Beefing up the Tangerine Tornado

DorianL

DorianL

solid fixture here in the forum
Staff member
Right, so I think it is likely that the twin electric fans were over taxing the ALT and for some reason this led to the ignition quitting on me.

So, the plan is to replace the ignition box, a programmable MSD 6AL-2 and beef up the charging.

Brian has kindly offered to build me a high output ALT. I am going to rewire + add a circuit breaker rather than a fusible link.

I also will put the battery minder on board so that I can "plug my car in the mains" just like the chevy volt :mrgreen:

Plus also add a battery disconnect and an in-dash volt-meter.
 
What should be interesting is to see if I can simply load the past ignition plot from my laptop onto the new box...
 

Are you sure that's high enough, the CS 144 is capable of putting that much out at idle. What happens when you are driving, the breaker might be tripping under normal operation???

The breaker is to protect when something goes wrong, in this case, when the alternator exceeds it's rated maximum output. Looks like Brian should know what that max rating is. They also have a 120a and a 150a breaker at Summit Racing.

That's my understand anyway.....maybe I'm wrong.

87vette81big said:
Slight change of plans Dorian,
Came across and picked up used GM DELCO CS 144 Alternators today.
V8 Style.
Skip the CS 130 build.
Slightly bigger alternator a CS144.
Deliver 80-100 amps at engine idle.

Need to know if you have any extra adjustabilty in your bracket.
Center to center bolt pattern is 7.5 inches.
Checked against 10si, 12, 15si alternators today. Roughly 6.5 inch.
CS 144 Police Car Heavy Duty.

Have enough CS144 alternators present for a few builds.
Use 2 on my 1963 Pontiac Grand Prix and my 1987 Corvette.
Click to expand...

 
go atleast with the 150A but that still too small, and i do think a fusible link is a better idea(can be set closer to the battery-starter junction/increasing protection)
This is in case of a short so a breaker is kind of useless since short do not happen very often, thats also why it need to have a hudge AMP rating like a fusible link.
Is you go the fuse route use twice the amp rating of the alt and try to get slo-blo fuse. but .. get a fusible link.. More discrete and it is designed for this purpose.
 
Using a circuit breaker is a good idea. Not everyone uses them.
I dont use circuit breakers myself on the alternator charge output wire.
Its personal preference to use or not.
Some of these CS144 early and late alternators put out more than 120 -140 amps.
Reports of up to 200 amps at 13.0 - 14.4 volts.
Depends upon the particular unit and build quality.
Just have to build and spin test for actual measured Current - amps output.

Thinking back EMF or e' of I killed Dorians MSD ignition.
Sharp power spikes in heavy amp loads through an inductor copper coil of wire.
Shut the power load off, ,12volts DC becomes 100 to 500 volts DC momentarily, few milli seconds or more.
Modern electronics not happy then.
Such as when electric cooling fans turned on then off.
Step up square wave power supply in all MSD units, SCR Switches or saturates ignition coil then cuts current off instant.
Primary ignition coil current collapse induces a high Kv voltage in secondary winding to fire each spark plug gap.

Personally, I think Vertex Magnetos are best ignition system.
Not for everyone.
Light the Fire with AC alternating current.
Not DC DIRECT Current like MSD does.

Use a good magneto once and win, wont ever want to use anything else.

Brian
 
http://www.summitracing.com/parts/prf-40030/overview/

?

Surge Protector, Electrical System, Regulates Spikes at 14.5 Volts, Each
prf-40030_w.jpg
 
DorianL said:
http://www.summitracing.com/parts/prf-40030/overview/

?

Surge Protector, Electrical System, Regulates Spikes at 14.5 Volts, Each
prf-40030_w.jpg
Click to expand...

Dont use that, its just a hudge diode with 14.5v cut-in voltage (i question this value thats pretty low to start with) shorting the excessive voltage across the pos and neg of the batt.
I would also made the device with 2 or 3 diode in serie for better reverse voltage protection (but this will offset the cut-in voltage from the original design) and safety if a diode happen to shorts and will help the diode to last longer"this usually for heavy duty aplication" and probably a big resistor to limit the current the device can conduct.(diode are cheap anyway and at 26$ for just that...)
If the overvoltage is from the alt(usually that happen with a defective alternator) your probably going to blow the alternator or the diode or both and then the problem that can occure are endless.
And its best have a volt gauge you know its charging and not overvoltage.
 
Got me thinking Dorian.
A Zener Diode of carefully selected value placed in parallel with respective polarity across your electric fan motors may provide decent protection for your MSD Programmable 6AL ignition box from back EMF power spikes.
There is EMF generated on inductive copper windings internal within the electric fan on startup,
And when the fan is switched off.
A Pie type filter works very well protecting from power spikes, problem is the choke coil would have to be very large and heavy in weight to handle the electric fan motor current loads being wired in series. In theory, High EMF voltage and current would be safely bypassed back to ground or the vehicle chassis ground.
Toroid Choke coils are efficient too in Pie type circuits.
There are CMOS surge protectors too, never seen one available for 12- 14 volt DC auto systems.

Brian
 
You must log in or register to reply here.
Back
Top