When Should Timing Chain Be Changed (L98)?
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From: OBAMA IS HITLER
When Should Timing Chain Be Changed (L98)?
At what mileage should this be replaced? Recommended sources? What other
items with the timing chain should be changed at the same time? Average labor hours to accomplish this? My engine is at 65k miles.
Also....how much more labor is involved with changing the cam at this point?
The cam thing is always in the back of my mind, but the labor hours must be a killer.
[Modified by bradvette, 4:19 PM 10/16/2003]
items with the timing chain should be changed at the same time? Average labor hours to accomplish this? My engine is at 65k miles.
Also....how much more labor is involved with changing the cam at this point?
The cam thing is always in the back of my mind, but the labor hours must be a killer.
[Modified by bradvette, 4:19 PM 10/16/2003]
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From: Loudon, TN
Re: When Should Timing Chain Be Changed (L98)? (bradvette)
Not saying there isn't one but I've never read about or heard of one. Now if for some reason you had to pull off the timing cover to replace the seals then you might consider it, but timing chains don't wear out as fast as timing belts. They can go for thousands of miles before they are worn out and by that time the engine is ready for rebuild anyway.
As far as time to do the job, who is doing the job? If a mechanic is doing it just call a shop and find out what the flat rate manual says because that is how much time they will charge you for, not how long it takes them. Most mechanics can do a job in much less time than what the manual says. If I was doing it, probably most of the day because I am slow and meticulous or slow and old, I forget which.
Changing the cam will require you to remove the intake manifold in addition to everything it takes to remove the timing chain.
The wife always asks how long do I think it will take me to do something on the car and whenever I quote a number of hours it invariably takes twice that because of unforseen problems. In all honesty it would problably take me a weekend to change the chain and cam. For a novice, probably a lot longer.
As far as time to do the job, who is doing the job? If a mechanic is doing it just call a shop and find out what the flat rate manual says because that is how much time they will charge you for, not how long it takes them. Most mechanics can do a job in much less time than what the manual says. If I was doing it, probably most of the day because I am slow and meticulous or slow and old, I forget which.
Changing the cam will require you to remove the intake manifold in addition to everything it takes to remove the timing chain.
The wife always asks how long do I think it will take me to do something on the car and whenever I quote a number of hours it invariably takes twice that because of unforseen problems. In all honesty it would problably take me a weekend to change the chain and cam. For a novice, probably a lot longer.
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Re: When Should Timing Chain Be Changed (L98)? (bradvette)
I would definitely change it if i changed the cam. Probably one of those things that never really must be replaced on an engine, but that eventually goes out with enough mileage, like 100-150K. I dont recall the name of the most popular chain, starts with a C?
You gotta talk to Scorp about how long it takes to do it.
You gotta talk to Scorp about how long it takes to do it.
Drifting
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From: Norcross GA
Re: When Should Timing Chain Be Changed (L98)? (bradvette)
:nonod: Do you want it to run, or run strong?
The chain generally doesn't break,... they wear down to the point where the engine gets tired. At the extreme's it can start to backfire.
The wear depends mostly on the oil maintenance.
Is it worn,... it is a visual thing. You could take a few measures,... but it still easier to just pull the cover and have a look. ANY slack in the chain will have an effect on power output. The HEI is at the tail end of the mech slack in the engine. i.e. proper spark control = max power Slack in chain, slack in gears = bouncing spark timing. Ka-pe-sh?
A decent replacement for the $,... Cloyes double roller,... street version. Set it up on the advanced keyway to compensate for chain stretch.
The chain generally doesn't break,... they wear down to the point where the engine gets tired. At the extreme's it can start to backfire.
The wear depends mostly on the oil maintenance.
Is it worn,... it is a visual thing. You could take a few measures,... but it still easier to just pull the cover and have a look. ANY slack in the chain will have an effect on power output. The HEI is at the tail end of the mech slack in the engine. i.e. proper spark control = max power Slack in chain, slack in gears = bouncing spark timing. Ka-pe-sh?
A decent replacement for the $,... Cloyes double roller,... street version. Set it up on the advanced keyway to compensate for chain stretch.
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From: OBAMA IS HITLER
Re: When Should Timing Chain Be Changed (ZylaRace)
Thanks guys. Nothing seems tired at all on my engine, in fact quite the contrary. I guess I'm still just used to timimg belts, which was on every car I ever owned until the vette. Then when the timing belt goes, you have engine damage. Great to hear the chain lasts so long. Look like if I ever decide to install a higher performance cam, I would also get a new Cloyes double roller timing chain, as per the recommendation. :cheers:
Burning Brakes
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From: Camden SC
Re: When Should Timing Chain Be Changed (bradvette)
Not every belt driven engine will cause mechanical damage.
I believe Gates or Goodyear has a web site where you can look up engines and tell if it's an "interference" (sp) engine. Smaller overhead cam engines tend to have problems with piston to valve clearnace when belts fail. Ugly.
A stock 350 should not be a problem.
Wouldn't change anything till you have a problem, change the cam, or doing work where you suddenly have major access to the timing cover. 70K miles or so, I'd probably leave it alone.
Drive on.
dlmeyers 90 coupe zf6 3 speed shocks
I believe Gates or Goodyear has a web site where you can look up engines and tell if it's an "interference" (sp) engine. Smaller overhead cam engines tend to have problems with piston to valve clearnace when belts fail. Ugly.
A stock 350 should not be a problem.
Wouldn't change anything till you have a problem, change the cam, or doing work where you suddenly have major access to the timing cover. 70K miles or so, I'd probably leave it alone.
Drive on.
dlmeyers 90 coupe zf6 3 speed shocks
