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Questions about Stroker...

Posted: October 28th, 2013, 10:40 am
by Stroker_ZJ
Hello guys,

I am new to the forum and have read through countless articles and postings about how to stroke the 4.0 motor. I just have a few questions that I could not find the answer for.

Currently, I have 220K miles on my 95 ZJ and the motor feels a little sluggish. I like to prepare and get everything organized for when the motor goes out I will know exactly what I want to do with it. I am wanting to go with a RELIABLE stroker kit (that will last as long as my OEM motor has) and has a substantial increase in power. Not wanting to win any drag races or anything crazy like that, just wanting a noticeable increase in power. My Jeep will very rarely be driven offroad...will be driven mostly highway and city...and would like to keep decent gas mileage. RIght now it is completely stock (3.55 gears). The only plans I have are to add a Kolak Exhaust, 2"bb, and 31" tires.

I spoke to a local machine shop and they quoted me around $2500 for parts and labor to stroke my motor. What do you guys think? What stroker kit do you think would "fit" for the purposes I stated above? I was thinking the 4.5L "Poor man's" simple stroker might be the best for me.

Thanks,

Jake

Re: Questions about Stroker...

Posted: October 29th, 2013, 7:38 am
by Cheromaniac
Stroker_ZJ wrote:I was thinking the 4.5L "Poor man's" simple stroker might be the best for me.
Make it a 4.6L modified poor man's stroker instead. After 220k miles, the cylinders in your '95 block may be "out of round" and "tapered" beyond acceptable factory tolerances so I'd advise that you have them overbored +20 or 30 thou.
Apart from the 258 crank & IC944 rods, everything else will either be reused stock parts or stock replacement.

Re: Questions about Stroker...

Posted: October 29th, 2013, 12:37 pm
by Stroker_ZJ
Cheromaniac wrote:
Stroker_ZJ wrote:I was thinking the 4.5L "Poor man's" simple stroker might be the best for me.
Make it a 4.6L modified poor man's stroker instead. After 220k miles, the cylinders in your '95 block may be "out of round" and "tapered" beyond acceptable factory tolerances so I'd advise that you have them overbored +20 or 30 thou.
Apart from the 258 crank & IC944 rods, everything else will either be reused stock parts or stock replacement.
Thanks for your response Cheromaniac! So I should go for the following setup and have my cylinders overbored .20 or 30 thou and I will be good to go? Would this be a complete rebuild? Sorry for my lack of mechanical knowledge.

4.5L "Poor man's" simple stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Sealed Power 677CP standard bore pistons
9.2:1 CR
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.088" quench height
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines, stock injectors with stock 49psi FPR for '96 and later engines
247hp @ 4900rpm, 300lbft @ 3500rpm

Re: Questions about Stroker...

Posted: October 30th, 2013, 8:31 am
by Wombat Ranger
Just make sure you buy pistons that are .020 or .030 over, standard bore pistons will not work in an overbored motor.

Re: Questions about Stroker...

Posted: October 30th, 2013, 12:46 pm
by Cheromaniac
Stroker_ZJ wrote:
Thanks for your response Cheromaniac! So I should go for the following setup and have my cylinders overbored .20 or 30 thou and I will be good to go? Would this be a complete rebuild? Sorry for my lack of mechanical knowledge.

4.5L "Poor man's" simple stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 5.875" rods
Sealed Power 677CP standard bore pistons
9.2:1 CR
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.088" quench height
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines, stock injectors with stock 49psi FPR for '96 and later engines
247hp @ 4900rpm, 300lbft @ 3500rpm
I suggest you go for this version:

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 HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.070" quench height
Ford 24lb/hr injectors for '87-'95 engines
248hp @ 4900rpm, 306lbft @ 3250rpm ('87-'95 camshaft)