42RLE + Stroker

[Cannonball]

I have two general questions:

1) does anyone have suggestions, use or have done a stroker of any kind on a 2003-2006 TJ with a 42RLE automatic transmission (this would be the Rubicon package with the auto trans)?

2) does any one have a drivability history on the stroker engine and trans combination above?

I have a 2004 Rubicon with the 42RLE automatic transmission running 35"s and 4:56 gears as my daily driver. I am running out of power on the highway between 65-75mph @ about 1950-2300 rpm and or in the sand/dunes. swapping a 5.7 hemi is not the answer but the one I get the most often. I drive this every day and dont want a tempermental build nor do I want one that wont run at all in winter. My wife gets in it and drives it too and dont want her to worry either. Reliability and drivability are key for me, I read people are getting mixed issues on reliability which I feel is mostly either due to wrong part selection or improper build or break in. But I dont get the feed back I am looking for with the drivability concerns.

The trans seems to be pretty much a computer controlled unit which by all comments cant be changed. It was designed to an engine with more HP than the 40 can produce and thus the curent problems not holding overdrive and or highway speeds. I get the impressions from other forums that had the 4.0 had 50 more HP and more torque the trans issues would go away. Perfect for a Stroker in my thinking.

I see people building the strokers for XJ's and early TJ's and lots of older units but the newer TJ rubicon and this trans combination have me looking for more answers and sugggestions and or guidance than I have been able to read in any posts all winter.

I am going to start with a junk yard engine from a 2003-2004 TJ so I know everything will swap in / bolt up correctly when its done. I cant lay this up for ever so once the engine build is done it gets installed and back out on the street in under a week (taking a weeks vacation to do it). I will have one shot to get this right or Ill prolly loose my job if I cant get to work and my wife if I spend the money and it all goes south with issues.

I dont need a high RPM engine just one that pulls harder and will still retain some fuel economics. Im thinking if it pulls harder and breathes better making more power I wont have my foot on the floor board wasting fuel as much either. Yes there is always a trade off so this is why I am here looking to all or you for input as to the correct way to do this once.

I do appreciate any and ALL responses and thank everyone of you for my ignorance. Ill ask a question once and learn from the answers maybe ask a related question but Ill never ask the same thing twice, Promise!

CB

PS I push a snow plow here in Wisconsin winters just to get to the main road and I tow a small utility trailer hnting / camping sometimes loaded weight is under 1000 lbs.

[lafrad]

The trans computer will have no idea that you put a bigger engine in front of it, so don't worry about that.

Just chose a reasonable cam for the stroker, and it will behave like a stock engine, just with more torque.

I live in SE Wisconsin and my build was: 4.2 crank, 4.2 rods, 4.0 pistons, Crane Cam. *no other changes* (not even injectors) and its been a nice driving machine, year round.

[Cheromaniac]

I am going to start with a junk yard engine from a 2003-2004 TJ so I know everything will swap in / bolt up correctly when its done. I cant lay this up for ever so once the engine build is done it gets installed and back out on the street in under a week (taking a weeks vacation to do it). I will have one shot to get this right or Ill prolly loose my job if I cant get to work and my wife if I spend the money and it all goes south with issues.

Sounds like my 4.6L modified "poor man's" stroker recipe is the one for you, and it's becoming increasingly popular because of its incredible simplicity. Basically the only non-OEM parts you'll need are:

258 crank
Keith Black IC944 +0.030" pistons
Accel 24lb injectors with EV1 to EV6 injector plug adapters

Once you have all the parts that you need, you could build the stroker at your leisure and when it's fully-assembled, swap it into your Jeep. If you hire an engine lifting crane and have a buddy to help, you can complete the job over a weekend.

[xtremzj]

I have a custom Golen 4.7 and my 42re is fine. It's all about keep those trans cool.