Timing

Yes. In '72, due to smog requirements, Ford changed the cam timing to 4 degrees retarded (relative to earlier 351-Cs), then advanced the static timing to get some power back. If your 351-C has ever had the cam chain replaced, especially with a roller chain, the cam timing may be back to the '71 cam-timing spec. It was the crank sprocket that got its keyway changed, incidently. So 16 degrees initial may be too much in this case, causing starting problems. Finally, todays quality of gasoline in many areas would have been used to kill roadside weeds in '71 rather than power high-performance engines. You need to find out where your cam timing is currently set, or ideally, change the chain to the much stronger roller type. Stock silent-chains wear out in as little as 20,000 miles due to the heavy valves in a 4-V engine. Once the cam timing is known, go ahead & set the ignition timing to what the engine likes, not what the book says. Start with about 6 or 8 degrees initial but don't exceed 38 degrees TOTAL (initial + centrifugal advance + vacuum) or you may experience detonation, even with "premium gas," at high speeds where you can't hear the death-rattle.

All engines are NOT created exactly equal! Years ago Mr. Herb Adams (engineer for GM) suggested a technique known as "Power Timing", where the engine "Tells" you how much total timing it can handle. It works like this: Start engine and bring it up to normal operating temprature. Rev it up to, between 2500 and 3000 RPM To make sure ALL of the centrifugal advance is IN., turn (advance) the Distributer until detonation is heard, NOW BACK it off (retard) 2 degrees. Tighten the distributer clamp. Your maximum timing is now set for THAT engine. This takes into acount all the variables, from cam, to timing chain slop, to compression ratio, Fuel Quality, etc. ALL of it!! All the best, Marlin.

[This message has been edited by MARLIN JACK (edited 02-08-2003).]

that is great if there is no load on the engine...



other than that, that method isn't gonna help you much....