Blew an engine I think...so venting :ack:
#1
Burning Brakes
Thread Starter
Blew the engine, block is cracked.
I was just heading into a 2nd lap of a shakedown run (being very conservative and not really stressing the car) and something went boom followed by a white/gray smoke that had a super-fine dust particle kind of cloud. Oil all came out and found some shrapnel which is aluminum that is obviously cast and with a large grain structure.
Here's the kicker, it was the first time to actually drive the car in 9 months.... more downtime again! wooooo! party!
I'll post details after I get a gander at it up on a lift. The post-mortem should be fun. Maybe I can be back on the track by Xmas time
update: shop called, block is cracked.
Here's the kicker, it was the first time to actually drive the car in 9 months.... more downtime again! wooooo! party!
I'll post details after I get a gander at it up on a lift. The post-mortem should be fun. Maybe I can be back on the track by Xmas time
update: shop called, block is cracked.
Last edited by OKsweetrides; 09-16-2010 at 05:34 PM.
#2
Burning Brakes
I was just heading into a 2nd lap of a shakedown run (being very conservative and not really stressing the car) and something went boom followed by a white/gray smoke that had a super-fine dust particle kind of cloud. Oil all came out and found some shrapnel which is aluminum that is obviously cast and with a large grain structure.
The shrapnel is either from the bellhousing or from the engine block. Haven't had a chance to look at carnage from beneath, but oil is everywhere in bottom of engine bay. I think if the clutch exploded, it ended up sending shrapnel to and severing all the dry sump lines that run back and forth near there which could explain the oil being everywhere.
Here's the kicker, it was the first time to actually drive the car in 9 months.... more downtime again! wooooo! party!
I'll post details after I get a gander at it up on a lift. The post-mortem should be fun. Maybe I can be back on the track by Xmas time
If it's a rotating assembly failure, that should prove to be interesting.
The shrapnel is either from the bellhousing or from the engine block. Haven't had a chance to look at carnage from beneath, but oil is everywhere in bottom of engine bay. I think if the clutch exploded, it ended up sending shrapnel to and severing all the dry sump lines that run back and forth near there which could explain the oil being everywhere.
Here's the kicker, it was the first time to actually drive the car in 9 months.... more downtime again! wooooo! party!
I'll post details after I get a gander at it up on a lift. The post-mortem should be fun. Maybe I can be back on the track by Xmas time
If it's a rotating assembly failure, that should prove to be interesting.
How many miles did you have on the engine. Can you estimate how many track days?
#3
Burning Brakes
Thread Starter
It's a cracked block.
From the ARE oil pan all the way to cylinder head. The shop just relayed that information to me. I'll try and snag some pictures tomorrow morning and get some up.
Itd say a rough estimate is 4000 miles of HPDE style things.
From the ARE oil pan all the way to cylinder head. The shop just relayed that information to me. I'll try and snag some pictures tomorrow morning and get some up.
Itd say a rough estimate is 4000 miles of HPDE style things.
Last edited by OKsweetrides; 09-16-2010 at 05:32 PM.
#5
Former Vendor
We were only on our second lap...
I can't wait to see what Mike comes up with. This is going to be one sick puppy when completed.
I actually snapped some pics before we went out:
I can't wait to see what Mike comes up with. This is going to be one sick puppy when completed.
I actually snapped some pics before we went out:
#6
Burning Brakes
Thread Starter
UPDATE:
It looks like the small end of a rod (3rd cylinder back on drivers side) went through the top of the block and the crack just continued all the way through the block.
When the engine gets replaced with an LS7 here in the next week or so, the ol' LS6 will get a tear down and see what exactly failed.
It looks like the small end of a rod (3rd cylinder back on drivers side) went through the top of the block and the crack just continued all the way through the block.
When the engine gets replaced with an LS7 here in the next week or so, the ol' LS6 will get a tear down and see what exactly failed.
#8
"AlohaC5" Senior Member
I feel your pain. I get my C5 back in one week from Virginia Speed and plan to take it to VIR at the end of October for a conservative 'shake down'. Good luck with the new LS7 project!
