Originally Posted by Comitatus' post='827496' date='Jul 8 2006, 09:28 PM

Ok B, Thanks for posting this up. The wires that I'm using are the MSD 8.5 Super Conductor Wires.

They are a very nice quality wire, and I was very impressed by them when I received them in the mail. They came with a sleeve over the wire to help with conducting the spark directly to the plug (to prevent arcing) and to help insulate against the heat.

I have a picture of them somewhere, and I'll have to find it and post it up.

My wires are zip tied together...so maybe that was the problem?



I am very disappointed that this happened, but i've been trying to keep a positive attitude about it, and have my motor come back stronger and better than ever.



I do still need to figure out what caused this in the first place...



I definitely think that we have it narrowed to ignition, whether it was the wires or the plugs, or maybe a combination of both...

Originally Posted by Comitatus' post='827514' date='Jul 9 2006, 12:22 AM

Ok, so as of right now, to remedy this....I need to run 9's and 10.5's for plugs, or maybe 10.5's all around.



And I need to make sure that my plug wires are gapped and free from interference.



What about the CAS wiring? Do you think think that might play into it, and maybe causes some noise on the plug wiring?

Originally Posted by Lynn E. Hanover' post='827526' date='Jul 9 2006, 06:14 AM

Mind if I speculate a bit?



I manged to break out the dowels at both ends of a NA 12A. Or more accurately, my driver ran two laps with the engine bucking like a mule, and would not take his foot out of it and return to the pits. It ran fine sitting still, but not under load.



It was my first attempt to run a crank triggered system and I had run the pickup pairs inside the same dash 4 braided stainless hydraulic line. The triggers were mounted on both sides of the front cover and ran through the fire wall, so I thought that shielding them from the high voltage lines was the most important thing to do. To keep the trigger wires from inducing each other, I twisted the pairs in opposite directions.



At anything over 4000 RPM the pickup pairs would induce each other and lite the opposite rotor housing 180 degrees too soon. It just lost the end irons. Everything else was fine.



Early on when I was still using the exciter boxes on the sides of the distributor, I could not get a split timing situation going. No matter what I did, both leading and trailing would fire together when I reved it up.



I asked a Mazda driver from NC about this and he didn't even blink. He just said throw those exciter boxes away. I did and never had another problem. Mazdas around the world had the same problem. So Mazda moved the boxes (just points eliminator SCRs) to the fender. No more problems.



I separated the pickup wires. Ran both through dash 4 and grounded the stainless shielding and had no more problems. The wires from the CAS are antennas and need to be shielded from high voltage energy.



The leading wires cross fireing has no effect at all. But a trailing wire picking up a leading hit from the other housing is the problem. Or inducing a CAS wire from one housing with a leading or trailing hit from the other

is a killer. The inductive high voltage wires act to remove the peaks and noise off the the high voltage and extend the burn time of the arc. This you may notice is helpfull in not killing the radio and not having so much noise in it that AM radio is not usable. This (inductive reactance) also acts as an additional load so as to reduce unwanted arcing around the plug boots. It is probabe that boot arcing is an after the fact (after the plug gap is up and arcing) and does not cause a misfire until it has happened enough times to make a carbon path inside the boot, and is seldom a problem. (I only had this happen once) This is another good reason for .010" plug gaps.



Until we bought the Drummond engines (well, the driver bought them) we never ran over 20 degrees of lead on both leading and trailing. Plenty of power and never any problems with heat or engine damage.



The Drummonds came set up to run 25 or 27 degrees. And he wanted more octane than we had been using.



So think about this. Why is one amount of lead a better choice than another, and what is the correct amount for any situation.



The short answer is about 100 pages. But the bullets are:



To arrive at the highest cylinder pressure at the ideal crank angle. Period. Nothing else to learn.



So what are the other 99 pages about? All of the problems that will be generated while attempting to accomplish this feat.



