3.0l 16v turbo rod bearing failure
11-05-2012, 04:43 AM
#16
Rennlist Member
You and I may email a little bit more about a certain subject....
11-05-2012, 04:55 AM
#17
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Gustaff, sorry to hear that, in case that you need a 3l crank i might be able to get one for you also a block
11-05-2012, 11:44 AM
#19
Race Car
Well you know how I feel. I know some have apprehension regarding the small journals, but I have zero doubts that if I were still running the factory stuff I would have grenaded my engine long ago with the abuse I've thrown at it.
Sucks it happened though.
Sucks it happened though.
11-05-2012, 11:52 AM
#20
Drifting
Also wondering this. Can one of the engine experts give us a seminar on how to tell whether the rod let go and smashed up the bearing, or the bearing let go and took out the rod?
11-05-2012, 12:32 PM
#22
Nordschleife Master
Thread Starter
11-05-2012, 12:33 PM
#23
Drifting
I was told by a pro engine builder a long time ago that first undersize was ok anymore and it was time for another crank, but this was on engines pulling 8k or more on track and the engines were dry sumped.
Last edited by blade7; 11-05-2012 at 12:49 PM.
11-05-2012, 12:56 PM
#24
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I’ll toss in a couple of answers / comments:
I told Duke that there was too much damage to use the MID, the sleeves have 3 orings that need to seal against the block in the area that was damaged. But on second look the 3.0 block has a much higher floor and it might be possible to save it with the MIDs. Duke – if you can give me a measurement on exactly how far up the missing metal goes I will take a closer look.
Knowing (guessing) failure mode – if the crank shows signs of high heat in the bearings area it was bearing failure. You can usually find pieces of the bearing that show signs of high heat and partial welding to the crank / rods. Rod failure usually does not heat the crank/rod.
Undersizing a crank journal – the problem is that you will remove some of the heat treated surface .The Porsche cranks have a very good heat treating on the journals, going to first undersize does not machine it all away – but it does thin it enough that I won’t use it in the race engine (OK for street engines)
Stroker cranks – make sure who ever does the work uses all the right processes – correct welding and heat treating is very important. There are a lot of hacks out there that do low budget strokers, then you have a journal that is not as strong as stock….
BTW – #3 looks like you might have had a little detonation going on at some point. Crank is not worth saving for a race engine – 99% of all rod failure cranks are bent. Nice groove on the #2 counter weight!
Also looks like the block is deforming a bit at high loads (look at the main bearing wear pattern). This is common on high power (500+) 944 blocks.
I told Duke that there was too much damage to use the MID, the sleeves have 3 orings that need to seal against the block in the area that was damaged. But on second look the 3.0 block has a much higher floor and it might be possible to save it with the MIDs. Duke – if you can give me a measurement on exactly how far up the missing metal goes I will take a closer look.
Knowing (guessing) failure mode – if the crank shows signs of high heat in the bearings area it was bearing failure. You can usually find pieces of the bearing that show signs of high heat and partial welding to the crank / rods. Rod failure usually does not heat the crank/rod.
Undersizing a crank journal – the problem is that you will remove some of the heat treated surface .The Porsche cranks have a very good heat treating on the journals, going to first undersize does not machine it all away – but it does thin it enough that I won’t use it in the race engine (OK for street engines)
Stroker cranks – make sure who ever does the work uses all the right processes – correct welding and heat treating is very important. There are a lot of hacks out there that do low budget strokers, then you have a journal that is not as strong as stock….
BTW – #3 looks like you might have had a little detonation going on at some point. Crank is not worth saving for a race engine – 99% of all rod failure cranks are bent. Nice groove on the #2 counter weight!
Also looks like the block is deforming a bit at high loads (look at the main bearing wear pattern). This is common on high power (500+) 944 blocks.
11-05-2012, 01:45 PM
#25
Drifting
11-05-2012, 01:58 PM
#26
Nordschleife Master
Thread Starter
The only "real" answer would be to do dry sump AND a redesigned crank but it is not really needed as long as you have dry sump since that will make sure you have high oil pressure at all times.
11-05-2012, 02:08 PM
#27
Sorry to hijack your thread duke, I really hope you can fix this as cheaply as possible. Since I am currently considering building my own 3.0l 16v turbo I have a couple of questions.
