Hurt the LT1: Video inside
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Hurt the LT1: Video inside Took the car to the track tonight and hurt it. On my second pass it did not shift into second and hit 7k or so RPM. I ended up going 7.92@82 mph... the car usually traps 88-89mph.
Anyhow, there was alot of chatter under the passanger valve cover so I figured I broke a 918, rocker or pulled a stud. Well i got the cover off to find everything okay! I just cant figure out what the noise is... I am wondering if I could have floated a valve and possibly had some contact. The car runs fine, it does not skip or miss... I just have this strang noise.
Any thoughts on what it might be?? The car has a cc306 (230/244 .544/.576) Comp roller tips (1.6) and SRP 11:1 flat tops with -5cc reliefs. Seems like I would have a ton of room, even with the impala gaskets. I hope it's not a bearing... I know it doesnt sound like it, but who knows at this point. I need to hook my pressure gauge and verify the psi. Although it is gettin oil up top just fine.
I also only ran 5qts vs running an extra qt to prevent starvation upon launch, but I only cut a 1.81 60' so I doubt that was an issue.
http://www.youtube.com/watch?v=uuLkhZVQacs
Anyhow, there was alot of chatter under the passanger valve cover so I figured I broke a 918, rocker or pulled a stud. Well i got the cover off to find everything okay! I just cant figure out what the noise is... I am wondering if I could have floated a valve and possibly had some contact. The car runs fine, it does not skip or miss... I just have this strang noise.
Any thoughts on what it might be?? The car has a cc306 (230/244 .544/.576) Comp roller tips (1.6) and SRP 11:1 flat tops with -5cc reliefs. Seems like I would have a ton of room, even with the impala gaskets. I hope it's not a bearing... I know it doesnt sound like it, but who knows at this point. I need to hook my pressure gauge and verify the psi. Although it is gettin oil up top just fine.
I also only ran 5qts vs running an extra qt to prevent starvation upon launch, but I only cut a 1.81 60' so I doubt that was an issue.
http://www.youtube.com/watch?v=uuLkhZVQacs
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Not yet, I pulled the dip stick and didn't see anything on it though. It sounds like it's coming from the rear cylinder... doesn't sound like a bearing at all, but you never know. The bottom end is fresh still... it has maybe 5k miles on it at most. New clevites, turned crank and all arp hardware.
Not yet, I pulled the dip stick and didn't see anything on it though. It sounds like it's coming from the rear cylinder... doesn't sound like a bearing at all, but you never know. The bottom end is fresh still... it has maybe 5k miles on it at most. New clevites, turned crank and all arp hardware.
If something's wearing, you'll find it in the oil and/or filter.
Might be able to save something or at least gain some peace of mind.
Certainly does sound noisier than it should be.
But if the springs are not broken, pushrods look strait and the engine is running
well, it's tough to tell what might be causing it without a leak-down test or a scope.
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Yeeaaah... I am HOPING it's not the bottom end, because I will not be going back with an LT1... thats for sure. I have built two of them and I am just about tired of it. I have been DDing the car since june without any issue and now this. Granted it wouldn't cost much to replace the bearings and have the crank cut/polished, I just don't feel like pulling the motor for a third time.
Sounds like it's coming from the valvetrain. Do a compression check and definately keep a eye on the oil. Get a stethoscope or a screwdriver and put it on each rocker and listen for any odd sound.
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its getting oil up top, you can see it spray on the cardboard... which is why I put it there. I assume the oil PSI is fine, but anything is possible at this point.
I just cant figure it out because the springs are fine, the rockers dont seem to be broken, it doesnt sound like a lifter and the noise is only on one side.
I just cant figure it out because the springs are fine, the rockers dont seem to be broken, it doesnt sound like a lifter and the noise is only on one side.
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I have never heard a gasket sound that way, but I just went out and checked and the rear header bolt is gone and I noticed the trans case is touching the primary (new case when built). This could be making that noise... but I don't know why it would be an issue after making this pass... seems like it would have shown up before hand.
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Thanks! I appreciate it... lets just hope its something small... I am hoping its a header gasket... but it just doesnt add up as to why the noise would appear after the pass where it hung up around 7k for a second or so. I bumped into neutral right away. As I said, the car does not skip or anything. The only thing I dont know at this point is the oil psi.
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Found a similar sound in another video on youtube... give me some hope
http://www.youtube.com/watch?v=tsWz4s4vrMM
http://www.youtube.com/watch?v=tsWz4s4vrMM