Thunderbolt valve clatter

Posted by steve-52/200 On 2011/11/22 14:00:33

As I zero in on getting the 52 fixed up ,The valves in the straight eight clatter .
The fellow that sold me the car said "that's what they sound like ,don't worry about it".It is a happy clatter something like the sound of a deisel ,
but my desoto with a 236 flat head six is so quiet when running you can barley hear it ,Ive had to put my hand on the car with the hood closed many times to see If it was vibrating or not ,to see if it was running or not.

I have a hunch the clatter is too loud and wondering if I should get the valves adjusted ,seems like a big job so I was wondering if I could do any "routine maintenance" ;the engine has an original 68,000 on it .I have had the piston rings replaced,by dropping the crank ,there were two broken oil rings on the car when I got it ,So the heads never been off ,I didnt notice any spots where the head is leaking gas .
.Currently the car does not smoke ,seems to have good vacumb ,starts up fairly easilly .The engine pulls well up the big hill I live on .I will borrow a stethoscope to check if its any one area on the head thats louder that another to check for generalized clatter vs one spot that is the loudest , and try to do so when the neighbors arn't looking so they dont think Im more nuts than I am .
So I am soliciting advice;

Could the timing be way off causing clatter? What is the proper timing ? right at TDC?
Does a regular timing light work on a 6v positive ground car? I am planning on getting one today .I guess I will need a dwell tackometer too .
If I change the timing, then I will have to redo the dwell, is that right ? I heard of an old mechanic's saying "timing affects dwell but not the other way around"or something like that ,very mysterious. The dwell was way off because I reinstalled points right out the box not knowing how to set them .I was insttructed by the machanic that they were off,and he adjusted them to 30 degrees dwell .this made a huge positive difference in quitness and higher end performance.As for the plug gap ,I did the same thing,installed out of the box ,whats the gap supposed to be? Could overgapped or undegapped plugs cause the valves to clatter because of poor combustion ?Inerestingly the clatter got much quiter after the Generator rebuild and the rewiring to correct the coil hook up ( it was wired backward)