[TedRamAirII]

Originally Posted by Va68goat

Hey TedRamAirII,

The flexplate came off of the 400 block I had when I bought the car. It's the only part that isn't new. When I had Paul build this motor, I sent him the old flexplate and he balanced it. Now that I have a new balanced flexplate, I'm hoping that is the problem. I did pull the plugs off one at a time and the knocking didn't stop. It's certainly not been a lack of effort of trying to get this motor right. I'm very new to cars but my friends are pretty good. We have checked everything that we can think of. It sounds like some sort of clearance issue...like hard metal hitting softer metal. It's hard to explain. Before we discovered the windage tray witness marks we pulled the converter back and it still made noise. I have no clue what else to do but try to replace the old flexplate. I think replacing the flexplate is a hail mary before I have to send the motor back to Paul. This motor has less than 200 miles on it!

I don't know Paul personally, but I'm sure he checked it over before putting in the effort to balance it. Have you taken the converter bolts out and just run the engine by itself? If you did, you could make take a small mirror or bore scope and get a eyeball on the bolts to the crankshaft flange. So the engine was shipped to you with the flexplate torqued, ready to go? Did anyone check it while the engine was out? Keep the faith, its going to be something simple!