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Old 07-15-2009, 11:50 PM   #21
Rider
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Hmmm... well not if the valve is one way, so to speak... although I must confess to wonderin what keeps it seated until vacuum opens it? The pressure of the exhaust gasses until they are released?
But see it would work more like a 2 stroke at that point. Intake, exhaust, intake exhaust. Where is your compression and power stroke (both valves closed)? Seems like the power stroke would open the intake valve and blow the exhaust out.
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Old 07-16-2009, 12:00 AM   #22
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But see it would work more like a 2 stroke at that point. Intake, exhaust, intake exhaust. Where is your compression and power stroke (both valves closed)? Seems like the power stroke would open the intake valve and blow the exhaust out.
The power stroke is caused by the explosion in the cylinder.

The fuel is expanding pushing out in all directions. The same force that drives the piston down would be forcing both valves closed.

The only time there is a lack of pressure in the cylinder is during the intake stroke.
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Old 07-16-2009, 12:01 AM   #23
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No! That is not possible because the knower of all things says that it is not!!! The maker of this website is probably a mechanical engineering professor but I'm sure that A M J knows better!!! Yeesh!
"Intake over Engine" configurations (what Phenix is referring to) aren't the same as OHV configurations, as shown in the original diagram. I don't give a fuck if the maker of the website is Albert Einstein, no one ever made an OHV engine with spring-less intake valves. (Except Ducati...)

Here's a picture of an IOE engine:



Does the intake valve move up and down all by itself? No, dumb ass, it does not. Harley's very first engines used a vacuum operated intake valve, but not in an OHV head.

BTW, the direction of the piston, up and down, back and forth, sideways, or at an angle up your ass, has no bearing on the function of the valve train, so why don't you go polish something shiny, and shut the fuck up.

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Old 07-16-2009, 12:04 AM   #24
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The power stroke is caused by the explosion in the cylinder.

The fuel is expanding pushing out in all directions. The same force that drives the piston down would be forcing both valves closed.

The only time there is a lack of pressure in the cylinder is during the intake stroke.
Yeah but wouldn't the downward motion of the piston pull the intake valve open? I guess what your saying makes sense, i just have a hard time envisioning it. But what else is new? With no spring to keep the valve closed why would it not just stay open at least part of the cycle. It certainly would not have been as efficient as today's engines with springs on both intake and exhaust. .

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Old 07-16-2009, 12:07 AM   #25
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The power stroke is caused by the explosion in the cylinder.

The fuel is expanding pushing out in all directions. The same force that drives the piston down would be forcing both valves closed.

The only time there is a lack of pressure in the cylinder is during the intake stroke.
We have a bingo.

The design worked so well, that Harley used it for maybe 2 years (?) before they switched to a cam driven intake, similar to the later flathead motor.

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Old 07-16-2009, 12:08 AM   #26
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I don't give a fuck if the maker of the website is Albert Einstein, no one ever made an OHV engine with spring-less intake valves. (Except Ducati...)


JC
You mean no one since 1959, right?
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Old 07-16-2009, 12:11 AM   #27
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JC
Horizontally apposed valves? Cool, I've never seen that design before.
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Old 07-16-2009, 12:14 AM   #28
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You mean no one since 1959, right?
Will you please prove it... I am so tired of this asshole calling me names! I never said that I'm an expert on engine design but apparently he is an expert in everything and no one else is allowed to post or have any opinion or thoughts what-so-ever!!! Fuck, I guess we should all leave him to his forum and peddle our stupid thoughts and ideas elsewhere...
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Old 07-16-2009, 12:15 AM   #29
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Yeah but wouldn't the downward motion of the piston pull the intake valve open? I guess what your saying makes sense, i just have a hard time envisioning it. But what else is new? With no spring to keep the valve closed why would it not just stay open at least part of the cycle. It certainly would not have been as efficient as today's engines with springs on both intake and exhaust. .
The direction of this piston doesn't matter.

You are thinking down = pulling.

The "pulling" effect is the low pressure environment on the intake stroke. On the other three strokes, cylinder pressure is greater than its surroundings which would force the valves closed.

I understand having trouble visualizing it. If only someone would design a website with an animated example...
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Old 07-16-2009, 12:15 AM   #30
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You mean no one since 1959, right?
Which, I believe, occurred sometime in the 20th century.

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