Motorsports Village

E85 Spark Plugs
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Author:  jmarkaudio [ Mon Nov 01, 2010 8:23 pm ]
Post subject:  E85 Spark Plugs

Considering that E85 has a high vaporization temp, I wonder if a hotter plug may be in order? I know that some of what I have read with methanol the trend is to go colder than gas, not sure why considering how much heat it pulls from the engine. I'm at the high limit I believe with the racing plugs, R5671A-7, and don't think I can use a projected nose plug. I will probably try a fresh set of 7's to start and check on the clearance I have for a projected nose. Any thoughts? Also, some of the stuff I have read with E98 is that you need a much hotter ignition, even more than my Digital 7, to get E98 to light well. Not that I have access to that yet, just a thought to work on. I may try the plug gap at .025 to start as well.

Author:  Ken0069 [ Mon Nov 01, 2010 9:19 pm ]
Post subject:  Re: E85 Spark Plugs

On my methanol engine I run a -10 or an Autolite 3932, which is suppose to be the same heat range. On my engine I was frying the plating on the threaded end and also across the ground strap with -8s and -9s. The engine seems to run better on the Autolite plug but they don't last as long as the NGKs do. Plug gap is at .022 as per MSD for this Digital 7 ignition, which shrinker says it a piece of s**t. O:) ;-) Just thought I'd throw that in before he did. =;

Author:  shrinker [ Mon Nov 01, 2010 10:11 pm ]
Post subject:  Re: E85 Spark Plugs

Awww you beat me too it.
Mark I have emailed you a word doc showing you the differences in scope traces from a Digital 7 to a Crane HI-6. I did the tests myself and these results are consistent with every other digital 7 car I have seen. The Crane is heaps better spark. The engines run better on the Crane Hi-6 when used with the Crane PS-92 coil. I only use that coil. Even the customers can recognize it. I wont fit a carby to an engine with a digital 7 on it.

Author:  jmarkaudio [ Tue Nov 02, 2010 9:22 am ]
Post subject:  Re: E85 Spark Plugs

Ouch!!! =P~ Unfortunately it's in the car, until it dies I'll have to run it. I do know it puts out some juice with the HVC2 coil, fried the stock center conductor on the HEI cap (high resistance, MSD sells a low resistance version) when I first got the car. Using the MSD billet distributor now.

Author:  shrinker [ Tue Nov 02, 2010 2:39 pm ]
Post subject:  Re: E85 Spark Plugs

Scope the Digital 7 and make sure its doing what MSD specify. They spec the same duration as the Crane and you can see from the doc I sent you what that is. That crane trace is smack on spec. We had discussions with MSD about it and the technical department eventually tried to avoid my customers questions, they made him hang on the phone from Australia for over 30 minutes waiting for an answer, but he didnt give up. eventually they said 'We dont know" They tried all the tricks, you have the wrong coil, you have the wrong wiring, you have the wrong voltage, we checked everything they asked and scope logged everything for proof and sent the data to them. They found no faults. he finished up triggering the Crane from the digital 7 computer side of things.
I also once did a test between MSD 6al, MSD 7al ,MSD 7al-3, MSD digital 7, MSD 10+ and a Crane HI-6 on the dyno with the gas bench. The 10+ was the best combustion the Crane HI-6 was very close second and the others were poor combustion with the digital 7 the worst. Far more CO and unburnt HC from the digital 7 and less stability in the arc trace on the scope.

The Crane is not perfect, it needs to have the PS-92 coil not the one they sell in the kit (the LS-92) The LS-92 coil is ok for high RPM four cylinders but not optimum for V8's. Crane will argue black and blue the LS coil is the best but its just salesman talk.

Author:  rick360 [ Tue Nov 02, 2010 5:24 pm ]
Post subject:  Re: E85 Spark Plugs

What type of scope are you using? Do you have a brand, model#, website etc? Hardly anybody uses them in the automotive world anymore. I honestly had never thought of them as being useful for hi-perf applications before you talked about it, but I can see where the voltage across the plug would be an indicator of things inside the chamber. I am getting more interested in them the more I hear. I have an electronics scope (Tektronix). I wonder if I could make (or buy) a probe adapter to use it.

