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How do I adjust my chain stretch?


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I've found lots of guides on this, but none of them are very specific as to what you turn to advance the camshaft.

 

At this point, all I've found is you wedge the chain, take off sprocket, and then that's where I'm confused.

 

What do you turn to adjust?

 

I assumed I would rotate the cam with sprocket off, but when I try going from hole #1 to hole #2, a valve just about goes into a piston on cylinder #6 before it can get to #2.

 

Do I just rotate the sprocket itself without rotating the cam or crank?

 

This is of course all at TDC, verified by distributor and with the head off(I set TDC before taking head off).

 

Might be a simple answer, but I rather ask than try it myself and break something.

 

Thanks,

Edited by Milenko2121
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Sounds like your rotating the crankshaft, sprocket and chain as one, after pulling the sprocket off of the camshaft

 

Take the chain off of the sprocket, rotate the sprocket to the desired hole position independently of anything else moving, put the chain back on the sprocket, carefully turn the camshaft the 4 degrees or so necessary to get the sprocket to line up on the dowel and put it back on.  Start the whole operation with the timing mark at zero (#1 piston at TDC) and don't rotate the crankshaft at all.

 

 

Don't forget to make sure that you're turning the engine the proper way also, when you check for chain stretch.  If you turn it backward your marks won't line up right.

Edited by NewZed
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The cam remains relatively stationary. You have the bright link lined up with 1, currently. You slip the chain off and line up the bright link with 2 or 3, then move the cam SLIGHTLY to line up with the new hole. We're talking maybe 5degrees of movement if that.

 

The only thing that moves is the cam sprocket inside the chain. Sometimes you can slip the sprocket back onto the cam and it slips into the new hole without turning the cam whatsoever (but that slack cha in is now tight....

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Hmm, well this is odd.

 

I had my wedge in the chain like always, and I took off the sprocket, turned it to #2 and put it back on but...

 

Now the timing chain is rediculously tight, there is 0 slack whatsoever, and when the engine is running it's making a horrible whining noise.

 

Could I get some insight on this, and how to correct the problem? I'm scared to drive the car in fear the timing chain will break.

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Hmm, editor isn't working.

 

I just took off the valve cover to check it again, and it has about half inch of deflection with my finger and an inch if I wedge a wrench in there.

 

The whining noise I assume is it eating away the chain guides.

 

Still worried about this thing though.

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"I took off the sprocket, turned it to #2 and put it back on but... Now the timing chain is rediculously tight, there is 0 slack whatsoever, and when the engine is running it's making a horrible whining noise."

 

Maybe it's not as 'stretched' as you think?

 

Uh, did you CHECK THE STRETCH INDICATOR????????? It's NOT checked with your finger, it's not checked with a wrench. 

 

Do you have the  Factory Service Manual? If not, GET ONE and READ IT!

 

If your timing chain stretch indicator doesn't indicate it's stretched, you are merely change valve timing for higher rpm power peak. It's compensating for the stretch by altering valve events so they occur in proper sequence relative to the crankshaft position, IT DOES NOT TIGHTEN  THE CHAIN! If you got a tight chain...my bet is your chain tensioner popped out and now you are grinding things up inside. Time to pull the front cover and find out!

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If your timing chain stretch indicator doesn't indicate it's stretched, you are merely change valve timing for higher rpm power peak.

 

One correction: advancing the cam (as he's doing) moves the power peak to a lower rpm.

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A stretched chain retards timing by moving the dot as indicated it restores proper valve timing. Exactly as I stated.

 

Remember all the experts tell you to "start at three on that performance rebuild!"

 

Chain TENSION is not addressed in this manner...which was kinda my point from the Get-Go!

 

It's so wrong, adding to the wrongness is part of the fun...

 

It's summertime.

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A stretched chain retards timing by moving the dot as indicated it restores proper valve timing. Exactly as I stated.

 

Remember all the experts tell you to "start at three on that performance rebuild!"

 

Chain TENSION is not addressed in this manner...which was kinda my point from the Get-Go!

 

It's so wrong, adding to the wrongness is part of the fun...

 

It's summertime.

 

A stretched chain retards timing (moves powerband UP) and going to #2 or #3 advances the cam (moves powerband down). If his chain wasn't actually stretched enough to noticeably retard cam timing, he is advancing the cam and dropping his powerband by going to the #2 hole. Hence my correction, as I agree with everything else... ;)

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I forgot the second set of quotes, my sarcasm was entirely lost. Let me try that again:

 

Remember, all the "experts" tell you to "start at three on that performance rebuild!"

 

Make more sense now? It does jibe exactly with what you're saying. I'm now off to help Uncle jack off a horse.

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I forgot the second set of quotes, my sarcasm was entirely lost. Let me try that again:

 

Remember, all the "experts" tell you to "start at three on that performance rebuild!"

 

Make more sense now? It does jibe exactly with what you're saying. I'm now off to help Uncle jack off a horse.

 

That comment does make more sense now. However, the original one I was correcting has not been clarified! :P

 

If your timing chain stretch indicator doesn't indicate it's stretched, you are merely change valve timing for higher rpm power peak. It's compensating for the stretch by altering valve events so they occur in proper sequence relative to the crankshaft position, IT DOES NOT TIGHTEN  THE CHAIN! If you got a tight chain...my bet is your chain tensioner popped out and now you are grinding things up inside. Time to pull the front cover and find out!

 

By putting the sprocket into the #2 hole, he is altering valve timing for a lower rpm power peak. I don't know how many times I need to repeat myself. Unless I'm somehow misunderstanding what you meant by that...

Edited by Leon
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That was foreshadowing the setup for the "experts" comment I was preparing suspense!

 

My sarcasm runs DEEP...

I must let it fester somewhat then let it bubble out in little drabs...

 

I thought "everyone" knew to put the timing sprocket at "3" for a performance rebuild that has "high rpm" performance?

 

To clarify a context, I was railed against by self-proclaimed experts on their post setup on a "performance" build that stated "timing chain set in #3".... They were so convincing with their dyno pull of 145, and 1/4 mile time of 16.75 That there was just NO WAY my stock "set at #1 shifted at 6500 89mph 15.50 time slip 225,000 mile stocker could be stock." After spending close to $15,000 the kid may even have eventually surpassed my time by a few 10th... But it convinced me that "they" must all be right and I was wrong so contrary to what people think I corrected my "wrong" statements afterwards... (Not that I didn't keep things in #1, mind you...or suggest that if people want cam timing adjustment the get a TOMEI sprocket since the stocker only allows adjustment one way...)

 

Can you tell which is sarcasm, and which statements a re sincere?

Edited by Tony D
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A stretched chain retards timing by moving the dot as indicated it restores proper valve timing. Exactly as I stated.

Remember all the experts tell you to "start at three on that performance rebuild!"

Chain TENSION is not addressed in this manner...which was kinda my point from the Get-Go!

It's so wrong, adding to the wrongness is part of the fun...

It's summertime.

Note in the next post, we are both saying the EXACT same thing, and I stayed consistent with the contention that dot swap page only changes timing not repair stretch.

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