I don't like turbocharging. It is just like crack. Once you try it, you cannot get it out of your mind. And just like crack, a little crack is no good after a while, so you need way more crack just to stay even. So you see people that seem perfectly intelligent gutting a third gen engine compartment and adding $25,000.00 worth of very short lived equipment, so that the rush will be bigger the next time. And it can all go away in a split second.



NA engines (piston or rotary) suffer reduced cylinder filling with increased RPM. Since the head space (compression volume) is not changing, the reduced cylinder filling is reducing the compression ratio with incrased RPM. Less fuel air mixture crammed into the same space, is the same as a larger head space, or a lower compression ratio.



So unless the NA engine is lugged at a high throttle opening (same as way too much advance) or it cross fires (same as way too much advance) you just about cannot hurt it.



I ran over 14:1 in my Fiat engines and never had a problem. Then I could buy 110 airplane fuel at the local airport. The rules had me running a little Weber DMSA-100 carb with a 23MM and a 27MM choke size. So as the revs came up the cylinder filling was so poor that the effective compression ratio dropped into the too low area and the 34 degrees of lead was just right. So the trick here is that the 14:1 is only the calculated compression ratio, and it vanishes as the RPMs come upoff of idle.



In the turbo (or supercharged) engine, the compression ratio goes up with RPM. Think about that for a moment. The engine becomes more vulnerable to sudden death as you rev it up. The effect is that the engine gets bigger in displacement as you rev it up, but the head space stays the same. So the cylinder filling is getting better with RPM rather than worse, as in the NA engine. Easy to understand so far.



So the one big killer of engines is ignition advance, and as the revs come up so comes the increased compression ratio and so the ignition advance must be reduced (retarded) with RPM so as to keep the maximum cylinder pressure right at (the same place as the NA engine) the ideal location in the cycle (about 18-20 degrees ATDC in a piston engine and 40-50 degrees in a rotary). Read Paul Yaws tech articals.



I will continue this later. I have to run. But while I'm gone, think about this.



The relationship of crankhaft degrees of advance in a piston engine and the 1/3 relationship of the cranckshaft degrees vice rotor face degrees in the rotary. How many degrees of rotation of usefull work in one vice the other.



Lynn E. Hanover

Originally Posted by Lynn E. Hanover' post='827701' date='Jul 9 2006, 09:35 PM

Note that systems used for supercharged drag racing engines operate at much higher voltages than are available in the MSDs we use in racing. (MSD-6AL)

Originally Posted by heretic' post='827725' date='Jul 10 2006, 03:13 AM

Also note that every such dragster I have seen, including our own, has the plug wires just sort of zip-tied together in a fat bundle instead of spacing them out. This being on engines with absurd ignition requirements, such as alcohol engines running 60psi boost. It takes a lot of juice to light a super high pressure wet fog!



If your plug wires are arcing, then they need replaced. I have never seen new MSD wires arc. If they do, that means they are faulty.

Originally Posted by Lynn E. Hanover' post='827526' date='Jul 9 2006, 06:14 AM

Mind if I speculate a bit?



I manged to break out the dowels at both ends of a NA 12A. Or more accurately, my driver ran two laps with the engine bucking like a mule, and would not take his foot out of it and return to the pits. It ran fine sitting still, but not under load.



It was my first attempt to run a crank triggered system and I had run the pickup pairs inside the same dash 4 braided stainless hydraulic line. The triggers were mounted on both sides of the front cover and ran through the fire wall, so I thought that shielding them from the high voltage lines was the most important thing to do. To keep the trigger wires from inducing each other, I twisted the pairs in opposite directions.



At anything over 4000 RPM the pickup pairs would induce each other and lite the opposite rotor housing 180 degrees too soon. It just lost the end irons. Everything else was fine.



Early on when I was still using the exciter boxes on the sides of the distributor, I could not get a split timing situation going. No matter what I did, both leading and trailing would fire together when I reved it up.



