When you are turning an engine into a stroker what exactly are you doing? All I really know is that it makes the displacement bigger, but I just want to know what exactly is going on.

 

You are putting the crank shaft and pistion rods out of an older AMC 4.2 litre into your 4.0. At the same time you have the cylinders in your 4.0 overbored .030. This gives you a new displacement of 4.7.

 

Ok so you're basically swapping in a bigger crankshaft and rods? And overboring just makes the cylinder diameter wider right?

 

Easiest way to say it, you making the piston travel farther up and down and making the bore larger... This is true for any engine you make into a stroker..

 

Yeah, the term stroker comes from the older 4.2 litre crank have a longer stroke on the rod journals. So, you turn a 4.0 litre into a "stroker" motor.

 

And here is the site for any and all thing Jeep stroker. If you are planning on attempting to build one, or are just curious about how it's done. Do some reading here, it will answer alot of your Jeep specific stroker questions...

http://www.jeepstrokers.com/forum/