removing timing chain & camshaft on a 79 triumph spitfire

Removing timing chain & camshaft from my 79 triumph spitfire.
the 79's stock "18-58-58-18 .240"lift camshaft and tappets have much wear, at 77,900 miles. It is being asked in forums "Which causes the destruction of the other, the tappet of the lobe, or the other way round?" This video is from 2015 when I was rebuilding the 79. The replacement camshaft, a reprofiled (aka-reground) 25-65-1 is failing after less than 12,000 miles. That's another video waiting in the future.

[@cratecruncher6687]

Nice video. Wow, 77k miles and that cam is BEAT. Clever way to show the cam sprocket tooth offset. Very informative!

[@holymolyitsclay]

Interesting video, thanks for putting it together. And nice shirt!

[@dennisking1555]

Did you remove the white lump of putty on the chain cover ? Believe it or not that was factory fitted as a noise reduction fixture

[@reinhardtrippmacher8776]

Thanks for this detailed video. My question is, once the chain and sprocket has been wearing like this, could it occur that the ignition timing is off in case the chain is stretched unevenly?

[@dadcolo]

yes, but not by much. I found it interesting how far off bad adjustment can be and still run well.

[@vza423]

I enjoyed the video and will be in the same boat shortly with a '76. What caused the pitting and dishing, or is it the result of time and wear. Many thanks.

[@dadcolo]

The pit is after the carbon has gone. I was told all these molten metals have carbon deposits, occasionally some deposits are larger than at other times. When the molten metal is mixed, it is poured into a mold called a blank, and hardened by a process. The camshaft is machined from one of those blanks, then it might be re-hardened (or not), and boxed for sale or fitting. If the molten mix has some larger undetected carbon deposits near the surface, time will wear down the metal and expose those deposits. The carbon quickly wears away. I was told the hardening process brings the metal tighter together, that would squeeze the deposits, but the hardening is not deep, and the larger carbon is still full size deeper in the cast. There are images of tappets, sliced, to show the metal, carbon deposits, and hardened outer surface. A re-ground camshaft (aka re-profiled I think) has more of the hardening removed to reshape the lobe. I bought one, don't waste your money there. My re-profiled had 12,000 miles when I discovered the lobes were wearing away, unfortunately the warranty had expired, the low mileage didn't matter.