Distributor question

[pjmopar]

Hey guys,

I need some advice. I am rebuilding a 71 383 magnum, Hughes Engines did the block and heads expecting close to 500 HP. I have a mallory dual point that I was running before the rebuild. Cannot decide whether or not to go pointless. Is there a big difference? If so, what brand do y'all recommend.

Thanks.

[72Challenger]

The dual points were good for their day, they did the job of increasing dwell and thus improved high-RPM spark. But by todays standards they are hopelessly outdated. The maintenance-free aspect alone makes a new distributor well worth the cost.

[DartGT66]

Add a MSD ignition box, and your dual point becomes maintenance free. No big current through the points anymore, and practically no need for adjusting & maintenance there.

[dwc43]

You can only use one set of your dual points with an MSD box. One set has to be disconnected. Your better off with a magnetic pick up and an MSD box. Single points on an MSD box can still bounce at higher rpms causing misfires.

[pjmopar]

What about the ignition package you can get at JEG's? It comes with the orange box, wiring, and distributor all for $197.00

[dgc333]

If you are looking for 500HP from your motor there is going to be some tailoring of the advance curve in the disributor necessary. One of the MSD or other brands that allow electronic shaping of the advance curve or have the mechanism up top easy to get at will make your life so much easier.

[72Challenger]

Not only that, but a 500 HP 383 isn't going to idle nearly as smooth as a stocker. It could really benefit from a multi-spark type ignition.

Confession: I'm using the stock breaker-point distributor in my truck, but it still triggers an MSD unit, and that's with a stock 440. After I'm done with my Challenger (right, like that's ever going to happen!) and I get around to rebuilding the truck, a better distributor is going in. For now, for a stocker, it works okay.

If you want something that works okay, the Jegs setup will avoid the need to replace and adjust points, but it won't work any better than what you already have. With what you had to pay Hughes for a block and heads, why cheap out on the ignition system?

[dwc43]

Originally Posted by pjmopar

What about the ignition package you can get at JEG's? It comes with the orange box, wiring, and distributor all for $197.00

The orange box is failure prone. IT also removes dwell as rpm goes up. It's not the choice. I'd get a good MSD box and Dist. from them and your set.

[TK]

I put 110,000 miles on a orange box.
I like points, I guess it is the hard headedness in me.

[dwc43]

Originally Posted by dodgetruckboy

I put 110,000 miles on a orange box.
I like points, I guess it is the hard headedness in me.

You got lucky then. Main thing about them is that they lose dwell at higher rpms and that will kill hp in a 500 hp engine.

[pjmopar]

I received an email from FBO they said that they would curve and phased my distributor to my engine. They advertise their units to go as high as 8800 rpm without losing dwell. Do they know what they are talking about?

[dwc43]

Yep. dwell is how long it takes to fill the coils primary windings to it's capacity before it's triggered and they colapse to the secondary windings and then produce a jump in voltage to be delievered to your plugs. There box is o.k. for a mild street engine, but you'll want the multi spark and performance of an MSD box for high hp engines.

[dart662dp]

would not even consider a gold/chrome/orange box
MSD and magnetic pick up. period.
not a fan of crane electronics, a little cheaper, but the only boxes that will work with crane boxes, are crane boxes! pita
the msd distributors are ultra slick as well Hmmmm, 3 step, trans brake, delay box

[345Dart]

The FBO system works very well and the recurving of your distributor to the components in a 500hp engine will make the world of difference too. I replaced a MSD 6A with the FBO system.
As for dwc43 ignorance of the FBO system - you make up your own mind many of us have already.

[dgc333]

Originally Posted by dwc43

Yep. dwell is how long it takes to fill the coils primary windings to it's capacity before it's triggered and they colapse to the secondary windings and then produce a jump in voltage to be delievered to your plugs. There box is o.k. for a mild street engine, but you'll want the multi spark and performance of an MSD box for high hp engines.

dwc43, dwell is the number of degrees of rotation that current is flowing through the primary windings of the coil. However, to saturate the coil it takes a fixed amount of time (milli seconds) at a constant voltage. So as the rpm rises the amount of time the coil has current flowing through it goes down. Just when the engine needs more potential to light the fire the ignition system is putting out less.

[dwc43]

Originally Posted by dgc333

dwc43, dwell is the number of degrees of rotation that current is flowing through the primary windings of the coil. However, to saturate the coil it takes a fixed amount of time (milli seconds) at a constant voltage. So as the rpm rises the amount of time the coil has current flowing through it goes down. Just when the engine needs more potential to light the fire the ignition system is putting out less.

Thanks, but I know what it is and that's what I said before in much simpler terms. Time and number of degrees is basicaly the same thing.

[dwc43]

Originally Posted by 345Dart

The FBO system works very well and the recurving of your distributor to the components in a 500hp engine will make the world of difference too. I replaced a MSD 6A with the FBO system.
As for dwc43 ignorance of the FBO system - you make up your own mind many of us have already.

