Msd ?

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Small Block

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I have a 440 in my 74 duster and it runs the MSD ready run distributor and does fine but now i have another 440 in the shop with dual quads ported 906 cast heads and 2.14 valves and roller rockers and 10.5 compression and was needing a distributor but will the ready run unit work ok for this motor? If so what is the MSD part # that i will need. It will only be a street machine on spiked gas. Help if you can. Thanks guys and gals. Don't know why i go by "Small Block"
 
He he he, Ya, that unit should do very well in that set up. Make sure it has a good coil and your set.
 
Are the MSD ready to run units multi-spark just like their control boxes up to around 3,000 RPM?
 
The MSD ready to run is more like a HEI ignition than a miniature 6A in a distributor. The directions show they don't have a separate tach output (a dead giveaway it's not multi-spark) and it grounds the coil to fire it instead of firing a high voltage pulse on the positive side.
 
Rocket said:
Are the MSD ready to run units multi-spark just like their control boxes up to around 3,000 RPM?
Click to expand...

As MadScientistMat stated the MSD ready to run is an inductive ignition just like the mopar electronic ignition or the GM HEI, it more closely related to the mopar in that the coil is not intgrated into the cap.

The ouput of this ignition is going to be a function of the coil used not the control box in the distributor, it's only function is to switch the gound on the primary of the coil on and off.
 
The ready-to-run unit is cheaper overall, and would probably make the same amount of power on a mild, naturally aspirated motor. The capacitive discharge units (6, 7, and 8 series boxes) cost more but put out a more powerful spark, and the spark energy doesn't drop off so much at high RPM. It depends on how much spark power you need. I wouldn't use the ready to run unit on a blown Hemi or a wild 340 with a 8,000 RPM redline, for example. Your 440 sounds like it's pushing the limits of what you can do with an inductive ignition and a single coil, but it may not have crossed them.

If I were using a conventional distributor on that motor, I'd probably go with a 6AL box. With that sort of compression and RPM, it seems like the spark may be marginal with the ready to run.
 
If you go with the ready to run you can always upgrade to the capacitive discharge box at a latter date if needed.
 
My builder says the ready run will do the job as stated here but any more motor and we will need to dig deeper. Should dyno this thing next week. I guess they are buying a Lakewood bell so they can do Mopars as i have threatened buying one($600) and renting it to em. The owner is a chevy/vette guy and they build some killer stuff but they have only been able to dyno fords and chevys. The PO who runs the shop does a bunch of Mopar stuff like Hemi's and this is his third motor for me and they are getting excited to be able to see what the Mopar stuff he builds really produce. I'll keep you posted.
 
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