Now it appears you're purposely acting obtuse. You'd have to live under a rock to have never seen any results from R&D being done in this field or paid any attention to any new engines that use quench as one part of the recipe in successfully running pump gas with quite high compression ratios.

 

This is my issue with a thread like this in the most fundamental sense.

Most of the items being discussed are but a single component of a far greater and more complex system. It is IMPOSSIBLE to speak in 'absolute' terms with regard to these items.

Perhaps, at one time, the 'quench' component of combustion chamber shaping had a great deal to do with the performance of the engine. This is what allowed (past tense) the running of high compression ratios with lower octane fuels.

Now, there are tremendous number of electronic aids and advanced fuel delivery methods that allow the regular use of 11:1 and greater compression ratios with pump fuel.

Quench is NOT a silly myth. It just isn't the defining factor in compression ratio versus fuel octane any longer. It is part of a greater and more complex system.

If the 'myth' statements made on this thread were not so absolute and narrow-minded, it would only be 3 pages long and have a bunch of "Huh...interesting" statements, "I was wondering about" questions, and "In my experience" stories.

 

So is the need for quench a myth? I was curious about the term "quench" so I Googled it to see how Wikipedia defined it. I found quench is definitely needed for 2-cycle engines because of their inducting air/fuel charge from the bottom of the cylinder. But it appears quench has little to no value for 4-cycle engines because the incoming air/fuel charge comes in at a somewhat perpendicular angle and swirls at a very fast speed when the piston comes up.

 

I'm done. I'm not responding to the continued incorrectness of the above statement or any other.

I don't think it makes a lick of difference, but yes, I do hold a BS in Mechanical Engineering. I emphasized my studies in Dynamics/Mechanics and also Materials with the intent of pursuing a career in automotive design. I am a licensed, and practicing, Professional Engineer (PE...it's a pain in the butt to earn and maintain) and have owned a very successful (even through the recession) Civil Engineering design firm for over 11 years.
--My only brother is a Civil Engineer.
--My Dad is a Mechanical Engineer.
--My StepDad has his BS in Civil and his MS in Mechanical.
--My Grandfather (on my Dad's side) was a Mechanical Engineer and worked on the Apollo missions...specifically the Saturn rocket through Boeing.
--My Mom and Stepmom both hold and Associates Degree as Engineering Technicians.
--My Wife is my business partner, holds her BS in Civil, and is also a PE.
--My Wife's parents are both technical draftsmen (CAD operators) in Civil Engineering firms
My point is, I'm a BRED Engineer. It wasn't a choice.

And I'm a gearhead. And my kids are probably doomed to my fate.

All that said, I freely admit that I don't know much about a bunch of things and am ALWAYS learning about things I thought I knew a lot about.

But I know enough to easily discount many of the statements being made in this thread.

To the reader of this thread in 2028: Go to another resource on the items being discussed here. Run. Please. Save yourself.

As I said...I'm out. Only morbid curiosity keeps me opening the darn thing and I regret it each time.

 

oh come on, we haven't even gotten to the Harbor Freight tools vs. Snap-On tools debates that go on forever....

 

This is the sign and statement of an intelligent experienced individual. Also an educated one.
The more you know, the more you find out how much you don't know.

Some folks just don't get there.

 

Well now he is just making up crap starting other threads.
Let's try to NOT reply to them. This thread is so ridiculous we don't need any more of them.

 

Just like our parents told us: Look but don't touch (the submit button)

 

 

I believe that the OP posts threads like this to stir the pot, and then sits back and enjoys the chaos he creates. Notice how he never or rarely replies to other's rebuttals to statements he has made? I believe this is a cheap form of entertainment for him. He is retired, lives alone in a mobile home in the mountains, and lives off the grid......

 

The bold is not a bad thing LOL. The rest speaks to an intelligent person.

 

What other post got 6000 looks in the first week? You can't buy attention like that.

 

yep. outside of Dunlap is pretty isolated it appears.

 

epic fail . to bad this is not in video format it would be a you tube hit

 

A myth is a story that has been passed from generation to generation for many years without a single bit of evidence to support that story. The funny thing about myths is the longer they are repeated the more uh "true" they become. Like the myth of Santa Claus and the myth of the Tooth Fairy. Every culture has it's myths and oddly enough most people actually believe those myths are true.

I have presented about 20 myths you commonly hear; some of them pertaining only to C3's and the rest pertaining to any brand of vehicle. It takes critical thinking to separate fact from fantasy and sadly most people aren't able to which is why these silly myths persist.

 

I cant help myself.

I feel like a gawker driving by a car accident or train wreck.

I wish I could look away... but. just. can't. seem. to. look. away.

 

I am waiting for you (or anyone on this forum) to explain #6 to me. How does the speed of coolant affect the radiator dwell time? Thanks in advance...

 

Of the 20-some myths I listed the "hot and running" myth is perhaps the silliest myth because one turn down is one turn down regardless of whether the engine is hot, cold, running, or not running. As the adjustment of hydraulic lifter plungers isn't the least bit critical anything between 3/4 turn to 1-1/2 turns down is plenty accurate. It takes a full 2-1/4 turns down to be able to hold a valve off it's seat so even 2 turns down would work just fine. As the valves slowly sink into their seats as the valves and seats wear the adjustment nut would have to be backed off to maintain "clearance" so 2 turns down would be too close for comfort. That's why G.M. chose an even 1 turn down as that positions the lifter plunger slightly less than dead center.

I don't know how on earth the myth of "1/2 turn down" adjustment ever got started but I suspect it came from the myth that 1/2 turn down prevents lifter pump up (which it doesn't) that happened with the old disc-type lifters used in the 1950's and early 1960's that did pump up very rapidly when the valves floated because of weak springs. Once the lifters got changed to the ball bearing check valve style and spring technology improved lifter pump up problems vanished.

The only way lifter pump up could be prevented was by giving the valves .001 to .003" lash and then you had the equivalent of running solid lifters on a hydraulic lifter camshaft but with bad valve train geometry.

 

It is getting painful.

 

1/2 TURN GETS USED BECAUSE THE CAM MANUFACTURERS RECOMMEND IT. Try reading a tech note from a cam manufacturer before pretending to know something you are clueless about.

Seriously, Learn both engineering and how to read tech info from manufacturers before you spew any more stupidity. Right now, you are just spreading nothing more than UN-informed and UN-educated crap.