4.0 Rebuild & Slight Upgrade


robo512

New Member
Joined
Jan 11, 2021
Messages
11
Location
NW Indiana
Hey everyone,

I am currently in the process of rebuilding my 4.0L out of my 2002 TJ. Cracked piston on cylinder #6 was causing horrible knocking. I am ready to order everything I need to do the rebuild, and I wanted to know if there is anything anyone recommends to add a bit more power while still using the stock crank/rods and also stock tune. The block needs to be bored since it is out of round so I wouldn't be opposed to boring over a bit more than I usually would. Maybe a cam upgrade or something too?
 

SkylinesSuck

TJ Addict
Joined
Mar 28, 2020
Messages
1,886
Location
Warrenton, VA
What am I looking at Price/work wise with a stroker build?
All the machine work costs will be the same. The only significant cost difference would be the price of the crank, custom pistons, injectors, and if you upgrade the cam which you are already considering. Oh yeah, and having the pistons pressed on to your existing rods.

If you keep the compression stock and the cam mild, you can do fine without a tune.
 

SkylinesSuck

TJ Addict
Joined
Mar 28, 2020
Messages
1,886
Location
Warrenton, VA
Scat crank ≈ $500
Custom forged pistons ≈ $500
Injectors ≈ $150-$200
Pressing pistons on to existing rods = cheap?

Everything else would be the same as a standard rebuild (depending on cam choice). There are a bunch of MAW's in there, but if you if behave yourself in that respect, there ya go. I recommend contacting Russ Pottenger russbnbracing@yahoo.com and talking to him about it if you are seriously interested. Strokers aren't always the most cost effective upgrade, but for somebody rebuilding their 4.0 anyways, it's almost a no brainer IMHO.