No ingnorance here buddy. I know it real well, that's why I told him to go MSD like most of the others did. FBO has no multi spark below 300 like an MSD box has so the FBO wont help to keep the plugs and cylinders cleaned out at idle. Believe someone else mentioned that as well. Glad you don't have a 500 plus hp engine or no use for an MSD box though.

[dust]

Originally Posted by 345Dart

The FBO system works very well and the recurving of your distributor to the components in a 500hp engine will make the world of difference too. I replaced a MSD 6A with the FBO system.

MSD has distributors with adjustable curve under the cap via a dial.

[dwc43]

Not to mention that you get rev limiters, and you can set the timming right from your seat with an add on to the MSD box. Can't do that with an FBO.

[dave571]

Multi spark is a great feature, but for most guys only really necessary on motors with cams with 260@50 or better.

Above 3000 rpm MSD is no better than any other performance ecu, be it FBO, mopar chrome, whatever one you like....

My motor is closer to 600hp than 500 and has no need for msd. My motor must not realize it needs msd to make any power.

In any case, MSD is a decent performance ecu. Holds a straight curve without dropping cylinders, just like and FBO, mopar chrome, whatever one you like.... Precision spark delivery, but hard on ignition parts. I personally would not run one in a street car. I have done so, but it becomes a pain in the a$$.

Yes msd has lots of features that can be bought for a price. I've never needed to adjust the timing from my seat, so I don't know why I would want to. I set it right the first time, under the hood.
Again, my motor must not realize it needs all that stuff to make power.

A properly curved distributor, with properly limited mechanical advance, and a quality ECU will give good power, no matter who's name is on it.
FBO will curve a distributor for a specific application. I don't think that's a service MSD offers among all of it's expensive products. An adjustable distributor is still not adjusted for your car. If all you want is an adjustable one, buy the MP unit. It has adjustable slots for the total advance, and spring selection will bring in the timing when you want.

But then again, I curve distributors on my own dist machine, have a test bench for loading coils and ecu's, run a 11 second 3800 pound BB car with regular ignition on it and only a 750 carb(not an 850 tq), what could I possibly know?

My .02

ps, I've been in 345dart's car. I know what it makes for power. It must not realize it needs msd either.

[Kevin Garceau]

so your saying on my 14.8:1 alky injected motor I could run a chrome box?

You say an MSD is no better than them.... dont forget the amount of output an aftermaket box has over a stock box.... Jouelles...or however its spelled.

Not everyne needs an MSD, I like the ease of start retards, built in rev limiters, shift points, programmable timing etc.....its not for everyone, but its definatly NOT the same as a chrome box.

Then again my small block is closer to 700hp than 600...

I dont idle enough to care about the multiple spark they could take that out, its the output and the other features that make it worth MY while, and money.

IHRA or NHRA stock/super stock... do they run stock ignitions or put in MSD?

[dwc43]

Good points Kevin. Most don't know that you need more power to light the fires with when cylinder pressures go up due to high compression and other forces and the stock or FBO wont cut it.

[pjmopar]

One thing I failed to mention that might help, and that is this car (71 Dodge Charger) is strictly going to be a street machine. The only racing that it will see will be between stop light to stop light. The duration of the cam is 228/232. Gear is a 3.23 (I know I probably need a lower gear) Detroit Locker.
I do appreciate your advice and comments.

[dave571]

Originally Posted by Kevin Garceau

so your saying on my 14.8:1 alky injected motor I could run a chrome box?

You say an MSD is no better than them.... dont forget the amount of output an aftermaket box has over a stock box.... Jouelles...or however its spelled.

Not everyne needs an MSD, I like the ease of start retards, built in rev limiters, shift points, programmable timing etc.....its not for everyone, but its definatly NOT the same as a chrome box.

Then again my small block is closer to 700hp than 600...

I dont idle enough to care about the multiple spark they could take that out, its the output and the other features that make it worth MY while, and money.

IHRA or NHRA stock/super stock... do they run stock ignitions or put in MSD?

Your points are good kevin but your reading isn't.

I nowhere state that msd isn't better on an application like yours. Clearly it is.

it is also clear that your alcohol injected car bears absolutely no resemblence to the street car that started this thread.

Of course the super stock guys run better ignition. For the same reason.


MSD is the same as any other presision ecu when the multi spark steps back to single, around 3000 rpm. FBO chrome or whatever. The differences are below that, and yes they are signifigant.

[dave571]

Originally Posted by dwc43

Good points Kevin. Most don't know that you need more power to light the fires with when cylinder pressures go up due to high compression and other forces and the stock or FBO wont cut it.

Talking out your a$$ as usual.

The coil in the fbo kit produces more KV than an msd coil. It will "cut it" on lots of applications. Some guys even run the fbo coil with msd for better performance on applications like Kevin's. Maybe not good enough for a dirt track car with the unbelievable 360/TQ combo but it will work on some applications.

I have never said MSD is crap, and will not say it. There are other systems that will work for most applications. To say MSD is the only upgrade worth considering on a street car is simply ridiculous.

