1993 Jeep Wrangler (YJ)

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(Yea, I know square headlights)







My 4.6L HO Stroker Engine Build

Engine Parts List - Summit Racing

Keith-Black Silvolite (UEM) forged stroker IC944 Pistons, 21cc dish volume (30 over) K&N Pro Series Oil Filters Part No. PS-2004
COMP Cams SK68-232-4 - Xtreme 4x4 Cam and Lifter Kit COMP Cams 104 - COMP Cams Engine Assembly Lube
COMP Cams 159 - COMP Cams Engine Break-In Oil Additive E3 Spark Plugs E3-58 - E3 Spark Plugs
Standard Motor Idle Air Control (IAC) Valve Harmonic Balancer RNB-594-018
Holley Fuel Injector Retaining Clips Part No. 534-103 VENOM High Performance Fuel Injectors Part No. HP-624-8

Engine Parts List - Quadratec

Crank Position Sensor - Part No: 55125.05 Throttle Position Sensor (TPS)- No: 55123.01
Map Sensor Quadratec Quadratec Part No: 55122.2001 Manifold Tem Sensor/Air Charge Temp Sensor - Part No: 55121.00
Performance Distributors Firepower Ignition Kit - Part No: 17610.60X  

Engine Parts List - Other

304 STAINLESS STEEL JEEP SINGLE MANIFOLD 1991-00 4.0 L # PH-051 - eBay 4.0L Performance Valve Springs & Retainers #HESSPRSS6 - Hesco
Rugged Ridge Jeep Air Intake System Part #17750.04 - AutoAnything Cardone Remanufactured Distributor Part No. 30-4693 - O'Reilly Auto Parts
Precision 63MM Throttle Body by Leigh Performance Machine  

Engine Parts List - Donnelly Machine/CarQuest

Jeep 4.2L 3.895" Crank & Rod/Crank Bearings, Clevite CB960P20 &MS1947P10 Engine Gaskets & Seals Set
Head Seat Rings & Freeze Plugs Cam Bearings
Hasting Rings # Oil Pressure Sender Part No. #
Rear Main Seat - FelPro Part No. #  

Machine Shop Cost - Donnelly Machine

$180.00 - Valve Job $48.00 - New Valve Seats
$47.50 - Mill Head (0.006) $125.00 - Degrease, Block, Head, Intake
$125.00 - Bore Cylinders (0.030) $65.00 - Install Cam Bearings
$10.00 - Install New Freeze Plugs $60.00 - Machine Head for Hesco Springs
$45.00 - Fit Pins $60.00 - Rod check and Truing
$ - Re-Fit Pistons $2.00 - Haz Mat

Build Pictures, Notes and Progress

↓    Click  the  Image  to  Enlarge       

  Well, after confirming the clearances for the Pistons I proceeded this afternoon to start the engine assembly.  I checked the ring gap, and have .016 on the top and .018 on the second rings.  Both above the calculated .0156 per ICON's minimum clearance.  With the correct crank bearings also now in hand, the first item to install was the crank.  I used the Comp Cams Assembly lube during the installation.  Next I installed the oil pump, the Melling High Volume unit I had installed last year when I got the Jeep.  Next came the pistons.  Even with the correct tools, the piston aren't the easiest to install, the ring compressor had to be just right to allow the piston to be tapped into the cylinder.  Next was the new Comp Camp.  Then came the oil pan.  Next was the lifters and placement of the head gasket.  Finally I installed the new timing chain and gears.  2012-10-16

  Today started out good,  Assembling the Timing Cover, Water Pump, Harmonic Balancer, Coil, Distributor, Oil Pressure Sender, Dip Stick, Oil Filter,, Engine Brackets and Alternator.  However when it came time to install the thermostat and housing, well I was on a parts search.  Don't know why, but for some reason I put it with the body parts, not the drive train parts, and it took a while searching and re-searching everywhere before I found it.  then I couldn't find the bolts for it.  Not sure why it was being so difficult, but bolts found, and it's now installed.  Next I started the process of using the special measuring push rod to determine what push rods I need to order.  Will take it and one of my old rods to the Machine Shop and get a proper measurement and get a set ordered.  Next I started the assembly of the Intake. Not too difficult, but I used the wrong bolts for the injector rail and snapped one off while torquing it down.  So off to the parts store to get a new set of bolts for the throttle Body.  I finished the day's work off by cleaning the A/C-Air Compressor housing for its build.  2012-10-17

