Major timing chain stretch - 38K miles
01-06-2008, 08:21 PM
#1
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Major timing chain stretch - 38K miles
fyi,,,
In the process of a head/cam swap and just completed the tear down. I was pleased there was negligle wear and could still see the factory machined cross-hatch pattern in the cylinder walls.
However, I was shocked at how much stretch the stock timing chain had. There was so much slack, it was resting on the timing chain plastic guide between both gears. Luckily, I will be upgrading to a double roller (recognizing I will have to machine the back of the oil pump for clearance). Surely, I was not in jeopardy of having the chain jump a tooth, but in another 20K miles or so, who knows.
Again, just my experience.
As a minimum, I would recommend installing a new TC if swapping cams. Even better, upgrade to a stronger chain.
rick
In the process of a head/cam swap and just completed the tear down. I was pleased there was negligle wear and could still see the factory machined cross-hatch pattern in the cylinder walls.
However, I was shocked at how much stretch the stock timing chain had. There was so much slack, it was resting on the timing chain plastic guide between both gears. Luckily, I will be upgrading to a double roller (recognizing I will have to machine the back of the oil pump for clearance). Surely, I was not in jeopardy of having the chain jump a tooth, but in another 20K miles or so, who knows.
Again, just my experience.
As a minimum, I would recommend installing a new TC if swapping cams. Even better, upgrade to a stronger chain.
rick
Last edited by huskeric; 01-06-2008 at 08:21 PM. Reason: type
01-06-2008, 08:30 PM
#2
Race Director
LS2 I assume? I broke an LS2, now I have a double roller. But a friend of mine broke a double roller, so who knows what is best?
01-07-2008, 08:47 AM
#3
Melting Slicks
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St. Jude Donor '08-'09
How much damage did you do when you broke the chain? Does having the blower impart any more pressure on the chain?
01-07-2008, 09:03 AM
#4
Melting Slicks
fyi,,,
In the process of a head/cam swap and just completed the tear down. I was pleased there was negligle wear and could still see the factory machined cross-hatch pattern in the cylinder walls.
However, I was shocked at how much stretch the stock timing chain had. There was so much slack, it was resting on the timing chain plastic guide between both gears. Luckily, I will be upgrading to a double roller (recognizing I will have to machine the back of the oil pump for clearance). Surely, I was not in jeopardy of having the chain jump a tooth, but in another 20K miles or so, who knows.
Again, just my experience.
As a minimum, I would recommend installing a new TC if swapping cams. Even better, upgrade to a stronger chain.
rick
In the process of a head/cam swap and just completed the tear down. I was pleased there was negligle wear and could still see the factory machined cross-hatch pattern in the cylinder walls.
However, I was shocked at how much stretch the stock timing chain had. There was so much slack, it was resting on the timing chain plastic guide between both gears. Luckily, I will be upgrading to a double roller (recognizing I will have to machine the back of the oil pump for clearance). Surely, I was not in jeopardy of having the chain jump a tooth, but in another 20K miles or so, who knows.
Again, just my experience.
As a minimum, I would recommend installing a new TC if swapping cams. Even better, upgrade to a stronger chain.
rick
01-08-2008, 08:00 AM
#5
Righto. The chains look dangerously loose all the time unless you turn the motor and keep pressure on it. I was concerned when I did my motors but when asking soem experts found it to be normal. My brand new chain was the same way.
01-08-2008, 01:56 PM
#6
Former Vendor
Chain slack
FYI - the newer LS2 engines with the single bolt camshaft and the chain tensioner are designed to have more slack. That is why we recommend changing back to the timing chain guides when converting to an aftermarket camshaft on the single bolt engines because the tensioner is designed to have more slack in the system than the timing gear/chain/guide combination used in the earlier 3 bolt camshafts (so we don't recommend mixing the parts together).
