[Z06] Another Z engine bit the dust yesterday
05-02-2013, 04:50 PM
#361
My motor had 26,000 street miles on it + 15 track hours. Prior to any track hours... the rocker arms were upgraded and increased capacity lingefelter tank installed. While tracking it... oils were changed twice as often as recommended and the motor short shifted at 6500RPM.
I did everything but the replace the exhaust valves because I was unaware of the problem when I had the motor done. Had I known and/or had the shop told me about the possibility of a $20K catostrophic engine failure due to a $50 exhaust valve... I would have had the work done and my final bill would have been $18K instead of $16K and I would "likely" not be looking at replacing it with a $20K motor right now. So... $18K total cost to do it right the first time instead of the $36K I am looking at today.
Knowing what I know today (which isnt everything) my recommendation is to seriously consider replacing/rebuilding/inspecting your LS7 heads prior to track use. If your motor is out and apart anyway... it becomes a no brainer in my mind.
KV
I did everything but the replace the exhaust valves because I was unaware of the problem when I had the motor done. Had I known and/or had the shop told me about the possibility of a $20K catostrophic engine failure due to a $50 exhaust valve... I would have had the work done and my final bill would have been $18K instead of $16K and I would "likely" not be looking at replacing it with a $20K motor right now. So... $18K total cost to do it right the first time instead of the $36K I am looking at today.
Knowing what I know today (which isnt everything) my recommendation is to seriously consider replacing/rebuilding/inspecting your LS7 heads prior to track use. If your motor is out and apart anyway... it becomes a no brainer in my mind.
KV
what a tough break. It's examples like this one which make the decision easy for many in here and ends a lot of the arguing.
Was this the one with the GT19 Lingenfelter package in it?
If so, how long had you been running it?
Last edited by '06 Quicksilver Z06; 05-02-2013 at 04:58 PM.
05-02-2013, 06:34 PM
#362
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All I know is after I blew the engine I talked to the Lingenfelter dealer that did the work and the company rep said they/he knew of a failure rate on the exhaust valves but it was so small (1 or 2%) that they dont/didnt mention it to their clients. I wish he had told me as I told him I wanted to fix "any weak links" in the motor and I had a reasonable budget to work with. Just goes to show ya... you can ask all the good questions ya want... doesnt guarantee good answers or advise. I think the exhaust valve failure rate is low for street driven LS7's... but I personally believe it is unacceptably high for LS7's that are tracked.
I bought the car with 26,000 miles and immediately converted it to a track car... so 15 track hours after having the car/motor done for $16K an exhaust valve broke and took out the motor. Pretty hard to argue about that
05-02-2013, 06:38 PM
#363
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I am considering a race prepped "CBM Motorsports" replacement engine... anyone have any advise or thoughts on that?
I would love to go with something like a "Katech Track Attack LS7" but the cost is absolutely astronomical
I would love to go with something like a "Katech Track Attack LS7" but the cost is absolutely astronomical
05-02-2013, 06:45 PM
#364
Ya... I got a "partial" GT19 Lingenfelter package put in/on the engine. The reason I say "partial" is that even though the work was done by an authorized Lingenfelter dealer... the heads never came off the engine. Having said that... I dont know if they would have replaced the exhaust valves as part of their "complete" GT19 package or not... so not wanting to slam Lingenfelter either directly or indirectly... I want to throw that disclaimer out there.
All I know is after I blew the engine I talked to the Lingenfelter dealer that did the work and the company rep said they/he knew of a failure rate on the exhaust valves but it was so small (1 or 2%) that they dont/didnt mention it to their clients. I wish he had told me as I told him I wanted to fix "any weak links" in the motor and I had a reasonable budget to work with. Just goes to show ya... you can ask all the good questions ya want... doesnt guarantee good answers or advise. I think the exhaust valve failure rate is low for street driven LS7's... but I personally believe it is unacceptably high for LS7's that are tracked.
