nicholas

Ok So i have an 88' limited, with a 4.0 and automatic transmission. I am not a mechanic, This jeep is the first vehicle I've ever "worked on" my self. I've done a very through tune up, following Crusier's tips. which has been an amazing help.

I am underwhelmed by the lack of power. I have attempted to boost the power by adding a bored out 60MM throttle body, upgraded fuel injectors, borla cat back, and a magna flow cat (I swapped in a test pipe for awhile but the drone was aggravating after 3 days), spectre through the cowl CAI.

My question Is Im debating if its better to attempt to swap in a HO intake and header, or to make it a stroker. My compression test was pretty consistent at 120psi across all the cylinders. it doesn't have a ton of miles on it 129k.

I am trying to find the best combination of power, reliability and hopefully retain MPG. Ive heard that strokers don't tend to last as long, but I've also heard that depends on how they are built. do you have to pull the block to stroke the motor? Also Im aware that the stroked motor will be significantly more powerful than the HO upgrades, but when you take into consideration, cost, and time, as well as wear and tear on the motor is it worth it?

any ideas?

XJwonders

Yes u would need to pull the engine to stroke it. But if u meant by stroking it as a cat, then u can leave it in the jeep. And start stroking the valve cover or the oil pan, whichever is your preference

cruiser54

Read this about the HO vs Renix.

Also, have you indexed your distributor yet?

Gotten rid of the "crush" in your downpipe?

HO myth buster


Renix in 90 made 182 HP. HO in 91 made 190 HP. That's 8 HP difference.

HO only made more HP than Renix at higher RPMs and not a bit more torque. HO had 58 mm throttle body versus a 52 mm throttle body on a Renix and also had a better design header. See where I'm going with this?

The whole 8HP was not mostly from the head, but from the bigger TB and better exhaust manifold.

Put a 60mm TB from www.strokedjeep.com on your present head, eliminate the "crush" in your headpipe with proper re-routing, and go for it.

HO stands for Highly Overrated.
__________________

Fred/N0AZZ

Its a 4.0 Jeep engine and a very good one of all they have made, but one thing it is not is a race car motor, be happy with you have.......Or swap in a V-8 for a lot more HP.

Ianf406

How many times have you copied/pasted this? Haha.


I love my Golen stroker. Unfortunately my jeep does not. I put about 150,000 rough abusive miles on it prior to doing the motor without ever breaking anything major.
In 10,000 miles since doing the stroker, my AW4 is failing, I need a new/stronger T-case, I warped/replaced the pinion in my D44, have replaced probably 15 Ujoints and most recently, my alternator bracket snapped in half upon startup on a cold morning (no, its not seized).

Now if I babied it or never went off-road, none of the above would probably happen. But if you want to throw a stroker (Or anything significantly more powerful) in there and abuse it, expect to have to beef up quite a bit of stuff to handle it or spend quite a bit of $$ replacing stuff.

Honestly, the stock 4.0 did just fine for me. Sure I love the extra HP/TQ and improved MPG but you can go almost anywhere with the 4.0 just how it is. For me, I usually have to drive 200-400 miles across the state to go to a challenging trail and it is nice to have the extra HP.

Regearing is another option to give you that seat-of-your pants feel.

cruiser54

I have to paste this. Otherwise, I would have to type it every time...LOL.

Metmknice

Late 89-90 ECU, might help a little.

cruiser54

thanks!! I forgot about that one. It helps.

nicholas

thanks for the replies! sorry for the slow response. I guess to clarify I am trying to find the best balance of possible performance/tuning increases. I am trying to find out from peoples experiences the pros and cons, to see if there is anything more I can do or want to do.

Cruiser- No I haven't reindexed the distributor yet, and I have been considering putting in an aftermarket header. Ive got a couple more things on the list before I get to the distributor. Also I have added a 60mm bored Renix TB and a through the cowl cold air intake. the intention of this post is to research future possibilities.

I have a 89 ECU sitting in the front seat. my jeep is an 88, Is there any way that it might have the same ECU settings if it was a late model 88, how can you identify that? before I switch out a good ECU?

what Ianf406 posted is kind of what I was looking for in regards to the stroker information. I was curious to hear from someone who's driven one for a while to see if the gains where worth it or not. it sounds like its not really the option I want to go.

I considered Re-gearing, I was looking into it. Right now i have a stock dana 30-35 rear with 3.55gears, I'm running 30x9.5 BFG AT's. Im also getting about 15mpg. Im not sure if the gains will end up being worth it. when you factor in the loss in top end, mpg, time and money actually re-gearing both axles.

So just for curiosities sake, IF I did want to swap out the intake manifold, would I also need to change the head? Ive read a number of posts about swapping parts but usually they are trying to swap in a whole new HO motor. I like the renix system, and am trying to understand just how interchangeable the parts are.

cruiser54

This should help then.

Cruiser’s HO into Renix Swap

This swap is easier than some will lead you to believe, generally those who have never done it. Those of us who have done it, like myself, will share with you the things that need to be done for a successful swap. Just think of it as swapping in a long block.

The HO and Renix have some differences but none that can’t be overcome very easily.

Any HO engine from an XJ or ZJ through 1999 can be used. One running change was that the rear of the head was no longer drilled and tapped for the temperature gauge sender beginning in the 96 model year. The sender can be relocated to the threaded hole in the thermostat housing taken from the HO engine. You’ll have to extend the wire to that location. Some brave souls even drill and tap the HO head for the sender.

You will be using the intake and exhaust manifolds from your Renix, along with all your sensors and wiring. Since the intake ports of the HO are slightly different, you use the Renix gasket. Exhaust ports are identical.
You will need to use your Renix distributor as it is different than the HO because they use different fuel management systems. The flywheel or flexplate from the Renix must be used so your CPS gets the correct signals. The valve cover from the Renix allows you to keep your CCV system intact and requires no modifications.

The HO block will have a plug in the coolant galley on the driver’s side of the block, closest to the front, which needs to be removed so your Coolant Temp Sensor can be installed in it’s place just as it is on the Renix. It requires a 5/16” square drive or a modified 3/8” drive that has been ground down to fit. Do this before installing the engine.

As for the knock sensor, which is located just above the oil pan on the driver’s side of the engine about mid way, all the blocks I’ve seen are threaded for it. If not, I’ve heard they may be drilled but not tapped. Tap the hole if that’s the case.


Revised 03/28/13

And yes, there is a difference between the 88 and 89 ECU. What are the 2 part numbers of the ones you have?