I don't wanna continue to highjack that guys thread so i'm going to start one regarding my ignition setup. While i'm doing my wiring harness swap i want to convert my truck to an MSD 6A box. The wiring that was in my truck (78 w200) was toast for the ballast resistor and coil wires were toast as well. the damn key switch wouldn't even start the truck cause of melted wiring. Anyways....My 6A box will be mounted on my drivers side inside fender by the hood hinge so it will have a lot of air flow passing it to keep it cool. So with the 6A box i won't need my ballast resistor or my ECU right? its all done with the MSD box right? Also since i'm wanting to do away with the voltage regulator for the charging system. I'll be ok with a single wire alternator as long as it has the reuglator built in right? I know my questions maybe off the wall and so on. But i'm just trying to simplify things while i rewire it to keep the engine compartment and wiring harness neat and tidy and everything works properly.
75 Power Wagon
03-08-2009, 12:32 AM
Yes, The MSD 6 Box replaces the ballast resistor and stock ecu. I suggest getting an msd distributor and coil with the ignition box, and that will help clean up your wiring a lot!
Also, the charging system and ignition system are two totally different systems... the voltage regulator is not related at all to the ignition so i would suggest talking about that in another thread, or at least realize it has absolutely nothing to do with modifying the ignition.
I have not had any problems with my voltage regulator, and would prefer the three-wire setup.
You might want to read this article for more information on the disadvantages of the one-wire setup:
http://www.madelectrical.com/electricaltech/onewire-threewire.shtml
I don't wanna continue to highjack that guys thread so i'm going to start one regarding my ignition setup. While i'm doing my wiring harness swap i want to convert my truck to an MSD 6A box. The wiring that was in my truck (78 w200) was toast for the ballast resistor and coil wires were toast as well. the damn key switch wouldn't even start the truck cause of melted wiring. Anyways....My 6A box will be mounted on my drivers side inside fender by the hood hinge so it will have a lot of air flow passing it to keep it cool. So with the 6A box i won't need my ballast resistor or my ECU right? its all done with the MSD box right? Also since i'm wanting to do away with the voltage regulator for the charging system. I'll be ok with a single wire alternator as long as it has the reuglator built in right? I know my questions maybe off the wall and so on. But i'm just trying to simplify things while i rewire it to keep the engine compartment and wiring harness neat and tidy and everything works properly.
thejudges69
03-08-2009, 12:35 AM
yeah i know there 2 different systems i thought i would try to kill 2 birds with one stone :D guess it didn't quite work haha. Anyways what advantage does it have to use an MSD distributor and coil? i'm looking at summits mag now and it seems there coil is a 2 wire still and the distributor is the same as a stock, meaning size and wiring.
75 Power Wagon
03-08-2009, 12:42 AM
yeah i know there 2 different systems i thought i would try to kill 2 birds with one stone :D guess it didn't quite work haha. Anyways what advantage does it have to use an MSD distributor and coil? i'm looking at summits mag now and it seems there coil is a 2 wire still and the distributor is the same as a stock, meaning size and wiring.
The msd distributor and coil come with the wiring that allows you to just drop in the complete msd system at one time and not use any of the stock wires. Having new plugins and wires without any splicing or using of the old wires...
The msd distributor is much better than the stock distributor. I put the whole system in my truck, and at the time, I was getting roughly 6-7 mpg.. and it started getting close to 10mpg at that time. (This was prior to the motor build).
IMO, it would really clean up the wiring to be able to just drop in all the msd stuff. and the performance gains are nice too.
76D100
03-08-2009, 03:19 PM
Good God! 6-7 MPG increased to 10!? How do you manage to feed that thing? When I put my Chevy HEI system in my truck, I noticed a small increase in power and mileage, would it be about the same as the MSD system?
Right now Im doing 19- 20 MPG but that's just a 318 with a low gear rear end hoping for 25 with the OD whenever its in.
thejudges69
03-08-2009, 09:50 PM
from the 75 power wagon avatar and his signature i'm going to assume that his truck is VERY far from stock. Sounds like a real runner.
