Since timing seems to be a popular topic as of late I'll throw my own question out there as well.

Last year I put in a MSD tach drive distributor and 6AL box along with the matching coil and 8.5mm low resistance wires (WOW!, what a difference, HIGHLY recommended). I now have the ability to set total timing, timing range/width (thus initial, total-range=initial), and the rate at which it comes in. So, the magic question is.................


Where do I start? Stock specs do me little good as I'm running 11:1 compression, 96 octane fuel, a high lift long duration cam, headers, duals, and a LT-1 intake with a vacumn Holley 670.

By the way, its also a 4spd so timing by measuring time elapsed versus rpm is possible.

Tanx!

ricknhis69 said: Where do I start? Stock specs do me little good as I'm running 11:1 compression, 96 octane fuel, a high lift long duration cam, headers, duals, and a LT-1 intake with a vacumn Holley 670. By the way, its also a 4spd so timing by measuring time elapsed versus rpm is possible. Tanx!

there are two things you can do with the msd.. is comes with three sets of springs.. the ones it has installed are the tightest.. the thick silver springs.. then you have blue and small silver springs..

this gives six combinations for the timing ramp rate.

then there are four timing limit bushings.

there is a chart in your manual for the dist that has all this info..

i used the lower middle spring option (one light and one heavy silver) and used the second smallest timing limit bushing( second highest limit).

there is no sure fire formula to total timing a hipo engine. it depends on what youve got.

i am running a fairly agressive engine and I am using the settings above..

you need to pick a setting and see what it does.. set yor initial timing via vacuum then drive it hard..

if you get clattering early but it catches up
then lower your ramp rate.. if you clatter in the top end and it doesnt go away, use a larger limit bushing.

i just put mine right about in the middle and its fine..

but if i was maxing it out.. i would start on second highest spring and limit bushing and work down.

the highest settings are very very extreme

slowest -> fastest ramp rate.
2 x big silver
1 x blue, 1 x big silver
1 x small silver, 1 x big silver
2 x blue
1 x blue, 1 x small silver
2 x small silver

btw... if youre running it for performance.. you should ditch the vacuum advance. msd makes a blocking kit.. (I have an extra if you want it) much more predictable.. and for performance with a stick... youll find a mech sec carb more linear also.

my .02 might not be worth that much