4.7L Stroker Engine

"Say... Is that a 4.7L stroker in your pocket?"
No, no... NO! ... Get yer mind outta the gutter! Not --THAT-- kind of a stroker...
THIS kind!

(And, YES... that was a gratuitous picture of a semi-naked woman.
A very, very, VERY
GIFTED semi-naked woman! )

So, whaddaya want a stroker fer bunkie?

Before you set out to build a stroker... sit down and make a list of equipment your XJ has now... and what kind of use the motor will see.

For example: Ya have 3.55 gears, 31" tires and drive it daily 300 miles one way to the Home For Unwed Mothers where you do charity work .
Maybe you are running 4.88's, 37" tires and only use it rock-crawling
Maybe ya have 33's, 4.10's & do a lot of towing.

(You get the picture...) Once ya have a basic list of things that will affect what rpm range the engine will be living at, check one of the tire / gear charts listed on the tech page & find out what rpms your motor is going to be running and build accordingly. Rpm's are gonna affect everything from cam choice to engine longevity so plan accordingly.

My 4.7L Stroker's Operating Conditions:

I am building this engine for my current daily driver (1990 XJ w/ 220k miles) which will see fewer street miles later but for time being will remain my commute/tow rig. I will be running 4.88:1 gears, 35" T'birds, daily highway use w/ occasional towing and a highway rpm of about 2750-3000 rpms. An appropriate cam was selected & some extra $$$ sunk into having the lower end assembled and spin balanced where a 'low buck' / lower rpm motor could get away w/ balancing the piston & rod assemblies individually or not at all. (Good idea to at least do the assemblies... cheap insurance.)

My Goals:

  • I'll take reliability over squeezing the last ounce of HP out of the engine!
  • The engine must run well on pump gas and have a final compression of ~9.5:1. (That means taking the time to get the 'quench' right & a bit more $.)
  • Parts and machine work for this rebuilt will be purchased/done w/ 25% off road & light towing duty, 75% street in mind.
  • 4.88's & 35's so engine must be happy at 2,750-3,000 RPMs at hiway speeds.

My 4.7L Stroker Engine Parts List

Part Description & any associated machine work for part.

Part Number

Item Cost

1990 4.0L short-block. Discarded from a buddy's motor swap. Free!
Thanks Martin & Jerry!
19?? 258 Crankshaft from a rusty bucket o bolts motor. No idea... I pulled from a rustbucket motor in my parts pile... Already had this in the ol' parts pile!
Block machine work: Vatted, new freeze plugs, new cam bearings, main alignment checked, cylinders bored .060 over, decked .010, assembled and balanced.
Piston machine work: 4.0L Sealed Power 677P .060 pistons & rings with 1.30 mm removed from dishes to achieve ~9.5:1 final C.R.
Crank machine work: Vatted, turned .030 / .010, snout trimmed for balancer fitment and balanced.

Throttle Body & Spacer machine work:Spacer and throttle body bored out to match gasket size below butterfly.
All machine work done by Terry Walters Precision Engines in Roanoke, VA. About $1700 total for ALL machine work on block, crank & head.
258 rods (reconditioned from eBay)   $45
4.0L Mopar Performance inline 6 HV oil pump
P4529241 $ 60.06
4.0L inline 6 factory 1-piece oil pan gasket 53007568 $23.80
Mopar Performance Cam & Lifters
256 dur. / .450 lift / 40 duration / 108 centerline

P4529230 $134.00
shipped from Summit Racing.
Roller Timing Chain
(NAPA N.O.S. from eBay)
#10-3085 $32.00
4.0L inline 6 HEAD GASKET
.043" thick Mopar Performance/Victor Reinz
P4529242 $20.16
1993 HO inline 6 cylinder head
w/ Valve cover & head bolts

