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Spark Booster Gizmos

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DaveCooper

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I have a 74 Elite with stock ignition. The main Jensen-Healey site has a self-described expert who raves about the MSD spark booster on the Lotus 907 engine, even with the stock points distributor.

Do any of you have actual experience comparing the stock (points) set up to the MSD with no other mods? Or, Pertronix's similar Second Strike gizmo to the stock ignition with no other mods?

Do these do much more than smooth out the idle and/or low rpm running? The MSD apparently cuts out at 3,000 rpm, so I don't see how performance would be that much affected; the Second Strike apparently works all the way up the curve.

If the spark boosters added that much, I would expect them to show up as stock in the later versions of the 907, or the Esprit. Are they worth the $200-$300?

Dave
 
This is JUST an opinion, Dave, but all that whizz-bang is simply a way to separate you from your money. A well maintained "conventional" ignition system is every bit as reliable and eminently more "servicable" than the "box-o-tricks" modules. If your wallet allows a spare in the boot, then mebbe it'd be an alright swap. Otherwise, a set of points and condensor in the glove box work jus' FINE.
 
I'm not familiar with the specific options you're looking at but my experience is that a system that eliminates the traditional cam & points is less sensitive to worn distributer shaft bushings than the stock ignition. Sometimes the bushings get worn so much that you can't set a consistent dwell on a stock system, and a system triggered with a rotor is less sensitive to shaft wobble.

However, I'd stay with a stock system where it's possible.
 
Thanks for the opinions. I'll probably give in to the temptation eventually, and report back that it made no difference at all. Here's the portion of the expert quote regarding MSD, from the "Jensen Healey Preservation Society" website, for what it's worth:

______________________________________


"The Best 907 Engine Modifications

(prior and subsequent stuff deleted...)

Multiple Spark Discharge
The MSD (Multiple Spark Discharge) ignition control unit installs easily. Its' wires just plug onto extended coil adaptors provided and the power lead. Takes only seconds to convert back to stock configuration. Unit provides instant starts and better fuel burning characteristics for better power and cleaner running throughout the rpm range. Save your engine, over 80% of engine wear is attributable to cold start cranking. I run mine with the stock distributor and points. Points last about 40,000 miles and no reliability problems that many people have with electronic ignition systems. I originally used this on a engine that was only running on 2 1/2 cylinders for a few months and it actually make the car drivable (it did get bad gas milage). For my money, the best single improvement you can make on your engine. Smog legal in California. Usually available from "performance" type auto-parts stores. The MSD Model 6a runs about$140, check around for best pricing. "
 
Not familiar with the MSD, but....

Points and condenser were relegated to the round file more than 25 years ago on mine. I have used a photocell ignition with zero problems (yes I know that I am now asking for it).

Dr E previously posted a pic of my car with me sticking my arm under the carbs. This was probably one of the half dozen instances of me burning the **** out of myself trying to access the distributor because of points.

Along with a gear reduction starter, electronic ignition is one of the best things I ever did to the car.
 
/bcforum/images/%%GRAEMLIN_URL%%/lol.gif Got Nomex?!! /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif

...that's JK's arm, BTW. The rest of the shot has the ubiquitous Swisher Sweet in it. A dark beard surrounding. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
 
I highly recommend the MSD 6A and 6AL ignition boxes, we have one on our 79 MGB and our 78 Midget and my 68 Sprite. It does everything as advertised, plus with the 6AL you get a rev limiter. You can burn anything with a good fat spark!
 
That'd be a "good LONG DURATION spark" y'mean.
 
DrEntropy said:
/bcforum/images/%%GRAEMLIN_URL%%/lol.gif Got Nomex?!! /bcforum/images/%%GRAEMLIN_URL%%/devilgrin.gif

...that's JK's arm, BTW. The rest of the shot has the ubiquitous Swisher Sweet in it. A dark beard surrounding. /bcforum/images/%%GRAEMLIN_URL%%/wink.gif
Click to expand...

LOL I stand corrected, I probably told him, "You adjust the points, while I go to the burn unit."

Not worried about flaming, I know what has worked for me, and what has not.

As a concession to the POD, I do run a Lucas rev limiter rotor.
 
No argie. My odd philosophy is well known. I can whip that dizzy out in no time, so it's not an issue fer me. Points and a condensor fit inna glovebox and cost roughly ten bucks. I'm cheap, I'm practical and I have LOTUS FINGERS. /bcforum/images/%%GRAEMLIN_URL%%/smirk.gif
 
My experiences are all that I can offer.

I first went to an Allison(now Crane) optical trigger to replace the points and condensor on my 6(I know different car, but same type of suck, squeeze, bang, spit system) back in 86. Worked great. The distributor bushings were getting a little worn as I could watch the dwell change and point signal on the oscilloscope screen was interesting.

At that time a replacement distributor for the six was almost as scarce as hen's teeth(unless I wanted to go junkyard shopping) and beaucoup bucks. So I decided to go to an optical pickup system. got the allison for less than 100. worked great, still have it, transferred it to two later 6's with well over a 100K miles on it, on the same distributor...

After a year or so I went to headers and SK carbs(weber style sidedrafts). After going through the jetting four or five times, on a dyno and with airfuel gauge(the ol' smog sniffer in the tailpipe, as I was a California smog tech then) I still had a low to mid range burble, that I couldn't dial out. So got a MSD 6 box and put it on. The carb problem was no longer a problem..... My 6 was driven at rpm levels mostly around 3-4K... You Lotus may be different, but I can recommend the Allison and MSD based on my experience.
 
I can't argue the efficacy, Ron. The MSD will allow good combustion with "wobbly" dizzy shafts. I'm coming from the "why not renew the bushes" angle. I, too, have nursed these cars thru the period when parts were next-to non existent, know the frustration of: "NLA". My proclivity is to keep the silly things as close to the way they were as possible, so I tend to go the stupid route and fabricate what I can't get on the "market".
Some things are truly "unobtanium" so consessions are now part and parcel, but I'm stubborn. /bcforum/images/%%GRAEMLIN_URL%%/jester.gif
 
I agree, now the distributors can be rebushed and plates rebuilt quite inexpensively. Was different way back and once I find something that compensates for a problem, I tend to stick with it in case that problem, even though corrected, should reoccur again. That way the bandaid, which has become a permanent patch works...
 
Update, on my 74 Elite:

This weekend, I gave into temptation and bought the MSD 6A for about $200 including tax.

It took about 90 minutes to install in the engine bay where my carbon filter used to sit, required that I run a hot wire from my battery up to the unit, and required that I clip a couple of stock connectors and crimp-on other types of connectors. Probably a 20 minute job for someone more competent.

And...the cold engine started up on the first crank and amazingly needed no choke to keep going. That was the first pleasant surprise. Then, on the road, it actually did pull stronger. Nothing crazy, but noticeable. Yes, the gizmo worked as advertised. Nobody was more surprised than me. Also, when completely warmed up, the idle was smoother.

So, $200 well spent. How does it work? I know what the advertisement says, but if every car from the mechanical points-era would benefit, why didn't they all come with something similar? The MSD is just a capacitor. Maybe the Lotus ignition was especially poor, or the ZS carbs and/or intake manifold chosen for the US market were a bad match for the stock ignition.

Whatever. Now the car starts in the morning on the first crank and pulls noticeably harder.

Later,

Dave
 
MSD is also multi-spark below a certain rpm range. If you get the chance to ever take it to a shop with a good scope, have him hook it up. You might find the secondary pattern interesting.
 
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