From the Cape Henry Model A Club. Attached is a video of a Model A engine with Piston Knock in #4 cylinder. Notice the noise abruptly stops when the #4 spark plug is grounded. The #4 piston and rod were removed and wrist pin and crank clearances were found to be well with in tolerances. Could be an exhaust leak, but that hasn’t been checked. Grounding the spark plugs with an insulated screw driver is a good method for tacking down Model A engine knocks.
|Posted by Editor on January 12, 2015 at 11:23 AM||2221 Views|