Suggestions For Daily Driver

[bigal389]

Hello All, first post with some questions. I've reading for a while and have a few questions for my first stoker build. i have a 2004 Wrangler X with 80k miles listed in my profile, it has 3.73's with the 42 rle trans. This is my daily driver with some light trails on occassion. I've had it for about a year and love it. I've spent some time fix the previous owners abuse but the one problem I still have is the fact the thrust bearing had worn into the crankshaft about a 1/4". It had a belt squeeling and I found the excessive crank walk when replacing the belt. I've never saw an auto do this, I replaced the mains and thrust bearing to get by until I get the funds to do a build. I want to do a version of the poormans stroker, but I have read where the quench on this build is not ideal. So my question is what would the ideal quench and cr be for a daily driven poor mans stroker. I plan on using the 4.2 rods and 677 pistons, my 04' head and block with a Clay Smith cam, not sure which one yet. I want the torque to be between 1200-4000 rpms so I can start back using my overdrive without lugging. Plus the extra power will be nice. I'm open to suggestions.
Thanks, Al

[Cheromaniac]

Do the modified poor man's stroker. It's an evolution of the original poor man's stroker but with 4.0L rods, custom pistons, and a 0.043" quench. You can get Bulltear custom forged pistons for a mere $475 which is little more than what you'd pay for a set of 4.2 rods and 677CP pistons.

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 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 ('96-'04 camshaft)

[bigal389]

Thanks, I have already conntacted Bulltear and am waiting for a reply. Are there any other pistons that work with the 4.0 rod with out machine work on the block? Woud it be better to do a mini stroker? Looking at your sight they appear to make good power and torque as well.
Thanks, Al

[Cheromaniac]

Thanks, I have already conntacted Bulltear and am waiting for a reply. Are there any other pistons that work with the 4.0 rod with out machine work on the block?

Not off the shelf. You'd still have to go the custom route e.g. Diamond, JE.

Would it be better to do a mini stroker?

Not really. A 4.6L stroker will make more torque at all rpm (and especially low down) than a 4.2L mini-stroker. The only advantage of the mini-stroker is the lower cost 'cause you could use cheap Silvolite UEM-2229 or Sealed Power 677AP pistons instead of custom items. The price of a 231 crank is about the same as that of a 258 crank so there's no cost saving there.

Looking at your site they appear to make good power and torque as well.

Yup. The slightly higher CR and lower quench of the 4.2L mini-stroker makes it a good upgrade over a stock 4.0L engine. If you add the usual external performance bolt-ons, port the head, and add a performance cam, the mini-stroker is indeed a little powerhouse.

[bigal389]

So if I were to go with the modified poormans stroker and add this cam

Advertised Duration : 274
Duration at .050" 224
108 Lobe Separation
Valve Lift based on Rocker Ratio
1.5 .450
1.6 .480
1.75 .525
Along with a larger throttle body, would have a pretty powerful 4.6 stoker right.
Al

[Cheromaniac]

So if I were to go with the modified poormans stroker and add this cam

Advertised Duration : 274
Duration at .050" 224
108 Lobe Separation
Valve Lift based on Rocker Ratio
1.5 .450
1.6 .480
1.75 .525
Along with a larger throttle body, would have a pretty powerful 4.6 stoker right.
Al

Yup and with that cam, you could even run a higher SCR (9.65) by reducing the piston dish volume to 22cc.

[bigal389]

Sounds good to me. I guess it's time for me to start sourcing parts to get the ball rolling.
Thanks, Al

[followgod2]

New to here and have some questions about this recipe. Have rebuilt honda engines but never performance engines.
I am looking for more of a performance street engine. nothing crazy just more hp and torque. Started this quest when i got beat by a mini van.
This is something i only drive in the summer on nice days and when my grandsons are over. Want something that will be reliable. Will probably not go off road because of all the work I have done to it.will be getting a different beater to do that next winter.
would this be the best recipe for me? I don't want to say money doesn't matter but have been saving and selling parts to finance this so I will not go cheap so i have to repair it constantly. I would rather build it once and build it right.
So here are my questions :
best brands for parts needed such as rings, bearings, water pump, map sensor etc...
what grade fuel will I need?
will factory rear end last? Will punch from time to time. Have 3:73
Trans has 125,000 on it, will it take the additional torque? Have moog u joints, will they last?
will do 24# injectors, adjustable map, bore throttle body etc
Thanks

