Timing chain worn out
Thread Starter
Instructor
Joined: Jun 2003
Posts: 114
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From: Sydney NSW
Timing chain worn out
Hello I pulled my cam to find that the double row timing chain (cloyes) unit has a good 1/2'' sideways movement is this acceptable or gone by its use by date? also behind the cam sprocket there is some light scuff markings on the block is this normal ? at the front of cam it has a cam button but it has not touched the inside of the timing case is there anything to be concerned with this? the eng. is a 1971 454ci. thanks in advance 
Le Mans Master
Joined: Aug 2010
Posts: 5,339
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From: Central Texas
While you are there you should change the timing chain and gear set. It is easy to do and it is time. Sounds like the end play on the cam is not adjusted correctly. You may need a shim or roller bearing behind the cam gear to take up the slack. All the cam companies offer these as I believe they are needed with roller cam installations.
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
More info.
Has the motor been rebuilt? Well a cloyes timing chain is not stock. Are u talking marks on a machined surface? Light scuff marks won't hurt cast iron but indicates gear set may have come apart previously. Is this a roller cam? No need for a cam button on flat tappet cam.
I ask if the motor has been rebuilt because many times the shop will alignhone or alighbore the main saddles and this moves the crank upward towards the cam - produces more chain slack if not corrected with a tighter chain.
cardo
I ask if the motor has been rebuilt because many times the shop will alignhone or alighbore the main saddles and this moves the crank upward towards the cam - produces more chain slack if not corrected with a tighter chain.
cardo
Thread Starter
Instructor
Joined: Jun 2003
Posts: 114
Likes: 0
From: Sydney NSW
Hello thanks for the replys yes the motor has been rebuilt about 10 years ago it and has a mild flat tappet hyd. cam the scuff marks has no ridge on the block just a shiny mark about a 1" long do not know why it would need a cam button what type of shim should I need when I replace the timing set ? thanks in advance
Le Mans Master
Joined: Oct 2002
Posts: 7,098
Likes: 378
From: Las Vegas - Just stop perpetuating myths please.
Sorry for the late reply.
Hello thanks for the replys yes the motor has been rebuilt about 10 years ago it and has a mild flat tappet hyd. cam the scuff marks has no ridge on the block just a shiny mark about a 1" long do not know why it would need a cam button what type of shim should I need when I replace the timing set ? thanks in advance
If your asking to tighten the timing chain u need a tighter chain. A few vendors sell chains in different under (and over) sizes. To choose the new size requires comparing a stock cam to crank spacing to your machined block cam to crank spacing. Sorry it won't be easy.
cardo
