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Discussion Starter · #1 ·
how many miles will a timing chain last?
when should it be replaced?

Jeff 280ZXT
 

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Re: how many miles tell you replace your timing ch

I was told 30,000 miles is a good time to change it. But I've talked to people that have told me they have over 100,000 on their cars or truck and have never done anything but have the oil changed. I think my wifes oldsmobile say 30,000 in the maintance schedule that came with it.
Hope this helps
Rob,
 

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Re: how many miles tell you replace your timing ch

> how many miles will a timing chain last?
> when should it be replaced?

> Jeff 280ZXT

I think they will last a very long time, 100,000+ if the engine is properly maintained and not abused (it's a double chain), but will stretch over time, which I think is why the timing gear on the cam has 3 adjustable positions to help pick up the slack.

Steve G
 

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Re: how many miles tell you replace your timing ch

In my experience, the cam sprocket has three positions to give you flexibility when degreeing your cam. I've seen some aftermarket sprockets for the Z with many more than 3 holes.

Chris
 

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Re: how many miles tell you replace your timing ch

> I was told 30,000 miles is a good time to
> change it. But I've talked to people that
> have told me they have over 100,000 on their
> cars or truck and have never done anything
> but have the oil changed. I think my wifes
> oldsmobile say 30,000 in the maintance
> schedule that came with it.
> Hope this helps
> Rob,

I would guess that 30,000 mile number is for timing BELTS.. and that's the lowest number I've heard. Usually 45K or even 60K is fine, but the higher you go the more you risk breaking it. (very bad!)

Timing CHAINS last much longer. I'm not sure when the Z's might have switched over to belts.. most newer cars have them.
 

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Discussion Starter · #6 ·
Re: how many miles tell you replace your timing ch

Timing belts I know its ever 70K because my whole fam has jap cars with belts=) Im the only one with a chain I know the chain last longer
 

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Re: how many miles tell you replace your timing ch

> how many miles will a timing chain last?
> when should it be replaced?

> Jeff 280ZXT
DONT SWEAT IT!!!! Man, if you dont have a Quarter of a million miles on your motor, you dont need a chain, you can take up the slack twice with the holes in the cam sprocket, but unless you race or abuse your Z, they will last a long long time.
 

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Discussion Starter · #8 ·
Re: how many miles tell you replace your timing ch

I did not think it needed to be changed for atlest 150K but I was not sure
thanks
 

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Oops, My mistake, I was thinking belts. N/C

N/C
> I would guess that 30,000 mile number is for
> timing BELTS.. and that's the lowest number
> I've heard. Usually 45K or even 60K is fine,
> but the higher you go the more you risk
> breaking it. (very bad!)

> Timing CHAINS last much longer. I'm not sure
> when the Z's might have switched over to
> belts.. most newer cars have them.
 

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What does degreeing the cam do?

> In my experience, the cam sprocket has three
> positions to give you flexibility when
> degreeing your cam. I've seen some
> aftermarket sprockets for the Z with many
> more than 3 holes.

> Chris

That's an interesting side effect, but I'm pretty sure the holes are for picking up the slack of a stretched chain. On that subject though: What effect does degreeing the cam have and what is the difference between that and just changing the distributor timing?
 

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Re: What does degreeing the cam do?

> That's an interesting side effect, but I'm
> pretty sure the holes are for picking up the
> slack of a stretched chain. On that subject
> though: What effect does degreeing the cam
> have and what is the difference between that
> and just changing the distributor timing?

Degreeing the cam (in the chevy world) is used to make sure that the valves are opening and closing when the spec sheet says it should. Since manufacture of a precision peice such as a cam can result in differences between cams, degreeing is used to bring the cam into spec (if it needs it). One thousands at the cam sprocket equals a half of degree of cam timing (if I remember correct) Also degreeing can be used as a tuning aid. Advancing the cam tends to shift the power band to the lower end, producing more power down at lower RPMs. The opposite is true as well. Be careful though, nothing is free, what you put at the bottom, you take from the top, and vise versa. Fiddling with cam timing is usually a band aid for poor cam selection, at least in the Drag Racing world. Pick the right cam, set it straight up according to the spec sheet that came with the cam, and button it up, and forget it.

2 cents worth, hope it helps

Ken
 

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Re: how many miles tell you replace your timing ch

> I did not think it needed to be changed for
> atlest 150K but I was not sure
> thanks
I've got 210K and no problems on my 83zxt. hmmmm, maybe I should be asking this question.
 
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