engine thrust bearing repair
11-04-2009, 05:04 PM
#3
Nordschleife Master
uh oh.. this doesn't bode well.
There are a couple of posts here about repairing blocks that have have thrust bearing failure.
Someone (I think Imoo?) mentioned a Candaian 928 that had a repair done by machining out the damaged part and using an insert?
However, probably much $$ compared to just getting a new engine (warning: make sure the engine is good - that means buying from someone who will warranty it, not just someone who says "ran great when I pulled it")
There are a couple of posts here about repairing blocks that have have thrust bearing failure.
Someone (I think Imoo?) mentioned a Candaian 928 that had a repair done by machining out the damaged part and using an insert?
However, probably much $$ compared to just getting a new engine (warning: make sure the engine is good - that means buying from someone who will warranty it, not just someone who says "ran great when I pulled it")
11-04-2009, 05:08 PM
#5
Captain Obvious
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That’s not so.
As long as the block isn’t cracked it’s fixable but it won’t be cheap or easy. I’ve seen one repaired and it worked flawlessly. The damaged area was machines flat and a 2 piece spacer was installed behind a new (early 32V) thrust bearing. Apparently the early thrust bearings have a larger surface area and are better over all, especially for a repair like this.
As long as the block isn’t cracked it’s fixable but it won’t be cheap or easy. I’ve seen one repaired and it worked flawlessly. The damaged area was machines flat and a 2 piece spacer was installed behind a new (early 32V) thrust bearing. Apparently the early thrust bearings have a larger surface area and are better over all, especially for a repair like this.
11-04-2009, 05:21 PM
#6
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If you say so, but I would never trust a block that the crank had gotten into.
By the time you spent all the money for machine shop stuff, you might just have more money into a questionable block than a good used short block would be.
By the time you spent all the money for machine shop stuff, you might just have more money into a questionable block than a good used short block would be.
That’s not so.
As long as the block isn’t cracked it’s fixable but it won’t be cheap or easy. I’ve seen one repaired and it worked flawlessly. The damaged area was machines flat and a 2 piece spacer was installed behind a new (early 32V) thrust bearing. Apparently the early thrust bearings have a larger surface area and are better over all, especially for a repair like this.
As long as the block isn’t cracked it’s fixable but it won’t be cheap or easy. I’ve seen one repaired and it worked flawlessly. The damaged area was machines flat and a 2 piece spacer was installed behind a new (early 32V) thrust bearing. Apparently the early thrust bearings have a larger surface area and are better over all, especially for a repair like this.
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11-04-2009, 05:38 PM
#8
Captain Obvious
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If you do all the work, besides the machining, the cost of maching is not that much (3-4hrs). They only have to touch one side of the journal. I have no reason to beleive that it will not be as stong as it was before. AND at the end, you'll have an engine that has all new gaskets too. If you buy a good used engine, the gaskets will probalby be old so you would want to re seal it anyways and that will add at least $350 to the cost.
The original question was if it's fixable and I'm saying it is. Is it practical or cost effective, well that depends but it certainly is doable.
11-04-2009, 06:24 PM
#10
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Don't they usually crack really bad when this happens?
Most of them I have seen do.
I will say that you may be right, on some blocks it may be possible to save them, I am just not going to do it.
And, you are also right, that was not his question.
Most of them I have seen do.
I will say that you may be right, on some blocks it may be possible to save them, I am just not going to do it.
And, you are also right, that was not his question.
If you do all the work, besides the machining, the cost of maching is not that much (3-4hrs). They only have to touch one side of the journal. I have no reason to beleive that it will not be as stong as it was before. AND at the end, you'll have an engine that has all new gaskets too. If you buy a good used engine, the gaskets will probalby be old so you would want to re seal it anyways and that will add at least $350 to the cost.
The original question was if it's fixable and I'm saying it is. Is it practical or cost effective, well that depends but it certainly is doable.
The original question was if it's fixable and I'm saying it is. Is it practical or cost effective, well that depends but it certainly is doable.
11-04-2009, 06:38 PM
#11
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My $0.02 worth.
Even if it were fixable - reliability would be something I would be very concerned with. I have thought of what I would do in this situation and decided if it did, I would buy a used engine and rebuild it.
Others may disagree, but I would not want to worry about how reliable the fix would be.
Good Luck,
Even if it were fixable - reliability would be something I would be very concerned with. I have thought of what I would do in this situation and decided if it did, I would buy a used engine and rebuild it.
Others may disagree, but I would not want to worry about how reliable the fix would be.
Good Luck,
11-04-2009, 06:50 PM
#12
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We're not sure yet it's TBF. It could be 2/6 rod bearing. The engine is seized hard. Need to get into the crankcase to find out for sure. I wonder if there's a way to snake a borescope down the oil filler area after removing the baffle to inspect the crank thrust webbing?
11-04-2009, 07:46 PM
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We're not sure yet it's TBF. It could be 2/6 rod bearing. The engine is seized hard. Need to get into the crankcase to find out for sure. I wonder if there's a way to snake a borescope down the oil filler area after removing the baffle to inspect the crank thrust webbing?
I have a 928 in the shop and it is getting a oil change tomorrow, if my dumb *** does not forget, I will try to see if I can see the rear of the thrust bearing area.
I will post a pic in a minute of the one I have.
Last edited by blown 87; 11-04-2009 at 08:15 PM.
11-04-2009, 09:24 PM
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i wasnt driving it hard and the rpms went high i dont know how it happened. heres what happen one day i got the water pump and timming belt changed shortly after I changed the oil/filter. next day after i brought the car back it started cutting off at low rpm / at stop lights. while driving back to the mechanic the car died without making any sounds on the interstate, i was driving slow but the rpms where above 1,000. I could not start the engine becuase the battery was drained again, I told the mechanic to drop the oil pan and also check out the thrust bearings, what else should I ask him? I took this car to performance independant porsche in san diego, the guy has alot of experience with porsches and has no complaints against him. he said he doesnt know what could have caused it.
