Grand Cherokee ZJ V8 to Stroker

[JeepFamily]

I'm looking for my next project and have found a few low milage V8 jeeps needing a new engines. If I were to swap the V8 for a stroker what issues am I up against? New PCM? Wiring harness?

[IH 392]

And at least a transmission too!, the six's don't share the bellhousing with either the Dodge or Daimler engines.

[JeepFamily]

Wow, thought u strokers out there would be all over this one. Is this unheard of such that no one knows? Aside from the details the major issue would be the transmission. Injectors should be fine since these engines aren't sequential although there will likely be other PCM problems.

[Cheromaniac]

I'm looking for my next project and have found a few low milage V8 jeeps needing a new engines. If I were to swap the V8 for a stroker what issues am I up against? New PCM? Wiring harness?

Enough things to make your head spin. Why don't you look for a lowish mileage 4.0L Jeep as the recipient for a stroker transplant? It'll save you a lot of grief.

[SilverXJ]

Transmission (associated wiring & mounts), engine mounts, engine wiring harness, PCM, possibly BCM, some fuel lines, new air intake, all the engine ancillaries like alternator, AC compressor (and associated lines), cooling fan, drive shafts, etc.

Its a lot of work, but the stroker is better in power and gas mileage than a stock 5.2L, possibly a 5.9L. The other option is to rebuild the 5.2L and hop that up. Heads, cam, etc. They can be built to put out some serious power, but in stock form it isn't impressive at all.

[IH 392]

IF!? I was going to V8 my Jeep I'd drop a 401 in it! at least It'll bolt right up to the existing trans, I wonder how many times I could lift the front tires off the ground before the gears exit the trans case!??

[JeepFamily]

I own 4 Grand Cherokees spanning many of the factory engines except the 4.7 L stroker although we did drive it as a 4.0 L for the first 200K miles. We have a 03 4.7L V8 HO, 97 5.2 L and a 98 5.9 L. The Stroker is performs equivalent or slightly better than the 03 4.7L and out performs the other two in power and definitely economy. The Stroker is king of low end torque. Overall I'm very very impressed with the Stroker. That covers the semi-technical reasoning, from an emotional, yes emotional perspective it annoys me when someone replaces a perfectly good 4 or 6 with a chevy V8 ? I firmly believe the Stroker will stand toe to toe with the chevy below 3000 rpm and will do it with a lot less gas. If you're looking for a buggy style jeep that will jump rocks in a heart beet at over 100 mph than the V8 is a good choice. At least for the vast majority of the stuff I do, the stroked 6 is the perfect solution. Also, finding a low mileage 4.0L is possible but I have trouble removing a perfectly good 4.OL. However, removing the V8 offers a bit more satisfaction

[Cheromaniac]

I firmly believe the Stroker will stand toe to toe with the chevy below 3000 rpm and will do it with a lot less gas.

My strokered XJ will stand toe to toe with a friend's WK 6.1 Hemi SRT8 up to 4000rpm and it's only at higher rpm that the SRT8 pulls away. The stroker's low rev torque and gas mileage are indeed impressive.

Also, finding a low mileage 4.0L is possible but I have trouble removing a perfectly good 4.OL.

Not a problem. Here's what you could do:

1. Buy a Jeep with a low mileage 4.0L engine so that you'll also have low mileage drivetrain/suspension/steering components.
2. Go to the junkyard and buy a high mileage 4.0L long block engine that's still a runner.
3. Rebuild the junkyard engine into a 4.6L stroker.
4. Swap your shiny new 4.6L stroker into the Jeep.
5. Sell on the low mileage 4.0L engine to another Jeeper to recoup some of the costs.
6. Sell some leftover parts from the junkyard 4.0L engine in ebay and sell others for scrap.

[doublins]

The Stroker is performs equivalent or slightly better than the 03 4.7L and out performs the other two in power and definitely economy. The Stroker is king of low end torque.