I bought the car with 26,000 miles and immediately converted it to a track car... so 15 track hours after having the car/motor done for $16K an exhaust valve broke and took out the motor. Pretty hard to argue about that
All I know is after I blew the engine I talked to the Lingenfelter dealer that did the work and the company rep said they/he knew of a failure rate on the exhaust valves but it was so small (1 or 2%) that they dont/didnt mention it to their clients. I wish he had told me as I told him I wanted to fix "any weak links" in the motor and I had a reasonable budget to work with. Just goes to show ya... you can ask all the good questions ya want... doesnt guarantee good answers or advise. I think the exhaust valve failure rate is low for street driven LS7's... but I personally believe it is unacceptably high for LS7's that are tracked.
I bought the car with 26,000 miles and immediately converted it to a track car... so 15 track hours after having the car/motor done for $16K an exhaust valve broke and took out the motor. Pretty hard to argue about that
I appreciate your response and hate that you have to cover tha expense after so few hours of use of your car.
Good luck with the replacement engine.
It's a shame that they apparently thought that your stock valves were up to the task, when they were not.
05-02-2013, 06:56 PM
#366
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Howie wasn't your guides out of spec on the engine you have now. I know you went with wcch but when they pulled them they where out correct?
05-02-2013, 07:53 PM
#367
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I agree with the "Find a <insert something else here> and start over" remark... but used LS7's sell at such a high dollar value that its not really worth it... to me anyway. The LS7's abilities have been so "over blown" that anyone who has one (that doesnt have a hole on it) think they have the goose that lays golden eggs.
Anyway... I'm outa here... just thought I'd share my experience.
KV
Anyway... I'm outa here... just thought I'd share my experience.
KV
05-02-2013, 11:39 PM
#368
Team Owner
DH
Last edited by Dirty Howie; 05-02-2013 at 11:41 PM.
05-03-2013, 12:17 AM
#369
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Correct. 2nd motor had 33K daily driving miles and 24 hours on the track. Guides were out of spec. Car did not exhibit unusual noise compared to first motor, burned no oil (except a little at on track days), and BlackStone was falling all over themselves saying how my motor was perfect. I also am very careful to get oil warmed up properly and keep it full. Plus I used Mobil1 0-40 on this motor. This was also a mid 2011 build.
DH
DH
Also that will help out the forum with the bronze results after running past 10k miles. mine are fine as far as a wiggle test goes after 22k. I'm getting ready to rebuild my transmisson next week while I'm at it I'm gonna pull the heads and get a bore gauge and get the real numbers. I'm dew for some new springs anyway I'll post up when I do
Last edited by z0sicktanner; 05-03-2013 at 12:23 AM.
05-03-2013, 01:09 AM
#370
Team Owner
Wow alot out of spec. that intake with .0052" I just got a set with .0056"on the intake side. the worst one was the exhaust side at .0141. guys that are running bronze guides ss valves or bronze and oem valves check your guides by 15k miles just to be sure.
Also that will help out the forum with the bronze results after running past 10k miles. mine are fine as far as a wiggle test goes after 22k. I'm getting ready to rebuild my transmisson next week while I'm at it I'm gonna pull the heads and get a bore gauge and get the real numbers. I'm dew for some new springs anyway I'll post up when I do
Also that will help out the forum with the bronze results after running past 10k miles. mine are fine as far as a wiggle test goes after 22k. I'm getting ready to rebuild my transmisson next week while I'm at it I'm gonna pull the heads and get a bore gauge and get the real numbers. I'm dew for some new springs anyway I'll post up when I do
I have 7K miles and 6 track hours on the WCCH. In 10 days I will be at the track. By the time I get home I will have 8K miles and 8 track hours. I stood in Richards shop 2 times and asked him when I should change the springs (I assumed I should on some kind of regular basis). Both times he looked me in the eye and said not to worry about it for at least 100K miles. And he knows I track it at least once a month. He even became a sponsor for our local Corvette Challenge.