  In addition to getting the correct Torque Converter this morning, I also got the new Push Rods.  So they were installed, and I pumped oil around through the engine after installing them.  I then added the comp cams break-in additive and the rest of the oil and pumped some more oil around before installing the exhaust and intake.  Unfortunately one of the apparently already cracked exhaust studs broke on me, so I'll have to get a new one.  Need to finish the transmission line installation, radiator and wiring, then perhaps I can start the engine and do the break-in running before letting it set while I do the body repairs.  2012-10-22

YouTube Video

  First, a big THNAKS to Bill Gangloff (lucdog). Bill drove down from Peoria to see me start the engine up. He spent more time on the road than he did here, but am I glad he came. Turns out I apparently did get the distributor 180ļ out of time. Either when I did the initial install, or when I primed the lifters, or when I pre-lubed the engine. Doesnít matter what, I did it.

After it didnít initially start, we checked for fuel and spark and had both. We re-checked all the connections, and tried a few more times before checking the timing. With the use of an engine pressure tester, we determined it was out 180ļ. So I proceeded to correct it. Still didnít start, so after some more checking, we discovered I was one tooth off on the distributer timing. Once more I pulled and re-installed the distributor, and we tried again. She started up and ran great.

Now we cranked up the RPM to the required 2,000 RPM, and started looking and checking everything over. Had a momentarily over 210ļ water temperature that caused us to lower the RPM, but it corrected itself and was likely an air bubble, as it didnít happen again.

About half way through the cam break in, the engine developed a miss. The Air Fuel Ratio started jumping with each miss. I suspect it might be due to the old stock spark plugs, and will install a new set of lower temperature plugs when I change out the break in oil and see if it returns. If it does Iíll have to start checking the new injectors and plug sires for problems. Almost everything is new, including the distributor, cap, wires, injectors, sensors, etcÖ So with the new Plugs it must be a faulty part, something I did incorrectly.

While it was running did add additional transmission fluid, and will likely need a little more when I get a chance to run it through the gears. It now has 9.5 quarts, and I believe with the deep pan should hold 10+ quarts.

Itís great to have it running with all the work and parts, and after the oil and plug change and one little exhaust change, I should be ready to start working on the tub.


  Well after yesterdays engine start and cam break-in, it was time to change the oil and install the new Spark Plugs.  I elected to do the break-in with the old plugs figuring there might me some oil or other burn off that I didn't want to harm the new plugs.  Not sure it was a wise idea, but I did it.  As you can see in the first picture, Cylinders 3 & 4 (and partially #6) either weren't cleaned enough, or have problems and likely caused the miss the engine developed during the break-in.  In the second picture you can see the cooler heat range NGK BKR6E-11 (RC9YC4) Spark plug next to one of the old Champion 4412's. (RC12LYC).  While I had the plugs out I also did a room temp wet engine compression test.  The results are as follows:
1 - 183psi
2 - 182 psi
3 - 186 psi
4 - 183 psi
5 - 185 psi
6 - 183 psi
All in all only a 4 psi delta, and what I believe to be good numbers for a 9'ish Compression Ratio Engine.  I also checked (once I knew you could and how) checked for any Engine codes, and only found batter disconnect code which was expected.  I changed the engine oil and filter and added the ZDD Plus Oil Additive.  I rechecked the manifold torques, and noticed two of the exhaust pipes had a sign of what looked like oil run oil of the pipe to flange area.  It's probably from the small oil leak that developed on the valve cover while running during the break-in.  While the engine was running (break-in) I re-torqued the valve cover and believe I have the oil leak stopped.  I also removed and extended the exhaust pipe to get the muffler to clear the skid plate, and further investigated the stock tail pipe position.  I'll probably take it back, and end up having one made that fits better and is 2.5", not 2.25" in diameter.  Now with the gas tank straps that arrived this afternoon, I can paint and install them and have the chassis done with the exception of drive shafts.  2012-10-30

  Took advantage of probably one of the last nice days to wash off the weekends mud off the M37, and roll out the YJ to start and run the engine again.  The intent was to let the engine run a good 30 minutes and see if the miss returned, and after almost 50 minutes, it did not.  The engine still runs and sounds strong, but when you rev it the Air/fuel ratio jumps around it it blows out some smoke.  It still smells rich, but the A/F ratio says different.  Fluid levels are all holding steady and looking clean.  2012-11-01