As mentioned above I would check the adjustment on the pushrods. Andrews should have a set amount to adjust them to. Normally so many turns after all the slack is taken out. I took out my stockers and put in adjustable and it got rid of a bad noise I had.

Also clean your tappet screen. If it is clogged it can certainly lead to a bad noise.

 

Reset the pushrods and changed the oil to valvaline racing oil 50w, NO change. Looks like top end is going to come apart next.

 

The Andrews EV-27 cam has some aggressive ramps, which lead to increased valvetrain noise, but it should be steady and not get "softer and louder" as you mention. Is the knock being heard at very regular intervals, or is it hit-and-miss? You might also shine a light down the sparkplug hole to see if you notice anything odd (metal shavings, etc.). Do your plugs show any indication of being hit by something? Sometimes the piston/carbon/broken rings/etc can damage the ends of your plugs and give you some insight on what is happening.

No smoke huh? Just the knocking sound?

 

No smoke, and hit and miss, and no knock when its cold just when it warms up. I changed the plugs when I bought it. I will look in the hole though.

 

If you have, or can get your hands on, a compression tester that might shed some light on things too. If you use one, remember to hold the throttle wide open as your testing to get the best results (it allows the best airflow when wide open).

 

took rear jug totally apart. Found wrist pin that goes through piston was short and loose, had to be from factory. replaced wrist pin put back together, sound was gone. happy day . The pin was about an eigth inch shorter than the one I put in