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renix with a 99-06 HO?


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Hope this helps.

 

XJ Cherokee and ZJ Grand Cherokee 4.0L engine blocks interchange. 

2000+ TJ Wrangler and WJ Grand Cherokee 4.0L engine blocks interchange. 

XJ/ZJ blocks, and the 2000+ TJ/WJ blocks do not interchange without significant modifications. (1991 to 1995 YJ and 1997-1999 4.0L TJ Wrangler blocks will interchange in XJ/ZJ and visa-versa).

TJ/WJ 4.0L Engine blocks underwent clean sheet design changes effective in the 1999 WJ Grand and 2000 TJ Wrangler. These blocks are not interchangeable with XJ/ZJ engine blocks. The reason is motor mount bolt holes and belt driven accessory mounting bolt holes are in different locations, or not present at all, TJ/WJ vs. XJ/ZJ.


                XJ: "Regular" (not Grand) Cherokees 84-01
                ZJ: Grand Cherokee 93-98 (Gen1)
               WJ: Grand Cherokee 99-04 (Gen2)
                YJ: Wrangler 87-95 (Gen1)
                TJ: Wrangler 97-06 (Gen2)


 

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You need to look over the info Cruiser posted. Depends on what block or donor from 99-01. Those years I think XJ only. The one from the Grand Cherokees (WJs), are not drilled and taped for the XJ accessories. I am not sure when the Wrangler blocks changed. The Renix block might be the strongest. I think there are two different castings for the Renix block, a US and Mexico. I heard the Mexican one is actually stronger.

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well as far as the blocks go for performance it shouldn't really matter to much right? Beside rods and pistons the performance should be the same, its the head I'm worried about because thats where everything goes. I found a nice new casted performance head i want to use but its only for the ho engine

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The cylinder spacing and bolts are the same. They should fit on all the blocks. The latter 96+ have locator dowel pins in the block. You would just have to align the head manually. HO is from 91-95. If for the later 96-up, I'd say dowel pin.

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Year............Casting No
1987-90......2686
1991-95......7120
1996-98......0630
1999-06......0331

 

Basic cylinder head facts from the Strokers forum:

Renix heads (can't remember casting number) have the lower ports and presumably less flow (don't recall actual flow numbers though)
7120 (91 to 95 I believe) this head somehow got the reputation as the "best" head... I can only guess because it's popular for the 4.2 head swap because some misinformed early swappers claimed the later 0630 head didn't have a water temp sender boss (sometimes is does sometimes is doesn't).
0630, 96-99 (98 on a ZJ I believe) this head is supposed to be identical to the 7120, I haven't flowed my 7120 yet but I believe it will flow the same. This head supposedly doesn't have a water temp sender location, but it does on 4 out of the 5 that I've seen... there's a small bolt in it depending on what model Jeep its in.
0331 2000+ (99+ on Grand Cherokees) this head is prone to cracking in its first few years of casting. It has Ports that are higher on the head and the intakes flow better than the intakes of a 0630 (and I suspect the 7120 as well but I will confirm that at some point).
The exhausts on the 0331 should be better for torque (perhaps worse for high RPM horse power, perhaps no difference), they are smaller, shapped much better, and the floor has been raised a lot while the "roof" was raised slightly making for a higher velocity port, more exhaust "scavenging" and thus better low end torque. How much is anyones guess as no ones done a dyno shootout of Jeep heads (unless HESCO has but they would never make the sheets public).

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thanks for the info guys! I'm doing a supercharger build and I was planning on upgrading to the newer throttle body so I already have one with a retrofitted renix tps. I'm also planning on over building the na engine to prepare for the boost in going to throw at it after this supercharger. I found a company that can make me a solid copper head gasket and ima go with upgrade head studs. Be a little less hp till I get the blower on but it'll be able to handle the boost when I'm ready . This is the combination I want to use.

 

https://www.mabbcomotors.com/catalog/Auto/National_Short_Block_Program_-_NO_CORE_REQUIRED/Jeep/Jeep_4.0_242_Short_Block_1991-1995_-_NO_CORE_REQUIRED_-_90_Day_Limited_Warranty/354

 

https://m.ebay.com/itm/Jeep-4-0-New-Stroker-Performance-Cylinder-Head-0331-7130-0630-/302056243866?nav=SEARCH

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The flow data on the head came from Dino's Website years ago, as to the 7120, flowing the best. It was marginal as I recall. I think a bit of shift in the casting could cuase one to flow better than the other. No data to support that.

                 As to the Mex block being stronger. That can be subjective or data I don't know. My info was from a stroker article years ago, posted on the web. It was more for an extreme stroker. The article said the Renix blocks had a thicker cylinder walls. There were/are casting improvements since then. Ford and Cosworth (I think) worked on the Duracast technique in the mid 90's. IE the Duratec and Zetech engines for the Ford Contours. The wall thickness was thinner, but less porosity.  Also, in the early 2000's or maybe even the mid 90's there was spheroidal cast iron.  I think you can do a web search and know more than I do about it. Again, stronger but thinner wall thicknesses. Also, less weight.

          As an aside sometimes you want more weight. I just gave away a few SAAB Sonnets. Long long story. Anyways, my brother still has a few engine blocks left. I was going to move them. They are V-4's. You should see the wall thickness on them.  They weight more than a bit.

 

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32 minutes ago, 75sv1 said:

As an aside sometimes you want more weight. I just gave away a few SAAB Sonnets. Long long story. Anyways, my brother still has a few engine blocks left. I was going to move them. They are V-4's. You should see the wall thickness on them.  They weight more than a bit.

 

I had several of the 96's with the German Ford Taunus V4 back in the day, but never a Sonnet. Wish I knew you were giving them away - I always wanted one. That little V4 was a tractor engine, and the rods and crank were beefier than most V8 engines. But I preferred the screaming 3-cylinder two-strokes most of all.  :laugh:

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