Great info threads in here...

[TrueBlueXJ]

Hopefully will be doing this over the winter. The steering box is the XJ has been leaking for about a year now, so it's time to UPGRADE.

[nick_n_ii]

Just to let you all know you can also use the J20 steering box, it has the same valving that the PSC after market box has.... And there cheep to buy new...

[nick_n_ii]

Disclaimer: I do not recommend nor endorse any of the modifications shown in this article; the information is provided for personal information purposes only. I am not an Engineer, metallurgist, or mechanic - I have absolutely no professional qualifications whatsoever in this regard - I have simply collected information from others and from my own experience. Use of any of the information contained herein is at your own risk. It is therefore your responsibility to maintain safety in and around your vehicle at all times. It is likely that some procedures featured here may void your vehicle’s (or parts thereof) warranty. It is also likely that some of the information featured shows procedures that may not be legal for street use in some or all states within the US and/or any other countries and may not be safe for on or off-road use. The article's author, or anyone related to this web page, cannot be held responsible for any damage, failure, or violations of the law, that might result from the use of any information contained on this page, or linked to on this page.


So I’ve noticed a lot of people lately having power issues with their 4.0 and considering serious engine modifications. Aside from bolt-ons (which can give you some more power but usually isn’t enough to turn those bigger tires) you’re left with two options : doing an engine swap like a Chevy 350, AMC 5.2 or 5.9, or any other engine or stroking. While the 350 is a very tried and true selection and possibly the most common sb v8 with the most aftermarket support, it requires a lot of other modifications, such as motor mounts, transmission, computers, wiring, etc. and becomes a mess. If your jeep is not a DD this would be a good swap to do, but it is going to take some downtime to do. It also requires a good bit of money, considering all of the parts you have to buy beyond the engine. If you buy a junkyard motor you also run the risk of finding one that needs a total rebuild, which is another costly thing. The 318 and 360 are good swaps to do, because they did come in grands so you can just find a junkyard 5.2 or 5.9 and take all the parts you need (or head over to the dealer). A little less fabrication is needed here – yet you still do need all of the extra parts. With a stroker the only thing that changes is the internals of the engine. You retain all of your stock sensors, harnesses, transmission, etc. etc. In a nutshell stroking is simply putting in a larger crankshaft, smaller rods, and doing an overbore. This combination results in a larger displacement.

The most common strokers are the of the 4.5-4.7 variety (4.6 possibly the single most common) and use the crank and rods from the AMC 4.2L inline 6. A stock pin height piston is used with your selected overbore. The bore you choose is dependent on the shape of the motor and your preference on displacement. This write-up will focus on the 4.6 variety, as that is what I built. I am estimating 240 HP and 335 ftlb (only 5 hp and 10 ftlb less than the 5.9). I have yet to do a dyno run; however that is soon to come. A well build stroker with ported heads, all accessories, and the right cam can achieve 260 HP and 325 ftlb, however this is a little beyond the scope of the average “budget” stroker.

Before you begin any work on your own stroker, I highly suggest you read over the information here, as well as Dino’s site, and the FSM’s engine overhauling section many times. You cannot know too much information when it comes to building an engine. Factory Service Manuals can be purchased from Dirk (Cue) very cheap, in .pdf format on a CD. I printed out the engine pages and blow up diagrams located in the parts diagrams, I found this information to be VERY handy while working on the engine. The FSM provides very detailed information, highly accurate diagrams, and all the torque and other specifications you’d ever need to know to build an engine. No mechanic should be without one.

First I’ll describe a little bit about my stroker. I use the 4.2 crank and rods from an 89 YJ, because the snout length on the crank matches the snout length of the 4.0 crank (I’ll discuss this further later on in the write-up). I am currently using the sealed power 677P pistons with a .030” overbore. I was going to use the H802CP pistons, however the factory sent me the wrong bore size and in the name of getting the stroker built quickly I went with the pistons I had on hand. I am using a sealed power RV cam with the following specs:
Duration: 208/208 degrees @ 0.050" lift
Lift: 0.448"/0.448"
Lobe separation angle: 110 degrees
Nothing too crazy, however it gives a good amount of low end torque, which is desired for off-road driving. I did a port and polish in my garage using a die grinder and the standard abrasives port & polish kit (which will be discussed later also) and used the 5.9 performance valve springs. My head was decked .017” a year before due to overheating and warping, I liked this number so I reused the head. The result of my decked head and higher performance pistons is a healthy 9.5:1 compression ratio. Had I used the H802CP pistons I originally wanted, I would have been looking at a 9.8:1 CR. This means I have to run on 93 octane gas, but it only ends up being 2 or 3 dollars more per fill-up. I’m using a borla longtube header for maximum low end torque. It is perhaps the most expensive header, but also happens to be the most powerful and has an excellent warranty.

