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I see a lot about spark plugs, which ignition system is best, etc on the forums. I also see guys stating that a mag takes horsepower to drive it. I'd just like to state, for what it is worth, some testing I have done over the years and what the results were. Nothing written in stone here, just my experience. Just my 2 cents (maybe overvalued).
When we were running an unblown gas boat in the 80's, the Vertex mag was old technology and the hot tip was the MSD 7A, and a trick distributor, crank trigger, etc. All tests we did were back to back runs and we never gained anything in changing to the MSD versus the Vertex mag, playing with spark plug gaps, etc. Time slips were identical. But the engine started quicker with the MSD over the Vertex.
In the 90's we ran an unblown altered on alcohol. Since alcohol is harder to ignite, we were sure there was something to be gained with electronics. So, same deal. We were running 149 MPH at the time...a 150 would be nice. We removed the old vertex and tried the MSD setup. Then we even tried the Mallory Hi fire 4 setup. Still 149 no change. But the engines started much quicker with electronic systems.
This year test: 2 blown alcohol boats, 1 a hydro, 1 a flatbottom. Both motors near identical. Hydro runs a Vertex mag, I run a Mallory super Mag 3 supposedly tricked out with high amperage. We swap mags between boats. Both boats run the same as they did before the swap.
As for spark plugs we run NGK. Not for any other reason other than they are easier to read. But when running the vertex or the mallory mag, we did find that if gapped above .040 we would lose some e.t., probably due to a misfire.
[ November 01, 2002, 07:33 PM: Message edited by: Fiat48 ]
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48, I agree :) . I do know that if the fuel in the cylinder is lit at the correct time (regardless of ignition type), you are only going to make the power that the fuel/air mix is capable of giving if all other mechanical assemblies are sound :D .
I do like the crank trigger setup as it is on the money as far as precision goes!
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I agree with the crank trigger. Accuracy in timing is critical. I'd like to have the acurracy of the crank trigger with the reliability and simplicity of the mag.
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Now.....to figure out a way to make it. I can't imagine it being that difficult. Then to put a patent on the process....$$ in the bank!
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I'd like to play with that! Betcha it is pricey, tho. Wonder if they'd like to test one on a Blown Alcohol boat? :rolleyes:
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Maybe less than you'd think? The old manual adjust system was about 600 bucks, the computer programmable one about a grand. Not sure what the newer HPX goes for. I could find out if you're interested; a buddy of mine (HeavyHitter on these boards) is a dealer. Not too bad really when you consider that it replaces the distributor, coil, amplifier box, and rev limiter in a standard system. Lots of benefits too when you think about having independent coil packs that have plenty of time to recharge between firing. I'm already too far invested in MSD stuff this time, but maybe for the next toy...
-brian
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Was less than I thought! I'll have to see how much room I have to get the trigger plate and pickup in there as I am dry sump on this one and the belt drive leaves little room. Also have to see what I sell at the upcoming swap meet. But no spark scatter is definately a tuning advantage.
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I run a Vertex mag and NGK plugs in my rig. Works really well and has never let me down.
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I used to work for a fuel team and the car would always nose over at about 1000 ft and the NGK were burnt up. We put in 8 NGK's and 8 Autolights one in each cyl. The car improved dramatically and of course the NGK's were burnt up but the Autolights were not. At that time the NGK plugs worked excellent for alcohol motors. I hope they have improved since then.
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[QUOTE]Originally posted by Fiat48:
[QB]I see a lot about spark plugs, which ignition system is best, etc on the forums.
Bob, did you or anyone do any expermenting with retarding the ignitions (msd or mag) on the top end?---I would like to try an air acuator to retard the mag 2 degrees once the motor hits say 6800 rpms---not really looking for any kind of a speed increase, just a way to let the motor run a little better on the bottom and help with any detenation on the top end----we did a retard deal on an injected alcohol motor with an msd and didn't see any performance change---the motor I would like to try it on will be a blown gas piece----would like your opinion
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blowngas:
[QUOTE]Originally posted by Fiat48:
[QB]I see a lot about spark plugs, which ignition system is best, etc on the forums.
Bob, did you or anyone do any expermenting with retarding the ignitions (msd or mag) on the top end?---I would like to try an air acuator to retard the mag 2 degrees once the motor hits say 6800 rpms---not really looking for any kind of a speed increase, just a way to let the motor run a little better on the bottom and help with any detenation on the top end----we did a retard deal on an injected alcohol motor with an msd and didn't see any performance change---the motor I would like to try it on will be a blown gas piece----would like your opinionNo, I have never worked with retarding the timing at top end. Not saying there isn't something there. I know the Pro stock guys do it and others. But I run Blown alcohol. Alcohol hates late timing and the exhaust valve temperature skyrockets. I watched a blown small block damn near melt the headers because he had late timing. He timing marks were wrong. When you think of the exhaust temperature it makes, it scares you to death. I set my timing on alcohol motors at 34. Lock it and leave it alone. I use only severe duty exhaust valves. On Blown gas (with good fuel) I set the timing at 32. I have been known to give them 36 for a run if I needed the power. I like to use a pyrometer on all engines and keep the gas motors at 1400 and the alcohols at 1200. But if you try running a pyro, remember that it can read a high temperature (I have seen 2500 degrees eek! ) and the motor is dead fat. That's fuel burning in the pipe.
I like to set the timing and leave it. Play with the blower overdrive/underdrive and fuel curve to get the speed/e.t. that I want. Late timing creates exhaust temperatures nobody wants. And little is saved from a motor that drops a valve.
Gas motors are picky and they like the fuel just right. Alcohol motors just have to be somewhere in left field to haul butt. To tell you the truth, most engines are never tuned anywhere near close. Most everybody racing has the same parts or close, it's the tuning that seperates them at the finish line. Fuel curve is #1.
I am rambling on here. A few degrees may actually help the top end slightly. less time for air fuel mixture to enter, compress, requires less timing to ignite. But if you play with it more than a few degrees...watch that exhaust temp.
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72Spectra:
I used to work for a fuel team and the car would always nose over at about 1000 ft and the NGK were burnt up. We put in 8 NGK's and 8 Autolights one in each cyl. The car improved dramatically and of course the NGK's were burnt up but the Autolights were not. At that time the NGK plugs worked excellent for alcohol motors. I hope they have improved since then.I've never had that problem. It's just that the NGK was so much easier to read due to their plating process. I tried a set of Accell plugs once and they cost me dearly. The plating on that plug must burn off at 2000 degrees! All I know is I destroyed a piston, stretched several valves and the plug looked like it was brand new and never run. I was on the lean edge I guess and the plug never gave me a warning.
