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4.2ish WJ mini stroker

Posted: June 7th, 2012, 1:36 pm
by Knoxes
Completely overwhelmed. I've been reading for days now, and just more confused than I was before I began.

I have a 2003 WJ - shopping for either crank - would prefer the 258, but I'll take the 232. Both seem to be somewhat available, but I'm confused by all of the options with those cranks. This will surely be the first of a LOT of questions about this process, but can somebody please simplify this and specify which casting number that I can use? I need to keep this very simple. The learning curve is very steep and any issues that can be eliminated up front, need to be.

Re: Need clarification

Posted: June 7th, 2012, 3:02 pm
by woodjeep
Unsure about the 232 crank but any 258 crank will drop right in. Some have a long snout...some have a short...if you get the short, the crank pulley bolts directly on...if you end up with the long...no big deal, add a hesco spacer in front of it(The crank pulley), under the main bolt. Everything else about the cranks are the same

Re: Need clarification

Posted: June 7th, 2012, 3:36 pm
by Knoxes
So if I'm reading the FAQ correctly, I want 8120508, 8125450 or 8132619 for the 258, correct? And I'll have to add the spacer.

Re: Need clarification

Posted: June 7th, 2012, 3:50 pm
by SilverXJ
If you want a 12 counter weight crank you need 8120508, 8125450, or 8132619. They are all 64mm snouts and you will need the spacer. If you want a 4 counter weight you need 3235444 or 53005535. The 53005535 doesn't need a spacer.

Re: Need clarification

Posted: June 13th, 2012, 8:42 am
by Knoxes
Is there any reason why I *shouldn't* buy a reman'd crank?

Re: Need clarification

Posted: June 13th, 2012, 9:17 am
by Cheromaniac
Knoxes wrote:Is there any reason why I *shouldn't* buy a reman'd crank?
No. All of the 232 cranks and nearly all of the 258 cranks (apart from new expensive custom billet grinds) are used castings that are 22+ years old anyway. A reman. crank will merely be a used crank that's had the journals reground undersize, polished, and with the oil holes chamfered so that it's ready to drop into your block. Some vendors might even supply the crank as a kit with matching rod/main bearings.

Re: Need clarification

Posted: June 13th, 2012, 7:13 pm
by EVIL95XJ
Cheromaniac wrote:
Knoxes wrote:Is there any reason why I *shouldn't* buy a reman'd crank?
No. All of the 232 cranks and nearly all of the 258 cranks (apart from new expensive custom billet grinds) are used castings that are 22+ years old anyway. A reman. crank will merely be a used crank that's had the journals reground undersize, polished, and with the oil holes chamfered so that it's ready to drop into your block. Some vendors might even supply the crank as a kit with matching rod/main bearings.
thats how i got mine, with bearings but the main bearings that came with it were different from the 4.0 bearings so u will need to get the right main bearings

Re: Need clarification

Posted: June 13th, 2012, 9:29 pm
by Retlaw01XJ
I'll throw this out there as another option...
A brand new stroker crank can be had for about $400. Made by Scat, sold by Summit Racing and others....

Re: Need clarification

Posted: June 14th, 2012, 10:50 am
by Knoxes
I noticed that there are a couple of cranks remanufacturers here in the SE - Charlotte and FL. Any opinions on the quality or a preferred shop?

I don't mind spending money when it will get a significant advantage - but I'm getting the impression that the reman'd are fine. I really appreciate the info - knowing the options really helps make a better decision.

Re: Need clarification

Posted: June 16th, 2012, 7:41 am
by dwg86
Personally I prefer an original amc crank (or reman). They were cast in the USA, and with a fresh grind your bearing clearances should be correct. I have heard a few of the scat cranks have had bearing clearance issues.

Stay witha a 258 crank don't use a 232. If you want to find a used 258 crank, check you local junk yards, or craigslist. You might be able to pick up a complete 258 engine for cheap on craigslist. I have pulled a couple 258 cranks out of a local "u pull it" junk yard. They cost around $40.00 and several hours of my time to pull.

If I were going to build another stroker, I would use the 4.0 rods with either the kieth black forged stroker pistons, or a custom set of forged pistons from http://www.bulltear.com. Keep your static comp ratio below 9.5:1 with a .040-.050 quench. I don't know what dynamic compression ratio will cause detonation. I would stay below 8.5 dcr.

My engine had a 9.25:1 static comp with a 7.8 Dynamic CR and a .040 quench. I ran 87 octane gas. No detonation problems ever.(I live in Atlanta Ga, around 1000 ft above sea level and summer temps close to 100 degrees). I know I would have been happier with higher compression ratio. I think I could have run 8.0 dcr on 87 octane. My combustion chambers were polished so this might have helped with detonation.

Roller rockers are nice, but for the price vs. the hp gain...I don't know if they are worth it. I have seen stock steel stamped rockers go 350,000 miles without being replaced. Now that is with stock springs. Higher spring pressures may wear the stock rockers faster.

My engine had 18,000 miles when my Jeep got totalled, so I don't know the longevity of my engine build. Up to that point my engine ran good. My stroker was getting around 19-20 MPG (2003 Wrangler, 3.07 gears, 235/75r15 tires).

Re: Need clarification

Posted: June 18th, 2012, 7:29 am
by Knoxes
Thanks for that info.

I need a shop manual - Chiltons' looks like it's just online now - subscription service. Haynes seems awfully broad - 1993 to 2004. Any suggestions?

Re: Need clarification

Posted: June 18th, 2012, 9:25 am
by gradon
Get the real FSM. Haynes is garbage and Chilton's is slightly better. Here you go:
http://www.ebay.com/itm/2003-Jeep-Grand ... 10&vxp=mtr
Make an offer and be happy with the great deal!
edit: apparently it doesn't include the 2002 fsm, which is the main manual you want, then the above has the 2003 supplement and other diagnostic manuals.
http://www.ebay.com/itm/2002-Jeep-Grand ... 55&vxp=mtr

Re: Need clarification

Posted: June 18th, 2012, 11:39 am
by superj
If you ask around on jeepforums or Cherokee forums, I am sure someone will send you a copy of your fsm for free. I got mine that way from a dude on jeep forums that way.

I have found a free down load of the 87/88 fsm on google docs for others interested in that particular edition

Re: Need clarification

Posted: December 3rd, 2012, 5:50 am
by Knoxes
Ok, this next question has been weighing on me since day 1.

Will I have to discharge the a/c to pull the motor? I really, really don't want to do that - it works brilliantly. And I just know that it won't go back together properly.

Re: Need clarification

Posted: December 3rd, 2012, 9:12 am
by Cheromaniac
Knoxes wrote:Will I have to discharge the a/c to pull the motor?
No that won't be necessary. Just unbolt the AC compressor with mounting bracket from the block and set it aside.