Timing non-running engine

[Kelly in tx]

My 460 manual says it can be timed at 325 rpm. Is that approximately the speed of the 12 volt cranking system? If not, why in heck would they talk about a 325 rpm timing? Thanks, kelly

 

[rustred]

you can reduce the idle that slow for timing.thats if the carb bushings are in good shape ,as not sucking extra air in then they will not idle that slow.

 

[pete 23]

I don't know what book you got a 325 rpm for timing a 460. It may have said 425 but even that is usually not attainable on those engines. The reason they want you to check timing at low idle speed is to make sure the centrifical advance is fully retarding at low speed. That is not critical to good operation of that engine. What is important is to time it at full throttle or at a minimum of 1800rpm and it is to be set to 30 degrees before top dead center at that speed. Then you slow the engine down and it should gradually retard relative to engine speed to near top dead center at low idle speed. I always check timing with out engine running first at top dead center and then check the advance. That tells you if the advance is working and that you have the proper distributor. Cranking speed is no where near that rpm either.

 

[504]

See if I can tell you how to set it with the motor off. Start at top dead center, and then move the crank shaft so the correct timing mark is where you want it. Loosen the disturber clamp hold down and remove the disturber cap and rotor,with the switch off short the condenser to ground(just use a screw driver, to the wire to ground)then hook a ohm meter to the points lead and to ground,twist the disturber till the points close(the meter will jump). You have just set the timing with out a light and without the motor running. This assume that the points cap has already been set. It is easier to do than write about it. We used to set all of the new rebuilds this way for the first fire up. (removing the cap is just for visual, it can stay on)

 

[teddy52food]

?????????????????????????? Spark happens when the points open not close. & why short the condenser?

 

[David G]

agreed, initial timing is only to prevent starter kickback.