A930Rocket

I tried to take the pic head on and it's close, but the wheel is so offset it looks like I took it from the side. The cold side is almost straight, so the shaft must be bent pretty good.

JBL930

So it's the shaft bending that has flattened the blades so bad, what could cause the shaft to bend like that?

sand_man

So are you going to continue the engine break-in with the 3LDZ?

A930Rocket

If it gets out of balance it quickly starts to wobble and eats itself I think.

A930Rocket

Yes.

sand_man

That should be intersting. A *REAL* firecracker of an engine with that old boat anchor of a snail! LOL!

Kevin

Impact at high speed.. They the metal blades wedge between the turbine housing and turbine wheel. At the same time you are running at a out of balance condition which starts to wipe the bearings out.. This then causes more contact between the housing and turbine wheel.. At some point the wheel bites into the housing and you bend the turbine wheel head.. It is almost ready to seperate itself and launch itself out the Zork tube.. Not good for the guy following you's windshield!!

125shifter

The paper towel problem could be worse, there was a failure a couple years ago when someone left a roll of paper towels at the inlet of a GE frame 7 gas turbine. That mistake probably cost over a mil.

A930Rocket

Kevin,

I mailed the turbo out today. Should be to you in two days. Will I have it back by Fri to install for the weekend? LOL

Jim

Rob S

Yeah, I felt pretty stupid. But as it was, the paper caused surprisingly little trouble. Before the paper towel discovery (and the aforementioned turbo damage from ingesting some rubber hose), the engine had been running strangely on the dyno. It was surging after it came on boost, and there was an oscillation that caused the engine to rock fairly violently on the dyno stand. One theory was that the surging could have been caused by an intake restriction (like the paper towel). But after removing the paper towel and fixing the turbo damage from the hose, we discovered a small tear in the rubber diaphragm of the BOV. This caused an odd open and close exchange between the BOV and wastegate. After replacing the BOV, the engine smoothed right out and produced more power. The moral: don't expect dyno tuning on a new engine to go smoothly. The tuning is relatively straightforward. It's recognizing and fixing all the gremlins that sucks up all the time.

Jim, do you have any idea what went through your turbine to cause that damage?