Blown engine, turbo has metal shavings ?

11000 Views 33 Replies 6 Participants Last post by racer70, Aug 30, 2017

Maddtvguy86

Discussion Starter · Aug 29, 2017

So my local tuner told me I had rods let go from cyl 2 and cyl 4! They said at first sight the turbo looked good while removing my engine. They said they can't see the inlet tho yet. Today I called and they said my turbo was garbage that there were metal shavings in it and it cost as much to rebuild as a new one. I have been reading other posts in this and I found this ......

"I saw a lubrication diagram for the EJ series engines awhile back. If memory serves me correct, the heads/turbo are on the same oil circuit and the bottom end is a separate circuit.

Any garbage that the bearings spit up will get dropped back into the sump and screened by the pickup/filter.

Even if a small amount of particulates got into the turbo itself... anything small enough to not cause immediate turbo bearing failure is no worse than metal shavings that get introduced during normal engine break in.

I think the mechanic
a) has no idea what he's talking about
b) is trying to make some more $ off ya
c) all of the above

All the spun bearings I have seen are due to the motor being doomed since day one (improper assembly, poor clearances, etc.) or due to oil starvation or excessive RPM.

Particulates in an engine spin bearings when they get BEHIND the bearing (during assembly) and mess up oiling clearances.

The easiest way to see if it is noise in the short block or valve train is to beg/borrow/steal a timing light.

Move the light around to each plug wire until you get a flash as close to the noise as possible. If you get one flash per noise, it's most likely something in the valvetrain. If you get two noises per flash it is in the short block.

If the noise turns out to be something in the valvetrain you most definately have particulates in the turbo bearings. See my above statement about particulates in the turbo bearings.

So could shavings get in my turbo or is it screened and they are just taking me for a ride ?

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racer70

· #21 · Aug 29, 2017

XJman said:
... it's completely possible in that length of time the particulate are up the turbo. ...

Well, there is junk everywhere. Oil, oil galleys, pan, ... Same as when the excrement hits the ventilating device. I highlighted the turbo because I assumed that everything else would be thrown away. Stuff that is not needs the same cleaning and the same paranoid inspection. With the block (if it is to be reused) there are often plugs that need to be drilled out to access oil galleys and then new plugs installed.

XJman said:
... there is a likely hood you may have damaged a head.

I don't think it is tremendously likely other than everything being filled with junk. Even if there are bent valves the head is not likely to have been damaged. Again, clean with extreme paranoia. I would change the valve guides and give the thing a valve job just because the heads are already lying on the bench. Freshening the heads will never be cheaper. I personally wouldn't bother for a street car, but this is also the time for mild specialist tricks like maybe bigger valves or mild porting and polishing and matching the intake manifold.

This is all just General Engine 101. Guys here who have actually done a few of these Soob engines will probably come by with more specific suggestions.

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XJman

· #22 · Aug 29, 2017

Contaminated oil can damage a head. Especially if the bearings were shot for that long and you have that much crap lubricating everything.

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racer70

· #23 · Aug 29, 2017

XJman said:
Contaminated oil can damage a head. ...

I'll bite. What can be damaged and how? A head is a casting with a bunch of added holes drilled in it. Not much to damage except by badly overheating it a la head gasket failure or by overenthusiastic porting.

Maddtvguy86

Discussion Starter · #24 · Aug 29, 2017

racer70 said:
I'll bite. What can be damaged and how? A head is a casting with a bunch of added holes drilled in it. Not much to damage except by badly overheating it a la head gasket failure or by overenthusiastic porting.

He has commented on my previous post where my first issue was my head gasket leak from my engine into my radiator.

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Maddtvguy86

Discussion Starter · #25 · Aug 30, 2017

racer70 said:
Well, I personally wouldn't bother for a street car, but this is also the time for mild specialist tricks like maybe bigger valves or mild porting and polishing and matching the intake manifold.

This is all just General Engine 101. Guys here who have actually done a few of these Soob engines will probably come by with more specific suggestions.

I don't know engine 101 ^^ what would porting and polishing do, that not usually included in re decking ?

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Maddtvguy86

Discussion Starter · #26 · Aug 30, 2017

XJman said:
Contaminated oil can damage a head. Especially if the bearings were shot for that long and you have that much crap lubricating everything.

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I thought I was crazy for a second but found out that I had both posts from different forums with you there

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XJman

· #27 · Aug 30, 2017

racer70 said:
I'll bite. What can be damaged and how? A head is a casting with a bunch of added holes drilled in it. Not much to damage except by badly overheating it a la head gasket failure or by overenthusiastic porting.

Everything that needs to be moving in the head. Bearing surfaces, cams, everything. The head is more than just a casting. This isn't a flat head Ford.

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racer70

· #28 · Aug 30, 2017

Maddtvguy86 said:
He has commented on my previous post where my first issue was my head gasket leak from my engine into my radiator.

Which can and does damage heads. But it in this thread he is asserting that babbitt in the oil can damage a head and I have no idea how that would happen.

