Stroking an Xj 4.0L

[worthin08]

I am looking to rebuild a old 4.0L and stroking it i was looking at taking a 4.2L crank having it rebalanced and blue printed and then taking teflon pistons and boring it out .020 and then put re doing head and putting a aftermarket cam with 240 duration and .430 lift and other good ideas and how much power and torque think i will get out of that and what else am i missing thanks

[Cheromaniac]

I'm not sure what you mean by teflon pistons but if you're planning on using 4.2 rods, you'll need aftermarket 4.0 pistons. If you go for the 677P's, you'll end up with a CR of 9.25:1 (no decking of block/head). If the head remains unported and you use the Mopar Perforamnce 28 cam that you mentioned, you'll end up with about 200-210 crank HP and 300-310 crank TQ.

[worthin08]

I talked to a guy selling teflon coated pistons and he said they were usually used for a stroker i am guessing the 4.7L but wouldnt they work in a 4.0 bored .020 over thats what i was planning on doing and the head gasket wouldnt work with bigger pistons would it and thats alot of torq and HP

[gradon]

The teflon coatings are on the skirts of the federal mogul/sealed power h802cp20(30,40,60) or h825cp pistons. H=hyperteutic piston(silicon in the alloy) C=teflon coated skirts. They are not "stroker" pistons but can be used in a stroker.

[worthin08]

whats would be the beast pistons to buy if i was just gonna use the 4.2L crank and rods and just leave the cylinder the stock size and just putting a big cam but i am looking at cams on summit racing what would be the best duration and lift i would want i am going to use it to play but also drive on road trips at times so i dont want the max thing but i dont want anything to small

[Cheromaniac]

Since it's an old engine, I strongly suggest you have the cylinders overbored to make sure they're round and true for good ring sealing. You could then go for a set of H825CP pistons which, with a +0.030" overbore and 4.2 rods, would yield a CR of ~9.5:1. Add a CompCams 68-231-4 cam together with Mopar Performance 5249464 valve springs and you'll have a very nice street combo with a wide, flat torque curve.

[worthin08]

i have been looking for a set of H825CP pistons which, with a +0.030" what website are they on and rings too i have found alot of the 677 pistons but not the H825cp ones i am wondering how much they are a peice and how much thr rings were and do you think the COMP Cams K68-231-4 be better or the COMP Cams K68-239-4 with the springs and lifters for each the are mopar performance cams what would be the advantage to the bigger one i dont know much about cams

[gradon]

Here's some pistons from a company I've bought from:
http://cgi.ebay.com/ebaymotors/Jeep-Che ... ccessories

Specify what size you want: standard, +.020",+.030",+.040",+.060". And yes, the 802s will work in 4.0s earlier than 96.

[SilverXJ]

I've also used MadDogRacing on ebay before and they were good. So is Falcon on ebay.

[amcinstaller]

dont buy the comp cams kits though, springs dont fit the head iirc

[Cheromaniac]

i have been looking for a set of H825CP pistons which, with a +0.030" what website are they on and rings too i have found alot of the 677 pistons but not the H825cp ones i am wondering how much they are a piece and how much thr rings were and do you think the COMP Cams K68-231-4 be better or the COMP Cams K68-239-4 with the springs and lifters for each the are mopar performance cams what would be the advantage to the bigger one i dont know much about cams

You can find all the parts you need under one roof at Summit Racing.
H825CP pistons for $32 each, and Sealed Power performance piston rings ($40 per set):

http://www.summitracing.com/parts/STL-H825CP30/
http://www.summitracing.com/parts/SLP-E-234K030/

Clevite main and rod bearing sets:

http://www.summitracing.com/search/?key ... 947P&dds=1 for HO block and http://www.summitracing.com/search/?key ... 704P&dds=1 for Renix block
http://www.summitracing.com/search/?key ... 960P&dds=1

Cam bearings:

http://www.summitracing.com/search/Part ... m+bearings

CompCams 68-231-4 cam at $139, and a selection of lifters:

http://www.summitracing.com/parts/CCA-68-231-4/
http://www.summitracing.com/search/make ... Rank%7cAsc

Mopar Performance P5249464 valve springs ($11 each), P4452032 retainers ($10 each), and P4529218 valve keepers ($20):

http://www.summitracing.com/parts/DCC-5249464/
http://www.summitracing.com/parts/DCC-4452032/
http://www.summitracing.com/parts/DCC-4529218/

Oil pumps:

http://www.summitracing.com/search/make ... Rank%7cAsc

Timing sets:

http://www.summitracing.com/search/Make ... Rank%7cAsc

[worthin08]

was looking at the comp cams why wouldnt the springs work for the 4.0l head

[worthin08]

ok I have another problem does it matter what 4.2L crank i get i am looking at on from an 1987- 1990 crank that has a 2in neck here is he link let me know what you think http://www.northernautoparts.com/Produc ... elId=20663

[amcinstaller]

the part number you have listed is fo cam, lifters, springs, etc. if i recall correctly, the springs fit a 4.2 head, not the 4.0 head. but if you go to the comp site and pick 4.0 springs, i think they fit, others can confirm?

[worthin08]

ok just ordered my comp cam kit and gonna re build the head later next week. but what clutch should i go with since i will be having a 4.6L and dont really wanna go with stock but dont want a crazy clutch ethier i was looking at a heavy duty ACT clutch from summit for 333 do you think that would be to much?http://www.summitracing.com/parts/ACL-JP1-HDSS/ thats the web address thanks