How many cylinders do you monitor at a time?

Also curious about the gas analyzer. Who sells them and how much US $ are we talking about.


Author:  shrinker [ Tue Nov 02, 2010 5:54 pm ]
Post subject:  Re: E85 Spark Plugs

I use a Picoscope Automotive kit. Its fantastic. Data logs into a laptop records 1000 screen shots so you can capture whole runs. Very fast sampling, far better resolution than an automotive industry tuneup machine.
They have probes seperate that reduce the secondary voltage down to low range and that would work on your scope. ... ition.html
The scope monitors all cylinders via the king coil lead, there is another accessory called a mix master that connects up to 12 plug leads together and displays them that way with a trigger from number one so you can identify which cylinder. But if you have a twin channel scope you can monitor all cylinders on channel B and trigger channel A with appropriate time frame so you can count through the firing order that way. Lots of ways to skin a cat.
At 7 grand a 180 microsecond duration lasts for something like 20 or 30 degrees of crank so you get to see all that time. Scopes are great.

I use an Andros gas bench. All sorts of manufacturers use Andros internals in their benches. Very good stuff, data logs to computer very very handy. Have no idea on cost. Also contact Bridge analyzers Robert Schrader is the owner, very smart man. Makes his own bench internals and all. Very helpful person, he and I have had lots of discussions. Ring him, say hello to him from Shrinker from smartcarby for me.

Author:  jmarkaudio [ Tue Nov 02, 2010 8:37 pm ]
Post subject:  Re: E85 Spark Plugs

Here is the screen shot Shrinker sent.


Author:  shrinker [ Tue Nov 02, 2010 10:37 pm ]
Post subject:  Re: E85 Spark Plugs

Screen shot of msd programable digital 7 on left side with crane HI-6 on right side.
Test on cold start engine run for 5 seconds each ignition. Same wiring, same tune etc. MSD using the correct recommended coil from MSD and confirmed with their technical department. Crane using PS-92 coil.
Note the MSD duration voltage drops below 500 volt and ceases conduction. The MSD has more residual ringing indicating greater wasted energy. The crane maintains higher voltage and therefor more current flow and consumes the maximum energy from the capacitor/coil. The crane easily made the engine run better,the owner even noticed it and it had more power and promptly purchased a crane and triggered it from the digital 7 computer output. I do not sell the Crane ignitions to my customers, they spend their money with other people. I make no profit. I have made someone else rich many times, perhaps i gotta change that system =; =; . But I have done the conversion to Cranes many times and never failed to improve the engine. I now refuse to fit my carburetors to anything other than a HI-6 or a 10+.

the text box at the top shows the time interval between the ruler lines as 60 microseconds for the MSD and 180 microseconds for the Crane. 180 is the specification claimed by both manufacturers. MSD tech had no explanation for why the units are not in spec. This is not the only time I have performed these tests, other peoples cars have yielded the same results. The MSD digital 7's shipped to Australia that I have seen are not up to specification when run in the cylinder. They produce correct duration in free air but not in the cylinder.

Author:  tomscharger70 [ Wed Nov 03, 2010 12:34 pm ]
Post subject:  Re: E85 Spark Plugs

Some of the things you guys write about go way over my understanding =; ..any ways...

I run my Hemi on stock Champion plugs, RN12YC. Ive tried a set of colder and hotter, but with my combo I have not felt any difference..

The ignition system has to be powerful. At first I ran my engine with the Digital 6 box and a HVC #8250 coil. I had major problems with this setup. Turned out that the Digital 6 box had fried.. I bought an older MSD 7AL2 box from a friend, also bought the #8251 coil.. Tested the spark and it was like a arch welder.. No more problems.

I run a .035 sparkplug gap if my memory serves me right..


