New Crate Engine 454 up and running
Little over a month ago my 1991 pace arrow blew the engine. Finally got it up and running again with a new crate engine. Just about dialed in now. One problem: seems to be backfiring thru the TB...
Forum Discussion
Years ago, I had a 'i83 Southwind with a 454 in it. As I recall, the shop manual stressed the routing of the ignition wires because of possible cross firing between cylinders when an wire for a firieing cylinder was routed next to a cylinder on a intake stroke.
Mine used to "sneeze" wnen under full throttle oe heavy load. As the pressure in a cylinder goes up, the voltage required to spark across the plug gap goes up, making the likelihood of a sneak path firing occur, when that sneak path goes to a cylinder in the intake cycle, you have a combustible mix, an open intake valve and you get a backfire through the intake manifold.
Mine used to "sneeze" wnen under full throttle oe heavy load. As the pressure in a cylinder goes up, the voltage required to spark across the plug gap goes up, making the likelihood of a sneak path firing occur, when that sneak path goes to a cylinder in the intake cycle, you have a combustible mix, an open intake valve and you get a backfire through the intake manifold.
