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Do I really need machine work? *DELETED*

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Old 08-28-2003, 08:02 AM
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Old 08-28-2003, 09:21 AM
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Default Re: Do I really need machine work?

perhaps the knocking noise is the common piston slap that many have discussed here...

GM designed the LS1 with a flaw ...the ring design sux .....it was recently redesigned to incorporate a new design for the pitons/rings...

I would try to confirm that this is the issue before any major work is performed.......
Old 08-28-2003, 09:29 AM
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Old 08-28-2003, 10:04 AM
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Default Re: Do I really need machine work?

You don't want to install this engine without identifying the issue.

take it apart and measure all clearances...

also it might be a lifter....cracked block, cam bearing failure, etc...

e-mail me if you need a spec sheet on the engine that gives factory clearances...

robertbartsch@kpmg.com
Old 08-28-2003, 06:38 PM
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Default Re: Do I really need machine work?

It's a good chance to do some basic upgrades too like better rod bolts & rings etc too.
Old 08-28-2003, 06:48 PM
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Default Re: Do I really need machine work?

If it were me, I would have a good machine shop go over all of the parts. I would make sure they take the piston pins out and check them also - could have been a wrist pin and since they are pressed in, you can't see them.

Then have them rebuild it with at least new bearings, rings, ARP rod bolts, and any other goodies you can afford (cam and springs, etc).

Are there any marks on the tops of the pistons or in the heads? I have heard of rare cases of knocking from things being ingested into the motor.
Old 08-28-2003, 11:11 PM
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Old 08-29-2003, 12:07 AM
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Default Re: Do I really need machine work?

You want to be careful. At my GM dealership, we have done a few LS1 motor swaps due to knocking. In additon to the piston slap, we have found that the teflon coating on the pistons wears off and causes the cylinder walls to be scored so badly that it needs to be resleeved. Take off the heads and inspect the cylinder walls. PM me if you need more info. I have one of these warrantied engines in my garage.

BTW, it is for sale... ;P
Old 08-29-2003, 07:07 AM
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Default Re: Do I really need machine work?

Definitely inspect everything while it's out of the car and easy to do. Don't be swayed by the power of denial because all the parts are so shiny!

The last thing you want to do is have to pull this engine back out because you did not identify the problem.

Good luck.

Tommy
Old 08-29-2003, 10:46 AM
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Default Re: Do I really need machine work?

Hey it knocked for a reason.

I would definitely check the wrist pins I have a buddy who had a bent one and the motor knocked.
Old 08-29-2003, 04:01 PM
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Default Re: Do I really need machine work?

Off to the machine shop it goes...with a scant 500 miles on it....
Don't feel bad - happened to me with a brand new motor too, but due to someone else's negligence. I couldn't prove it, so a brand new LS6 with less than 1,000 miles had to be completely rebuilt on my nickel!

It's much better this time around! Trust me it is best to get it all gone over and everything checked.
Old 09-02-2003, 08:29 AM
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Default Re: Do I really need machine work?

Hey Black02:
Are u the one that was told your new ls6 engine destroyed itself as a result of knocking that was purportedly caused by a stock LS1 engine management tune (e.g., a LS1 PCM)?

...So you re-built the new engine?

Please provide a status report...
Thanks...
Old 09-02-2003, 07:30 PM
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Default Re: Do I really need machine work?

You want to be careful. At my GM dealership, we have done a few LS1 motor swaps due to knocking. In additon to the piston slap, we have found that the teflon coating on the pistons wears off and causes the cylinder walls to be scored so badly that it needs to be resleeved. Take off the heads and inspect the cylinder walls. PM me if you need more info. I have one of these warrantied engines in my garage.

BTW, it is for sale... ;P
Can you tell me specifically what is causing piston slap on most LS1's? Mine suffers from it and i want to know what exactly is hurt or flawed causing this? Thanks
Old 09-02-2003, 07:51 PM
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Default Re: Do I really need machine work?

Hey Black02:
Are u the one that was told your new ls6 engine destroyed itself as a result of knocking that was purportedly caused by a stock LS1 engine management tune (e.g., a LS1 PCM)?

...So you re-built the new engine?

Please provide a status report...
Thanks...

Yep, that's me - The engine is in and running great!

Got it tuned with LS1 Edit this time around - we are headed to the dyno tomorrow to fine tune and see what it will turn.

Track times coming soon too! Ran it once, but we hadn't raised the shift points - it was shifting at 5,800. Also it didn't have Torque management deleted and it is running rich. Ran 12.92 @ 109 in the heat like that. Should be in the 12.60's next time out.

LTs kill the bottom end torque, so with no convertor, it isn't gonna run any super times. All in good time (and budget)! My goal is to run consistent 12.00s.
Old 09-03-2003, 02:44 PM
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Default Re: Do I really need machine work?

Black02:
Great news. can you tell us how the rebuild was done? ...just new bearings, forged pistons, forged rods, rings, valve job,

...exactly what was done?

Old 09-03-2003, 08:44 PM
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Default Re: Do I really need machine work?

Black02:
Great news. can you tell us how the rebuild was done? ...just new bearings, forged pistons, forged rods, rings, valve job,

...exactly what was done?


Block align honed and bores honed .003
ARP main and head studs
Lunati NHRA stock class forged pistons
Manley forged rods
Clevite racing bearings
Comp Cams lifters
Plasma Moly file-fit rings
heads shaved .012
Cometic .054 head gaskets

I think that covers it!

By the way - just dynoed 360HP/355ft-lbs at a dyno that is generally 10 under most other dynos.

I'm very happy with that. I'll let you know how it goes at the track Friday night.
Old 09-04-2003, 10:24 AM
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Default Re: Do I really need machine work?

Blacko2
....so the head has basically not hurt by the knock condition ....I assume you are running the stock ls6 cam; right?
Old 09-04-2003, 03:11 PM
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Default Re: Do I really need machine work?

Blacko2
....so the head has basically not hurt by the knock condition ....I assume you are running the stock ls6 cam; right?
The heads were damaged - that's why the .012 shave and some hand work on the chambers to clean them up - they weren't bad, but needed a little work.

I am running the stock LS6 cam - it does the job for what I want for the next few years.

I want to stay below a 12.00 for now - no rollbar till the daughter has her own car and doesn't need the back seat!

After that I'll be going with a direct port system and a more N20 friendly cam!

Sorry to hijack the post...
Old 09-04-2003, 06:39 PM
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Default Re: Do I really need machine work?

Here is a very simple question that hasn't been asked.... How was the oil pressure? I perfectly good engine will knock without oil pressure. 98's and 99's are very well known for this.
Old 09-04-2003, 07:46 PM
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Default Re: Do I really need machine work?

Here is a very simple question that hasn't been asked.... How was the oil pressure? I perfectly good engine will knock without oil pressure. 98's and 99's are very well known for this.
Had nothing to do with it.




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