I want to buy an additional engine that I can tinker with. What is considered generally the "best" casting of the i6 4.0L? I know I've read the code before, but I'd like to hear what you think.

I'd imagine it'd be something from 97-01, but who knows. Maybe people mix-and-match.

 

449? Or do some people think others are better? Eventually I want to make the engine a stroker.

 

According to Scotty Kilmer, the 4.0 in Grand Cherokees were a thicker casting. But I am not sure if that is accurate.

 

This is something I would be curious about too if there is a difference.
I toy with building an engine, well really have my friend do all the heavy lifting, too.
Maybe not a stroker pe se but maybe a little something something.
But would have to bolt staight in an '00 and be able to swap over all the things that are different on an '00 compared to other years.
Not to mention accept a TUPY head.
Of course I do toy with the idea of changing everything necessary to run an engine with a distributor.
Using the engine wiring harnesses, computer, head, and complete exhaust like what would be on a '99 XJ.

 

Scotty's actually local to me...
I'd say for most things he really knows his stuff... would be curious to know if he backed up that statement with anything that could be referenced.

 

That's all BS! Kilmer is an ***. They are all cast using the same molds and the only differences would be metallurgy, as in composition. The later 99-04 Grand Cherokee blocks are a different casting altogether and they won't fit into an XJ without custom mounts, plus some of the mounting holes for accessories aren't there.

The 00-01 XJs use the same block as the older ones and a TUPY head will bolt onto ANY block, although you'd be shortchanging yourself if you use one because the exhaust ports are a lot smaller and would strangle a stroker. I saw a really nice steel header and dual cat system made by one of the companies that build strokers, but I don't remember which one. If you have the money, Edelbrock or Dart make heads for strokers and roller rockers as well. Somewhere on YouTube there's a video where they got 242 hp out of a 4.0. That's 1 hp per cubic inch without forced induction!

The thing with the 00-01 XJs is they use the waste spark ignition system in which 2 plugs fire every revolution, one on compression and one on exhaust. It does nothing for performance except reduce nitrous oxides in the exhaust for better emissions. If you're going to build a stroker, build a firebreather! Anything else is a waste of time and money.

BTW, you can safely bore them out .060" oversize, just don't expect to be able to rebuild it after that.

 

It is a pretty recent video about a modded 4.0L with massive HP. But there wasn't anything I remember about the block being "better" other than it came from a GC.

 

have a look at "Youtube Keith Newcomer Jeep Stroker"

there is quite a few vids of him building up various BIG horsepower engines, and I am 99% sure what block casting he prefers gets discussed

I would like my XJ to sound like his do when powered up fully on the dyno

 

This is why I have always said I like Dave... I don't even completely agree with you but I can be sure that everything you just said there had truth in it and no one can check you on that.

I don't want to pull up the video and timestamp it but he specifically says that the blocks he uses have more webbing in the metal which makes them stronger and more resistant to vibration hence the NVH stamp.

 

Newcomer does specifically show this

to my knowledge, all '96 and later blocks are NVH casting, featuring the webbing...and a bolt "girdle" structure across the the main bearings

 

Renix had the highest nickel content. You guys are splitting hairs.

 

Yeah, that is something I discovered doing research into this question. The way it is worded in that Newcomer Racing video is weird though. The narrator makes it sound like "if you can do it with this WJ block, you can do it with any of them", which doesn't make sense to me because the whole point is the WJ block is thicker. Maybe I am mishearing what he's saying, but I've replayed that part over and over and over, lol. It's basically been my classroom.

 

The only modifications they made to the WJ block was to relocate the oil filter and move the mounting locations so it would fit in the body because they moved the mounts to balance the 4.7. Why would they extensively modify an engine that they had already planned to stop production on in 2007? The crankshaft girdle did quite a bit to add strength to the bottom end although it's more of a windage tray then anything else. The main strength of the 4.0 is the 7 main bearings instead of the 4 in older straight 6's.

The EPA caused the final demise of the 4.0 because it was not going to pass the future emission standards being imposed. The 4.0 is unique in the fact that it is an "oversquare" engine that still produces the torque of an engine with a long stroke. The only reason it lasted so long as a production engine is it's classed as a "truck" and the emission standards were delayed for trucks as opposed to cars. Remember cars had converters in 69 but trucks didn't get them until 89.

 

VERY familiar. I watch those videos like everyday, haha. Thanks.

 

Yeah, it is 100% a loaded question. I asked it on purpose so I can survey the range of answers and figure out from there what I need to look for and buy.