blown motorized bike carnage!

[Deleted member 12676]

I'm sorry flash but Fabian has beat the crap out of your illogical viewpoint. His test results can't be ignored. To say that he just lucked out multiple times is totally ignoring the weight of his evidence.
And if you knew anything about the engineering concepts of a two stroke you would know that too advanced an ignition creates greater combustion pressure which stresses the bearings and allows the possibility of detonation (especially if there is an intake air leak which is common with these engines).

 

[flashstar]

I'm sorry flash but Fabian has beat the crap out of your illogical viewpoint. His test results can't be ignored. To say that he just lucked out multiple times is totally ignoring the weight of his evidence.
And if you knew anything about the engineering concepts of a two stroke you would know that too advanced an ignition creates greater combustion pressure which stresses the bearings and allows the possibility of detonation (especially if there is an intake air leak which is common with these engines).

What results? I don't see any raw data...

I produced a fascinating paper last year that analyzed an interesting (theoretical) correlation between the growth of shaving in the 18th century and the rise of a hygienic culture. Even though I had over 100 data samples and ran as much statistical analysis as possible, I could not show causation. I am almost 100% personally sure that an increase in shaving in that century produced an increased focus on bodily hygiene. Unfortunately, there was no way to control for all of the error in the data since it was not collected in a scientific way (in the 18th century). Such is your "data" on the Jag CDI.

I never said that the $70 Jag CDI doesn't affect anything. What I do know from economics is that everyone (even a madman) is rational from his/her own perspective. Fabian, you might believe that the Jag CDI is worth its weight in gold. That certainly doesn't mean it is.

Disprove this: A smaller plug gap and richer jetting will prolong the life of a HT engine as much as the Jag CDI.

Jaguar, if you knew anything about the engineering concepts of a two stroke, you would know that detonation is always possible. Detonation is possible in any engine. Since you claim to be a 2-stroke master, what is the maximum allowable combustion pressure on a HT? How much does a Jag CDI reduce combustion pressure, by itself? Does the effect a Jag CDI has on combustion pressure vary based on the static compression ratio (is this a linear or logarithmic relationship)?

Until we get some concrete data and have these questions answered, the Jag CDI is a black mystery box.

Fabian, since you appear to be ok with fireballs flying at your legs by all means do what is rational to you.

I err on the side of caution and will rebuild my top end preemptively.

 

[Deleted member 12676]

To wait for complete collection of every miniscule piece of data possible is to wait forever.
All thru history advances have been made by making decisions on a fair amount of evidence available. If people had Flash's attitude no advances would of ever been made and we would still be living in caves.
Yes you do "err on the side of caution", with the emphasis on err (error).
But that is a lie also. You are not being cautious, just fearful. To be cautious is to side with things that result in more safety, which is what the Jaguar CDI does. Having a normal spark retard with high RPM is just plain safer for the engine. period.

 

[flashstar]

Having a normal spark retard with high RPM is just plain safer for the engine. period.

How do you arrive at your "normal" spark retard? How are you sure you hit the "optimum" amount? Sure, it's typically safer to retard ignition timing. You don't get something for nothing though and where you get safety here, you typically lose performance. I say typically because no one seems to have any concrete data or repeatable measurements for the HT engine.

Maybe the gains in performance on the stock CDI outweigh a theoretical, slight drop in safety if a smaller plug gap and rich jet are used? Who knows? For a supposed expert, you are very light on actual data, even the basics.

 

[velzie]

I produced a fascinating paper last year .

What journal was it published in?

You describe a meta-study: a review of literature to effect a statistical calculation in order to determine a correlation. Correlation does not mean causation. The study isn't scientific, it is a problem of philosophy that uses mathematics: you perform no experiment. You shouldn't compare literature review with the type of mechanical experimentation done by Jag and Fabian.

A smaller plug gap and richer jetting will prolong the life of a HT engine as much as the Jag CDI.

I think you just gave yourself an experiment to perform. I believe that with a stock CDI at WOT and a Jag CDI at the same rpm, the Jag set-up will undoubtedly be more reliable, all other factors being similar. This is based on well documented evidence of spark retard causing greater engine reliability. It is built into quality 2-stroke machines produced by well known companies. You would save a lot of people money if you are correct.

The stock CDI is definitely a limiting factor when it comes to these machines. Jag has taken what is known about spark retard and applied it to these motors to produce a product that is in line with previous findings. Fabian has performed enough rigorous field testing that shows the limitation of the stock CDI and the improvements that Jag's CDI produces.

Although there is a lack of direct scientific study comparing two very similar designs to produce concrete evidence written in a peer-reviewed article, I find it hard to doubt these findings without evidence of your own.

 

[velzie]

How much of Jag's website have you read, since you claim he doesnt give 'actual data'? Think of his website as a review of literature he has read combined with his own experimentation. To prove him wrong review the literature and perform your own experiments.

You are aware that his CDI has select-able ignition curves? So the one who owns a Jag CDI is in control of the 'optimal' curve for their application.

 

[sactownie]

Does the installation of a jag cdi make the motorbike more reliable? I have had 3 stator failures in about 9 months of motorbiking and they always happen miles from home when I didnt bring my spare tools/coil LOL

 

[Fabian]

you might believe that the Jag CDI is worth its weight in gold.

I can accept that it might not be worth it's weight in gold, because gold isn't reflective of it's value to engine reliability. A more reflective statement is that the Jaguar CDI is worth it's weight in anti-matter.

Until we get some concrete data and have these questions answered, the Jag CDI is a black mystery box.

How can the Jaguar CDI be a black mystery box, when you can just unscrew 4 screws to see inside - it's not in any way like a Peter Brock fuel/energy polarizer.

Fabian, since you appear to be ok with fireballs flying at your legs by all means do what is rational to you.

I have over 55,000 kilometers of rationality to keep me safe and secure on my motorized bicycle, without the theatrics of fireballs and shrapnel ejecta to embellish the story.

Disprove this: A smaller plug gap and richer jetting will prolong the life of a HT engine as much as the Jag CDI.

Would it be reasonable to assume that your suggestions have already been done; many times over?

 

[Fabian]

I have had 3 stator failures in about 9 months of motorbiking and they always happen miles from home when I didnt bring my spare tools/coil LOL

Well there's your problem.

Every time that i've chosen not to take my tools along, i have had a Murphys Law moment.

 

[Fabian]

I produced a fascinating paper last year

What journal was it published in?

I would also like to know what journal it was published in?