I have a 78 GMC C15 with a well modified 292 driving a 700R4/1800 stall to a 3.73 posi rear. The engine has maybe 4000 miles on it and I bought it from Leo Santucci when he lived in CT. and his engine shop built it with all ARP studded lower end and 30cc pistons. The head came from Walt Pierce by way of Tom Lowe and is highly modified. Motor has a stage 1 Crower roller cam. On the wheel dyno it showed 199 HP at the rear wheels. It was fine for a long time and then started making a lot of noise, a chattering - squealing noise and we determined it was coming from the lower end. End play on the crank was found to be about 3/16". We could push the crank back and forth and watch the pulleys move. We pulled the motor and found that the crank was somehow being pushed forward and the rear main bearing cap ate into the crank itself. The bearing and cap is shot. I had put a magnet on the pan when the noise started and it has a plugged bypass so it doesn't look like anything else got trashed but the magnet was loaded with metal. Regardless, the motor needs major repairs. The problem is we cannot figure out why the crank would push forward. The stage-2 trans from Bowtie Overdrive seems OK, flexplate is ok, it all looks ok though we have not torn apart the trans yet. Has anyone ever seen this problem with extremely excessive crank end play and have any idea why it would happen?
Last edited by Steve Odell; 10/06/20 01:26 PM.