#9
Burning Brakes
Thread Starter
Thanks for the well wishes for it. But I think the engine is more a testament to durability than initially telling. I *BEAT* on that engine. To have it survive as many mis-shifts and still perform till the second it let go; venerable engine design.
funny side note, it was a good thing I did the shake down at the track, made things a whole lot safer.
but Jmorgan07z06, your car flies, so power remotely close to that would be nice!
funny side note, it was a good thing I did the shake down at the track, made things a whole lot safer.
but Jmorgan07z06, your car flies, so power remotely close to that would be nice!
#10
Race Director
Thanks for the well wishes for it. But I think the engine is more a testament to durability than initially telling. I *BEAT* on that engine. To have it survive as many mis-shifts and still perform till the second it let go; venerable engine design.
funny side note, it was a good thing I did the shake down at the track, made things a whole lot safer.
but Jmorgan07z06, your car flies, so power remotely close to that would be nice!
funny side note, it was a good thing I did the shake down at the track, made things a whole lot safer.
but Jmorgan07z06, your car flies, so power remotely close to that would be nice!
Last edited by GeorgeZNJ; 09-18-2010 at 07:49 PM.
#11
Burning Brakes
Thread Starter
It's ok, ask as many questions as you want!
I have Moton coilovers front and rear with 800/600. These are paired with T1 sway bars and T1 lower A-arms (a hold over from when I had the T1 suspension bits).
Tires, well, I have steering "knock" (can't think of the term off the top of my head) with 315's in front but stuffed 345's in rear in Hoosier R6's on 18x11 and 18x13's. They stick out a healthy bit. I'll actually run a narrower tire to help reduce the knocking around that I feel in the steering wheel. It settles down significantly turns however.
Things to note: I run a few mm spacer in the rear. The front steering wheel rotation has to be limited or you'll cut the A-Arms (may be that T1 bars are different geometry).
I have some power mods and various other things, just shoot me a PM if you wanna know. I've accumulated a list of things/changed over the years.
#12
Race Director
Thanks, just trying to decide if I need a dry sump, or if an accusump is fine. I'll be running a new crate LS6 with bolts ons and a cam. My car is mostly a street car with 6-10 track days (HPDE's) a year. I was impressed that you got 4k out of yours. track tires are 295/30/18-F 315/30/18-R. I'm really starting to think theses sticky tires have a lot to do with the oiling problems.
Last edited by GeorgeZNJ; 09-19-2010 at 09:37 PM.
#13
Burning Brakes
Thread Starter
GeorgeZNJ,
To further bolster your confidence, I had TF215's and a pretty healthy cam with .600 lift. I went with those because I damaged the stock valvesprings when I had a really bad misshift and let out the clutch. The engine despite all the times of accidental downshift, quite a durable thing!! I've yet to see my bimmer friends survive as many miles with such... brute abuse.
Stickies will always lead to oiling problems, no bones about that. Just make sure that your oil pressure gauge works really well and keep an eye on it. My stock sensor crapped out at the ~7000mi. mark. It got replaced by an autometer one.
To further bolster your confidence, I had TF215's and a pretty healthy cam with .600 lift. I went with those because I damaged the stock valvesprings when I had a really bad misshift and let out the clutch. The engine despite all the times of accidental downshift, quite a durable thing!! I've yet to see my bimmer friends survive as many miles with such... brute abuse.
Stickies will always lead to oiling problems, no bones about that. Just make sure that your oil pressure gauge works really well and keep an eye on it. My stock sensor crapped out at the ~7000mi. mark. It got replaced by an autometer one.
#14
Safety Car
Thanks, just trying to decide if I need a dry sump, or if an accusump is fine. I'll be running a new crate LS6 with bolts ons and a cam. My car is mostly a street car with 6-10 track days (HPDE's) a year. I was impressed that you got 4k out of yours. track tires are 295/30/18-F 315/30/18-R. I'm really starting to think theses sticky tires have a lot to do with the oiling problems.
#15
Race Director
Yes, a6's and r6's. Right before this one let loose, I ran Watkins Glen for two days hard, with the NNJR PCA guys, red/black run group. To the OP, sorry for the thread hijack.