Head machine work:Pressure checked for cracks, ported & polished to gasket, surface planed flat w/ minimum material removal, 3-angle valve job plus new oem springs, retainers & locks.
Try East Coast Auto Source for some excellent prices on Jeep 4.0L parts!
Casting #7120 $93.01
Modified oil pan (* - Clearanced with a B.F.H. for the oil pump.)
4.0L inline 6 valve seal pkg. (12 ea) P4529240 $ 9.06
4.0L inline 6 Mopar Performance pushrod pkg (12ea) P4529675 $ 8.64
Banks Torque Tube Header
Thanks to D.C. of DC4WD for the smokin' deal!
4.0L Mopar Performance inline 6 manifold attaching package P4529680 $27.52
4.0L inline 6 intake / exhaust gasket
* Note - Be sure to get a gasket that matches the year of your head! Latest HO heads have SMALLER ports!
53010238 $10.80
2002 TJ equal length intake
Shown w/ linkage mounts & TJ fuel rail which was removed. Reuse Renix fuel rail w/ minor mods.

Another eBay score!
P/N 4854197AA (1999-2002) $77.00
HO throttle valve (throttle body) w/ MAP on flange.

Bored out to 62mm. (Bought a mid 90's HO intake to get throttle body & cable brackets.)
Another eBay score!
  $25 after reselling intake it was sittin on!
62MM Throttle valve spacer w/ hardware.

L&B RACINGeBay seller name: res069tu
Ford Motor Sports 24 #/HR fuel injectors

eBay strikes again!
Ford Motor Sports
# F1TE-D5A
4.0L inline 6 fuel injector o-rings set.
(These are also available from AutoZone for a few $ less.)
#83503637 $13.00
4.0L inline 6 oil filter mount o-rings
The following are the part numbers & dealer item description for Renix (metric) oil filter mount o-rings:
33002970 o-ring .799x.103
33002971 o-ring 1.296x.13
33002972 o-ring oil filter AD
* Depends on HO or non HO block. Mounts have different mounting bolt. $10.00
Magnetic oil pan drain plug AutoZone $1.69 + tax
Mopar Performance ECU (Renix XJ's - 87-90 )

They are -not- marked P4529334 on the ECU; that is only the Mopar Performance part number!
Actual Bendix computer is #P4532129 as marked on the ECU itself!
Mopar Performance # P4529334
Bendix # P4532129
Thanks Bill!

  • I have approximately $1900 in the block and head including ALL parts, machining and labor.
  • Keep in mind you CAN build a stroker for MUCH LESS $$$... depends on what ya want and how ya wanna go about it. For me, I'll sink a few extra $$$ now to have an engine even more reliable than the old Renix motor is at 210,000.

Stroker Engine Assembly Pics

Right after figuring out how to get it onto the engine stand without a hoist... the first thing was to give it a fresh coat of Mopar Black paint.
MMmmmmmm! Paint fumes!

Shot of the bore showing Sealed Power 677P .060 over pistons.
Pistons were dished 1.30 mm deeper prior to assembly in order to get the compression below 10:1.

You need to assemble the pick-up tube to the pump. I gently tapped it into place with a rubber mallet & a Crescent wrench set on the flange. First put the pick-up tube in the freezer and GENTLY heat the oil pump with a propane torch set on LOW heat. A few taps (with a little grease) and it went right in.

Installing the Mopar Performance HV oil pump. (Pick-up tube was not installed in this test fit pic.)

Oil pan WILL need to be clearanced here with a ball-peen hammer to allow enough room in pan for oversized Hi-Volume pump. Don't get carried away... as ya can bust the pan where this plate is welded in if you're not careful!

Same area of oil pan shown from outside. Again... Don't get carried away with the hammer!!! When done, pan should set flat against bottom of block all along both sides of pan when centered up with a couple of pan bolts.

Installing the Mopar Performance camshaft. Be sure to oil up the cam with the included lube!

Installing the roller timing chain. Be sure to align the timing marks as shown.

