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Difference in 4.0l Blocks per year?

200SportXj

NAXJA Forum User
Location
Sleepy Eye, MN
Im looking to build a stroker motor for my xj, I went on craigslist and found a complete 1987 4.0l block.

From what I understand that is the very first year of the 4.0.

My question is, is the actual block identical? and can all my accessories/intake manifold/header/head bolt onto this older block.

I have a 2000 xj with a 4.0 that runs fine, so i just wanna build the 1987 in the garage and throw it in someday.

I know the connecting rods were a hair different because they moved the pin location. But i know they are both 242 cid from 1987-1992 and then 93-97 was 242 non HO, then 98-01 was the HO version which is just a different intake manifold and diff header design.

Fill in the blanks for me, thanks!
 
You will be better off with a newer block with noise and vibration improvements - check this link for a complete rundown on blocks, heads, cranks, and rods:

http://www.fourwheeler.com/techarticles/engine/129_0711_1987_2006_jeep_40l_inline_six/index.html

Anorg stroker links:

http://www.angelfire.com/my/fan/stroker.html

Blocks:
Year............Casting No
1987-90......53005535 (8933002665)
1991-95......53008405
1996-98......53020569
1999-04......53010449

The main webs of the '96 and later blocks were stiffened with extra ribbing and a main bearing girdle was added to reduce noise, vibration, and harshness (NVH), making these the best blocks to build upon. All Jeep 4.0 blocks have a deck height of 9.450-9.456".
 
But i know they are both 242 cid from 1987-1992 and then 93-97 was 242 non HO, then 98-01 was the HO version which is just a different intake manifold and diff header design.

Just to get ypu some correct info, both my 96's are HO motors. And 96 is the first year for the increased webbing.

Good Luck too!
 
All the bosses are different on 01 blocks

I don't think this is is true, so proof is required.

I do know that any 1991-2001 XJ or 93-98 ZJ engine block will interchange with any other. You simply re-use the flywheel (if required), manifolds, belt driven accessories, sensors, and head as needed on the donor engine block. I would think that the earlier blocks also interchange, I just don't have any threads to link to as proof.
 
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Insofar as I am sure, the COP head is the big issue, not the block. But, that being said, I would choose a later block to get the extra (read needed) main bearing support.

The blocks changed sometime after '01 so that would make mounting the accessories a tad difficult... With the AC compressor on the Driver's side for instance.
 
Well im picking up the block regaurdless, its worth 50$ in scrap alone prolly. at 10 cents a pound and it weighing 500lbs. Ill figure it out once i get it in my hands on tuesday and ill document and post pics
 
Bore and stroke are the same...........

YOU ARE WRONG

The displacement differs between 1990 and 1995 and 1996–2006 4.0L engines by 2 cubic inches. Both had a bore of 3.88 in (99 mm), while the stroke decreased slightly from 3.44 inches (87.38 mm) on the earlier engine to 3.41 inches (86.61 mm) on 1996 and later engines.

GFY
 
Note from DJ
Don’t forget if the stroker build is to be used in a street legal Jeep in your State of NM, it will need all of the sensors and electronics the match the Jeeps body VIN# in order to pass Smog tests requirements of NM I think.
 
From Wikipedia:

"The displacement differs between 1990 and 1995 and 1996–2006 4.0L engines by 2 cubic inches. Both had a bore of 3.88 in (99 mm), while the stroke decreased slightly from 3.44 inches (87.38 mm) on the earlier engine to 3.41 inches (86.61 mm) on 1996 and later engines. The displacement of both engines still rounds to 4.0 litres (3999.83 cc v. 3964.95 cc). The small stroke change (0.03"/0.77mm) was accomplished by moving the piston pin, rods are the same."

Insofar as the Emissions Hardware is concerned, it is a Federal Requirement that all of the hardware for the vehicle, as shipped from the factory, be maintained. Most states just go along with it sa as to not lose out on the FEd money for roads...
 
YOU ARE WRONG

The displacement differs between 1990 and 1995 and 1996–2006 4.0L engines by 2 cubic inches. Both had a bore of 3.88 in (99 mm), while the stroke decreased slightly from 3.44 inches (87.38 mm) on the earlier engine to 3.41 inches (86.61 mm) on 1996 and later engines.

GFY


was accomplished by moving the piston pin, rods are the same, just the connecting rod was different, they are indeed still the same block. sorry, your wrong lol:rof:

Note from DJ
Don’t forget if the stroker build is to be used in a street legal Jeep in your State of NM, it will need all of the sensors and electronics the match the Jeeps body VIN# in order to pass Smog tests requirements of NM I think.

NM? you mean MN. We have no smog testing here, and everyone is really laxed about checking vehicles.
 
was accomplished by moving the piston pin, rods are the same, just the connecting rod was different, they are indeed still the same block. sorry, your wrong lol:rof:

From my basic understanding, stroke is controlled by the crank so lengthening the rod won't change stroke. Just a wild assumption. Also the connecting rods are different but the rods are the same as previous years? Very interesting.

and a main bearing girdle was added to reduce noise, vibration, and harshness (NVH), making these the best blocks to build upon.

Could you explain how the girdle does this and how it is different than the earlier blocks? Just interested in the details as I have a vague idea of what a main girdle even is. I have noticed my renix runs like a tractor compared to newer jeeps.
 
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