Purple Shaft 280/280 cam

Hey abodyjoe,
Glad to here his car runs great.
I run my stock distributers with the vacume advance off and then turn up the total timing to 34 or higher.
The distributer can be recurved if the motor wants it due to how it's built and going to be used.( a msd distributer comes with all the differant cams
so this can be done)
Most of the time in drag racing ,i have found that adjusting the total timing and making sure it's all in, by the stall speed of your converter works best for drag racing.(this is done by using light weight springs)
This also gives the highest flash rpm for your converter.
Hitting the converter with the most torque possible out of the hole is the best way for the fastest 60 foot times.
The vacume advance on a stock engine gives the engine more initial timing and improves the way a stock motor runs at idle.
THIS IS ONLY USED FOR STOCK MOTORS.
When running a high performance motor and running more total timing YOU SOULD UNHOOK THE VACUME ADVANCE BECAUSE YOU WONT NEED IT.
The car will start fine and run smoother at idle after setting the total timing higher.
Theres no need for the initial timing like before when the total was less.
When you change the total timing ,and make it higher then the stock setting, you could run into DETINATION PROBLEMS USING THE VACUME ADVANCE AFTER SETTING THE TOTAL TIMING.

Alot of cars at the track will lock there distributers out and set there total
timing.What this means is ,they are not even using the weights in there distributers and there timing never changes.
Locking out the distributer will make a motor HARD TO START, and i would not do this for a street car, but even some hard core street people do this.

This is why you install light weight springs in your distributer and use the weights in the distributer to advance the timing as the rpms increase.THIS DOES NOT MAKE THE MOTOR HARD TO START.

Another thing they do is lock out the vacume advance so the timing is more stable at higher rpms.
The vacume advance rod can move around at high rpms and cause your timing to move around with it.
This is why msd high performance RACE DISTRIBUTERS don't have a vacume advance.
Msd distributers can be made to have the total timing come in at many differant rpms ,so you have many choices.(If you need them)
This is good for cars that are running high compresion and there motors are prone to detinaion and they want less timing at lower rpms while under a high load and more at higher rpms to gain more horse power when detination is less likely to happen.

If a street motor is build with the correct compresion for pump gas,it will not need anything but the total timing set for the most power.
MOST PERFORMANCE MOTORS WANT ALL THE TIMING THEY CAN GET AND THE INITIAL TIMING IS NOT EVEN PART OF THE TUNE.:thumrigh: