| Author |
Message |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1894
Registered: 11-2002
| | Posted on Sunday, July 06, 2003 - 6:18 pm: | |
>>then cranking the engine for a turn or two to set the tension. Doe's that sound factual?>>
Well that's the procedure if the covers are off and you can check the tension by hand (tool).
If the covers are on the chain is tensioned by sound. Tighten until chain whines, then back off until the sound normalizes. |
Bill Steele (Glassman)
Member
Username: Glassman
Post Number: 293
Registered: 4-2002
| | Posted on Sunday, July 06, 2003 - 5:49 pm: | |
Didn't mean to start a fight there guy's but thanks for the input for what now seems very logical and a stupid question to begin with.
Now tell me, I have located the timing chain tensioner assembly. There is a large nut that is tight against the housing, with a longer bolt with a square end on it. How do I properly adjust the tension? I am assuming that the bolt will not be able to be turned by hand? If you use a wrench how do you know when it is tight enough?
The manuals I have are very vague, and there is a comment about loosening the nut, tightening the bolt, and then cranking the engine for a turn or two to set the tension. Doe's that sound factual? |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1878
Registered: 11-2002
| | Posted on Sunday, July 06, 2003 - 12:21 am: | |
>>doesn't adjust cam timing other than in the context of properly tensioned vs. loose chain.<<
That context being, timing can't be properly set with a loose chain.
However, if timing was set with a properly tensioned chain, then timing will be inaccurate with a loose chain. How inaccurate depends on how loose the chain is.
But imo the far worse problem with a loose chain, than timing, is the fact all the flopping around is causing further stretching and gear wear and can even chew into the aluminum of the front cover, allowing all those extra metal filings into the oil/sump/engine.
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Mike Dawson (Miked)
Junior Member
Username: Miked
Post Number: 111
Registered: 2-2001
| | Posted on Saturday, July 05, 2003 - 11:45 pm: | |
Actually the cam timing does change as the chain wears. The chain increases in length as the pins and links wear which means that the cam position (relative to the crankshaft) will retard over time.
The linear distance for any specific number of chain links will increase due to the wear and because the crank and cam are still the same distance apart, the cam will not be rotated as far as it was at the time when the timing was originally set. You have to adjust the cam sprocket/cam relationship to get the cam timing back to spec.
The tensioner takes up the slack created by the stretched chain and keeps the chain from jumping teeth but doesn't adjust cam timing other than in the context of properly tensioned vs. loose chain.
One of the advantages of timing belts is that they don't "stretch" nearly as much as a chain. |
Dave Burch (Merlyn)
Junior Member
Username: Merlyn
Post Number: 105
Registered: 8-2002
| | Posted on Saturday, July 05, 2003 - 9:38 pm: | |
Actually only one of the statements in mine. I believe if you look again you will see that Bill Steele asked the question," Does anyone know if adjusting the timing chain tension can result in loosing the valve timing, by moving the cam pointer marks off from the timing chain marks?"
not me. I was only responding. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1871
Registered: 11-2002
| | Posted on Saturday, July 05, 2003 - 9:34 pm: | |
>>Does anyone know if adjusting the timing chain tension can result in loosing the valve timing, by moving the cam pointer marks off from the timing chain marks? <<
>>I am merely pointing out that the adjustment of the tensioner will have no effect on the position of the timing marks, that is of course unless the chain is loose enough to allow it to jump a tooth.<<
Those are both your statements.
I'm not the least bit confused about chains or Ferrari Engines.
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Dave Burch (Merlyn)
Junior Member
Username: Merlyn
Post Number: 104
Registered: 8-2002
| | Posted on Saturday, July 05, 2003 - 9:26 pm: | |
VR, I don't understand the tone of your post. I was not asking anything.
I am merely pointing out that the adjustment of the tensioner will have no effect on the position of the timing marks, that is of course unless the chain is loose enough to allow it to jump a tooth.
The slack taken up by the tensioner is the section of chain that is leaving the crank sprocket.
It works the same way as on a bicycle. The section of chain under tension is taut, the section leaving the crankpin is loose. On a bicycle it doesn't make much difference as the chain acceleration off the crank pin is so low, but no matter how long the loose section the relation between the driving sprocket and the driven sprocket remains the same. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1870
Registered: 11-2002
| | Posted on Saturday, July 05, 2003 - 8:25 pm: | |
>>The timing marks are aligned when the side opposite the tensioner is taut<<
So what portion of the revolutions does the chain become loose?
>>Changing tensioner adjustment should have no effect on the timing. <<
Well, a chain is either tensioned correctly or it's not. And if the above is true (which it's not) then what question are you asking?
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Dave Burch (Merlyn)
Junior Member
Username: Merlyn
Post Number: 103
Registered: 8-2002
| | Posted on Saturday, July 05, 2003 - 8:11 pm: | |
The timing marks are aligned when the side opposite the tensioner is taut. The tensioner just takes up slack on the overrun side. Changing tensioner adjustment should have no effect on the timing. |
JRV (Jrvall)
Intermediate Member
Username: Jrvall
Post Number: 1869
Registered: 11-2002
| | Posted on Saturday, July 05, 2003 - 8:04 pm: | |
I suppose if the chain is that loose the marks can't align in the first place, how could they, the chain is what allows the marks to align . Think about it.
But supposing the chain is very loose,(like years & years overdue for adjusting), the mere tighening of the chain "should" actually put the marks back on time, if in fact it was timed properly to begin with, with proper chain tension.
HTH's |
Bill Steele (Glassman)
Member
Username: Glassman
Post Number: 292
Registered: 4-2002
| | Posted on Saturday, July 05, 2003 - 7:52 pm: | |
Does anyone know if adjusting the timing chain tension can result in loosing the valve timing, by moving the cam pointer marks off from the timing chain marks? ( If that make's sense )
One of my manuals gives an obscure instruction for moving the timing chain on the sprocket to re-align the marks! |