4.125" crank? Is that the distance from the center line? How does the crank size change cubic inches? What's the formula?

4.200" bore? Guessing that's diamater or the cylinder?

How do bore and stroke relate (I realize that this can be done via simple math.... but I'd rather find out from the horses mouth than figuring it out myself)

Which is better? and why? More stroke or more bore?

Also... from bottom to top what is the length of a stock LS1 cylinder area...

How tall (high) are stock pistons? (00, but any year accepted).

sorry for all the questions... but I'm now to the point where I'm trying to understand the bottom end... and I'm sure there are many others out there that would find this info useful

Thanks

<small>[ October 23, 2002, 11:02 PM: Message edited by: horist ]</small>

 

By using a larger stroke crank (4.125") it allows the piston to travel farther through the cylinder. You're basicaly taking a normal 12oz beer(stock cylinder) and turning it into a tall-boy 16oz beer can.

<small>[ October 23, 2002, 11:30 PM: Message edited by: felton316 ]</small>

 

First cubic inche of an engine is expressed in the formula radius squared x pie(3.14xxx) x stroke x number of cylinders.

4.125 stroke is how far the crank will move the piston from bottom dead center to top dead center.

Bore is the diameter of the cylinder.

Simple calculator for displacement HERE

Argument on which is better usually ends with more stroke is good for stronger mid range and larger bore is good for higher RPM horse power.

Length from the botom of the cylinder to the deck is roughly 8 5/16.
Stock stroke is 3.624

I don't have a stock piston handy.

 

www.howstuffworks.com has a huge section explaining engines and hwo the work. i used that many times to explain different things about engines and torque converters and the like.

 

I am a honda guy myself but bore and stroke are incredibly important to hoda engines. Heres kindof how it goes. Engines are one of three ways 1.)square- Bore and stroke are the same 2.) Oversquare- bigger bore than stroke 3.) undersquare- bigger stroke than bore. What this really means is an oversquare engine has lower piston speeds and less internal stress at high RPM due to lower inertial loads this lower piston speed also gives the cylinder more time to fill with air. Undersquare engines have faster piston speeds which means more internal stress this causes accelerated wear and is harder on the rings especially if it causes ring flutter. On the plus side undersquare engine produce more low end power due to intake port velocities. If your engine has good breathing characteristics and can take the stress undersquare is the way to go. By the way an ls1 can take it. and since it doesn't rev very high I don't think it would have any trouble filling the cylinders. A nice port and polish of the heads and intake compliment the undersquare engine. So my personal opinion is if you polish and port stroke is king. But what does A honda tuner know?

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by felton316:
<strong>You're basicaly taking a normal 12oz beer(stock cylinder) and turning it into a tall-boy 16oz beer can.</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Excellent description!!! <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" />

 

gotta love the how stuff works web site, and the beer example.