Author:  Ken0069 [ Wed Nov 03, 2010 3:15 pm ]
Post subject:  Re: E85 Spark Plugs

I noticed that the spec on that Crane ignition says it is limited to like 14 to 1 compression? :-k

Author:  shrinker [ Wed Nov 03, 2010 3:41 pm ]
Post subject:  Re: E85 Spark Plugs

Whats 14 to 1 compression? is it 200 psi cranking pressure or 280. Thats just sales talk. Depend on the cam doesnt it.
Just the other day I ran the Crane on that engine that the scope traces were taken on. The engine now has a blowthrough setup on it. We ran it up to 13.3psi boost measured in the manifold under the carby with 10.5 to 1compression ratio in the engine with a crane F286 cam and AFR heads. I took scope traces all the way and it was fine.
The compression doesnt matter its the resistance across the gap during current flow that matters. Ionization voltage is one thing, its related to pressure but its mainly affected by mixture. The thing with the MSD's is they lack GUTS. I have traces of some models where the duration of discharge is a square wave, the duration voltage stops then starts again in regular patterns. Its some sort of weird design. What matters is imparting as much energy as you can into the gap and doing it quickly not slowly over a long period like some ignitions do. Stockers benefit the most from inductive long duration ignitions but racing is a different story.
It depends on the fuel condition in the chamber, as to what is the best ignition. Its very difficult for customers to find out what they need to match their engine, the advertising is just junk and doesnt help anyone. All they talk about is rubbish. The more you vaporize the fuel the more current will pass the gap. More fuel is more conductive and its when you start fixing the fuel that the limitations of the ignitions start to surface. That MSD trace is running out of energy the Crane didnt. The Crane performed to spec the MSD didnt. Make your choices Gentlemen. Put the MSD into a cylinder with junk vaporization and it will look fine because its like being in air. Fix the fueling and it lets you down.

Author:  Ken0069 [ Wed Nov 03, 2010 7:09 pm ]
Post subject:  Re: E85 Spark Plugs

Tom you should be able to post without waiting for approval now. I missed that setting when I allowed you access. \:D/

Author:  rick360 [ Wed Nov 03, 2010 7:26 pm ]
Post subject:  Re: E85 Spark Plugs

It is interesting that the MSD had a wider(longer) initial pulse above ~2.5-3KV but then was <1KV much earlier as the Crane kept the voltage >1.5KV for nearly the entire 180uS.

In the Crane trace what are the erratic waves just before the vertical end line?

The final ringing oscillation freq looks different between the two. Is the the inductance value between coils, the impedance of the boxes or a resonant freq of the capacitor in the box and the coil inductor?


Author:  shrinker [ Thu Nov 04, 2010 5:16 am ]
Post subject:  Re: E85 Spark Plugs

rick360 wrote:
In the Crane trace what are the erratic waves just before the vertical end line?

Thats the start of flame folding. The MSD has it as well but its just at the point where it runs out of energy so it only just manages to start the combustion. The MSD has dissipated all its energy in a shorter time period than the Crane and you may think that that would be like having more advance, that is true to the limited extent of the microseconds involved but what you need with alcohol fuels is amps flowing across the gap over a time period to heat the liquids present. The missfire rate or the rate of insufficient ignition energy with the spark profile of the MSD would be worse than with the Crane. You have to factor in that race engines have tight squishbands and turbulence so at high rpm you need duration of arc to keep pumping energy into the gap while the wind tries to blow it out. In my Sparkplug reading docco you can see examples of that.
The MSD is all voltage whereas the Crane is all amps. Imagine it like an electric arc welder, its the amps that melts the metal. When you have all voltage the physical number of electrons that cross the gap is less so you engage less fuel molecules and thats why you see just a faint glimmer of flame on the MSD trace. The Crane takes longer to get a flame but it gets a more stable one. AND THAT GENTLEMEN is what you see on a gas bench when you run an MSD verses a Crane. You see closer to correct gas relationships. Which translates to more power from less fuel and less need to overfuel a cylinder to get some light HC's working for you so the engine lasts longer and the oil stays cleaner etc.
rick360 wrote:
Is the the inductance value between coils, the impedance of the boxes or a resonant freq of the capacitor in the box and the coil inductor?
I suspect its the capacitor and coil resonance freq.

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