Hi all,
just thought that I would share some interesting stuff with you all
after I have been tinkering around with my cam chains. I have spent the last
week or so looking into the death rattle coming from my 1970 roadster. I
bought the car about two weeks ago. The car was in Sydney and I live in
Alice Springs. I flew to Sydney on Monday and started my drive back to Alice
on Tuesday. A rather long drive, 2900 kms. I think that is about 2000 miles.
All that aside, I became aware of the top chain becoming a little more noisy
each day. When I got home I immediately started looking into the problem. I
contacted the previous owner. He said that the cam towers were definatly
shimmed after the head was resurfaced. All the chains, guides and tensioners
were replaced. He said that he was also a little concerned about the rattle
but due to the fact the he had to sell the car he didn't do anything about
it.
There is no doubt that the chains are touching the top support
bracket and that the top chain is very slack. Even at idle after the engine
has been running for a while the chain is hitting the support. The
frustrating thing was, why so soon after being replaced should the chains
rattle. I decided the only way to see what was happening was to watch while
the engine is running with the rocker and inspection plate removed. (very
messy) The only way to do this was to make a rocker cover and inspection
plate out of perspex. This what I did. Fitted them to the car and satrted
the engine. With in about 5 minutes I could see that oil was pouring out
from the bottom of the top tensioner between the tensioner and the head. I
removed the tensioner and sure enough the gasket showed signs of not being
sealed properly.
So, here is my theory as to what has been happening. I invite feed
back just in case I have missed something obvious, I'm really good at
that!!. I think that the bottom bolt holding the tensioner was not tight
enough. I "thought" that might have been the case when I removed the
tensioner but didnt think too much of it at the time. So with all this oil
going AWOL the chain can't have been getting enough oil and has stretched
way too quickly. There is almost no sign of wear on the tensioner, so I
guess that I am lucky there. I have sent the tensioner off to be checked for
flatness and has been given a clean bill of health. The sprocket on the cam
also looks new.
Next, I am going to feed in a new cam chain by using the joining
link and turning the engine by hand (wish me luck) and installing spacers on
the tensioner. The same company that checked the tensioner for flatness is
making some spacers. Any how, hope this little essay was of some interest to
some one out there. Any feed back would be appreciated. I will hopefully
have the new parts in a couple of days and can start to enjoy this wonderful
little car.
All the best everone..........BTW the Shasta
meeting looks like alot of fun!!! Might have to make the crossing and come
to the next years. All I need is a place to
stay.......hint hint..........Se ya, Brian.
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