the compressor housing to the waste gate valve. When you close the valve slightly it will give you more boost. This is not recomended unless you have a boost gague to keep tabs on the pressure. Also I would get everything working properly before you do this mod

Ah yes - well I do have a boost controller. I think thats kind of what you're getting at, right? Yeah I'll do some playing around with it once I get the other stuff sorted out.

LCkoolJ · 05-22-07, 11:33 AM

Ok! Got the oil situation sorted out - YAY! I ran a 1/2" ID hose straight into the oil pan and no more oil! Thanks for the help. Cruiser_guy - how did you run a 1/2" line to your oil return on the pump? My pump only has a 1/4" OD tube going into it for the return. Did you change that somehow or does your pump have a bigger return inlet on it? Anyway, that problem seems to be solved, but I still have very little boost, although I can feel the power difference when I drive, so I think my guage may not be reporting correctly. I have attached a pic of how I have the boost controller and the outlet for the boost guage setup. The hose barb closest to the firewall (coming out of the boost controller) goes to my wastegate actuator, and the other one goes to the guage. Do you think the guage should be tapped in closer to the turbo/at an angle to catch air flow?

Tapage · 05-22-07, 12:29 PM

Disconect and tap you wastegate line .. ride test, you would see a bunch of boost and fast .. if it's, your boost controler are bad .. ( maybe ) but you can separate the turbo issue from the boost controler issue.

jus cruzin · 05-22-07, 03:35 PM

very shiny!

jus cruzin · 05-22-07, 03:39 PM

I noticed that the boost control screw looks like it is screwed out. if you screw it inwards it should gain more boost. the more you shut the valve the higher boost level. do this at intervels and test , repeat if ness

ozwallaby · 05-23-07, 03:03 AM

Looks like you've got it beat, but this info may help someone. Drain back line should be large1/2" id min. and always pointing in a downward direction from the turbo. If you're draining directly to sump it should enter the sump as high as possible. The oil can become airated (frothy) and tends to slow down as far as flow goes.

LCkoolJ · 05-23-07, 07:08 AM

Thanks - that's exactly what I did. The return line actually comes out of the side of the turbo with an elbox pointing straight down. I welded a 1/2" pipe with an elbow pointing upwards as close to the top of the sump as I could. Its working great now, and I can really feel the power difference, but I'm still not showing more than 5lbs of boost on the guage. Do you guys think that the fitting for the boost guage should have a stem that hangs down inside the intake pipe to capture the velocity of the air to drive the guage? Or maybe have the fitting tapped in at an angle with the open end facing the turbo? Or is pressure simply pressure, and if I'm only showing 5psi then that's all I'm pushing?

LCkoolJ · 05-23-07, 07:52 AM

Another question - what's the "comfortable range" for EGT? I back off when it gets up around 1000 - 1100. At what point to things start to melt? It gets up there pretty quick too, I don't know if thats normal or not. If I really accelerate through the gears, by the time I shift into fourth, I'm right up there. Basically I can accelerate hard through 1st 2nd and 3rd, and then kind of coast into 4th. Should it get hot that quick? I cranked up my fuel a bit, she blows some black now when I step on it, but I could give it some more I guess. I kind of wanted the happy medium between decent power without smoking obnoxiously!