FrontEngineDragsters.Org Forum
Technical => Matt Shaff's Engine Shop => Topic started by: George on June 20, 2013, 05:14:02 AM
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It's time for a new thread.
I currently run the MSD 12LT magneto with a tach convertor to run the rpm modules. We upgraded the engine last year and the engine builder/ dyno operator talked me into a MSD digital 6 + system. We dynoed the engine with a MSD 6 with good numbers. MSD told me not to run the Digital 6 + if I were using the same battery for both the ignition and to start the car. I didn't see any on track difference between the Digial 6+ and the 12LT mag.
Spark plug gap is the reason I tried the electronic system as I could run a .030 gap. With the mag .018 is the maximum. I'm told the wider you can open the plug gap the greater the potential power.
What's your take on this? Thanks. George
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With my injected alcohol motor and 14.5:1 compression, I was told to take off the MSD 7AL3 and go to a mag. Now I'm putting a blower on , and the mag is the only way to go.
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They make ignition other than a MAG?
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They make ignition other than a MAG?
Yes, and there are some very fast cars running them. ;D
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yea those old long cars running two mags are so slow at 330 mph in 3.7 seconds.
If god wanted man to run other ignitions he would have gave man brains to make magneto's. I'll take a MSD mag any day.Besides not all cars have a battery on board.
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From what I am learning battery development is gaining on this question. I need ballast on the front of my car, why not make it useful? If I can hang a powerful battery on the nose of the car and not have the added $$ of initial cost of a magneto and the $$ of having it tested on a regular basis. A magneto is a generator , several moving parts= service $$. Just got mine back today. A $300 checkup .
In my next project I will take a hard look at a 16 volt system.
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Old long cars? Surely you are referring to the modern 300' cars running twin 44 amp systems?
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Yea that would be the ones.Maybe ol' instead of old is how I should have stated it.
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First I do not see where it would not work fine in that combo. Seriously i think either style would work fine I just like magneto myself. I also happen to have 2 mag 12s that ran great on blown alky motor making 44 lbs boost. Bob Newberry once talked with me and Barry Patton about the larger mags and said he could not find any advantage to the bigger ones on alky. I guess someone did since most all top alcohol(blower) cars are running mag 44 now days and of coarse the A/Fuel cars are running two of them.
Only draw back to mag IMO is most the time they are happier firing a motor that is spinning pretty good,they can be unhappy with slow spinning motor.
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What plug gap did you run with the blown alky combo?
Is a slow spinning engine an engine being started ? If so would a system higher than 12 volts be better?
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I'm going with 16 volt battery for this reason. I have been told by lots of folks it will spin considerably faster. Now if you had to add weight 2 battery would spin the crap out of it but thats about 75 lbs total so probably not good thing.
We ran NGK 9 plugs in funny. Im pretty sure but its been good while.
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Do you remember the Gap?
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Im sure there's cpl out in shop I'll look around tomorrow.
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The MSD looses it's edge above 3000rpm, and the Mag really shines above 4000 rpm and at high cylinder pressures. It's a combination of amps, and duration of spark that makes an ignition system, and without an alternator, the MSD doesn't have the same juice at the end of the day.
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The MSD looses it's edge above 3000rpm, and the Mag really shines above 4000 rpm and at high cylinder pressures. It's a combination of amps, and duration of spark that makes an ignition system, and without an alternator, the MSD doesn't have the same juice at the end of the day.
It's boiled down to these two questions.
How does the MSD perform with a 16 volt battery compared to a 12 or 20 amp mag. In a blown alky engine combo.
If the ignition system will support it, will increased spark plug gap make more power.
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The best way to test, would be with a pressure box like the one Austin Coil made decades ago. It's designed to test ignition system performance under possible cylinder pressures till it blows out the spark.
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The best way to test, would be with a pressure box like the one Austin Coil made decades ago. It's designed to test ignition system performance under possible cylinder pressures till it blows out the spark.
That would be the proof.
I think some folks know but maybe they are not on this forum? ;)
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George I don't know if this will help you but I run a 7al3 box in my car and have had no issues at all with it . My motor has 14.8 compression on alcohol and we have sprayed it with a 250 shot of nitrous . I really have nothing to compare it to as I have never tried a mag in mine
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George I don't know if this will help you but I run a 7al3 box in my car and have had no issues at all with it . My motor has 14.8 compression on alcohol and we have sprayed it with a 250 shot of nitrous . I really have nothing to compare it to as I have never tried a mag in mine
Thanks for the input. What battery do you run? Do you use it to start the car? Spark plug and gap?
