Dealer on Turbo -"Normal casting Imperfection"

[Tejasdge]

Dealer said that this was a normal casting imperfection. :-{} I need some ammo for the next round guys.



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[Gary - K7GLD]

What are we looking at here? Is that really anything serious - or merely where a casting seam was dressed down for smoothness?

 

[RDietze]

is that the turbine or the compressor?



looks too dirty to be the compressor and too clean to be the turbine? i'm guessing it's the compressor?



is that a crack on the blade? because mine has the scuffing on the blade like you show - it was my thought it was for the microbalancing of the wheel (scuffing)

 

[RDietze]

Originally posted by Gary - KJ6Q

What are we looking at here? Is that really anything serious - or merely where a casting seam was dressed down for smoothness?

you beat me to the "submit reply button"



DAMN!

 

[Tejasdge]

This is the intake side. It appears to be casting imperfections as the dealer stated, but at the speeds that it is spinning, I am concerned about longevity and potentially lower boost and turbulence from the rough surface and/or out of balance. Is it really a problem?

 

[rbattelle]

I assume you mean the scrapes on the blades

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Tell that dealer that COMPRESSOR BLADES ARE NOT CAST!



Man, that kind of stupidity from dealers makes me angry. Get your truck out of there before they screw it up really bad. Take it to a Cummins shop and have them do an independent assessment on it, then take that to another dealer and tell them to fix it under warranty.



You may also send a picture of that to Holset, and ask them to comment.

 

[Tejasdge]

Sending the pic to Holeset was my thought also, but I don't have much faith in them commenting. I guess I'll have to take a leap of faith and try.

 

[rbattelle]

Try phoning them... it's harder to ignore someone on the phone. And jglasgow is working on their roof! Ask him to take your picture to them!!! The thread about it is here.

 

[chrleb1]

It looks to be a scrape on the blades. This could mean that the impeller is slightly bent and could lead to serious problems. First the bearings (sending metal into your oil), then with the play it will eat the housing and send metal though your intake into your motor and then bye-bye turbo.

 

[jglasgow]

Those blades don't look like the ones that I've seen in the recycling boxes. I'll be working at Holset/Cummins all day tomorrow and would be glad to take a photo in to them to look over and get their opinion. -John

 

[dseabaugh]

If that is on the intake side is something getting through the filter or is the turbo spitting out parts and eating them again?

 

[Tejasdge]

That would be great if you could get them to take a look at it jglasgow. I tried to find Holeset with a search, but had no luck. Anyone have a web site and/or E-mail for them? Phone number would be good also.



I do think that the imperfections are being polished since they are higher than the rest of the blade. Can't see it spinning true the way it is now.

 

[Vaughn MacKenzie]

I know one blade of an impeller is typically machined off a bit as part of the balancing process, could this be the case? Maybe it took more griding than usual to balance this one out? Still not quite sure what we're looking at.



Vaughn

 

[Tejasdge]

Vaughn,

That is possible, but it looks as if the shiny area's are raised and getting more so(shiney) as time goes on. It would be very helpfull if someone that works with turbos would let us know if this is normal or not.

 

[jwilliams3]

Every new turbo has an impeller blade that is painted white about (1/2"wxlength of blade from center to od)

The impeller is cast aluminum and the turbine is some sort of high-nickel type of metal.



The white paint mark is put there for inspection purposes.



You have absolutely nothing to worry about!

Also the aluminum stock that is machined off of the impeller itself is for balancing purposes.



Your turbo's impeller looks, fine.

I have looked at thousands of them!



--Justin

 

[rbattelle]

Originally posted by jwilliams3

Your turbo's impeller looks, fine.

I have looked at thousands of them!



--Justin

I (very respectfully) disagree. I could be wrong (wouldn't be the 1st time, for sure!), but I think it's abnormal.



Jglasgow, is holset actually casting their blades, then finish machining them? Or are they machining the blade/rotor assembly from a block?

 

[nickleinonen]

that compressor wheel doesn't look all that bad to me... aluminum will discolor with heat and if it had any type of oil film or clear spray to protect it, that will aid in the discoloring. i will take a pic of my compressor wheel later today to see how it looks, but here is a pic of how my compressor wheel looked new [±40km on it] .

 

[jwilliams3]

This is from Holsets website:



Compressor Wheel (Impellor)

Compressor impellers are produced using a variant of the aluminium investment casting process.



A rubber former is made to replicate the impeller around which a casting mould is created. The rubber former can then be extracted from the mould into which the metal is poured. Accurate blade sections and profiles are important in achieving compressor performance. Back face profile machining optimises impeller stress conditions. Boring to tight tolerance and burnishing assist balancing and fatigue resistance. The impeller is located on the shaft assembly using a threaded nut

 

[rbattelle]

Originally posted by jwilliams3

This is from Holsets website:



Compressor Wheel (Impellor)

Compressor impellers are produced using a variant of the aluminium investment casting process.



A rubber former is made to replicate the impeller around which a casting mould is created. The rubber former can then be extracted from the mould into which the metal is poured. Accurate blade sections and profiles are important in achieving compressor performance. Back face profile machining optimises impeller stress conditions. Boring to tight tolerance and burnishing assist balancing and fatigue resistance. The impeller is located on the shaft assembly using a threaded nut

Then I stand corrected, apparently these compressors are cast. But I would think all the finishing machining would eliminate any "casting imperfections"?

 

[jglasgow]

I showed the guys at Holset the picture this morning and they said the (scrapes) on the blade is White out , It's used for balancing . They also said that the shiney part of the housing is probably the angle the picture was taken. They want to know what kind of problems you are having other than apperence. They also said to check to see how much play was in the shaft and maybe get another picture straight on . Hope this helps, _John PS There biggest complaint is noise.