1. Is it possible to fix this #2 rod bearing failure a cheaper way than dry sump?
2. Would raising the deck with a block filler make the engine twist less in a high power car?
3. How much would a dry sump set me back?
1. Is it possible to fix this #2 rod bearing failure a cheaper way than dry sump?
2. Would raising the deck with a block filler make the engine twist less in a high power car?
3. How much would a dry sump set me back?
Last edited by KSira; 11-05-2012 at 02:10 PM. Reason: Added a question
11-05-2012, 02:09 PM
#28
Nordschleife Master
Thread Starter
I’ll toss in a couple of answers / comments:
I told Duke that there was too much damage to use the MID, the sleeves have 3 orings that need to seal against the block in the area that was damaged. But on second look the 3.0 block has a much higher floor and it might be possible to save it with the MIDs. Duke – if you can give me a measurement on exactly how far up the missing metal goes I will take a closer look.
Knowing (guessing) failure mode – if the crank shows signs of high heat in the bearings area it was bearing failure. You can usually find pieces of the bearing that show signs of high heat and partial welding to the crank / rods. Rod failure usually does not heat the crank/rod.
Undersizing a crank journal – the problem is that you will remove some of the heat treated surface .The Porsche cranks have a very good heat treating on the journals, going to first undersize does not machine it all away – but it does thin it enough that I won’t use it in the race engine (OK for street engines)
Stroker cranks – make sure who ever does the work uses all the right processes – correct welding and heat treating is very important. There are a lot of hacks out there that do low budget strokers, then you have a journal that is not as strong as stock….
BTW – #3 looks like you might have had a little detonation going on at some point. Crank is not worth saving for a race engine – 99% of all rod failure cranks are bent. Nice groove on the #2 counter weight!
Also looks like the block is deforming a bit at high loads (look at the main bearing wear pattern). This is common on high power (500+) 944 blocks.
I told Duke that there was too much damage to use the MID, the sleeves have 3 orings that need to seal against the block in the area that was damaged. But on second look the 3.0 block has a much higher floor and it might be possible to save it with the MIDs. Duke – if you can give me a measurement on exactly how far up the missing metal goes I will take a closer look.
Knowing (guessing) failure mode – if the crank shows signs of high heat in the bearings area it was bearing failure. You can usually find pieces of the bearing that show signs of high heat and partial welding to the crank / rods. Rod failure usually does not heat the crank/rod.
Undersizing a crank journal – the problem is that you will remove some of the heat treated surface .The Porsche cranks have a very good heat treating on the journals, going to first undersize does not machine it all away – but it does thin it enough that I won’t use it in the race engine (OK for street engines)
Stroker cranks – make sure who ever does the work uses all the right processes – correct welding and heat treating is very important. There are a lot of hacks out there that do low budget strokers, then you have a journal that is not as strong as stock….
BTW – #3 looks like you might have had a little detonation going on at some point. Crank is not worth saving for a race engine – 99% of all rod failure cranks are bent. Nice groove on the #2 counter weight!
Also looks like the block is deforming a bit at high loads (look at the main bearing wear pattern). This is common on high power (500+) 944 blocks.
Interesting observations Chris. I suppose I could have had light detonation shortly after the build (2 years ago) when I ran at the track in very high outside temp. Afterwards I increased the ignition retard at high IAT a little bit more.
All bearings are Swaintech coated so the marks in the bearing might look worse or better depending on the behaviour of the coating. I guess the bearings will end up looking more worn. The no 2 rod bearing is partly welded to the journal and partly fragments. The journal and small end of the rod is blue due to the heat.
Yeah nice groove right!? It's like the crank started to knife edge itself
11-05-2012, 02:10 PM
#29
Drifting
I hope it's the answer, it wont alter the fact number 2 has less flow/pressure, I guess you'll be investigating even better oil and inspecting the bearing frequently.
11-05-2012, 02:31 PM
#30
Rennlist Member
but it does thin it enough that I won’t use it in the race engine (OK for street engines)
Stroker cranks – make sure who ever does the work uses all the right processes – correct welding and heat treating is very important. There are a lot of hacks out there that do low budget strokers, then you have a journal that is not as strong as stock….
Stroker cranks – make sure who ever does the work uses all the right processes – correct welding and heat treating is very important. There are a lot of hacks out there that do low budget strokers, then you have a journal that is not as strong as stock….
Last edited by refresh951; 11-05-2012 at 02:47 PM.