This thread is a continuation of the discussion in, What's this loud tapping sound from my new engine? If you haven't read the previous thread, you may wish to review it--it establishes the background for this thread.
While What's this loud tapping sound from my new engine? discussed both this problematic, Proformance Unlimited engine and the new engine, this thread will focus solely on the Proformance Unlimited engine. The ongoing discussion on the new, FE Specialties engine will continue here: 390FE (406ci) for #50, built by Tom Lucas at FE Specialties. Thanks!
Here an illustration that shows our organization method (click on it if it's difficult to see):
On Friday I heard from Tom Lucas at FE Specialties that in addition to everything else, he found these new problems with the Proformance Unlimited (also known as Pro-formance Unlimited) engine:
- Several of the main bearing saddles were tapered, which explains the shiny streaks shown in the main bearing photos. It needs to be re-align honed. One saddle had a taper of nearly 0.001".
- The connecting rods were bored about 1/2 of a thousandth larger than they should have been.
- The bushings in the connecting rods were too large, so the fit was bad. They had between 0.0008" and 0.0010" clearance. They'll have to be re-bushed.
- The deck hadn't been machined properly on the block, so it needs to be re-decked. According to what I read from Tom, the deck was out 0.0025".
- The connecting rods I received were stock 390 FE rods. I did not receive the Eagle H-Beams listed in my invoice!
I'll provide more updates then!
Thank you all very much for your superb advice on this topic!
Robroy