Slightly broken/bent fins! Whats the effect?

[nube90]

Got this 14b to replace my blown one, it was cheap but I didnt notice the bent fins until I brought it home and took of the exhaust housing. If its bad could I just take the wheel off and replace it with my old wheel which is in good shape without throwing it out of balance?

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[GVR4592]

The chips and bends will affect the balance, but there's really no way to determine how fast it's going to wear out. You can't replace the wheel without re-balancing. See if you can find a turbo rebuild shop in your area, some diesel shops rebuild turbo's. They should be able to balance it for you if you replace the wheel. Your other option is to just run it and see how long it lasts. If it was me that's what I would do, 14b's are pretty much throw away turbo's.

 

[nube90]

About how long would it take to wear out, estimated? Im only going to run it at stock boost and right now there is no shaft play at all.

 

[nube90]

Pics with highlighted areas. on the second pic there is a slight chip out of the fin that isnt highlighted.

http://i101.photobucket.com/albums/m64/90TSiAWD/DSC00968-1.jpg

http://i101.photobucket.com/albums/m64/90TSiAWD/DSC00963-1.jpg

 

[DSMunknown]

The chips and bends will affect the balance, but there's really no way to determine how fast it's going to wear out. You can't replace the wheel without re-balancing. See if you can find a turbo rebuild shop in your area, some diesel shops rebuild turbo's. They should be able to balance it for you if you replace the wheel. Your other option is to just run it and see how long it lasts. If it was me that's what I would do, 14b's are pretty much throw away turbo's.

While I agree with most of what you said, Luke, I am going to have to respectfully disagree about using a damaged center housing. Here's why:

Many technicians prefer to replace the entire center section and reuse the housing or replace the complete turbocharger to aviod repair problems.

...

When overhauling a turbocharger, it is very important that you do nothnig to upset the balance of the turbocharger wheels. If you bend the turbo shaft loosening or even one blade slightly, the turbocharger will be out of balance and may self-destruct the first time it spins up to boost pressure.

 

[GVR4592]

About how long would it take to wear out, estimated? Im only going to run it at stock boost and right now there is no shaft play at all.

There's no way to tell except to run it and find out.

 

[92awddsm]

While I agree with most of what you said, Luke, I am going to have to respectfully disagree about using a damaged center housing. Here's why:

And not trying to be a dick but your cut and paste is also incorrect. If you slightly bend a fin, the balance will be the same. By bending, you are not adding or removing weight in a given area, you are only changing the flow of that particular area. You can not upset the balance unless you remove, add, or relocate the weight to another area. Bending the shaft itself is a totally different story but what is "bending the turbo shaft loosening?" You need to find a more reliable source of information before you use it as grounds for telling someone else they are wrong.

Now, for the topic at hand. Yes, the balance will be affected by the 2 chipped fins on the turbine wheel. Just swapping the wheel isnt as easy as you think and may not work as expected. The turbine wheel and shaft are a 1 piece assembly so you would have to completely disassemble both turbo's to make one. Afterwards, you would still need to rebalance the rotating assembly because it is balanced as a complete unit and the compressor wheel in this turbo will have a different balance than your old wheel. Now, if your shaft from the old turbo has any wear, you will end up with shaft play even with new bearings. If you are set on using this turbo for any length of time, you need to have it rebalanced. This should cost less than $100 at almost any big diesel repair shops(cummins, mack, cat/carter, etc) becuase most of them do all in house turbo repairs and rebuilds. If it were me personally, I would get my $ back and just buy something in better shape.

 

[elfroggo]

And I would not agree with that statement. Do you think planes would fly if the wings were not at an exact angle that produces the correct amount of lift? If you put a wing on backward would it still fly? The weight is unchanged.

Having bent fins would definitely have an effect on the balance of the turbo wheel. It's not just the weight that needs to be balanced but also the forces each fin encounters as it cuts through the air.

 

[silver bullit]

Since you have it off rebuild it then you have a new sealed turbo etc.. going back on your car then you dont have to take it off later when the seals go out.

 

[92awddsm]

Do you think planes would fly if the wings were not at an exact angle that produces the correct amount of lift? If you put a wing on backward would it still fly? The weight is unchanged.

By bending, you are not adding or removing weight in a given area, you are only changing the flow of that particular area.

Here we go again comparing apples to oranges. A turbo dont fly so lift on the wings isnt as detrimental as it would be on a plane.

 

[nube90]

One thing listen to the wisemen dont argue with them, they are wisemen for a reason.

Well the turbo was only 100 bucks so I cant really expect much I dont think the owner knew that the fins were chipped because it was off a wrecked car, and I dont have the money to rebuild it im going to save up and buy a new one when this one bits the dust.

 

[DSM-Talon-John]

I got a question, dont mean to steal the thread but whats with all the bitching and disagreeing with wisemen lately? Ive noticed it in 2 or 3 threads the last 2 days.

 

[92awddsm]

I got a question, dont mean to steal the thread but whats with all the bitching and disagreeing with wisemen lately? Ive noticed it in 2 or 3 threads the last 2 days.

Let me know when you find out. The strange part is that most all the wisemen are 30+ and have been into or around dsm's since their introduction. But there is always those people that got their fist dsm a year or so ago and they think they know all there is to know about them. And then there are those that think they know everything about all cars.

 

[oldman]

I personally don't see any problems with disagreeing with a wiseman as long as it's done respectfully, which is the case here. As for bent fins affecting balance, depending on how and how bad it's bent, anytime you change the distance (radius) between the material (weight) and the shaft, balance will be affected.

 

[DSMunknown]

And not trying to be a dick but your cut and paste is also incorrect. If you slightly bend a fin, the balance will be the same. By bending, you are not adding or removing weight in a given area, you are only changing the flow of that particular area. You can not upset the balance unless you remove, add, or relocate the weight to another area. Bending the shaft itself is a totally different story but what is "bending the turbo shaft loosening?" You need to find a more reliable source of information before you use it as grounds for telling someone else they are wrong.

Well, Keith, I'm "not trying to be a dick but" in actuality I accurately quoted Mr. Duffy. Need proof? Then please click here. Please scroll down to page 335. If Mr. Duffy or his editors didn't do their jobs in catching a potentially awkward sentance, that's not my fault.

And I never said Luke was wrong. I simply disagreed with part of his statement.

 

[92awddsm]

The turbine wheel and shaft of an mhi turbo are so hard and brittle that the turbine fins usually crack and break when bent more than .050-.060" when cold. I have had a 16g cartridge rebalanced with 2 fins that were bent about .085"(due to a stupid move on someone elses part) and balance was still perfect. Now, if you bend fins on a larger diameter wheel, it may affect balance. On the small mhi wheel, it didnt.

And what I stated in reply to DSM-Talon-John really didnt apply to this thread at all, it was more about a couple of things I had seen in a couple of other threads. My apologies for making it come across as if this was a problem thread. I dont see a problem at all debating real life experience against what is written in a book. And I was being sincere when I said "not trying to be a dick".

 

[DSMunknown]

That's not how I wanted to come across either. Sorry if I did.