I was wondering if the side walls of my cylinders would support something like .030 of .040 over pistons. If anyone knows about this of has done it what is the horsepower and torque gain an a mod like this one, and how much did it cost you.

 

I've asked this question before but have never really gotten a straight answer. someone will chime in.

 

I'm hoping some other folks will chime in, but from my way of thinking, you probably cannot take the cylinder walls out too far on these 4.0L's. Regardless, there usually isn't much of a gain in hp/trq from just boring out the cylinders. Opening up the heads would better IMO...

 

I agree with Bill.
The bigger bore alone won't give you much HP gains.
You'd have to put a stroker kit in it, if anything like that is available for the 4.0.
Since the power is in the head flow, it's where the attention should be spent first...

 

I was resarching this awhile back and read somewhere that you cant bore out much because of close cooling jackets and doing so would weaken the walls in some places.

But boring out a little, and making a stroker at the same time, would be interesting.

 

Same what I had ran across as well.

 

boring out an engine is used to get rid of cylinder wall wear - not to make power or anything like that...my 440 bored .030 makes it approx 446 cubic inches. you can make power by stroking a motor or increasing the amount of air going in and coming out of the engine....that's basically it, other than using nitrous.