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George I use an Oddesy battery in my car Yes I do use it to start the car . So far no issues . Spark plug gap .025
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Thank you again for sharing. Not many have shared information in this thread. My car is for sale and in my next project I will be using a 16 volt battery. As for the mag or no mag question , I'll start with the MSD digital 6+ I already have. If it's a problem the plug gap will get smaller until that's a problem.
George
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George we use a second battery to start our car. We use a small battery on board for the transbake and recorder. It is enough of a battery to start the dragster if I stall it after the burnout, but it struggles to do it.
We use a heavy duty cable connector like you would have for a blower starter or winch. It is mounted at the rear of the car just under the seat near the lower wheelie bar mount. We use a battery cart with either 1 or 2 batteries to start the car and then just disconnect and pull forward. The small battery stays on the charger while in the pits. We run a mag usually but will be using our MSD ignition on the engine in the car now.
We do have a new 16V battery that was given to us by one of our sponsors, BUT WOW are the chargers expensive.
I need to stop being cheap and just get one.
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Supercat. Thanks for sharing. George
What are you using for ignition and what is the plug gap?
I found some helpful information on 16 volt systems: http://www.dragracingonline.com/technical/v9-battery-1.html
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George we run a spark gap of .018 for the mag and a gap of .050 on the MSD we use the NGK race plugs. We will most likely go up on the gap with the 16V battery installed. I do have a resistor for my gauges and trans brake. I am going to check with Race-Pak to see if I need to use a resistor for their products.
That was a good link on the 16 Volt battery. We are using the XS Power D-1600 deep cycle for our car. We are also using the Tilton high torque starter.
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George we run a spark gap of .018 for the mag and a gap of .050 on the MSD we use the NGK race plugs. We will most likely go up on the gap with the 16V battery installed. I do have a resistor for my gauges and trans brake. I am going to check with Race-Pak to see if I need to use a resistor for their products.
That was a good link on the 16 Volt battery. We are using the XS Power D-1600 deep cycle for our car. We are also using the Tilton high torque starter.
What MSD box are you using ? Coil?
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George the MSD parts are
Box 6AL pn 6420
Coil HVC II pn 8261
Distributor pn 8517
Crank trigger
2 Step pn 8739
Our engine is a 12.5 to 1 462 Buick that is about 850 HP and 673 ft/lb on a decent tune with carb and race gas. We now have the 4port Hilborn as a throttle body with 8 Enderle nozzles at the valves on methanol so it should run pretty good in a 1200lb car.
What is your build?
John
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George the MSD parts are
Box 6AL pn 6420
Coil HVC II pn 8261
Distributor pn 8517
Crank trigger
2 Step pn 8739
Our engine is a 12.5 to 1 462 Buick that is about 850 HP and 673 ft/lb on a decent tune with carb and race gas. We now have the 4port Hilborn as a throttle body with 8 Enderle nozzles at the valves on methanol so it should run pretty good in a 1200lb car.
What is your build?
John
John. Our engine is a SBC 4.030 X 3.48 . Dart 230 iron heads.Shaft rockers. Ross pistons 13.4:1, Scat 4340 crank, Callies steel rods.Custom roller cam, Hilborn 2 7/16 on alky, Waterman 400 pump. Dynoed 641 hp with MSD 6. Now using MSD 12LT mag. Last time we scaled it we were 1480 wet with driver. I have added a few things since that weight -in. Probably closer to 1500 now. We ran a 5.10 in testing Memorial Day weekend but have been rained out in every other outing this year. July 20th is our next attempt.
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George,
First I'm not trying to be smart butt.It looks like you have both msd6 and mag.Why not just do some back to back test runs. Heck if you did 330' shots you would probably see if there was differance or not.If it was me thats what I would do. Im running mag 12's or will be for 2 reason two sitting on shelf and I like mag better.
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Wide open, I have run both and have seen no difference. Lots of variables. I was looking for others to share their information. Like plug gap. ;)
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Test cell (dyno) probably more appropriate than track for such comparison.
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Test cell (dyno) probably more appropriate than track for such comparison.
Yes sir. I'm sure someone has done that. I just haven't been able to find them.
Although, my stuff has been on a dyno it's two different worlds. That is dyno vs. race track. The dyno loads the engine harder than my car does.