The Stovebolt Site Forums The Shop Area Engine Shop MSD Ignition!

I have been doing alittle research and see that MSD offers the 6AL ignition box for the 235. If you go to their site, http://www.msdignition.com/ , shop by vehicle and look at a 61' chevy truck it offers a box for the 235. It wont for the 60' though, go figure. I was wondering if anyone has made this upgrade? It looks like you can make it work with a pertronix setup aswell. Anyone done this before?

MSD seems to offer a distributor (the 8515) for the 1962 235 C10, but the fine print in the description for the 8515 MSD distributor says that it will not fit a 235 or 261. The 8515 seems to be for a 230. However, if the 250-292 HEI distributor can be modified to be installed in a 235-261, could not the MSD 8515 be similarly be modified? I have the MSD 6AL ignition in my 327 in a Corvette; a very good ignition system.

Hoyt

What is the supposed advantage of the MSD system over the much more affordable stock HEI system? MSD stands for "Multiple Spark Discharge" and the pattern on an oscilloscope shows five distinct firing lines. Does the spark plug really need to fire five times for every power stroke? Each firing impulse has to be extremely short-duration to fit all of them into the time frame where normally a single spark would happen.

I can see the reasoning behind using this type of system on a race engine- - - - -maybe- - - -but it seems to be a really expensive and totally unnecessary option for a street engine. Also, the procedure for adapting a stock HEI system to the stovebolt engine is well known and simple to accomplish. MSD seems like a fool's mission for someone who needs to brag about another expensive toy on his stovebolt.
Jerry

I saw that too concerning the distributor, but as I read the site, you do not need the distributor for the box to work. You can use pretty much the ignition box with the stock system or a pertronix system. It's the timing benifits that I am lookiong for. Better starts in the cold weather, better performance ect...

First of all I'm not looking for bragging rights. I'm looking at something to improve the ignition system on my truck for more efficient starts and over all performance. The explaination on the site seems to make alot of sense on how the system can improve that. See this: CAPACITIVE DISCHARGE
The MSD 6 Series Ignitions feature a capacitive discharge ignition design. The majority of
stock ignition systems are inductive ignitions. In an inductive ignition, the coil must store
and step up the voltage to maximum strength in between each firing. At higher rpm, since
there is less time to charge the coil to full capacity, the voltage falls short of reaching maximum
energy which results in a loss of power or top end miss.
The MSD Ignition features a capacitor which is quickly charged (within one millisecond)
with 460 - 480 volts and stores it until the ignition is triggered. With the CD design, the
voltage sent to the coil is always at full power even at high rpm.
MULTIPLE SPARKS
The MSD 6 Series produces full power multiple sparks for each firing of a plug. The number
of multiple sparks that occur decreases as rpm increases, however the spark series always
lasts for 20° of crankshaft rotation. Above 3,000 rpm there is simply not enough "time" to fire
the spark plug more than once, so there is only one powerful spark.


That is taken from their instruction sheet for the box I was looking at for a 235 stovebolt.

Some more info from their site:

http://www.msdignition.com/products/ignitions/

It shows brief discriptions of the boxes they offer for daily driver, street/strip, drag,...ect. They offer quite a variety of systems.

Thasnk you for your explaination. I was involved in the first attempt by General Motors to introduce a Capacitive Discharge ignition system in the late 1960's and even attended some training sessions at their technician training center in Memphis, Tennessee. GM abandoned the idea for reasons of the system being too expensive and unreliable for production vehicles, choosing the much simpler and economically-produced HEI system instead. They produced untold millions of them, with a great deal of success. CD systems haven't gotten much better in the 40-something years since then. They're still an expensive and unnecessarily complicated method of lighting off the fuel charge in a cylinder. Race applications, maybe. Street use, no way!
Jerry

In a good working engine, the sparkplug fires off and the fuel lights. MSD has five sparks per cycle, whats the advantage of the other four, if the first one lights off the fuel? If the first one doesn't light the fuel, the engine tune is not right and needs fixed, sounds like MSD is being used as a bandaid for improper tuning.

On high end race motors with tones of compression and radical cams, they have there place.

Joe