2000 WJ 4.5L Stroker Build

**StrokedWJ** · 02-01-2009, 02:22 PM

Some of you may have already seen this on MC or NAGCA but I figured I'd post it here too. I think I may be the only one running this 4.5L Stroker in a WJ at the moment

Build:
This thread will document our rebuild of my 2000 Jeep WJ's engine. It had ~140k on the clock when the annoying "tick" turned into something a lot worse!

I was already over at a friend's shop, getting my LA's repaired and had him take a listen. We knew it was bad, so he dropped the pan to take a look. He found about 1/5 of the #4 piston in the bottom of the oil pan. The picture makes it look a lot worse than it ended up being. Amazingly there was no damage to the cylinder wall!

So I decided since I needed to replace the piston, might as well upgrade while we're in there. Plan is to go with a 4.5L Simple Stroker from Dino Saava's 4.0 performance site. I modified it a little bit b/c the 677cp pistons were hard to find. Most of the work was done in Chris's shop. I had some help from a member of jeepstrokers.com and the local Carquest Machine shop.

Specs:

* Jeep 4.2L 3.895" stroke crank
* Jeep 4.2L 5.875" rods
* Sealed Power H802CP standard bore pistons (dished to 18cc's)
* 9.20:1 SCR
* 7.96:1 DCR
* Stock 4.0 camshaft
* Port & Polish cylinder head
* Mopar/Victor 0.043" head gasket
* 0.081" quench height
* stock injectors with stock 49psi FPR for '96 and later engines
* 247hp @ 4900rpm, 300lbft @ 3500rpm (thats what Dino's site says)

I also decided to bore the TB out to 62mm and replace the exhaust with a Magnaflow.

The teardown pics...

Engine out (it was a real PITA to get it out with 5" of lift and the ARB on the front):

Getting ready for the stand, but didn't have the correct bolts

We got it on the stand the following day and torn down.

**StrokedWJ** · 02-01-2009, 02:22 PM

the parts:

H802CP standard bore pistons, dished to 18cc

OEM throttle body bored to 62mm

Hot tanked & Sandblasted head

Victor Reinz Gasket Set, Melling oil pump, Piston rings, Cloyes Timing chain, Clevite Main bearings, AMC 258 Rods

Magnaflow 12586 2.5" muffler 5"x11"x22"

The head will go in for the port and polish and I'll have the machine shop install the pistons on the rods Monday. Hopefully we'll have her up and running sometime next week!

Also in but not pictured are the 4.2L crank, rod bearings, and hi-flow cat.

I had all of this typed up as it was ordered, but my laptop HD crashed, so this is all typed from memory/receipts I had laying in front of me. Parts list:

**StrokedWJ** · 02-01-2009, 02:23 PM

we got the bottom end rebuilt. With the pistons installed I measured a average deck clearance of .042", which, with the .038" compressed gasket height gives me SCR of 9.19:1 with a quench of .080". I wasn't thrilled about the high quench height, but its better than the numbers in Dino's recipe so we'll see how it works out.

**StrokedWJ** · 02-01-2009, 02:24 PM

We finished up the installation today! The 4.5L started right up on the first try. The motor acted like it hadn't even been out of the jeep. Both Chris and I were pretty amazed. We'll backtrack a bit to get caught up with the pics.

Ported

Painted up

Re-installation

FINALLY DONE!

Its working great. We let it idle for a while, then changed the oil. Took it for a 10 minute test drive and everything looks good. I had 87 octane in the tank and we didn't notice any pinging, but I'm planning to run mid-grade while gas is so low!

Still need to get my exhaust installed, its too quiet right now...

**StrokedWJ** · 02-01-2009, 02:27 PM

10 straight hours of teardown + 3AM =

That version wasn't nearly powerful enough!

**Ridin' Around** · 02-01-2009, 02:29 PM

Quote:

Originally Posted by YHC2000WJ

10 straight hours of teardown + 3AM =

That version wasn't nearly powerful enough!

cmonson · 02-01-2009, 04:55 PM

did you do a cam change at all? You mentioned letting it idle for a little while...

I hope you broke in the cam to the lifters if they are new!!!

**the88thpianoman** · 02-01-2009, 05:02 PM

Quote:

Originally Posted by cmonson

did you do a cam change at all? You mentioned letting it idle for a little while...

I hope you broke in the cam to the lifters if they are new!!!

Said he used the stock cam.

**Jones** · 02-01-2009, 05:02 PM

Very nice work, how are the performance gains?

**StrokedWJ** · 02-01-2009, 05:12 PM

Yeah, I reused the stock cam and lifters.

So far I can definitely tell theres a power increase. After giving it a little while to break in and the bank act. recover enough to have my exhaust installed, I'm gonna take it over to the local dyno and see what kinda numbers its really making. I think it'd be good to document b/c this was a fairly low budget build. I wanna see what kind of power increase we're looking at vs. dollars spent.

**squashman702** · 02-01-2009, 08:43 PM

Mind doing a price breakdown?

**xJoshxx** · 02-01-2009, 09:05 PM

i too have the 00 wj is the ECM/PCM giving u any problems or hickups?

i would like to do this to my I6 plus u didnt have to have the block bored did u? just bigger pistons rods and all teh other junk pretty much bolt on.

**StrokedWJ** · 02-01-2009, 09:58 PM

Quote:

Originally Posted by squashman702

Mind doing a price breakdown?

Its in my post...

Josh, no problems with the stock computers. According to the scan tool, it ran a little lean for the first little bit then it started adding a little extra fuel to compensate. And you're right no overbore just had it re-honed. The 4.2L connecting rods are actually shorter. Its the increased stroke from the 4.2L crank that makes the difference.

SET2JET · 02-02-2009, 12:22 AM

nice write up very informative

**Bama_WJ** · 02-02-2009, 01:16 AM

Very nice. I plan on doing this as soon as my 4.0 takes a dump. Hopefully not any time soon though!

02-01-2009, 05:02 PM	#9
Jones Infowars.com Join Date: Jan 2008 Location: Arizona Posts: 7,624 Profile Gallery Classifieds My Jeeps	Very nice work, how are the performance gains? __________________ What is it about Ron Paul?

02-01-2009, 04:55 PM	#7
cmonson Registered User Join Date: Nov 2006 Location: Columbus Posts: 1,549 Profile Gallery Classifieds My Jeeps	did you do a cam change at all? You mentioned letting it idle for a little while... I hope you broke in the cam to the lifters if they are new!!!

02-02-2009, 12:22 AM	#14
SET2JET Registered User Join Date: Jan 2006 Location: Decker MI Posts: 764 Profile Gallery Classifieds My Jeeps	nice write up very informative