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[Uncle Ben]

Before TDC, the "right way" is toward the top of the cylinder. Geez! Do
I have to explain everything?

Uncle Ben

 

[Oscar_Lives]

Before TDC, the "right way" is toward the top of the cylinder. Geez! Do
I have to explain everything?

Uncle Ben

The expansion of the gases still pushes the piston in only one direction, no
matter where the crankshaft is.

 

[Uncle Ben]

CompUser wrote:
....

http://www.streetrodstuff.com/Articles/Engine/Detonation/Page_2.php

....
A most interesting and informative article. Thank you!

It seems that what I learned many years ago about engine knock (and
overconfidently echoed in this topic) is quite wrong, and I stand
corrected. Read it for yourself to understand.

 

[Uncle Ben]

The expansion of the gases still pushes the piston in only one direction, no
matter where the crankshaft is.

Of course, but before TDC it is the wrong way, and after TDC it is the
right way. You don't want any expansion of gases to occur before TDC.

I'm withdrawing from this silly discussion because CompUser in a post
above referred us to an article that brings me up to date on the
problem of knocking. He was right.

Uncle Ben

 

[Oscar_Lives]

Of course, but before TDC it is the wrong way, and after TDC it is the
right way. You don't want any expansion of gases to occur before TDC.

I'm withdrawing from this silly discussion because CompUser in a post
above referred us to an article that brings me up to date on the
problem of knocking. He was right.

Uncle Ben

Well, yeah, the TDC thing is correct, but that is a matter of timing: "WHEN
the piston gets pushed", not what DIRECTION the piston gets pushed. I was
confused when you said the piston gets pushed the wrong direction by the
expanding gasses-- and the expanding gasses can only push the piston in one
direction!