Maddtvguy86 said:
I don't know engine 101 ^^ what would porting and polishing do, that not usually included in re decking ? ..

I'm guessing that by "decking" you mean taking a cut off the top of the block to increase compression. Like I said, I don't know these Soob engines in detail -- never have had one apart. Sometimes a head is cut for this purpose, too. "Porting and polishing" refers to the intake and exhaust passages in the head and often includes work in the intake manifold. Step one is to open up the passages and smooth out sharp corners to improve gas flow. This is generally done with a die grinder and a carbide cutter. Step two is to go in with sanding rolls and smooth the surfaces of the ports, again to improve gas flow. It needs to be done by an expert, though, because in some heads the ports are better left small to increase exhaust gas velocity for better extraction as the piston passes TDC. The momentum of the gas in the head continues to drag exhaust gas out of the cylinder even though the piston is no longer helping. Kind of like flushing a toilet, actually. An amateur, also, can accidentally cut through the casting into the water jacket, instantly ruining the head.

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racer70

· #29 · Aug 30, 2017

XJman said:
Everything that needs to be moving in the head. ...

So you don't actually know. Got it. Wave your arms all you like; I'll not respond again.

Maddtvguy86

Discussion Starter · #30 · Aug 30, 2017

racer70 said:
Which can and does damage heads. But it in this thread he is asserting that babbitt in the oil can damage a head and I have no idea how that would happen.

I'm guessing that by "decking" you mean taking a cut off the top of the block to increase compression. Like I said, I don't know these Soob engines in detail -- never have had one apart. Sometimes a head is cut for this purpose, too. "Porting and polishing" refers to the intake and exhaust passages in the head and often includes work in the intake manifold. Step one is to open up the passages and smooth out sharp corners to improve gas flow. This is generally done with a die grinder and a carbide cutter. Step two is to go in with sanding rolls and smooth the surfaces of the ports, again to improve gas flow. It needs to be done by an expert, though, because in some heads the ports are better left small to increase exhaust gas velocity for better extraction as the piston passes TDC. The momentum of the gas in the head continues to drag exhaust gas out of the cylinder even though the piston is no longer helping. Kind of like flushing a toilet, actually. An amateur, also, can accidentally cut through the casting into the water jacket, instantly ruining the head.

Thank you for the detailed explanation. By decking I assume the people I am using mean resurfacing to fit the new block with no leaks. I'm
not sure if the compression changes from WRX heads on a STI block, one post was saying it reduces HP but I know nothing about it.

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XJman

· #31 · Aug 30, 2017

racer70 said:
So you don't actually know. Got it. Wave your arms all you like; I'll not respond again.

You have 2 cams, 8 valves, all in the head. All moving, all using oil delivered to lubricate. You obviously have never taken down an engine with oil issues.

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EJ257

· #32 · Aug 30, 2017

racer70 said:
So you don't actually know. Got it. Wave your arms all you like; I'll not respond again.

Watch yourself...

It's common for the entire top-end to be referred to as the "heads", just like someone would refer to the entire bottom-end as the "block".

XJman

· #33 · Aug 30, 2017

I've gone through this exact issue with my old ladies stratus. Bearing goes, doesn't tell me the car is banging like crazy drives untold amount of miles. Any postulation on Earth can be proposed but the facts are the material can get to the heads, destroy the springs, cams, bearings as well as the valves in some applications.

As that material is getting eroded by the material from the failed bearing it creates more and the issue compounds.

The ops problem is not of the turbo is dead. Or can a spun bearing destroy the turbo. At this point it is what is causing his lubrication failure.

If you are so sure of yourself, pour some sand in your heads and let me know how it turns out for you.

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racer70

· #34 · Aug 30, 2017

Maddtvguy86 said:
Thank you for the detailed explanation. By decking I assume the people I am using mean resurfacing to fit the new block with no leaks. I'm
not sure if the compression changes from WRX heads on a STI block, one post was saying it reduces HP but I know nothing about it.

Yeah, a skim cut just to square things up is probably a good idea. On some racing engines this kind of a cut is used to equalize cylinder volumes. Essentially it is to correct a factory cut that was not perfectly parallel to the axis of the crank. The setup is shimmed a few thou at one end or the other, creating a sloping cut. The same kind of thing is sometimes done to heads in order to equalize combustion chamber volumes where they come from the factory slightly out of whack.

Re swapping heads, in general the block doesn't care what head is bolted to it. So you are simply looking at the differences between the heads. In addition to combustion chamber volume (=> compression ratio), there may also be differences in valve sizes (and count!), OHC profile, etc. The head specs and digging in the parts books will give you most of what you want to know. The EEC computer may become an issue, too, if you give it a different head than it was programmed for. Personally, I would not mess with a head swap on a street car. This kind of thing can be a lot of fun though. In Olden Times, I pulled the Holley carb off my 289 Cobra and installed a set of 48IDA Webers originally built by Kar Kraft for a GT40. Pretty amazing difference. My rationalization was that I was doing a little bit of vintage racing with the car. It was kind of dumb, though, because the Cobra was basically a street car for me.

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