Having had, in the same jeep, with the same transmission, axle gearing, and tire size, a 4.0L I6, a 4.7L stroker I6, and a 5.2L Magnum V8, all in that order, I will respecfully disagree with your statements. The V8 outperforms the stroker in all areas, including low-end torque, top-end power, and fuel economy. It's not even a close matchup- This is one man's observation, but you cannot get a better basis for comparison than having the motors in the same exact vehicle with the same driver, weight, drivetrain, tires, lift, aerodynamics, etc, etc, etc. It is not a close contest at all- the 5.2 (and by supposition the 5.9) is superior to the stroker all else equal.

That said, both my stroker and my 5.2 have been tuned via an SCT tuner, by the same tuner (FlyinRyan), and there were HUGE gains achieved with the 5.2 from the stock tune, which had it's timing way too retarded and it's fueling way too rich, but, after tuning each for best power, the 5.2 wins, hands down.

[SilverXJ]

The 97 5.2L ZJ I have is a marginal improvement over a 4.0L. Of course it is using the factory tuned. The stroker XJ will walk all over the ZJ and still get better gas mileage.

[doublins]

The 97 5.2L ZJ I have is a marginal improvement over a 4.0L. Of course it is using the factory tuned. The stroker XJ will walk all over the ZJ and still get better gas mileage.

I believe you- I reverted to the stock 5.2 tune to confirm via logging the factory ignition advance maps for Ryan (using a ram 1500 pcm) and was amazed at how piggish the stock tune was- it makes more noise than power in stock form

That said, I'm sure weight, gearing, etc all come into play between your XJ and ZJ, as well as transmission, tires.

I am only speaking with respect to my TJ and my experience with the three engines, and in my jeep, the 5.2 has been the best performer. The 4.7 was a big step up from the 4.0 to be sure, though.

[JeepFamily]

The 5.2 is 212 HP from the factory and I'm having difficulty seeing tuning turn around a 70+ horse deficit when compared to a stroker? If the engine were turbo charged and you increased manifold pressure and that would be understandable. Can you also provide specifics on the stroker as there are near infinite combinations providing a very wide range of performance? In terms of torque, I agree 5.2 and 5.9 quite torquie (word??) which is a surprise given the 4.0, 5.2 and 4.7 have roughly the same stroke. the 5.9 is king of the factory engines with a stroke of 3.58", still short of the 3.912" of our 4.7 stroker. For reference here are 0-60 numbers for various Grand Cherokees with different engines. I don't have these for our stroker but used numbers from Mopar Racing.

4.0 - 10.9 seconds
4.7 Stroker (5.8 estimated from Mopar Racing)
5.2 - 8.8 sec (8.2 estimated from Mopar Racing)
5.9 - 7.0 sec (7.1 estimated from Mopar Racing)
4.7 - 9.0 sec
4.7 HO - 8.3 sec

These aren't rock crawling #s but provide some reference for comparison

[SilverXJ]

I believe you- I reverted to the stock 5.2 tune to confirm via logging the factory ignition advance maps for Ryan (using a ram 1500 pcm) and was amazed at how piggish the stock tune was- it makes more noise than power in stock form

Maybe I'll eventually have to try a tune on my 5.2L.

4.0 - 10.9 seconds
4.7 Stroker (5.8 estimated from Mopar Racing)
5.2 - 8.8 sec (8.2 estimated from Mopar Racing)
5.9 - 7.0 sec (7.1 estimated from Mopar Racing)
4.7 - 9.0 sec
4.7 HO - 8.3 sec

I find it hard to believe that the 4.7 stroker was so much quicker than the 5.9L. But of course that is also estimated. On the 4.7L HO, Motor Trend recorded a 0-60 of 6.9s http://www.wjjeeps.com/ho_engine.htm.

[JeepFamily]

I'm also interested in tuning my 5.2 if nothing else to improve economy above 13 mpg. The 0-60 numbers were provided by Jeep. I provided the Mopar Racing estimates for the 5.2 and 5.9 only as reference when looking at the 4.7 Stroker since I do not have actual #s for the Stroker.