Working on a '55 IH pickup with a straight six, overhead valve, solid lifter engine. It has a knock that I at first suspected was a rod or wrist pin. But it is loudest when cold and at idle, and can barely be heard at all when running at speed. Sounds about like a diesel fuel pump on an old tractor, but this ain't diesel. Compression is within 10% on all cylinders. I adjusted the valves with each cylinder on TDC, and then confirmed in the manner IH said, with the engine hot and idling. That's when I discovered that the knock goes away with the .019 feeler gauge on the #6 intake valve. Pulling the plug wire on that cylinder doesn't eliminate or reduce the knock. I'd appreciate any advice or ideas.
The Jalopy Journal