Now for the more general tech: First I’ll discuss the crankshaft. The crankshaft used in a 4.6L stroker is the AMC 4.2L crankshaft. This crankshaft shares the same size and location for the main bearings, which means it bolts directly in. The following casting numbers and details are found on Dino’s site (http://www.angelfire.com/my/fan/selection.html)
Year.........Casting No......Description
1971.........3199738.........For Borg Warner automatic
1972-80...3214723.........12 counterweights, 66lb, 64mm nose
1981-86...3235477.........4 counterweights, 46lb, 64mm nose
1987-90...3727...............4 counterweights, 46lb, 54mm nose

For comparison, the 4.0 crankshaft has 8 counterweights, weighs 55lb, and has a 54mm nose.
The #3214723 crank is reputed to the the strongest. The extra counterweights dampen vibration-inducing harmonics to produce a smoother running engine.
The 12 CW crank has more rotating m**** which means it is harder to slow down – which makes it more resistant to stalling. While this is desired, the 4.6L stroker is fuel injected and thus stalling out is not as much of an issue. The 87-90 crankshaft is the easiest to work with because it has the same nose length as the 4.0 crankshaft. In order to use the 71-86 crankshafts, a 1cm spacer has to be machined and put on the nose in order to get the harmonic dampner pulley located in the right spot. Because of this reason, I chose the 89 crankshaft. I purchased my crankshaft from advance auto parts. It was more expensive than the junkyard route, however it came to me remanufactured – meaning it came with the correct dimensions, matching main bearings, and even cam bearings.

The main girdle located on 96+ 4.0 engines is a good thing to have, it ties together all of the main caps – thus providing more rigidity and decreasing noises/vibrations. Using this girdle requires the main bolts from a 96+ 4.0, as it has the stud on top of the bolt that the girdle rests and bolts onto. The main caps that came with the block can be reused, however because the 4.2 crankshaft is larger than the 4.0 crankshaft, the girdle has to be shimmed up to clear the larger crankshaft. To do so, simply put 2x 3/8” washers in-between the main cap and girdle. There will be just enough thread left on the bolt to safely secure the girdle down. These can be bolted down to stock specification.

The stock oil pump can be re-used, but my oil pump was already 128K miles old. I decided to go ahead and replace the oil pump while I had everything out. Instead of going with the simple stock oil pump I wanted a little more flow, so I got the high volume oil pump from advance auto parts. When installing the oil pump, I recommend removing the access plate and packing the pump full of Vaseline. This provides more suction and instantly gets oil pumped to the rest of the engine on initial startup, rather than having a few seconds of dry running which can cause undesired damage. Instead of this you can also use a drill to turn the oil pump before starting to get oil pumped through, or buy a pre-oiler (which is most desired, but again isn’t the best option for a budget build… a pre-oiler can always be installed later on if desired).

