Has anyone ever found discrepancies in Honda documentation? Well, ...besides me.
I wonder if Honda ever printed the incorrect formula for the speed of light. How many would believe the speed of light actually changed because of it?
Imagine the power of the clerk who mistyped and changed the speed of light or the coefficient of gravity. We could all be floating above our chairs or flying off into space!
Personally, when I find printed material with clear violations of the laws of physics, at the very least, I look upon it with a jaundiced eye. When I find documentation differences printed, I prefer to fall back on supported science (or actual testing) to provide me with the correct answer.
The 550s in the US all came with 10K caps. This makes the spark duration longer, and is beneficial for the fuel burn.
I wonder if there's any proof.
Yes, there is proof. Just none readily available that will satisfy all.
Now over time all caps increase in resistance
Please provide your supportive evidence.
I have plug cap resistors that have remained at 10K ohms since installed in 1974. When can I expect these parts to fall out of tolerance?
Alternately, if you mean that everything that mankind makes will eventually fail, then I must certainly agree, of course.
...and if you start with 10KΩ caps, you're already much closer to the point you have to replace them.
What? You start with an in tolerance working component, and you must immediately plan to replace them? I don't think this type of part is classed as a routine consumable.
The resistors in the boots are 10-20% tolerance components >WHEN BRAND NEW<. None of them ever had absolute accurate numbers, as humans are incapable of perfection. Further, these parts don't need precision specifications. And, that is part of the beauty of this circuit design.
The resistor is a compressed stack of carbon granules. See, there is this cylinder and ram press. They pour in some carbon granules, then operate the ram to a certain pressure, and when released, out pops a resistor. Sure you need to adjust the pressure applied and the granule volume to obtain the desired resistance. But, once you have the recipe, you can let the machine run as fast as it can until you run out of granule supply. Then step back and admire your big pile of resistors you can then sell to NGK.
Are all the resistors exactly the same? No. Can some have voids inside? yes. Could these voids arc internally and vaporize some of the squished granules? Yes. Will that alter the resistance value? Quite possibly. Can the part ultimately fail? yes. (it was made by mankind, remember.) Can they change to infinite resistance? Yes. Can they form another spark gap within the cap? Yes. Will the engine still have spark at the plugs? yes, until the sum of all the gaps require more voltage to bridge than what is available. Is it what was designed? No. Is that desirable? no. Life goes on.
Remember that the sparkplug's only task is to ignite; the flamefront of the burning mixture does the rest.
Agreed, as far that goes. However, the size of the initial flame front can determine if there is time to ignite the entire mixture before the exhaust valve opens or for the majority of the power stroke. At high RPMs, this is a concern as there is not much time between ignite and end of power stroke.
You can burn and entire field of hay with a single match and burn it all, but maybe not before the fire dept. comes to put some of it out. However, if you light off the entire edge of the field at once, the whole field might go before the fire dept arrives.
The combustion chambers for the SOHC4 are swirl quenched. Kind of a mini tornado going on with a spark plug tip in the swirl. The longer the spark while the mixture is swirling the more involved and larger the initial flame front becomes, leading to a more complete burn during the time of the power stroke.
While my sample size is small (9), ALL my 550s came to me with 10K caps installed. Even the 74 that I got with 1500 miles on it in 1975 had these. It will be tough to convince me that 10K WASN'T stock for the US model 550. I also remember an encounter with a Honda parts counterman. I had to replace a plug boot that got smashed on the 550. Without looking up the proper number, he retrieved one from the back, assuming they were the same as the 750. When pressed on the matter his books confirmed the 550 had a different part number cross to the NGK offerings he had in stock. He returned with the correct 10K cap, meant for my 550.
I never had direct access to his books.
I remember that I've tried to learn more on this more than a decade ago, but back then I couldn't find anything on 'tuning of the spark duration by adding resistance',
Perhaps an analogy can help you.
Turn the garden hose spigot on and watch the water stream at the end shoot a short distance before gravity overcomes.
Now put a restrictor at the end of the hose which reduces the outlet diameter. Note that the water now shoots way farther before gravity overcomes. The restrictor is behaving similar to the resistors in the spark circuit. The energy flow is slowed by the resistor, but the sum of the energy available is still transferred. It all happens in less than a millisecond.