Make sure to install the oil slinger before putting timing cover on!
Installing timing cover into shortblock and new timing cover oil seal.
Buttoning up the bottom-end with "modified" oil pan and a new 1-piece gasket. Flip the block over and drop those well lubed lifters into their bores. After *** a little head-work (LINK HERE) ***, it was time to put the head onto the block. Be Carefull! Do not trash the gasket! Use a couple of head bolts to line it up.

Obviously, there are a heckuva lot of pics leftt to be posted... hang in there! My BRAND NEW Western Digital 250GB hard drive committed suicide last fall while consolidating several drives including the one that had many of my website articles & pics. I've found a site that shows how to attempt to 'repair' the drive long enough to transfer files out... we'll see how that goes. Western Digital graciously refused to honor the warranty but did send me to a 'partner' that quoted $2,000 to retrieve my data.

Now we're talkin'! It's offficially a 'long block'!
Head is on & torqued down. Lifters and pushrods are in and rockers are installed. Still need to button down the oil pan after installing the timing cover.

Old parts discarded from 4.7L Stroker build-up (Link to pics here.).

Links To Other Stroker Pages or Related Info

I highly recommend you read through Dino's info which is at the top of this list befire you do anything else!

After that, take your time and just go on down the list of sites. Think it through as ya go and get an idea of both the homebrew and shop built philosophy to building a 4.0L based stroker.
It's pretty much a 'you get what you pay for' world but with some ingenuity and planning you really can build a torquin' motor for about the same $ as a standard rebuild.

http://www.angelfire.com/my/fan/stroker.html Dino's page! http://www.jeep4.0performance.4mg.com/stroker.html Another Dino page!
http://home.earthlink.net/~gfreedy/Strokers/ http://cliffordperformance.net/
Robert W. Bryce's excellent stroker tech article.
http://www.rockcrawler.com/techreports/stroker40/index.asp http://www.hescosc.com/index.html
Joe Attardo's tech on modifying a Renix TPS's to work with HO throttle bodies.
258 / 4.0L Head Article
http://www.off-road.com/jeep/cherokee/xjtech/engine/40ltr/proj45.htm "MUST READ!" - Tim Weaver's EXCELLENT 258 / 4.0L head article.
Several stroker tech write-ups in this index.
"MUST READ!" - Tim Weaver's EXCELLENT 258 engine rebuild article!
LOTS of photos of the machine work in this one!

Last... but not least...
Lurk and learn.


That means to
Take SEVERAL days to READ through existing articles & forum posts!

Seriously, if you'll do a little reading you WILL learn a great deal about stroking your 4.0L Jeep engine and gain an idea of what questions you NEED to ask.
Everyone will be great answering ANY questions for those seriously trying to get it right the first time but be sure to read, search and plan before asking the ultimate 'Noob' question...

"Can someone post a detailed list of every part I need for my stroker with prices and where to buy everything at?"

I can almost guarantee you that this is one question you won't get answered...

Believe me... every question YOU want to ask has already been asked (and answered)!

  1. IF you've read all of the above information...
  2. AND you've visited ALL of the the sites above...
  3. (AND have actually READ the information they provide...)
  4. AND you have thought about what kind of motor you want to build...
  5. THEN it's a good bet you can now answer 95% of the questions you had at the beginning.

Now it's time to answer your remaining questions about 4.0L based strokers by visiting the motherlode of Jeep stroker engine info at:

Join the Yahoo Strokers Group Here. The Yahoo Strokers Group! Join the Yahoo Strokers Group Here.

Hang out for a few days reading the old posts and post any questions ya might have left!

Check the Stroker Group's 'Files' section out too! There is a LOT of info stashed there!

And yeah, I moved the Yahoo Stroker's Group link down here to the bottom just so you might actually do some research before asking questions...

If you have pics of your own repairs or can suggest other methods - please contribute your ideas (and pictures) to this article!

Revised on: May 3rd, 2007

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