The rods from the AMC 4.2L I6 are used, as it has the same pin bore as the 4.0 (which allows for the stock type 4.0 piston to be used) and fits perfectly (obviously) on the 4.2L crankshaft. The piston you use is up to you, every piston has different pin heights and dish volumes. The following part number and information are also pulled from Dino’s site:
Stock 4.0 cast aluminum '87-'93 #83500251, '94-'95 #4773157, '96-'04 #4798329----1.601" 13.1cc
Keith-Black Silvolite hypereutectic #2228----1.581" 11.5cc
Sealed Power hypereutectic H802CP----1.592" 15.8cc
Sealed Power cast aluminum 677P----1.585" 17.5cc
The smaller the dish volume you have, the smaller the combustion chamber, and thus the higher the compression ratio. If you get the 677P pistons like I did, the part numbers for the rings are:
SLP-E-245K030 is the part number for moly Sealed Power rings, a set of 8 @ 50 bucks
SLP-WE-245K-30 is the part number for the same ring, only in a single piston set @ 15 bucks
TSR-S0660-30 is the part number for the Total Seal ring. It has a gapless 2nd ring and I would highly recommend it for anybody who has the extra money to throw down, they're 150 for a set of 8.
The land sizes on the 677P are 5/64 5/64 3/16. I highly recommend the total seal rings if you can afford the extra 100 bucks. Total Seal is a much better ring, and reduces blow-by and provides a much better seal.

Camshaft choice is another important aspect of the stroker build. If you are going with the absolute low buck stroker you can re-use the stock camshaft, but only with a compression ratio up to about 9.1. Anything above that has too high cylinder pressures and can cause detonation. A list of camshaft specs is found on Dino’s site http://www.angelfire.com/my/fan/Jeep4.0Camshafts.htm. The cam you choose can either give you lots of low end torque but low HP, or high HP and not as much lower end torque. If your jeep doesn’t see much insane offroading that often and is a solid DD, you may want to consider a camshaft with specs in-between to give you enough power on the road as well as on the rocks, or if you spend a lot of time in the mud and require power throughout the rpm band.

The timing set from the 4.0 engine will work just fine, however you may choose to upgrade to a dual roller timing set. The stock distributor will work, as well. However some modification of the distributor is required when putting in an aftermarket cam. The tabs on the distributor must be cut off, as the distributor will not align the same as with the stock cam. This is due to a slight difference in the gearing of the cam. No worries, however, as the clamping action of the retainer and bolt is sufficient to hold the distributor from rotating during usage. I have 2,000 miles on my stroker and it hasn't budged, Aaron Clements has 10K on his and reports the same thing.

The cylinder head is the final consideration for the stroker. The intake valve on the 4.0 is 1.91” and the exhaust is 1.50”. The following casting numbers are again thanks to Dino:
Year............Casting No
1987-90......2686
1991-95......7120
1996-98......0630
1999-04......0331
As a matter of fact, I’ll just copy the following paragraph from Dino, as I cannot write it any better.
The early '87-'90 non-HO heads have low intake ports that flow rather poorly. The later HO heads have higher intake ports that flow more air by allowing a straighter shot into the cylinders. The '91-'95 HO heads with casting no. 7120 have the highest intake and exhaust port airflows, especially at lower valve lifts where it is most important, and are the best for performance. The '96-'98 0630 heads are almost identical except that they don't have a port for the coolant temp. gauge sending unit. The '99 and later WJ heads with casting no. 0331 have smaller exhaust ports to produce a faster warm-up of the catalytic converter and improve emissions, but performance also suffers because the ports don't flow as well as those of the 7120 and 0630 castings. The 0331 heads are also prone to crack if the engine overheats so these should preferably be avoided. All of the 4.0 heads respond well to a good port job, with gains of up to 20hp possible on a 4.6L stroker engine.

As far as fuel is concerned, almost all stock fuel delivery components are used, excepting the fuel injectors and possibly the MAP sensor. Most people use 24# FMS injectors found most commonly on mustangs. These injectors are easily identifiable by their blue color.

[nick_n_ii]

