The Hodaka Club Forum

Arizona Shorty wrote:

Second thing: detonation isn't caused by hot spots. That would be pre-ignition. Detonation is a flash burn started by a spark plug at the right time, flame spreading at a given rate, and then something upsets the balance, usually in the squish band, and the flame front goes from sedate to exponentially fast. That flash bang is detonation and it beats the starch out of engines. The something that sets it off is usually low octane, moderate engine speed, too high compression for the gas in use, and lots of throttle. As engine speed rises to near redline, detonation recedes. Detonation one thing, pre-ignition another. And there is no such thing as pre-detonation, which term has not been used here, yet, but has been used in a lot of other places on the net. Just wanted to nip it just in case.

Oh, and all seizures are caused by breakdown of the oil film on the piston/cylinder wall. What causes the breakdown is variable, but unless the oil breaks down, nothing seizes. That's' three things. Sorry.

Y'all can go back to the running discussion.

With all due respect.. above in Red..This is not correct...Detonation has nothing to do with the spark nor is it set off by the spark.. It does occur AFTER ignition.. But detonation is the result of 2 colliding flame fronts. This is due to a rapid pressure rise in the cylinder that will ignite the F/A mix with NO SPARK.. This newly ignited F/A mix starts a 2nd flame front. This 2nd flame front collides with the oncoming spark ignited flame front (the one that you want) and this COLLISION is the detonation.

As for the 1st law of thermodynamics... I do not see how that is up for debate?
The total amount of energy and matter in the Universe remains constant, merely changing from one form to another. The First Law of Thermodynamics (Conservation) states that energy is always conserved, it cannot be created or destroyed.

I have seen vaccume applied to a ping pong ball create energy.
Now you see why we tune or jet our motorcycles. Tuning or to jet makes bad oil break down less quickly or running lean breaks down bad oil quickly. Running your motorcycle very lean can break down good oil, When oil breaks down pistons suffer seizure. Proof of the matter is I have had three piston seizures that were not the result of oil break down. One the wrist pin clip tang broke off chewed things up and the piston seized oil did not break down. Same thing happened with a broken ring. Like we say just tune the engine and use good oil.-----------Clarence

Never tap on a bee hive with a stick----

Kels wrote:

Arizona Shorty wrote:

Second thing: detonation isn't caused by hot spots. That would be pre-ignition. Detonation is a flash burn started by a spark plug at the right time, flame spreading at a given rate, and then something upsets the balance, usually in the squish band, and the flame front goes from sedate to exponentially fast. That flash bang is detonation and it beats the starch out of engines. The something that sets it off is usually low octane, moderate engine speed, too high compression for the gas in use, and lots of throttle. As engine speed rises to near redline, detonation recedes. Detonation one thing, pre-ignition another. And there is no such thing as pre-detonation, which term has not been used here, yet, but has been used in a lot of other places on the net. Just wanted to nip it just in case.

Oh, and all seizures are caused by breakdown of the oil film on the piston/cylinder wall. What causes the breakdown is variable, but unless the oil breaks down, nothing seizes. That's' three things. Sorry.

Y'all can go back to the running discussion.

With all due respect.. above in Red..This is not correct...Detonation has nothing to do with the spark nor is it set off by the spark.. It does occur AFTER ignition.. But detonation is the result of 2 colliding flame fronts. This is due to a rapid pressure rise in the cylinder that will ignite the F/A mix with NO SPARK.. This newly ignited F/A mix starts a 2nd flame front. This 2nd flame front collides with the oncoming spark ignited flame front (the one that you want) and this COLLISION is the detonation.

As for the 1st law of thermodynamics... I do not see how that is up for debate?
The total amount of energy and matter in the Universe remains constant, merely changing from one form to another. The First Law of Thermodynamics (Conservation) states that energy is always conserved, it cannot be created or destroyed.

Read it again. I was setting out a sequence of events ending in detonation. Spark first, normal flame front, and then before the normal flame can complete the cycle, detonation. I didn't say detonation was caused by spark, only that without spark and flame first, there is no detonation which by definition is a post-ignition event, the diametric opposite of pre-ignition which is something that happens before there is a spark. The point was that detonation is not caused by hot spots, but instead by a break down of the smooth burn of fuel.

And I looked up the thing about energy. You are correct that what is paraphrased is the first law of thermodynamics, but you leave out the first part of that law which states that in a closed system energy is conserved. Hate to point out that internal combustion engines aren't closed systems, and although the first law of thermodynamics is widely accepted and has its applications, if it only holds true in a closed system, it isn't a law. Quantum physics attempts to validate this law within the context of the universe, in that for purposes of energy, the universe is a closed system, but apologies to Einstein, the universe is not a closed system either, which is why his theory of relativity is a theory, not a proof, not to mention that even as a theory, his theory has been questioned of late. I understand the idea that energy is transferred and so on, but have no source of proof that it cant be created or destroyed. That is a concept based on assumption, not a law, and since most of the energy in an Otto cycle goes out the tail pipe, I am not certain why it was brought up.

"but apologies to Einstein, the universe is not a closed system either, which is why his theory of relativity is a theory, not a proof, not to mention that even as a theory, his theory has been questioned of late."-------- A misquote.

Einstein's Theory of Relativity indeed was a theory when he proposed it early in the 20th Century. Today after nearly a century, Relativity is one of the mainstays of Modern Physics and is relevant in all things from GPS to black holes and the fate of the Universe. It is neither a proof nor a theory but a modern concept such as Chemistry and Physics. Proofs of relativity have been going on since day one of his proposed Theory of Relativity and none has been proved wrong to this date. Things can all be questioned but require proofs to overturn.

Sorry, just struck a nerve there. Actually, you should apologize to Einstein.

Maxie

PS--Even though I did poorly in Thermodynamics I did much better in Astronomy which is not just about stars, it's the study of the Universe and its properties.

I finally realize I know nothing about anything but making my hodaka run purr take me there and bring me back. ---------Clarence

Clarence, you're the genius on this one, you're right again. Thanks for reminding us, We sometimes get off track it seems.

Thanks for your input on all things.

Max