Reply to "Carb backfires"

Mr. Nelson, be aware that the valves and ports in your 351-C are the same size as in a big-block Ford 460- and are larger than in some versions. So the valve-train is heavy and typically spinning all that weight, rapidly wears the timing chain- especially a stock 'silent chain'. About 20,000 miles is all one can expect to get from a reasonably driven Cleveland, before a fresh chain is needed. A 'stretched' chain may actually jump a tooth or two during start-up. A 351-C is not an interference engine so no further damage will occur, but will either act like yours or worse- not start at all.

In addition, the stock harmonic balancer inner hub and outer ring (where the timing marks are) are NOT bonded together, only pressed in place with a thin rubber strip separating them. So after decades of time, the rubber damping strip in between the iron parts shrinks. That allows the inner and outer parts to shift, changing the timing mark toward the 'Retard' direction. I've seen timing marks 180 degrees out of true time from this; obviously, setting timing without checking for true Top Dead Center on such an engine will give fearfully wrong ignition timing.

So first, one should verify the basics when resurrecting a long-dormant engine. For instance, original rubber fuel lines are often brittle and will crack with engine vibration, causing a fuel fire; the 22 gallon gas tank is mere inches away from the carb.... Stay in touch with this problem; long-distance trouble shooting is guesswork at best so we'll likely all learn something.