231-(see NP231)
242-(see NP242)
249-(see NP249)
35C-(see DANA35C)
45RFE-automatic transmission in the V8 WJ
8.25-Chrysler 8.25" axle found in XJ rears)
8.8-Ford 8.8" axle (Ford Explorers, good aftermarket replacement for those seeking disc brakes and a stronger axle than the 44)
9"-Ford 9" axle (late model version was very strong)
ARB-A company based in Australia that produces popular winch-compatible bull bars and differential air lockers.
AFU-All F---ed Up
AT (A/T)-all terrain (all terrain tread) tire
ATF-Automatic Transmission Fluid
ATKO-BF Goodrich all terrain tire
AW4-the automatic transmission used on the XJ since 1987
AX15-5 speed manual stick in a pre-99 6 cylinder TJ
AX5-5 speed manual stick in a pre-99 4 cylinder TJ
BB-Budget Boost. An inexpensive, popular 2" lift used by many Jeepers.
BFG-BF Goodrich tires
BFH-Big F-cking Hammer
BL-body lift
BS or Back Spacing. backspacing, distnace from the mounting flange of a wheel to the inner edge (rim) of the wheel. i.e. larger BS will cause the wheel to sit "into the fender" more, smaller BS will cause the wheel to "stick out" more. Absolutely necessary to determine proper wheel and tire combination
BTT-back to top
BTW-by the way
C101-Bulkhead plug for wiring on Renix Jeeps
CAI-Cold Air Intake
CAT-catayltic converter
CB-citizen band radio
CJ-Jeep Wrangler's Older Model Years. "Civilian Jeep"
CJ-2A-Civilian version of the MB, split windshield
CJ-3A-Updated version, single pane windshield
CJ-3B-High hood version of 3A to fit larger engine
CJ-5-Early years were 81" wheelbase, later years were ~84". Built until 1983.
CJ-6-Stretch version of CJ-5, 101" wheelbase
CJ-7-smilar to late CJ-5, but with ~94" wheelbase. Built until 1986.
CJ-8-Scrambler Pickup, stretch version of the CJ-7, 104" wheelbase.
CJ-10-somewhat rare here in the U.S. Heavy Duty Truck.
D30 (D30r)-(see DANA30)
D44 (D44i)-iron Dana 44 axle (TJs)
D44a(see D44) but with aluminum housing (V8 ZJs and WJs)
D60-(see DANA60)
DANA30 (DANA30r)-front axle (r = reverse cut) All modern Jeeps
DANA35C-axle (YJs, ZJ, WJs, TJs)
DANA60-axle (very strong)
DC-Daimer Chrysler
DJ-Postal Jeeps, usually 2wd
DW-death wobble. Side to side movement of the front axle that causes the Jeep to shake violently. Most common on lifted ZJ's before a wheel alignment has been done. Can be caused by worn steering stabilizer, improper wheel alignment, or worn front suspension components.
ECU-Engine Control Unit (same as PCM). Very popular mod. Common one made by Mopar.
EFI-electronic fuel injection
F2R-front to rear swap lift
FAQ-frequently asked questions
FC150/170-Forward Control Cabover trucks
FIPK-(see K&N FIPK)
FM-FlowMaster muffler
FSJ-Full Size Jeep (SJ's and J-trucks).
FSM-field service manual
FUBAR-F---ed Up Beyond All Recognition
FWIW-"For what it's worth..."
GC-Grand Cherokee
GPW-Willy MB built by Ford
GS-Grand Slam (what is this???)
GSE-Grand Slam East (what is this???)
HO-High Output. New engine option for WJs
HP-high pinion. Usually accompanied by RC gears - the pinion enters the differential higher, which allows for better driveline angles.
HTH-hope this helps
IAC-idle air controller
ICE-This flashes on overhead display when the temperature is below 32 degrees
IFS-independent front suspension
IIRC- If I Recall Correctly
IMHO-"In my honest opinion..."
IMO-"In my opinion..."
IRS-independent rear suspension
JC-Jeep chick
JGC-Jeep Grand Cherokee
JU-Jeeps Unlimited
K&N FIPK-Fuel Injection Performance Kit refers to an air intake kit from K&N
KJ-Jeep Liberty All Model Years
KOLAK-maker of good aftermarket parts
LA-Long arm
LCA-lower control arm
LMFAO-"Laughing my f---ing a-- off!"
LOL-"Laughing out loud"
LOM-lamp outage module
LSD-limited slip differential
LWB-long wheel base
M170-Military CJ-6 with wider passenger door opening for abulance duty.
M38A1-Military version of the CJ-5
MA-Willys SWB 4x4 built under govt contract.
