Quote:
Originally Posted by intex1982 how do u lock out the timing? |
With a GM style big cap HEI, remove the cap and rotor. Remove the weights and springs. Using two medium electrical tie wraps, bind the advance mechanism fully advanced by wrapping the tie wraps around the mechanism. Orient the tie wraps knots down under so that the rotor will go back on. reinstall the rotor and cap.
Loosen of the distributor bolt and turn the timing back a bit (it will now be very advanced) Start the motor and reset the timing to 34-36deg at idle without vac advance. reconnect the vacuum advance.
The vacuum advance may need to be limited now to around 12-15deg.
if the motor is now hard to start when its hot, install a ignition power switch on the 12+ power wire going to the HEI ( big red wire). Any good single pole single throw automotive switch with a rating of 10amps or more will do.
Crank the starter with the switch off then throw the switch and it will fire easily. this setup is often done on race cars with big rough idle cams that need full advance full time because of the overlap.
it will indicate to you if your car can use more intial advance for a beter launch (it usually helps especially if you have a initial bog) try it.
later you can recurve your mechanical advance for around 20-22deg initial and a smooth advance curve limited to 34-36deg at 3000-3200rpm. Just right for a 268H voodoo cam. Requires that you limit the amount of advance travel to around 12-16deg in the distributor.