b4d93r

This morning I was watching PowerBlock TV on Spike and on Trucks they had part 5 of their Project Cheap Cherokee. (This is the first time I saw this so I was really interested.) For those not familiar, they are taking an 88 Cherokee 2 door (sport?) and upgrading it. Now the credibility of the hosts are in question (more on that later) but I thought I would get the opinion of a couple things they were doing from you guys.

They ultimately decided to make the 4.0 as a stroker by adding parts from a 4.2 (mostly the crank and rods). According to them you will get a longer stroke with everything remaining stock. (No head changes or anything like that.) They were bragging about the increased HP which would be near or equal to a V8. I don't exactly remember the specs but they went from a 3.2 to 3.9 stroke (Again my numbers may be off). My question is wouldn't you need to change either the piston rods or at least the valves to avoid the piston and valves hitting each other? (They may do this as they have just tore down the engine.) Also, has anyone ever done this and if so, whats the advantage of using the 4.2 parts vs. just swapping the engine?

Now for my questioning of their credibility. They started out the episode with the XJ on the dyno. (not an engine one but the one where you actually run the vehicle and see the wheels turning.) one of the guys was on the side of the XJ with a clear view of it and could see the wheels spinning. They were getting really cruddy results and he asked the guy in the XJ if he had it in 2WD or 4WD.

What the???? Dude, you are right there! You could see the wheels spinning! I think it would be obvious what he had it in.

ol"blue

There was a link on here the other day in one of the other threads, (I can't find it now) detailing the complete build. The 4.0 has a bigger bore. So using the 4.2 crank and rods (with their longer stroke) in the 4.0 block makes a 4.7 or 4.8L with about 80 more HP than the 4.0L. I might have it off a little as I'm going from memory. Can someone post that link please?

b4d93r

Ahhh, see thats why I asked. I didn't know the 4.0 had a bigger bore. That would make sense. It's like putting Windsor heads on a Cleavland.

I'll have to search some more and see if I can find that thread. It sounds interesting as I have a 4.0.

ol"blue

Someone had asked a question, and I think it was one of the Mod.'s that put a few links in their reply. I clicked on one of those links and it was that above mentioned write-up. I tried a search, even re-read a lot of posts, but to no avail. Sorry I couldn't be of more help.

jpdocdave

http://www.jeep4.0performance.4mg.com/stroker.html

lots of ways to build it, they're building one of the cheapest ones on trucks. i'm building one in my yj. mine should have the same numbers as a stock gm 350. i think its an awesome motor. only thing needed to change are fuel injectors basically on the outside. the 4.2 crank is a little longer from the multiple belts used on them, compared to the 4.0 serpentine system. thats about it.

b4d93r

Cool link. thanks for posting it.

I found out that my future son-in-law's GF's dad has a couple of Xjs out at his place. Think I may go take a look at them and see what he wants for them. Might be able to get some decent parts off them. Maybe even a "project" motor!