Last edited by GeorgeZNJ; 09-20-2010 at 09:01 PM.
#16
Race Director
GeorgeZNJ,
To further bolster your confidence, I had TF215's and a pretty healthy cam with .600 lift. I went with those because I damaged the stock valvesprings when I had a really bad misshift and let out the clutch. The engine despite all the times of accidental downshift, quite a durable thing!! I've yet to see my bimmer friends survive as many miles with such... brute abuse.
Stickies will always lead to oiling problems, no bones about that. Just make sure that your oil pressure gauge works really well and keep an eye on it. My stock sensor crapped out at the ~7000mi. mark. It got replaced by an autometer one.
To further bolster your confidence, I had TF215's and a pretty healthy cam with .600 lift. I went with those because I damaged the stock valvesprings when I had a really bad misshift and let out the clutch. The engine despite all the times of accidental downshift, quite a durable thing!! I've yet to see my bimmer friends survive as many miles with such... brute abuse.
Stickies will always lead to oiling problems, no bones about that. Just make sure that your oil pressure gauge works really well and keep an eye on it. My stock sensor crapped out at the ~7000mi. mark. It got replaced by an autometer one.
#17
Is Lightning that bad? I have heard a few comments about it's banking but I didn't realize it was that drastic. I haven't heard of any engines letting go there yet.
#18
Burning Brakes
Regarding banking - I've asked this question before and nobody seemed able to answer it: why do banked corners cause greater oil starvation than flat corners? I see this time and again - people comment on how concerned they are to take the car on banked corners...why? I'd really like to see data (lateral G in banked vs lateral G in flat). Does anyone have data of the "lightbulb" at Lightning and can show us lateral Gs (assuming lateral Gs are the cause of oil starvation). I'd really like to know if this is an internet/urban legend or if there is truth to it.
George - are you going to have a new engine in time for that TrackDaze event at Lightning in October?
George - are you going to have a new engine in time for that TrackDaze event at Lightning in October?
#19
Race Director
Regarding banking - I've asked this question before and nobody seemed able to answer it: why do banked corners cause greater oil starvation than flat corners? I see this time and again - people comment on how concerned they are to take the car on banked corners...why? I'd really like to see data (lateral G in banked vs lateral G in flat). Does anyone have data of the "lightbulb" at Lightning and can show us lateral Gs (assuming lateral Gs are the cause of oil starvation). I'd really like to know if this is an internet/urban legend or if there is truth to it.
George - are you going to have a new engine in time for that TrackDaze event at Lightning in October?
George - are you going to have a new engine in time for that TrackDaze event at Lightning in October?
#20
Safety Car
Regarding banking - I've asked this question before and nobody seemed able to answer it: why do banked corners cause greater oil starvation than flat corners? I see this time and again - people comment on how concerned they are to take the car on banked corners...why? I'd really like to see data (lateral G in banked vs lateral G in flat). Does anyone have data of the "lightbulb" at Lightning and can show us lateral Gs (assuming lateral Gs are the cause of oil starvation). I'd really like to know if this is an internet/urban legend or if there is truth to it.
Back in 2005 with my C4 I took a first taste of HPDE at Pocono in May. The car had around 70k mi and was really well maintained with a cam. I had new supercars on the front and new NittoRII on the rear. I had a great time at the 2 day event. I went to another 1 day at Summit in July. I had been to Summit before though once or twice over the years (single day, 80 min, on street tires strictly, running very slow in beginner groups).
So right a day or so after the July event a grinding noise developed. On inspection of the engine, the GMPP timing set gears were destroyed (that's a GMPP issue), but also, the Main & rod bearings were found to be badly worn. It's conjecture on my part, but I feel it's logical to conclude that most of the wear to the bearings and the timing gear occurred at Pocono. From an engineering viewpoint, if I were designing a sports car, I would design it for street use which would not include a lot of banking for sustained periods of time. I've asked a few turners in the PA area and yes--when the run at Pocono--they use a sump.
You can say it's a legend...but I still have the bearings.