[Cheromaniac]

The modified poor man's stroker recipe will serve you well and run on 87 octane. The only non-OEM parts that you'd use internally are the 258 crank and Bulltear custom pistons/moly rings. By keeping the rest of the engine stock, you'll preserve the engine's legendary reliability. The only other engine parts you'd need to replace are the main/rod bearings (Clevite), oil pump (OEM), timing set (OEM), freeze plugs (brass), lifters (Crown Automotive), water pump (OEM), and injectors (Accel 24lb'ers with EV6 harness-to-EV1 injector adapter plugs). Given the number and frequency of aftermarket flat-tappet cam failures, I suggest you sacrifice a few HP for the sake of reliability by keeping your original stock cam.
The factory rear end and the stock tranny will cope fine with the extra torque of a stroker. I've been running my stroker for 78k miles.

[bigal389]

What compression height would be needed to run the 4.2 rods with a zero deck height?
Thanks, Al

[Cheromaniac]

What compression height would be needed to run the 4.2 rods with a zero deck height?
Thanks, Al

1.630".

[bigal389]

ok I've found a cast piston with the right bore, the wrist pin is .004 smaller and the comp. height is 1.660. It has a 3.080 dia. by .270 deep dish. which if I calculated correct ends up at 13.63 cc's which equates to 10.54 cr if the pistons are machined to a zero deck and the wrist pins are resized to fit the 4.2 rods. What is the max cc's to run on the head when I polish the chambers? What is the max cr on pump gas?
Thanks, Al

[DaVictory]

Ok, guys here it goes.

I have done plenty of engine work but I've never tried stroking a motor so here it goes. A friend of mine was having problems with the motor in his 2003 WJ becoming worn out (lifter noise) so he brought it to me for a look and then we heard about the pistons cracking problems too that would sound like lifters. So moving along I ripped into the motor and found the cam and lifters to be worn. I also found cylinder 1 to have a broken piston skirt. I ordered up the Crane Cam #753901 and lifters as suggested by the tech at Crane. I then took the head to a machine shop to get tore apart and cleaned to make sure there were no cracks....checked out good! Then while I was there the head mechanic/owner suggested that I stroke it with the 4.2l crank and rods from a motor he had just received. He called the customer who said he would let them go for $80!! I couldn't pass up this opportunity to build a great powerful daily driver. So here's what were doing..

Stock bore 3.875"
Speed Pro Pistons H802CP w/ E 925K moly rings
Port & Polish head work
Stainless header
Crane Cam #753901
Crane Lifters
Cloyes timing gear set
Airaid Cold air intake
Dynomax cat back exhaust
62mm throttle body
24lb injectors

Any suggestions? I've read about the possible pinging but have been reassured by the machine shop owner (a jeep enthusiast) that with this newer jeep the computer will adjust so it will not be a problem. Just to be covered we were going to use 89 octane. Thanks for any help in advance.

[Cheromaniac]

Stock bore 3.875"
Speed Pro Pistons H802CP w/ E 925K moly rings
Port & Polish head work
Stainless header
Crane Cam #753901
Crane Lifters
Cloyes timing gear set
Airaid Cold air intake
Dynomax cat back exhaust
62mm throttle body
24lb injectors

Any suggestions? I've read about the possible pinging but have been reassured by the machine shop owner (a jeep enthusiast) that with this newer jeep the computer will adjust so it will not be a problem. Just to be covered we were going to use 89 octane. Thanks for any help in advance.

That's very similar to my original 4.6L low buck recipe so it'll work, but I think it'll need a diet of 91 octane or higher to avoid pinging.

[bigal389]

image.jpg

This is the recipe that I have decide to use. What do you think? I am not sure on the DCR. Will that be acceptable on low octane or will I need to run mid grade?