hi guys i got a msd distributor and coil and a msd6al box from my wife i have a few questions about the tension springs im not sure witch ones to use and im not sure what you need to know to be able to help me . its a 402 engine. i have the specs of my cam but not sure what i need to put on here so if anybody is willing to help i would appreciate it. thanks brian.
The different springs will determine the RPM that full mechanical advance is achieved. I suggest an hour or two on a dyno. Maybe somone else on here has an easier method that is cheaper. When I was a kid, I would go out to a seldom used stretch of pavement and drive the snot out of my car with different combinations of the springs. Not really knowing what I was doing, but man it was fun trying to make it perform better.
I don't know MSDs specifically but this is where you should aim to start the setup with 18 degrees base timing, and 18 degrees mechanical for a total of 36 all in by 2800 RPM. Also run vacuum advance to a manifold vacuum port, and set it to add approx. 14deg timing for a total of 50 at low load. At full throttle this will back off with no vacuum to your 36.
Does your 402 have any mods? cam? If not you may want to start it off at 15-16 initial for 34 all in.
the springs adjust when all the timing will come in, here's an article to help understand it, http://www.corvettefever.com/techarticles/distributor_recurving_power/index.html
-- Edited by pudge444 on Wednesday 30th of December 2009 09:01:44 PM