I'm thinking he is not worried about my springs because I am running the stock CAM.
Whats your opinion ?
DH
05-03-2013, 02:26 AM
#371
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Chad
I have 7K miles and 6 track hours on the WCCH. In 10 days I will be at the track. By the time I get home I will have 8K miles and 8 track hours. I stood in Richards shop 2 times and asked him when I should change the springs (I assumed I should on some kind of regular basis). Both times he looked me in the eye and said not to worry about it for at least 100K miles. And he knows I track it at least once a month. He even became a sponsor for our local Corvette Challenge.
I'm thinking he is not worried about my springs because I am running the stock CAM.
Whats your opinion ?
DH
I have 7K miles and 6 track hours on the WCCH. In 10 days I will be at the track. By the time I get home I will have 8K miles and 8 track hours. I stood in Richards shop 2 times and asked him when I should change the springs (I assumed I should on some kind of regular basis). Both times he looked me in the eye and said not to worry about it for at least 100K miles. And he knows I track it at least once a month. He even became a sponsor for our local Corvette Challenge.
I'm thinking he is not worried about my springs because I am running the stock CAM.
Whats your opinion ?
DH
05-03-2013, 11:15 AM
#372
Race Director
Curiosity got the better of me; it's been over a decade since I drove the Glen, and that was the 1967 configuration:
in a 1967 Lotus 49:
I really don't recall anything about it -- not even the layout -- since I spent much more time at Monza and Spa. I did some checking and this is the closest approximation of the original course:
in a 1967 Lotus 49:
I really don't recall anything about it -- not even the layout -- since I spent much more time at Monza and Spa. I did some checking and this is the closest approximation of the original course:
Last edited by AzDave47; 05-06-2013 at 10:53 PM.
05-03-2013, 03:24 PM
#373
Team Owner
The cam has a lot to do with it yes. but if your tracking the car I would get new ones by 50k you can change them without taking the heads off so for me it's worth it just in case. Richard is right really they should be fine. then again I've seen some springs lose seat pressure in 20k miles. If I remember right richard uses the Brian Tooley springs not a 100% sure but he uses great parts
He says I'm good for 100K.
That doesn't mean I will wait that long
DH
05-06-2013, 10:45 PM
#375
Howie, your iron levels in your OA is a bit high. This is "normal" per blackstone for the LS7, but I wonder if it's those powdered metal (ferro-magnetic) exhaust guides before you did the heads...
My iron levels were always high (and read as normal per blackstone) and sho nuf, my exh valves were out of spec... If all the LS7's tested are track cars and eating their exhaust guides, they will all read high iron... That's my opinion, but my future OA's will tell for sure.
The OA's with only high iron were one reason I went for the wiggle test and then some.
My iron levels were always high (and read as normal per blackstone) and sho nuf, my exh valves were out of spec... If all the LS7's tested are track cars and eating their exhaust guides, they will all read high iron... That's my opinion, but my future OA's will tell for sure.
The OA's with only high iron were one reason I went for the wiggle test and then some.
05-07-2013, 12:57 AM
#376
Team Owner
Howie, your iron levels in your OA is a bit high. This is "normal" per blackstone for the LS7, but I wonder if it's those powdered metal (ferro-magnetic) exhaust guides before you did the heads...
My iron levels were always high (and read as normal per blackstone) and sho nuf, my exh valves were out of spec... If all the LS7's tested are track cars and eating their exhaust guides, they will all read high iron... That's my opinion, but my future OA's will tell for sure.
The OA's with only high iron were one reason I went for the wiggle test and then some.
My iron levels were always high (and read as normal per blackstone) and sho nuf, my exh valves were out of spec... If all the LS7's tested are track cars and eating their exhaust guides, they will all read high iron... That's my opinion, but my future OA's will tell for sure.
The OA's with only high iron were one reason I went for the wiggle test and then some.
DH
05-07-2013, 05:29 AM
#377
Burning Brakes