I asked a Mazda driver from NC about this and he didn't even blink. He just said throw those exciter boxes away. I did and never had another problem. Mazdas around the world had the same problem. So Mazda moved the boxes (just points eliminator SCRs) to the fender. No more problems.



I separated the pickup wires. Ran both through dash 4 and grounded the stainless shielding and had no more problems. The wires from the CAS are antennas and need to be shielded from high voltage energy.



The leading wires cross fireing has no effect at all. But a trailing wire picking up a leading hit from the other housing is the problem. Or inducing a CAS wire from one housing with a leading or trailing hit from the other

is a killer. The inductive high voltage wires act to remove the peaks and noise off the the high voltage and extend the burn time of the arc. This you may notice is helpfull in not killing the radio and not having so much noise in it that AM radio is not usable. This (inductive reactance) also acts as an additional load so as to reduce unwanted arcing around the plug boots. It is probabe that boot arcing is an after the fact (after the plug gap is up and arcing) and does not cause a misfire until it has happened enough times to make a carbon path inside the boot, and is seldom a problem. (I only had this happen once) This is another good reason for .010" plug gaps.



Until we bought the Drummond engines (well, the driver bought them) we never ran over 20 degrees of lead on both leading and trailing. Plenty of power and never any problems with heat or engine damage.



The Drummonds came set up to run 25 or 27 degrees. And he wanted more octane than we had been using.



So think about this. Why is one amount of lead a better choice than another, and what is the correct amount for any situation.



The short answer is about 100 pages. But the bullets are:



To arrive at the highest cylinder pressure at the ideal crank angle. Period. Nothing else to learn.



So what are the other 99 pages about? All of the problems that will be generated while attempting to accomplish this feat.



I don't like turbocharging. It is just like crack. Once you try it, you cannot get it out of your mind. And just like crack, a little crack is no good after a while, so you need way more crack just to stay even. So you see people that seem perfectly intelligent gutting a third gen engine compartment and adding $25,000.00 worth of very short lived equipment, so that the rush will be bigger the next time. And it can all go away in a split second.



NA engines (piston or rotary) suffer reduced cylinder filling with increased RPM. Since the head space (compression volume) is not changing, the reduced cylinder filling is reducing the compression ratio with incrased RPM. Less fuel air mixture crammed into the same space, is the same as a larger head space, or a lower compression ratio.



So unless the NA engine is lugged at a high throttle opening (same as way too much advance) or it cross fires (same as way too much advance) you just about cannot hurt it.



I ran over 14:1 in my Fiat engines and never had a problem. Then I could buy 110 airplane fuel at the local airport. The rules had me running a little Weber DMSA-100 carb with a 23MM and a 27MM choke size. So as the revs came up the cylinder filling was so poor that the effective compression ratio dropped into the too low area and the 34 degrees of lead was just right. So the trick here is that the 14:1 is only the calculated compression ratio, and it vanishes as the RPMs come upoff of idle.



In the turbo (or supercharged) engine, the compression ratio goes up with RPM. Think about that for a moment. The engine becomes more vulnerable to sudden death as you rev it up. The effect is that the engine gets bigger in displacement as you rev it up, but the head space stays the same. So the cylinder filling is getting better with RPM rather than worse, as in the NA engine. Easy to understand so far.



So the one big killer of engines is ignition advance, and as the revs come up so comes the increased compression ratio and so the ignition advance must be reduced (retarded) with RPM so as to keep the maximum cylinder pressure right at (the same place as the NA engine) the ideal location in the cycle (about 20 degrees ATDC).



I will continue this later. I have to run. But while I'm gone, think about this.



The relationship of crankhaft degrees of advance in a piston engine and the 1/3 relationship of the cranckshaft degrees vice rotor face degrees in the rotary. How many degrees of rotation of usefull work in one vice the other.



Lynn E. Hanover