Speed Secret #6

[jim_howard_pdx]

Speed Secret Number 6

If you want to pitch for the Angels, you had better have a good curve ball!

To get maximum torque and power, you had better run an optimized ignition curve!

Nothing and I do mean NOTHING can help your engine if your burn event is mis-timed or incomplete. NOTHING else matters in the quest for power than getting your compressed mixture to pre ignite, and establish a flame that propogates from the center of the cylinder to the edges of the piston.

THIS IS WHERE THE POWER IS MADE.

So what starts this event. VOLTAGE.

First off, you should be running racing plugs or at a minimum, a high performance plug. What do racing plugs offer???? They are built to take high cylinder pressure events. Stock plugs are built for 2,500 rpm and 100,000 miles of use. Racing plugs are designed to deliver voltage when the car is at maximum torque under load. Things get hot, intense, and down right nasty. Your plug needs to be designed to take all this and LAUGH while it says "IS THIS ALL YOU'VE GOT?"

Do you need platinum or iridium?----NO. Do you need a weird multi electrode model?----NO.

I buy the NGK Racing plug. I bend the grounding electrode end out and use a cutting wheel to notch a V in the tip. This is an old NASCAR modification. When the spark fires, the kernal extends into the combustion chamber instead of just being limited to either side of the center electrode or the grounding electrode.

Then I bend it back to .045 to .055 gap. I usually have a minimum of 55,000 volts, and the longer the spark gap is, the more air/fuel it is exposed to when the voltage crosses the gap.

Next, you should run fresh wires anytime you suspect the wire is getting cooked. I use spiral core ignition wires for ALL COMPUTER CONTROLLED CARS, and ALL MULTIPLE SPARK IGNITION BOXES. I use solid core copper for NON COMPUTER, NON STEREO CARS. Do not use carbon core wires on any high performance application. The resistance is ok, but the carbon has weird inductance and conductance factors that effect your HP in strange and interesting ways. Also, never run a solid core wire on a computer controlled engine. You will have strange and weird things happen.

Run a fresh cap and rotor with brass posts.

I like MSD and Crane Hi-6 boxes. Most high performance engines find it easier to fire the mixture when they are up in revolutions. But ignition quality suffers during low rpm driving. So a multiple spark ignition fires that cylinder 6 times per power stroke up to 1500-2000 rpm where the engine really needs the extra help.

Use a great coil. I like the ones sealed within epoxy, since they take high vibration environments really well.

Have a competent race shop outline the best possible curve for your drivetrain configuration. Your ignition curve should be different for a 3.0 rear end ratio than for a 4.88 rear end.

On my 358, I start out with 12-14 degrees initial advance, with a total mechanical advance of 32 degrees. The advance is slow and steady from an intial advance that includes the vacume of 12-14 degrees, and provides a maximum of 42-44 degrees all in by 3,000 RPM's. Under load the engine never sees more than 32, but when cruising on the freeway with very lean part throttle mixtures, the engine runs a lot cooler with the 42-44 degrees.

You can re-curve your distributors yourself, I just did mine showing my son how to completely disassemble and put it all back together. Just get a shop manual and a recurve kit for your application. When disassembling the distributor check the bearing for wear. If the shaft rattles inside the bearings, get a rebuild or a blueprinted stock unit, or step up to a billet high performance unit.

If you have points, these have got to go! It is time to go with a magnetic trigger and an ignition box. Check with your motorsport dealer for suggestions on your applications and have them outline two or three options.

I chose a durospark distributor, (rebuilt unit 26.00). Then I tore it apart, made some changes, changed the curve springs and I have a great setup with only about 40.00 invested. You can pay up to 250 dollars or more for a billet unit, but it generally will not make a substantial difference over a well built durospark unit.

On my duraspark unit, the distributor has a 15 degree stop or a 20 degree stop. I had to switch mine around to set it at 15 degrees. Make sure you or your shop works to establish a hard stop where the ignition cannot advance beyond the 32 degrees when under load. This is an important safeguard to reduce or eliminate detonation.

Finally, some race engines with hi test racing fuels can take more advance curve. So be willing to experiment. Never judge by the seat of the pants feels. If it does not improve your times, then set it where it get the very fastest times you can achieve. I have seen people recurve their distributor to a "book value" or "recommended value" and lose et time. What good is that?????

When you finish with the ignition curve, NOW you can go ahead and set up the carb or fuel injection. Remember the IGNITION CURVE MUST COME FIRST when power tuning!!!!

