Opinions... MSD HEI vs Stock Ignition

[Jeff10]

Hi Everyone,

I've searched the forum, and I guess there are a lot of opinions about MSD ignition systems.

Based on my other posts, it's pretty obvious that I have quite a few projects going with the 1971 Bronco that I purchased several months ago. "Colorado clean and immaculate" obviously means something different to me than it did to the PO.

The Bronco was advertised as having an MSD ignition system. The headers were shot, and after replacing them, it became clear that different plug wire boots would help get the wires away from headers. Thinking I had an MSD ignition system, I ordered new HEI wires and new MSD cap.

I found the MSD system in the back of the Bronco on Saturday... in a box along with MSD wires. Looking closer at the distributor on the motor, I see some text that suggests that the distributor is a remanufactured distributor. (I am guessing it is probably stock.)

I will do some more digging; but, I doubt that there is a MSD HEI controller among the collection of parts.

My question is this.... Would I gain some performance and more reliable starting on the trails by moving to the HEI system? Or, am I just looking to complicate things too much? My guess is that I am only looking at the cost of the controller, although I don't really know if there were any issues with the distributor in its past life.

Thanks again for your help.

Jeff

 

[broncnaz]

If your current dizzy is a points type then yes you would see some increase with a electronic igintion. Points types are ok but need to be adjusted to maintain performance. Where electronic setups are set and forget.
Now as for a MSD setup IMO they are not worth the money especailly on a more or less stock engine. MSD seems to have a high failure rate probably why it was sitting in the back of the bronco. just be aware that not all MSD dizzy's require a igintion box. So you might want to check that as well as wether or not the dizzy is any good becuase if its bad a box wont do any good.
For the most part a stock igintion that is set right and has had the advance curve set so all the advance is in before 3000 rpm will be as good as any aftermarket stuff. Its just the stock stuff is a little harder to mess with to get it setup where the aftermarket stuff is usually already setup or at least setup better than stock and is usually easier to modify if needed.

 

[jw0747]

if your stock distrib has points/condenser your best bet would be to chunk it and the MSD set-up and get a Ford Duraspark ignition. It is Ford's electronic ignition that appeared on 302s et al. in the mid-late 70's. 99% trouble free. Available in most junkyards and auto parts stores. Ask me how I know.

 

[StnePny]

I ran a Ford Duraspark Distributor & a MSD 6A Box

 

[pcf_mark]

If you have stock points type distributor you can run the MSD with only minor wiring. You use the points as the low current "switch" and they will last forever and you never need to change them. The points tell the box when to fire and that controls the coil. Also gives you a convenient tach output if you need it.

MSDs did get a sporadic rap for being unreliable. In my experience of using them in street and drag racing it is not exactly true. I have no off road / high dirt experience. But I have beaten the pants off them with rough riding cars launching on a trans brake. MSD made some improvements in the 90's and these units can be identified by the wiring diagram being on a large label on the bottom. If you do not have the label it is an older unit and may have reliablity problems.

An MSD will get you multiple spark "fires" under 3000 rpm usually giving you a smoother idle and cleaner plugs. Additional benefit is that if your carb is way too rich an MSD will fire the plugs under all conditions (say on a hill while it is practically flooding out). Also if you wire it correctly you can switch back to the points to limp home if the box goes bad.

I am running the factory distributor and wires and MSD6

 

[NC-Fordguy]

I've been running a msd system on my trail bronco for several years without incident. The control box is mounted on the inner fender with isolators.

Lot's of guys here like the duraspark. Several jeep guys I wheel with have or had the duraspark system on their CJs.(AMC used Ford ignition systems) I don't if it's a jeep thing or what but I've seen to many modules fail for my liking.

 

[blubuckaroo]

There has been a lot of debate about the fatter spark of HEI and the longer pulsating spark of CDI. The truth is, unless you're running very high compression or high RPM (not capable with hydraulic lifters), none of this is of any value. The aftermarket GM type HEI retrofit is a monstrosity and some of the cheep ones have had the shaft break at the weld. Google MSD and you'll find a lot of unhappy customers. My favorite is the Ford Duraspark. Not stock mind you, but one set up properly for your particular motor and use. These guys can hook you up with a rebuilt Duraspark distributor for around $150. http://reincarnation-automotive.com/ They set up the curve and vacuum advence to your cam, gearing, transmission, and vehicle weight. You won't be unhappy with the results. If you still want the cool factor look, just put on a nice MSD or Accel distributor cap.

 

[Jeff10]

Hi Everyone,

Thanks for all the great input.

To complicate things a little, I may convert to propane in the near future.

I'll find out exactly what what I have now, and with your advice, that will make the decision a little more straight forward.

Thanks for the advice. I'm sure more questions will follow.

Jeff

 

[pcf_mark]

A key feature of MSD, which is why it was created in the first place, is it can fire a very lean mixture. MSD was developed in the post first gas crunch era. If you want to lean it out and save some mileage and MSD will still light it.

 

[broncnaz]

A key feature of MSD, which is why it was created in the first place, is it can fire a very lean mixture. MSD was developed in the post first gas crunch era. If you want to lean it out and save some mileage and MSD will still light it.

MSD was developed for racng to light off high compression engines it wasnt developed for very lean engines while a lean mixture is harder to iginte and a high perfromance igintion will have a easier time igniting it. running lean is never good. Also leaning the engine out doesnt mean you'll get better mileage. All in all even MSD igintions really dont put out much if any more than a factory igintion system. A igintion system only puts out what is needed to jump the spark plug gap. just because the system is advertised to put out 45K volts doenst mean it does it only means its capible of doing that so even most factory setups can do that. Yes MSD puts out multipule sparks but the duration of each spark is less. and amperage also tends to be less where the stock type setup has a higher amp spark for a longer duration.

I'm not saying a MSD setup doesnt have possible benefits but I just dont think they are worth the $$ on a fairly stock or even mild engine.

 

[John Marinan]

I may be mistaken, but the MSD HEI does not require a control box. It's essentially the same as the GM HEI and completely self contained.

 

[pcf_mark]

http://www.streetlegaltv.com/features/shop-tours/msd-ignition-a-peek-inside-the-famous-red-box/

Read the section on Autotronic Controls which was how msd started with lean burning engines. Leaner does not always equal improved mileage I agree. More spark cycles increase the odds of hitting a piece of the charge that actually fires.

OEM parts are always the most well developed, well engineered and reliable parts.

 

[broncnaz]

Ok I'll stand corrected although it appears that the "Electrasonic Fuel Induction System" never got anywhere and the technology went to racing. Like I said I dount doubt it has benefits. multispark can help as lean mixtures or bad combustion chamber/piston crown design can lead to flame out and a nother spark can help reignite the mixture. On the same note most electronic igintions or should I say coils will through a spark that has a pretty decent duration and does about the same thing.

 

[Jeff10]

Now I'm Curious

Hi John,

I may be mistaken, but the MSD HEI does not require a control box. It's essentially the same as the GM HEI and completely self contained.

Looking at the MSD distributor on Saturday I recall seeing a four-conductor plug (at least that's the number I remember) coming off wiring from the distributor. The only reason I was thinking there was a controller originally installed was because of the connector.

Obviously, I haven't done as much homework as I should. I'm just trying to gather a little basic information in preparation for that work in the future.

Thanks

Jeff