Part Two: The Intake Port

[huskihl]

I ported probably 15 of my own saws including work to the upper transfers before I had any 90° tools. Fortunately, you’re working on probably the widest known set of upper transfers in the common saw world. You can actually get in there with a 1/4” or 6mm ball burr well enough to raise them up a few degrees. Or a stack of cut off wheels will make a nice straight line and then you can get in there with the ball and clean up the inside of the cut.

 

[huskihl]

From what I understand, everything left within the confines of the squish band is wasted fuel and does not get burned or transferred into power. Anytime you notch anything in the top of the piston, you’re adding to that wasted charge and slowing down squish velocity

 

[Powerstroke Cowboy]

What he is saying is that when you take a notch out of the piston, you'll have a huge squish clearance in that area when the piston is at TDC. That will cause fuel mixture to be trapped. Tight squish is a good thing.

Thanks for the explanation. I appreciate it.

A few ways to learn, ask questions of those that know, or trial and error. I prefer the first.

 

[Powerstroke Cowboy]

From what I understand, everything left within the confines of the squish band is wasted fuel and does not get burned or transferred into power. Anytime you notch anything in the top of the piston, you’re adding to that wasted charge and slowing down squish velocity

Thanks for taking the time to explain this. It's much appreciated.

 

[thompsoncustom]

From what I understand, everything left within the confines of the squish band is wasted fuel and does not get burned or transferred into power

Why would that be? Why would it not get burned like the rest of the fuel.

 

[huskihl]

Why would that be? Why would it not get burned like the rest of the fuel.

The flame is confined to the combustion chamber I believe. It all happens a little bit too fast for me to imagine in my mind’s eye

 

[thompsoncustom]

The flame is confined to the combustion chamber I believe. It all happens a little bit too fast for me to imagine in my mind’s eye

after TDC when the flame is going and the piston is headed down I would think anything in the squish band that might not have been lite at first would be burned up.

 

[huskihl]

after TDC when the flame is going and the piston is headed down I would think anything in the squish band that might not have been lite at first would be burned up.

It’s probably burned up, but at that point in time I believe it’s too late for it to have any effect

 

[thompsoncustom]

It’s probably burned up, but at that point in time I believe it’s too late for it to have any effect

Very well could be.

 

[farminkarman]

It’s probably burned up, but at that point in time I believe it’s too late for it to have any effect

This would be the correct answer. If you think about an engine trying to making good power at 10k+ rpm, the combustion chamber needs to be small, or you need multiple spark plugs. The flame front in the combustion chamber can only travel so far before the piston has already begun moving downward.

 

[Mastermind]

Good stuff in here.

 

[thompsoncustom]

Combustion chamber at 33,000FPS
If you go to the 16min mark it's a nice close up of the piston and flame

 

[Powerstroke Cowboy]

That's pretty cool!!

 

[00wyk]

It’s probably burned up, but at that point in time I believe it’s too late for it to have any effect

Basically, you want the fuel in the squish really to be nearer the spark plug and center of the piston.
Not only does the squish ignite later on in the process, but it is also a very small amount of fuel and air compared to the main charge.
What a small squish does is push all that charge right up into the combustion chamber instead of letting it sit on the edge of the piston.
Now you're appreciating more how efficient Hemi engines are, aren't you? Squish is for suckerz!
Hemi's are a lot like the Universe - everywhere is the center.

Now here's food for thought:

 

[Nutball]

Is maximum width and flat opening desirable in an intake port, or is narrower or rounded actually better? I'd think wider and flatter would allow it to be raised without the usual side effects of raising it.

 

[Ketchup]

I prefer wide to low and round. Mostly because of case compression. It could direct colder charge towards the transfers. A circular port probably has better velocity though.