So read up on this, ask a couple of shops for their feelings and recommendations, buy a recurve kit, a manual, and take some time to play. You will be surprised with faster et times when you optimize the correct curve for your application.

I am certain to get into more detail with the NOS crowd and Super or Turbo charged engines, so please read through the discussion.

Let me know what works for you, and outline your cubic inches, cam, compression ratio, rear gear, and how it ran before and after. Let everyone who reads know what you have experienced with a properly curved engine.....

I will tell you one thing, on many an engine, a static curve will hurt potential et. So with computer controlled cars it is possible to dial in specific advance by the rpm and load condition of the engine. This lets you get everything possible out of your powerplant. Let me know if any of you are running this type of custom optimized computer modulated curve. They really can help you win a bunch of races.

Yes a wicked curve will beat your competitor. I promise you that it will be worth your effort to get this dead on correct.

[95mustanggt]

Do you have a picture of one of your "notched" spark plugs?

[Eric4Nitrous]

Nice tips..but you said every engine should have a racing plug. Not every motor needs a hot *** plug. I wouldn't run a hot plug in a motor unless it had alot of compression, cam lift, big heads, and such like that. An everyday commuter motor doesn't need hot plugs.

[chris91LX]

I was told to run colder than normal plugs for nitrous. I'm using the Autolite 3924's with Edel. 6032 heads, TFS Stage 1 cam, Ported Cobra intake and a 125 shot of nitrous. I've heard that shaving the spark plug tip was dangerous if you don't do it right, ie lose the tip into the cylinder.

[jim_howard_pdx]

For everyone reading and enjoying the discussions in my speed secret threads, by now you know that I leave things out, or hint at stuff, or downright give you nonsense to see who out there is figuring out the physics and engineering going on in the pursuit of speed and quickness.

If you were following speed secret number 5, I made a completely false point right out of the gate. Finally Go Fast Mercury and Moxie looked up some stuff, thought it over, and commented on the controversy.

Please read my reply to GoFastMercury, because I explain all that I left out of the thread to test you all, get you thinking, discuss the point and understand the implications.

If you don't read this final response of mine, you might make some poor engine building decisions. So go back and look at the end and you will find the actual kernal of information that will make you say AH HA......Now I see the connection......

[jim_howard_pdx]

Thank you Eric! Eric is one of my favorite guys here at mustang works. Just look at his times and his rides and you know this guy loves to shake and bake.

But today only Eric, you get my "sleeping on the job" award.

ALL racing plugs are COLD plugs.

When we discuss the heat range of a plug, we are really discussing the overall length the engineers build into the center electrode to absorb combustion chamber heat and contribute to the ignition event.

To simplify this and put it in an example for everyone, a poor overall cylinder pressure engine with poor quench is going to need a HOT plug to fire the poor mixture the stock engine produces.

So factory stock engines typically have HOT plugs, plugs with LONG insulators to heat up their center electrodes.

High performance plugs have dramatically shorter insulators to keep the center electrode "cool" so they will not contribute to predetonation or detonation effects on high dynamic compression race engines.

And that is all I plan to say about plug "temperature".

[Eric4Nitrous]

I'm glad i'm so highly regarded by you But back to the point of the plugs. My nova runs a very HOT plug and runs just fine. My mustang on the other hand runs a very cold plug for the multi stages of nitrous. So racing engines don't all have cold plugs unless they run nitrous or sorts. I know lots of N/A guys that run hot plugs in very high compression motors. If you run a cold plug in a N/A high compression motor it's gonna foul them out every time you start it.

[jim_howard_pdx]

Please do not shave the thickness of the grounding electode on your plugs!!!! There is no need to do this, they will not effect horsepower or torque. They really don't. You want to keep that grounding electrode tip thick and happy, cause it is taking a h e l l o a lot of heat and pressure during your runs.

What I do AGAIN is to bend out the gounding electrode tip in order to gain access. I use a thin cutting wheel or a thin hack saw blade and I cut a vee shape into the tip of the grounding electrode. No as the center electrode fires the spark across the gap it grounds to the electrode but the spark event then "SEES" more of the air fuel mixture that was squeezed into the V that I cut in the tip.

So I am after a better preignition environment. That is why we v cut the grounding electrode tip. Then we run a HOT ignition box with 55-75,000 volts and push that electode gap to .055 or even more if we can get away with it. We want to expose AS MUCH air fuel mixture to the voltage event as humanly possible.