75 Power Wagon
03-08-2009, 09:57 PM
from the 75 power wagon avatar and his signature i'm going to assume that his truck is VERY far from stock. Sounds like a real runner.
lol... and you are correct. We actually put all the msd ignition stuff on prior to doing the motor build. Back when it was a tired stock bore and stroke 340 with only headers, exhaust, intake and 670 holley 4bbl. It did give me a substantial increase in mpg, but those are low numbers to begin with. But all together there was a power increase, and it was well worth it to do everything.
But, I have been one to go a little further than necessary in upgrading everything. so you can take that however you want to. lol
Also, my truck is not a daily driver.. it's just the toy hot rod that I drive on my days off and work on ALL DAMN WINTER! lol
If you do not go with the MDS distributor, I suggest at least getting a connector from MSD so you can put the wires in a pigtail and clean the wiring up that much more.
rick 1978pwagon
03-08-2009, 11:53 PM
I have The msd 6a with the dist and coil and it is a great system get away from the stock Stuff if your budget allows. Hey power wagon 75 are you my twin brother from another mother seems like we have a lot in common as in engine and access oh ya and trucks?
thejudges69
03-10-2009, 02:39 PM
Ok i talked to the company that made the wiring harness i'm installing and he really didn't understand the reason for changing the distributor and coil as well. Now the coil i am going to change for sure. the one thats on the truck is broke anyways. But the dist. i have is a 2 wire and i don't have any of the factory plugs anymore so its more of less putting ends on everything and plugging it all back in. Was that the only reason for really changing the distributor? just the plugs? just wanna make sure i'm understanding this.
B-300
03-10-2009, 03:20 PM
The stock distributor can be used to trigger the MSD 6A via the magnetic pickup wires (purple and green twisted pair).
The MSD distributor is easiar to change the timing curve on than the stock distributor.
rick 1978pwagon
03-10-2009, 08:25 PM
you could also get away from vacuum advance with a msd dist set up a bit more money but no more vacuum hose.
3834B
03-11-2009, 04:06 AM
Why would yo want to get away from the vacuum advance?
charlie1935
03-11-2009, 09:07 AM
Why would yo want to get away from the vacuum advance?
So it will use more gas! ;)
rick 1978pwagon
03-15-2009, 10:25 AM
The msd distributer has different springs you could use to customize what you want be it daily driver or serious off roader but was told getting away from vacuum advance was going to have minimal effects if any at all?
3834B
03-15-2009, 01:44 PM
Really sounds like a bunch of bunk. For years engines ran and ran well using full manifold vacuum to the distributor. Emmission standards changed that.
The way it was taught to me was at idle the air/fuel mixture is very lean, in turn lean mixtures burn slower than rich mixtures therefore you want the spark timing to arrive sooner. A small block with initial timing set at 10 degrees would likely jump to 20-22 degrees with full vacuum at idle. This would be optimum.
Not sure how removing this advance i.e. a distributor without a vacuum cannister would not affect performance and as charlie1935 eluded to fuel efficiency. The minute the throttle is opened vacuum would drop to zero and this portion of the advance would be lost.
The mechanical advance would then take over. This part of the advance is strictly RPM dictated and engine load has no affect. I think the small blocks run about 32-34 degrees total advance. Of couse you need this kind of advance because of the engine (increased) RPM.
Now, while cruising at highway speeds and light throttle is being used not much horse power is required. I think somewhere between 40-50 ponies. At this time there may be as much as 50 degrees timing advance when you factor initial, mechanical and vacuum working at once.
Not seeing how removing vacuum on a stock or street engine would be an advantage. It's been quite a few years and beers so if I am off here someone please chime in.
B-300
03-15-2009, 02:01 PM
Think of it this way:
As rpms increase you need more timing advance to start the fire early enough it burns well as the piston comes to TDC. (mechanical advance is rpm proportioned.)
Also as load decrease you can start the fire earlier due to the slower flame response caused by a leaner mixture. (This is were ported vacumm advance works and helps the transition from low to more load for tip-in throttle response without ping when tuned correctly.)
