Cam Compatibility?
Posted: July 17th, 2012, 4:57 pm
Before I order my new cam, I'd like a little confirmation that 4.0 and 4.2 cams are swapable. Summit Racing has a Comp Cams 252h pn 68-200-4 listed, but it only comes up when searching AMC 258. If you search a Jeep 4.0, Summit wants to sell you the cam that seems most popular on here but it has more than .480" lift, and would most likely require valve springs.
The reason I'm more interested in the 252h is because it's a big improvement over stock, but still only has .433" valve lift, which I assume would work just fine with stock 4.0 springs in a 4000 max rpm motor without any valve float or over compressing the springs.
The reason I'm more interested in the 252h is because it's a big improvement over stock, but still only has .433" valve lift, which I assume would work just fine with stock 4.0 springs in a 4000 max rpm motor without any valve float or over compressing the springs.