In a message dated 4/26/2005 6:47:54 PM Central Daylight Time,
tr6taylor@webtv.net writes:
> Michael----Before tearing down the front of the engine, you can do a "chain
> stretch and tensioner" check. It's not a foolproof method, but can tell you
> a lot.
> Here's how:
> a) Move the engine to where it stops with the timing pointer over the timing
> marks.
> b) Remove the distributor cap.
> c) Move the engine in its running direction a few degrees, till you see the
> dist. rotor move CCW.
> d) Move the rotor by hand, taking out any play, still in the CCW direction.
> e) Move the engine opposite the direction from in c) above. Watch how many
> degrees it takes before the rotor catches up with this new direction.
>Anything
> more than a couple of degrees indicates play between the crank sprocket and
> the cam drive chain.
The "straight-edge test" is OK, I guess. You can also get a good idea how
much
> play there is between the links by laying the chain on a table, and give it
> the "accordian" test.
> You can also do a sprocket wrap. Try lifting up on the chain at the sprocket
> mid-point, to see how well it follows the pitch of the sprocket teeth. This
> test can also identify a worn sprocket, when using a new chain.
> Finally....I've installed new chains and found that the chain tensioner had
> a job to do. The last one I put on was so snug that it got my attention! (I
> still used the tensioner, of course) There should be no movement between the
> damper/timing hub and the
> crankshaft, or its sprocket.
Dick,
Thanks for the procedure. I will check this out in the coming weeks. I will
have to wait until I get a new timing chain in to do the sprocket wrap you
mention to check for worn sprocket. I hope the chain metal is softer than the
sprocket metal and will wear out or stretch first. When I reinstalled the
timing
cover a while back it did not seem too difficult to position the new tensioner
and I did not experience a very tight fit as you mentioned on the last one you
did. Thus likely a pretty stretched chain.
The 2-3 degree slack I have in the crank pully is worrying me, especially as
it is not supposed to be there. I do not think the pulley is moving on the
crank as the key is there to prevent this. The crank sprocket is also keyed as
well. To really see what is going on I will need to tear it down. But first I
will do the stretch check above. I may pull the head again and check the valve
seats while I have the rocker shaft assembly off.
Did you have a comment on replacing just a few rocker arms on an other wise
decent rocker shaft with only minor pitting on one rocker arm contact? Thanks
again. Cheers!
Michael Rankin
1971 TR6 CC 61212 L
Louisiana, USA
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