Ignition question involving use of ballast resistor

Jack wrote:

>
> At 2500 rpm, a V6 is firing each plug over 20 times a second.
>
> Each intake and exhaust valve is opening and closing at the same rate.
>
> 125 explosions a second, all synchronized to maximize power output.

Its not a car engine, but given the stats you quoted above you should
enjoy this little read....


http://www.sandersaircraft.com/aircr...readnought.pdf

Steve wrote:
> Jack wrote:
>
>> At 2500 rpm, a V6 is firing each plug over 20 times a second.
>>
>> Each intake and exhaust valve is opening and closing at the same rate.
>>
>> 125 explosions a second, all synchronized to maximize power output.
>
> Its not a car engine, but given the stats you quoted above you should
> enjoy this little read....
>
>
> http://www.sandersaircraft.com/aircr...readnought.pdf


Holy Crap!

Each cylinder displacement is as big as a small V6!

And there is 28 of 'em!

"Each piston has traveled 50 feet in linear distance, changing direction
100 times per second, with the total linear travel of all 28 pistons
adding up to a ¼ mile."

What controlled fury!

Look at the crew who probably serviced the carburetor:

http://www.vintagecarburetors.com/about.htm

happy looking bunch, eh?

On Dec 30 2008, 9:56*pm, Jack > wrote:
> 1987 Dodge Dakota 3.9L carbed
>
> I recently posted on rec.autos.tech about the problems I was having with
> an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
> could use one or the other with no problem, either the MSD ignition with
> the stock coil or the MSD coil with the stock ignition, but if I had
> both installed I would get a stumble on accelerating from a dead stop.
>
> From this behavior I deduced that, for some reason, the problem was
> being caused by too much ignition voltage. To test out that theory I
> installed a 1 ohm ballast resistor in line with the +12 volts going to
> the coil. Voila, the problem vanished and I was back to strong, smooth
> acceleration from a dead stop. So then I tried a 1/2 ohm ballast
> resistor and the stumble returned, but not as bad, so I went back to the
> 1 ohm resistor.
>
> The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
> or so primary. I don't know what impact this has on the situation but
> it's info that I have and I figured I might as well throw it in if I am
> going to all the trouble of posting this and you are going to all the
> trouble of reading it.
>
> Now we get to meat of the my puzzlement. The ignition wires that I have
> on the engine measure about 3000 ohms per foot. For about $45 I can buy
> some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
> about electricity, but not enough to know whether or not these wires
> would enable me to run the MSD ignition and coil without the ballast
> resistor. After all, the point of an MSD ignition upgrade is to get
> longer stronger spark to the plug.
>
> I don't have a clue as to why the engine stumbles with both the MSD
> ignition and coil installed. From the symptoms it seems to me that it
> must be because of too much voltage at the coil tower, but why that
> might be causing the problem is beyond me.
>
> Could it be because the high voltage is leaking out to ground somewhere
> on the way to the plugs? I checked the engine at idle in a dark area at
> night and saw no evidence of arcing. Could the high resistance wires be
> the cause? If so, what is the rationale? I can't think of one.
>
> Well that's it. At present, I am more than happy with the ballast
> resistors. The truck runs great. Just curious as hell as to what might
> be going on.
>
> Jack

> iron monkey,
well you should put the msd in and the coil pack in . then you should
run a NOVIS
system on your cars brain box to change the factory setting . to a
higher voltage . You can also up the fuel and air ratio , novis is a
wonderfull tool .

IRONMONKEY wrote:
> On Dec 30 2008, 9:56 pm, Jack > wrote:
>> 1987 Dodge Dakota 3.9L carbed
>>
>> I recently posted on rec.autos.tech about the problems I was having with
>> an MSD 5900 Blaster ignition and an MSD 8202 Baster 2 coil. It seems I
>> could use one or the other with no problem, either the MSD ignition with
>> the stock coil or the MSD coil with the stock ignition, but if I had
>> both installed I would get a stumble on accelerating from a dead stop.
>>
>> From this behavior I deduced that, for some reason, the problem was
>> being caused by too much ignition voltage. To test out that theory I
>> installed a 1 ohm ballast resistor in line with the +12 volts going to
>> the coil. Voila, the problem vanished and I was back to strong, smooth
>> acceleration from a dead stop. So then I tried a 1/2 ohm ballast
>> resistor and the stumble returned, but not as bad, so I went back to the
>> 1 ohm resistor.
>>
>> The stock coil has about a 1.5 ohm primary and the MSD coil has a .7 ohm
>> or so primary. I don't know what impact this has on the situation but
>> it's info that I have and I figured I might as well throw it in if I am
>> going to all the trouble of posting this and you are going to all the
>> trouble of reading it.
>>
>> Now we get to meat of the my puzzlement. The ignition wires that I have
>> on the engine measure about 3000 ohms per foot. For about $45 I can buy
>> some MSD Street Fire wires that are only 500 ohms per foot. I know a bit
>> about electricity, but not enough to know whether or not these wires
>> would enable me to run the MSD ignition and coil without the ballast
>> resistor. After all, the point of an MSD ignition upgrade is to get
>> longer stronger spark to the plug.
>>
>> I don't have a clue as to why the engine stumbles with both the MSD
>> ignition and coil installed. From the symptoms it seems to me that it
>> must be because of too much voltage at the coil tower, but why that
>> might be causing the problem is beyond me.
>>
>> Could it be because the high voltage is leaking out to ground somewhere
>> on the way to the plugs? I checked the engine at idle in a dark area at
>> night and saw no evidence of arcing. Could the high resistance wires be
>> the cause? If so, what is the rationale? I can't think of one.
>>
>> Well that's it. At present, I am more than happy with the ballast
>> resistors. The truck runs great. Just curious as hell as to what might
>> be going on.
>>
>> Jack
>
>> iron monkey,
> well you should put the msd in and the coil pack in . then you should
> run a NOVIS
> system on your cars brain box to change the factory setting . to a
> higher voltage . You can also up the fuel and air ratio , novis is a
> wonderfull tool .

Novis? Never heard of it and can't find anything about it thru google.

Are you sure of the spelling?

Jack wrote:
> Steve wrote:

>>
>> http://www.sandersaircraft.com/aircr...readnought.pdf
>
>
> Holy Crap!

That pretty much sums up an R-4360 ;-)
>
> Each cylinder displacement is as big as a small V6!
>
> And there is 28 of 'em!

28 cylinders, 56 spark plugs, 4 magnetos. One caburetor (actually a
hybrid called an "injection carburetor" with venturis the size of coffee
cans.
>
> "Each piston has traveled 50 feet in linear distance, changing direction
> 100 times per second, with the total linear travel of all 28 pistons
> adding up to a ¼ mile."
>
> What controlled fury!

In this case, controlled SEA Fury ;-)

And when those engines were installed in a B-36 or a Globemaster, they
would run *continuously* for 20+ hour missions. A B-36 had SIX 4360s,
each of which had two turbochargers in addition to its 56 plugs. That
made for one very busy flight engineer! Turbocharger wastegate,
throttle, mixture, prop pitch, and several other parameters were all set
and monitored by the FE. Good old days!