SPHELL

OK, you may or may not know that I've put a twin turbo setup on my EA. It's all bolted in however it's still not plumbed up to the intake....so the car's still N/A just with two hairdryers hanging off the side. Just a bit of a run down, it's using two Garrett T28 N1 spec GTR turbos, mounted on separate manifolds being fed from 3 cylinders each. So one turbo sits infront of the other alongside the engine.

Anyway, I've been driving the car like this for a bit (with the wastegates constantly open), and what I've noticed is that the front turbo gets A LOT hotter than the rear one. The turbos are oil and water cooled and I have checked the oil feed lines and also the water lines for blockages and both are fine. When I turn the car off after a drive, the front turbo makes a lot of 'sizzling' noises like something is leaking out while the rear one is quiet. Although I can't see any leaks except for a small amount of oil around the oil feed line.

What I have noticed is that when the car's idling, if I put my finger on the front turbo's compressor wheel to stop it spinning, it will stay stopped until you either rev the engine or give it a flick to start it spinning again. If I do the same thing to the rear turbo, as soon as I let the compressor wheel go, it will spin up again.

I believe both turbos have been rebuilt recently as there is no shaft play and there are paint markings over the compressor wheel nuts (for warranty purposes I'm guessing).

Now I'm no where near a turbo expert so this might be way off, but is it possible that some dumbass has put the turbine wheel on the front turbo on backwards.....so that it's not spinning properly and maybe the exhaust gas is just kind of sitting in the turbine housing for too long causing it to heat up excessively?

Or could it be something else totally different?

Cheers,
Doug

 

shano6

With the engine off, try spinning each comp. wheel with the same effort. If the front one is harder to spin/does'nt spin for as long, it's a good chance that you've got a tight/buggered bearing. Is it noisy at all? This can be caused by the wrong sized bearing, just a faulty bearing, or a lack of oil, etc.

SPHELL

nah both comp wheels spin about the same. it doesn't feel tight....it's nice and smooth and no shaft play.

73gscoupe

i would go along the lines of either oil or water line problems. I dont think its possible to put the turbine of a turbo in the wrong way.

how are your water and oil lines arranged?

SPHELL

the oil feed line is coming up from a T-piece in the oil pressure sender, it splits into two braided lines at the top of the rocker cover and goes to each turbo. The oil return lines are directly on the bottom of the turbos and drain directly down into the front LHS of the sump.

The water feed line T's into the hose that runs off the metal pipe that runs out of the water pump and around the back of the engine. It splits into two at the rocker cover and goes to each turbo.

you can see oil and water feed lines in this pic.


The water return lines come out the other side of each turbo, join back into one then run to the radiator overflow tank.

See in this pic (they are the black hoses)


hope that helps

not ford

Be careful running the engine with the turbos not hooked up!!

Because they're not working to make boost its very easy to over spin the turbos and destroy them. You should have never put them on if you didn't intend to hook them up immediately.

SPHELL

thats why the wastegates are open and theres a sock over the outlet to give them some resistance against the compressors.

au-steve

hope its an explorer sock

btw thats a really nice looking engine bay, is the intake manifold (RHS of engine) stock? it looks cool as well, any info on it?

EB SIX ON N2O

yes that is one way to over heat a turbo.
silly to have them hooked up and only free reving.
imo you cant over spin them when they are not producing boost.

not sure what your problem is buddy.

__________________
gone to ford forums.com.au.............

SPHELL

thanks, the inlet manifold is just an ED one that's been painted in some VHT hi-temp paint. I was careful not to get it all greasy when I re-installed it :)Makes all the difference when it's clean.

As for the turbo overheating, I shortened the front turbo's oil drain line...almost cut it too short as I had a hell of a time getting the thing plugged back into the sump. Anyway, now the oil drain is dead vertical straight out of the turbo into the sump.....and the turbo seems to be running cooler...So maybe it wasn't draining properly???

Only driven it twice since then so I'll have to see. Thanks for your help guys.