MAF-mass air flow sensor. Measures airflow coming into your engine in front of the throttlebody. Uses a form of resistor that is cooled by the air passing by it and mathematically determines the "mass" of the air coming into the engine. These are traditionally bottle necks for heavy breathing engines as they often have a screen in them to protect the measuring element. There are many different designs and high performance large capacity ones out there. These are a big headache for GM owners but Jeep has stayed with MAP
MAP-manfold absolute pressure. A sensor that tells the computer how much air is flowing into your engine. Eliminates the need for a MAF sensor but is less responsive than one.
MB-The MA was quickly replaced with the MB... used throughout WWII.
MT (M/T)-Mud terrain (mud tread) tire
MTR-Goodyear mud terrain tire
NP231-Command-trac transfer case (2H, 4H, N, 4L)
NP242-Selec-trac transfer case (2H, 4PT, 4FT, N, 4L)
NP249-Quadra-trac transfer case (4H, N, 4L)
NV3550-5 speed manual stick in a post-99 6 cylinder TJ
NVRnoise vibration harsness
NYWD-No you will die!
OBA-on board air
OBC-on board computer
OBDII-on board-diagnostics
OEM-Original Equipment (standard equipment on our vehicles like it came from the factory)
OHC-Overhead console
OME-A manufacturer of small lifts and shocks and steering stabilizers. Their SD40 steering stabilizer is very popular.
O/T (OT)-off topic
PCM-Performance Control Module (same as ECU)
POS-Piece of sh-t
PSI-pounds per square inch
QD-quick disconnect
QD-Quadradrive
QT-Quadra-Trac
RA-Road Armor
RC-reverse cut. This is a ring and pinion set with the helix on the gears cut in the opposite direction to normal. It allows the pinion to enter the differential higher up in the casing, and, when used in the front differential, makes use of the stronger side of the ring gear when moving forward.
RE-Rubicon Express
ROTFLMAO-"Rolling on the floor, laughing my a-- off"
RR-rock rails
S4W-4" Lift made by teraflex for '99-current Grand Cherokees
SAE-standard american equivalent
SAS-solid axle swap. Taking out the crappy IFS (ala Liberty) and replacing with something you can 'wheel on.
SFA-solid front axle
SJ-Early Full size Wagonneers, Grand Wagoneers and Cherokees.
SNAFU-"Situation normal. All f---ed up"
SOA-spring over axle. A popular conversion for Jeeps with leaf springs. You take the spring from under the axle, and remount it on top.
SRA-solid rear axle
SWB-short wheel base
SYE-slip yoke eliminator. A kit used mostly in 231 transfer cases to shorten the rear output shaft
TB-throttle body
TB-track bar. that positions and centers the axle (front or rear) relative to the body.
TC-transfer case
TC-torque converter
Tera-Teraflex. Maker of Jeep products including lifts
TJ-Jeep Wrangler's Model Years 1997-Present
TPS-throttle position sensor
TQ-torque converter
TR-trail ready
TSB-technical service bulleten
TSi-TSi package, a package offered on Grand Cherokees from
TSL-triple stage lug (as in ss tread pattern)
TV Cable-Throttle valve cable (controls shift points)
UC-Up Country package, a package offered on Grand Cherokees from
UCA-upper control arm
VIC-vehicle information center
VC-vicuous coupling. Method of coupling front and rear driveshafts together in 249 transfercase while in highrange and offers differentiation between the two. 96-98 models bypass this and lock in low range
WAG-wild a-- guess
WFO-Wide F---ing Open (Full Throttle)
WOT-wide open throttle
WJ-Jeep Grand Cherokee's Model Years 1999-Present
WTF-"What the f---!"
XC-transfer case
XJ-Jeep Cherokee's 1984 - Present
YJ-Wrangler 1987 - 1995. Exact same wheelbase as CJ-7... square headlights
ZJ-Jeep Grand Cherokee's Model Years 1993-1998

[muddeprived]

Originally Posted by nick_n_ii

Just to let you all know you can also use the J20 steering box, it has the same valving that the PSC after market box has.... And there cheep to buy new...

direct bolt in?

[nick_n_ii]

Ya, it has 4 bolt holes and if I remember right the XJ only has 3. you can either use just 3 or drill the fourth hole for more strength....

[nick_n_ii]

In here is links and write ups of very useful info..

[okcjeeper]

Info on tire siping.
http://www.discounttire.com/dtcs/tireSiping.dos