Timing Chain FINAL Diagnosis, Need Comments
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 7,248
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Timing Chain FINAL Diagnosis, Need Comments
Welll.... The Final Diagnosis was...
BROKEN CHAIN! ;)
Putting my Cloyes Gears & Jwis SS Chain on tomorrow. Also going to replace the Cam Sprocket bolts with NEW ones. No damage to cam or cam bolts I believe.
My mechanic said he used some type of magnet to get all the chain pieces out. He said he got all of them and none went thru the oil pump or anything, dunno if it's even possible for chain pieces to go anywhere.. I may get the broken chain & pieces tomorrow and have pics if he hasn't thrown it out.
Question!
Other than a Compression Test on all Cylinders, is there anything else I should do? If I get lucky and they all come out good at 200psi or so, am I in the clear? What else should I inspect?
Should I take the valve covers off? Inspect all pushrods? Test spring seat pressure? What needs to be done to give her an A-OK bill of health?
Thx,
[Modified by MelloYellow, 9:04 PM 8/3/2001]
BROKEN CHAIN! ;)
Putting my Cloyes Gears & Jwis SS Chain on tomorrow. Also going to replace the Cam Sprocket bolts with NEW ones. No damage to cam or cam bolts I believe.
My mechanic said he used some type of magnet to get all the chain pieces out. He said he got all of them and none went thru the oil pump or anything, dunno if it's even possible for chain pieces to go anywhere.. I may get the broken chain & pieces tomorrow and have pics if he hasn't thrown it out.
Question!
Other than a Compression Test on all Cylinders, is there anything else I should do? If I get lucky and they all come out good at 200psi or so, am I in the clear? What else should I inspect?
Should I take the valve covers off? Inspect all pushrods? Test spring seat pressure? What needs to be done to give her an A-OK bill of health?
Thx,
[Modified by MelloYellow, 9:04 PM 8/3/2001]
Team Owner
Joined: Apr 2001
Posts: 26,794
Likes: 614
From: Elmhurst, IL (West Suburb of Chicago) & Home of MEGA Horsepower
St. Jude Donor '06
Re: Timing Chain FINAL Diagnosis, Need Comments (MelloYellow)
Your intial diagnosis was right on from the beginning. Unfortunatley I don't have any technical advice to give you as this isin't my strong area. I did however want to wish your C5 a speedy and as painless recovery as possible and so far sounds like your off to a good start considering the POS stock chain crapped out on you, just when you were ironically concerned and very vocal about upgrading timing chains (and are the reason I upgraded to the C5 R Racing chain when I did my heads and cam 2k miles ago.
By the way I have a similar set up to you other than having a C5 and wanted to ask you whether it is worth the $ to upgrade to the same highflow cats that you have. What type of cats exactly did you have and where I can get them and for how much $. Can you really feel the difference with the low end torque.
Thanks man and good luck,
Nitrovette
[Modified by Nitrovette, 9:41 PM 8/3/2001]
By the way I have a similar set up to you other than having a C5 and wanted to ask you whether it is worth the $ to upgrade to the same highflow cats that you have. What type of cats exactly did you have and where I can get them and for how much $. Can you really feel the difference with the low end torque.
Thanks man and good luck,
Nitrovette
[Modified by Nitrovette, 9:41 PM 8/3/2001]
Melting Slicks
Joined: Aug 2000
Posts: 2,248
Likes: 1
From: Newland US
Re: Timing Chain FINAL Diagnosis, Need Comments (MelloYellow)
MelloYellow,
Sounds like you were pretty lucky. Personally, I'd pull the covers and check the push rods. If none are bent.....that would be great. If you find any that are bent, then it would be a good idea to check for bent valves associated with those push rods.
On the older small block Chevy, pieces of the chain or sprockets could get in the pan and from your mechanic's comment, this is still possible on the LS1. Guess you'll have to trust your tech if he says he is sure that he got all the pieces out.
I was pretty sure the chain gave up the ghost when you said the starter just, "whirred", but I really thought you would get some valve or piston damage.
Sounds great.
Good luck.
