Worn Timing Chain Cover

In a recently purchased 1963 Thunderbird with a rebuilt 390, when the RPMs get up high enough there was a knocking noise from the front of the engine. Upon stripping it down and getting the timing cover off, it's evident that the timing chain and fuel pump eccentric have been hitting on the timing chain cover and have worn in grooves. This is only at the top of the camshaft timing gear. I assume this was the knocking noise. Why would the timing chain and eccentric be eating through the timing cover?

Somebody didn't tighten down the (2) philips head cap screws that hold the cam in. OOOOOOOOOOOOOr , it might be the johnson rod idler pin.

What happened is someone replaced the timing chain and did not remove the spacer from between the cam and the cam gear and the fuel pump eccentric will hit the cover,if it did not wear through the cover all you will need to do is take the cam gear off and remove the spacer. I did the same with the 390 in my 65 country squire,before installing the motor I installed a timing chain set while it was easy to work on the motor and I read in the instructions about removing the spacer but it did not move when I too the gear off so I thought it did not have one. Well when I fired the motor I noticed a noise so I took it back apart and found the spacer.

I found one once where the guy had drove the rear plug in so far that it pushed the cam forward. I guessed that he had installed the plug prior to stuffing the cam.

A couple of things to check......63 engines still had the old style cam button retaining plate. Most upgrade to the newer style. Check to see which you have. My 406 was upgraded to the newer style installed and I noticed the same thing that the fuel pump eccentric and sprocket hit the timing cover. Remove the spacer as Jeff advised and put some clay or putty on the end of the fuel pump eccentric and timing sprocket and put the cover on with a few bolts. Then check the clearance to the cover. G.

Sorry, forgot to post back, but that night we tore it all down and it was because they had left the old spacer in even though the new gear comes with it built in. Thanks muchly.