Been searchin and found a lot of really good info. I got a question though. Any of you ever had a 4.0 to start with and swapped under a 4.2 block? :evil: I am lookin at doin this, but I wanna make sure all my 4.0 accessories are gonna bolt up. Will my AA bell housing to the T18 swap from a 4.0 to 4.2? Will all the little $hit bolt up?
I thought Newbies were the ones who needed to do searches?
1) it's too easy to stuff a 258 crank in a 4.0L block and get 4.6-ish liters to bother with messing around with the 258 short block. Just make sure you get a nice set of Acurate Power pistons for the final assembly to control the compression ratio. They're pricey, but they pay for themselves in the cost difference between 93 and 87 octane gas.
assuming you don't have the time or resources to do this (saw your other post) I don't think you'll have a problem using the 4.2L block, since most of the accessories hang off the front cover, the intake manifold, or the p-side of the block. you might want to confirm if that aluminum AC/alt. bracket can be mounted to the block of a 4.2L
the bellhouing will bolt up, no prob. For future reference, Novak Adapt can machine pretty much any bellhoung to accept the MPI crank sensor for the shockingly low cost of $50.
I thought Newbies were the ones who needed to do searches?
1) it's too easy to stuff a 258 crank in a 4.0L block and get 4.6-ish liters to bother with messing around with the 258 short block. Just make sure you get a nice set of Acurate Power pistons for the final assembly to control the compression ratio. They're pricey, but they pay for themselves in the cost difference between 93 and 87 octane gas.
the bellhouing will bolt up, no prob. For future reference, Novak Adapt can machine pretty much any bellhoung to accept the MPI crank sensor for the shockingly low cost of $50.
Hmmmmmmm, thats odd newbie, I did search and you still had some new info to offer :flipoff2: Thanks, and you are right, I got the 4.2 and cant afford any other route right now.
hey keith, i did this conversion on my wrangler, works fawkin awesome, I did a MPI at the same time tons of power!!!!! look at the RoCk SkuLLz website in the tech section. I have a link there to my 4.0L head article... if you have any questions you can e-mail me or you can usually catch me on our RoCk SkuLLz bulletin boards
So Keith, are you planning on putting the whole 258 in there, or just the short block? Just doing the short block would work real easy. If you plan on swapping in the 4.2 head, you might have problems with the manifolds. 258's built between '81 and '86 use a smaller 7/16 head bolt, so you will have to pick up some centering dowels from Hesco, or re-drill your block to the 4.0's 1/2 inch bolts. There are also some water jackets that need to be adressed. Check out Tim Weavers 4.0 head swap for details.
I am pretty sure your 4.0 flywheel will fit on a 258 block and both are internally balanced, so that shouldn't be a problem. Make sure you use your old water pump if staying with serpentine belt. They both look the same, but a v-belt pump turns backwards from a serp. drive 4.0. Also check that the 258's crank isn't longer in the front. You may have to chop off 1/2 inch to make the harmonic balancer fully seat. check out Rob Bryce's stroker site for some more info.
Sweeeeeeeet. Thank you very much Gentlemen. I am not certain what I am gonna do yet, but it seems like I am either gonna swap in a complete TJ motor (probly not cause of money) or just swap the 4.2 short block (a little more realistic financially right now) Either way time is dwindling
I don’t know if it would help to finance your project, but I’ve been half hearted in my search for a 4.0 L head to put on my 4.2 w/MPI.
If you have a complete TJ motor, then you probably have an extra head, cover, and header right? Maybe I could buy those parts from you to fund the new motor?
It was just a thought.
I hate hearing my motor ping.
So which motor are you talking about?
I have a 4.2 with about 3000 miles on it. I just need the 4.0 head stuff.
I’m going to have the head worked on to make it fit my 4.2, so I’d be fine with the older head and you keep the new TJ motor.
I haven’t been on the POR site for a long time, so I’m not up to speed on your rig these days. I did a search…ouch that sucks on your motor.
It looks like the only stuff you’d have for me would be the head and the valve cover.
I couldn’t give you enough to off set the other motor, unless you were talking about that $300 job. I don’t really know that a head is worth. Maybe $150? I don’t’ really know. :rasta:
sorry
Well, I figure since its a brand new head with 20K on it, and everything there is crate motor from chrysler, its probably worth a little more than that. Butr for now, I am gonna attempt to swap all my junk onto a 4.2 block I got a hold of. If I sell it all, I will let you know, keep your eyes on for sale
If you still are looking for an engine, Area 51 in Rancho
(was there today) has a 1988 cherokee with a complete 4.0. You will need to pull it but there prices are cheap. Also, Parts Mike has a 4.0 long block but I don't know what he wants for it.
Newbie! ouch!
I'm not new I've just been :zzz: for over a year.
It was a newbie thing to do though. :emb: I haven't looked at prices for a cylinder head for a long time. Sorry if that offer was insulting. I'll check a couple of pick and pulls in my area and I'll see if you still have your parts.
Where is Rancho? There are a lot of Ranchos in California. I was trying to find "Area 51 in Rancho" on the web and I got a bunch of junk.
The timing chain cover may be thicker on the 4.0. I just finished a 4.0 to 4.6 stroker swap. From the original 87 block to a newer 93. The T.C. cover on the 93 was a tad thicker, so I needed to modify the alt.bracket. Otherwise the swap was straight forward. Nothing like 260 H.P. and 330 ft/lbs from a little six cylinder! There is a boat load of this information here... http://groups.yahoo.com/group/strokers/
-Jon
An '88 is going to have the old Renix injection system, not the more common MPI. Hesco can still provide you with the parts to use it though including a harmonic balancer CPS for the Renix system.
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