The reason why we use Magneto's on top fuel drag cars is that they produce MORE voltage as the RPM increases, while a distributor typically delivers more voltage at low rpm, and falls off as the rpm increases.

So I would expect that Eric 4 Nitrous is probably using a super box on a distributor, or a Magneto should his rules allow it.

On our racing aircraft engines we use TWO magnetos, so if one fails the other can keep the plane in the air.

Now on NASCAR our Ford guys are running durospark distributors with two reluctors and two hall magnetic triggers stacked one atop another with a switch in the cockpit, so the driver can switch should one trigger fail!

Here is a secret you do not need if you are running the drag strip. But if you autocross or road race, this speed secret is a nice way to finish more races!!!

Hope this helps!

Thanks for all the early and good responses.....

Eric, have you had a cup of coffee yet?????????
(Sorry, gotta tease ya even if I do respect you!)

[jim_howard_pdx]

Eric makes a really good and significant contribution. He says that some of his high compression buddies run HOT plugs to keep them clean.

Eric caught my dis-information and he wins the first award for thinking this all the way through.

A racing plug is always a cold plug?

That is PATENTLY FALSE.

Racing plugs come in all different heat ranges. For a turbo application we tend to keep the electrodes short, because the rpms are so high that the ignition events are packed in very tightly every minute the engine runs. So without a short cold plug, the high heat being generated each minute would literally burn off the center and grounding electrodes all together.

Have you ever seen the picture of a melted grounding electrode? They can look very bizarre. It was the rpm and time that did that damage, not predetonation or detonation.

For an engine with excessive overlap like my 428 with 114 degrees of overlap, I had to run a plug three ranges hotter than stock just to keep the plugs clean.

Sooty plugs will not kill horsepower if the next spark still ignites the mixture. The danger is that every engine misfires, and when they do a sooty spark plug can actually get "fouled" to the point that it will not fire as often as it does fire and that costs you big time.

I had a bad spark plug wire on my 358. We found it when we pulled all 8 plugs to diagnose a detonation problem. One plug had a completely filled space of oil, fuel, and carbon between the center and grounding electrodes. Almost as if you took a spatula and shoved a yuchy mess into the space.

My son was horrified. Worried that a valve stem was leaking oil, or that the rings were damaged or improperly indexed.

I pulled the wire, tested its continuity and found it to be open. We cut off the end near the spark plug, re-crimped the connector and voila.....a perfectly firing engine.

Eric points out a very important point, and that is you need to play with different heat ranges at the track during test events, so you can find the one that best produces the quickest times while also keeping the plug clean.

What is really strange and bizarre to me, Is that a team can build 3 engines for a season, and each might need a different plug. One engine we might build for altitude tracks. One engine might be built for high track temperatures. One engine might be built for a slow track (one that has very poor stick at the starting line). Each of these three engine's might have different cam timing, initial timing, or advance curves. And each requires a different plug.

That is why I say ( AND THIS IS TOTALLY TRUE ) you must establish you ignition curve first, and then tune everything else around that starting point. Otherwise you have no baseline.

Conversely, any time you change any engine tune element, you need to go back to your plugs and see if the heat range needs to be altered to take advantage of your other change.

Man....I lied again....on my last response I said that was all I was going to say about spark plug heat ranges. Guess no one can trust me.......

Eric, thanks for making this thread more fun. I was worried that it would be dull and boring.

[Eric4Nitrous]

no problem Jim. Just had to clear up some points. It's cool. Dull and boring?? Not with me involved it isn't.lol

[jim_howard_pdx]

Eric, I have to tell you that you, Kevin Price and ol pkrwud are the guys that keep me coming to this site.

Keep up those awesome speed quests. And stay safe, cause things happen awfully quick during 6 second blasts.

And thanks for catching my "all racing plugs are cold plugs" line....I was wondering who was going to call me on that COMPLETELY ERONIUS STATEMENT.

Have a great weekend. I will be pounding a couple of Corona's tonight!. (With lime and salt.) Just right for a thirsty ol fart like me.

You go, Eric the ROCKET MAN!!!!

[jim_howard_pdx]

Eric,

Did you catch my final post on speed secret number 5????

I purposely made a false claim right out of the shoot, over 500 people read the thread before anyone looked up the stock rod and stroke length of a 428 and 427 FE engine.

Read that final post and you will see the real secret of how rod length fits into power production, and why I work at all costs to keep it as long as I possibly can with the race engines I build.

Let me know what you think of the final conclusion.

Hey, its almost Miller time!!!!!!

Have a great weekend everyone.