[72Challenger]

Originally Posted by pjmopar

One thing I failed to mention that might help, and that is this car (71 Dodge Charger) is strictly going to be a street machine. The only racing that it will see will be between stop light to stop light. The duration of the cam is 228/232. Gear is a 3.23 (I know I probably need a lower gear) Detroit Locker.
I do appreciate your advice and comments.

With that gear ratio, and mostly in-town driving, you will be spending most of your time under 3000 RPM. So the multi-spark will be a factor. The MSD box is around $200 by itself, you then still need something to trigger it with. So it will definitely be the most expensive solution. But do you need it?

Remember that ignition systems don't make power. But an ignition system that doesn't work perfectly will cost you power. In most cases, a single spark, of the right intensity, at the right time, will ignite the mixture in the combustion chamber, and that's that. It won't get any better than that. The Orange box is one step better than a stock ignition. So is your existing Mallory dual point for that matter. I would only change to the setup from Jegs if you're interested in the no-maintenance aspect, not because it will work any better. The FBO system is a much-improved stock-style system that works better than anything you can get from Mopar Performance. The MSD is a capacitive-discharge system that provides much higher spark energy than the other systems and also will give multiple sparks below 3000 RPM. Keep in mind that those additional sparks do absolutely no good if the first one did it's job and set off the mixture correctly. Nor will the extra energy somehow magically make that combustion "better" if the standard spark would have done the job.

Every engine has its own requirements. Why don't you call Hughes and ask them what they recommend for an ignition system? They would know better than anyone what makes their engines run best.

[Kevin Garceau]

Your points are good kevin but your reading isn't.

Above 3000 rpm MSD is no better than any other performance ecu, be it FBO, mopar chrome, whatever one you like....

my reading looks fine, as you can see from your quote above. .Im not saying he needs a 600 dollar ignition, I was just making a point comparing what you said. The MSD produces more joulles than a stock ignition...considerably more, which help light the fire with high pressures etc...IT IS NOT THE SAME above 3k

The MSD box is around $200 by itself, you then still need something to trigger it with. So it will definitely be the most expensive solution. But do you need it?

I have ran my with stock distributor for many years. When you have the MSD in place the dist just points the fire....

[dart662dp]

ever try to light nitromethane with a stock box?
i converted to msd on my slant 6s long ago, 12:1, 248/253 .508 cam, the only advantage i saw with the stock type box was a smoother idle. have continued using them as engine size has increased, and will continue to do so.
when you are trying to get power out of a slant, you need all the help you can get! the slants have long since blown up, but still running the same old 6t msd on the v8. Have it on my car, and truck, both street driven.

No, not everyone needs the multi spark under 3,000 rpm, or the longer duration spark over 3,000. There are definate advantages to running the multi spark units, better economy, more complete combustion, easier starts, lots of plug and play goodies etc. Just because a motor runs pretty darn good an a stock box, does not mean it does not need msd, it will run better with it. MSD would have gone out of business back in the 70s if it had no advantages.
Have seen many bottom ends blown out by misfires at high rpm that COULD have been prevented by a GOOD ignition. Hydraulicing a cylinder with power adders is no joke, one sneeze and the motor is junk. Why take that chance?

it may just come down to personal preference, try the points, try the conventional ecu's, and try the multi spark unit, and come to your own conclusion. it is gona be pretty obvious.
I do not see people removing their msd units from street cars to install a gold/chrome/orange box. Nor do i see as many DEFECTIVE multi spark units as i do the multi painted units.

The 440 source has msds for $120-$150

[dave571]

Originally Posted by Kevin Garceau

IT IS NOT THE SAME above 3k



..

Educate me.

What's the difference in dwell and output? an MSD isn't doing multiple spark in the higher rev's so what is the benefit of it?

[dgc333]

Originally Posted by dave571

Educate me.

What's the difference in dwell and output? an MSD isn't doing multiple spark in the higher rev's so what is the benefit of it?

In a conventional ignition system (points or electronic) current flows through the primary windings creating a magnetic field that staturates the secondary windings in the coil. When this flow of current is interupted the magnetic field collapses (points open or ecu swiches off) and a potential (i.e. voltage) is generated in the secondary windings of the coil once this potential builds up to a level necessary a spark jumps the plug gap. To get maximum ouput from a coil this saturation takes a measurable amount of time. The term dwell is the angular measurement of the time that current is flowing in the primary winding. Problem is that even though the dwell stays the same across the rpm range the actual time decreases and the coil requires time to saturate. So conventional ignition systems have less potential output at higher rpms than at lower rpms.

A capacitive discharge system like an MSD works on a different principle. A capacitor is charged up in the MSD box and then a much higher (several hundred) voltage is discharged through the primary windings of the coil. It is the rapid rise in voltage in the primary windings that produces the potential in the secondary. Because the coil is operating at much higer voltage levels the coil has the potential to produce a hotter spark. The MSD system operates fast enough that the system can actually produce multiple sparks at low rpms. Again because things are happening much quicker at high rpms the system can no longer keep up the multiple sparks and reverts back to one.