Exhaust cam question

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Dec 27, 2012 | 07:17 AM
  #1  
First of all...Happy Holidays everyone.

I had the misfortune of secondary tensioner failure in the fall ( I was waiting for the new tensioners to come in but luck being what it is lol.) A potential good note was that the car was not running at the time the failure occurred. I went to start it and it would not turnover in the slightest. Figuring that something bad had happened I opted for a tow home.
Subsequent investigation showed that the shoe had come off and bound itself in between the secondary chain and the sprocket. The chain had stretched and broke half a link but had not come apart.
So with that in mind I figure that since the motor did not turn over and that the chain had not completely broke the exhaust valves should not have been bent.
I just removed the exhaust cam and all the shims appear to be fully out, as in the valves are fully seated.
Am I wrong with my thinking? That is the question. If they are fine I will go ahead and replaced the chain and tensioners after setting the engine at its proper location with respect to DTC and go from there. If my thought process is in error please point me in the right direction.

Cheers
Dale
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Dec 27, 2012 | 07:27 AM
  #2  
Very fortunate!

The key is if the chain slipped a sprocket tooth or two. It is not entirely clear if the ' . . . it would not turn over in the slightest' meant that the starter failed to rotate the engine or the the engine would not start.

With the exhaust cam out it is a simple matter to check compression and/or a leak down test to verify if all valves are properly seated. With good results you are about the luckiest guy around.
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Dec 27, 2012 | 07:30 AM
  #3  
Wow, thanks for the quick reply. The starter failed to rotate the engine. Will go ahead with a compression check.
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Dec 27, 2012 | 10:16 AM
  #4  
Of course, Secondary Chain replacement involves removal of the Primary Chains for access (there is no Master Link on the OEM Secondary Chains). The Front Cover must be removed. You should also replace the Primary Chain Tensioners when everything is apart.
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Dec 27, 2012 | 01:51 PM
  #5  
I actually found a master link replacement chain so the task won't be so bad.
Cheers
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Dec 27, 2012 | 03:05 PM
  #6  
You will get many people telling you not to use it. Please listen to them.
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Dec 27, 2012 | 04:12 PM
  #7  
What is the problem with this type of chain? The chains on my dirt bikes come like that from the factory and I have never had a problem, curious I am.
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Dec 27, 2012 | 04:27 PM
  #8  
Dirt bikes are not 'totaled' if a chain comes off.

There have been reports from this forum's members of repair links coming apart with the pieces found in the crankcase.

These repair link replacement chains have been used by indy shops for a long time but I would worry about it every time I drove it. I know the jump from the secondary to the Full Monty is a big one but if put to a vote the forum members would probably say that they would do the complete job.
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Dec 27, 2012 | 04:45 PM
  #9  
+1 For the complete job and would never contemplate a repair link
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Dec 27, 2012 | 04:55 PM
  #10  
Valid points.....full job it is. Its winter sooooooo not like I don't have the time
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