WJ Stroker build recipe.

[bellator50]

Newbie here and I apologize in advance if I'm beating a dead horse I searched but did not find a definite answer and hope someone here can straighten me out.

I have acquired an 01 Jeep WJ. The #3 piston was at the bottom of the oil pan so a build is in place. I have a complete AMC 4.2 and would like to build a stroker. I'd like to build a mild one but essentially need a recipe. The Jeep will be more for a daily driver. Can someone point me out to a poor man stroker build.

[Cheromaniac]

Here ya go:

4.6L modified "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black UEM-IC944-020 forged pistons
9.25:1 CR
Stock 4.0 camshaft
Ported 0331 cylinder head
Mopar/Victor 0.043" head gasket
0.070" quench height
Accel 24lb/hr injectors for '96-'04 engines
245hp @ 4800rpm, 315lbft @ 3000rpm ('96-'04 camshaft)

You'll need to:

Rebore/hone the cylinders +0.020"
Reuse your 4.2 crank (have journals checked by machine shop, regrind undersize if necessary)
Have the small ends of your 4.0L rods clearanced for the IC944 pistons
Source a reinforced 0331 head from Clearwater Cylinder Heads (the OEM '01 head is crack prone)
Buy an IC944 piston/ring set, new OEM oil pump, new OEM timing set, freeze plugs, upper/lower gasket sets, set of new lifters, harmonic balancer, water pump, thermostat, Accel injectors plus EV6 to EV1 adapter plugs

[bellator50]

THANKS!. I'm assuming the quench height will turn out what it is with the parts used or do I need to do something else to achieve it. Also ... my block looks to damaged to bore out. What years and models fit .

[jsawduste]

That's a hell of a lot more quench then I would run with the fuel we have in this Country.

[FlyinRyan]

That's a hell of a lot more quench then I would run with the fuel we have in this Country.

X2, IMO that is unacceptable.

[bellator50]

That's a hell of a lot more quench then I would run with the fuel we have in this Country.

OK, so if it's to much quench,what is acceptable and how do I reduce it. Deck it?

[Cheromaniac]

That's a hell of a lot more quench then I would run with the fuel we have in this Country.

The 0.070" quench of the modified poor man's stroker is less than the 0.073" quench of the stock 4.0 but I agree that it would be better to reduce it to more like 0.040"-0.050".
Each 0.010" decked from the block will reduce the quench by the same amount, reduce the combustion volume by 2cc, and raise the CR by 0.2:1. If you want to keep the CR the same as it would have been if the block was undecked, you'd need to add 2cc to the combustion chamber volume for every 0.010" decked from the block.

[bellator50]

This sounds like more of a headache than anticipated.

[jeepxj3]

Buy Bulltear or RaceTec pistons and the Headache is cured.

[Cheromaniac]

This sounds like more of a headache than anticipated.

Here ya go. Less headache:

4.6L Modified "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Custom forged +0.020" bore pistons, compression height 1.380", dish volume 26cc
9.25:1 CR
Stock '96-'04 4.0L camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.043" quench height
Accel 24lb/hr injectors for '96-'04 engines
245hp @ 4800rpm, 315lbft @ 3000rpm

[bellator50]

Ok back in. Haha what year of HO head would work and do you have a suggestion of where to get pistons.

[Cheromaniac]

Ok back in. Haha what year of HO head would work and do you have a suggestion of where to get pistons.

You can get a set of Bulltear pistons from http://www.bulltear.com/catalog/product ... cts_id=242
As far as heads go I think you have two options; either an '02-'06 OEM head or a reinforced #0331 casting from Clearwater Cylinder Head at http://www.cylinder-heads.com/automotiv ... der-heads/

[SilverXJ]

x2. It would be easier to stick with the 0331 head. But make sure its not an early non- 'TUPY' head.

[bellator50]

I'm a bit stumped. I used the stroker compression ratio calculator with info provided on this post but numbers are not adding up. Can someone point out my error. The calc does not show option for a 0.02 bore over so I manually entered it.

[Cheromaniac]

Make the chamber volume 57cc and the altitude 0 feet.