Mark
Sounds like you were pretty lucky. Personally, I'd pull the covers and check the push rods. If none are bent.....that would be great. If you find any that are bent, then it would be a good idea to check for bent valves associated with those push rods.
On the older small block Chevy, pieces of the chain or sprockets could get in the pan and from your mechanic's comment, this is still possible on the LS1. Guess you'll have to trust your tech if he says he is sure that he got all the pieces out.
I was pretty sure the chain gave up the ghost when you said the starter just, "whirred", but I really thought you would get some valve or piston damage.
Sounds great.
Good luck.
Mark
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 7,248
Likes: 0
Re: Timing Chain FINAL Diagnosis, Need Comments (Nitrovette)
Thx Nitro:
I have the C&L 2.5" SD Cats. Depends. What is your mod list? RWHP? Cat-Back setup? Headers?
I would do it again, but can't confirm any positive results since I didn't do a before & after. SOTP I'd recc it for any H/C car.
Heya MDT,
No word on the valves yet. Pistons I'm not real worried about. They'll be gone soon enuff. Ya, I should check the pushrods. Will ask my mech.
[Modified by MelloYellow, 9:57 PM 8/3/2001]
I have the C&L 2.5" SD Cats. Depends. What is your mod list? RWHP? Cat-Back setup? Headers?
I would do it again, but can't confirm any positive results since I didn't do a before & after. SOTP I'd recc it for any H/C car.
Heya MDT,
No word on the valves yet. Pistons I'm not real worried about. They'll be gone soon enuff. Ya, I should check the pushrods. Will ask my mech.
[Modified by MelloYellow, 9:57 PM 8/3/2001]
Burning Brakes
Joined: Oct 2000
Posts: 1,094
Likes: 2
From: Seattle suburb wa
Re: Timing Chain FINAL Diagnosis, Need Comments (MelloYellow)
your engine needs to be rebuilt.
you will have pieces of metal in the oil pan.
you need the bare block triple washed.
you have (some) bent pushrods.
you very likely have at least one if not 4 bent valves.
very likely you have some minor piston top damage.
I wouldn't cheap out at this point..
David
"been there done that"
you will have pieces of metal in the oil pan.
you need the bare block triple washed.
you have (some) bent pushrods.
you very likely have at least one if not 4 bent valves.
very likely you have some minor piston top damage.
I wouldn't cheap out at this point..
David
"been there done that"
Thread Starter
Le Mans Master
Joined: Apr 2000
Posts: 7,248
Likes: 0
Re: Timing Chain FINAL Diagnosis, Need Comments (no cure)
Heya no cure:
We've talked. You know I'm switching to an All-Bore setup. New block. New pushrods, etc... I have no desire to incur extra labor at $50-$100 an hour. I'll let a tuner build the new engine and tear down the core on return. 4 bent valves, I expect you are right. I think the compression test will tell. I hear no mechanical noise when the chain went. The compression should answer that. I've driven with less than optimal compression and that should save me $1 grand a month which I'd rather spend on my new engine. Pistons are being scrapped anyhow when the new engine arrives. I doubt they have anything more than small eyebrows. I have a pic of my old eyebrow the size of a pencil lead when a CC941 broke. I may get lucky. We'll find out tomorrow or Monday. Others have broken chains with minimal damage. We'll know soon enough. The professional tuners expect minimal damage that I've talked to.
We've talked. You know I'm switching to an All-Bore setup. New block. New pushrods, etc... I have no desire to incur extra labor at $50-$100 an hour. I'll let a tuner build the new engine and tear down the core on return. 4 bent valves, I expect you are right. I think the compression test will tell. I hear no mechanical noise when the chain went. The compression should answer that. I've driven with less than optimal compression and that should save me $1 grand a month which I'd rather spend on my new engine. Pistons are being scrapped anyhow when the new engine arrives. I doubt they have anything more than small eyebrows. I have a pic of my old eyebrow the size of a pencil lead when a CC941 broke. I may get lucky. We'll find out tomorrow or Monday. Others have broken chains with minimal damage. We'll know soon enough. The professional tuners expect minimal damage that I've talked to.
