distributor springs

[joshua dewitt]

looking to curve the distributor to around 2200-2600 rpms for the street, built 318 302 heads, 9.5:1 compression, a-904, 3:55 gears....mp340 camshaft....air gap intake, headers, rtc.
now, i have it apart. has two spring the light one factory and the loop spring heavy one.
when orange ecu box came with some mopar really light springs, feels almost too light to me, pondering what to do. have read use 1 factory light spring, (non loop) and one m/p light spring, but feels too light, any one dealt with what works best for the street? to get into the ball park? they gave me #p2932675 by the way...

 

[tekslk]

With that compression if it comes in early you will probably like it, I doubt it will ping with that compression, so stick it in and try it you may like it.

 

[TrailBeast]

Mr Gasket spring kit 925b says to use both of the light springs for mostly race and light cars.
From what I understand the heavier the car the heavier the springs needed.
Also those spring are light and sure don't feel like they could resist much do they?

Anyway, you could do what I did and swap em out, then put it all back together and use a timing light to see where the advance comes in.
I expect it'll come in at about 2200, so you might want to remove the slotted spring only and replace it with one of the light ones.
I think that would get you up around 2400-2500 before the advance comes in.

Then from that point you need to see what the engine likes to get it right, and there is no better diagnosis than MPH on a repeatable surface. (like a track)

 

[toolmanmike]

The timing light is your friend if you have a particular curve in mind but like the guy's said, performance tells the true story. Try the factory light spring only and if it screams and doesn't ping, that's what you need. If you get a little ping, add the Mr Gasket spring and see if the ping goes away but the performance is still good. If you don't have a light you won't be able to check total with the vacuum advance plugged but if it doesn't ping it's probably ok. Timing can be a tricky combination but it can make a big difference if you find the correct mixture. tmm

 

[moe7404]

if i remember right with light mech advance you do NOT run any vac advance. your advance at cruse speed 50-60 MPH will be way to much. i found out the hard way. it will knock out the piston rings. over revving a stock chrysler engine will knock out piston rings all so. keeping a stock chrysler engine under stock RPM is a MUST. its NOT a race engine UNTILL YOU make it one.

 

[joshua dewitt]

So, withthe two factory light springs be ok. My vacum advance is stamped 8.? Is this the 1/2 vaccum value? Ie: 16" vacum to pull is off?