V8 in an MJ ?

[512tr]

Does anybody know if any V8's will fit in front of an AW4 or any adapters available?

[square]

AMC V8 would bolt up, don't now if it would clear the rad thow..

[Pete M]

advanceadapters.com sells all sorts of adapters. None of them are especially cheap. Consider stroking your 4.0L out to 4.6L. It bolts right in, produces v8 power, and isn't as hard to keep cool (as many v8 MJs/XJs have proven to be).

Jeep on!

--Pete

 

[87manche]

advanceadapters.com sells all sorts of adapters. None of them are especially cheap. Consider stroking your 4.0L out to 4.6L. It bolts right in, produces v8 power, and isn't as hard to keep cool (as many v8 MJs/XJs have proven to be).

Jeep on!

--Pete

 

I second the stroker opinion. When the renix needs rebuilt, it will become a 4.6L. Let's just hope that's sometime in the FAR future.

[512tr]

Thank for the replies :)

 

The 4.0 Renix in my MJ runs great, as mentioned in an other post I drove it non stop for 1200 miles last month.

Before a started, I changed spark plugs, disconnected and dismantled the TB and cleaned it out, adjusted the TPS,

opened all electrical connections to the Renix sensors and sprayed them with WD40, checked all vacuum connections,

cleaned the air filter etc, etc, and the Renix performed very well, with an average 22 MPG, with GEM top on and loaded with 800lbs.

 

However, sooner or later I will look for more power, that’s why I'm checking different options for an upgrade.

 

The options are a V8, building a stroker, supercharger, turbo or a stroked SC/turbo engine.

 

I'm quite familiar with the 4.0L HO , have been running it in my YJ for 7 years now, it's a good, strong and reliable engine....but we always want more power(we are just grown up kids) :lol:

 

I have already supercharged my YJ, it's a good powerful option, but expensive, running 5.5 psi boost, but will soon increase it to 8 psi.

 

 

Have found out that the cheapest and easiest way to increase power in the Renix, is to stroke it to 4.5L, using a stock 4.2 crankshaft, 4.2 rods and 4.0 pistons, bigger injectors and an adjustable fuel pressure regulator.

This is the simplest way of stroking, further is to use the HO head, cam, manifolds and TB, going even further to 4.7-4.9 will be mush more expensive.

 

Then you have the turbo option, found these pics on the net, a simple primitive turbo setup...the pics have been stored on my computer for a long time

...so I don't know the story behind them, or how it turned out, but will do more research on the turbo option.

 

 

 

And then you have the V8 option, Advance Adapters do not have any options for the AW4…bottom of page.

 

[87manche]

first off, the yj is NASTY! That looks like some huge power under there.

Second, I can see the electronic controls of the AW4 being a problm, since it uses the TPS and a myrid of other things fed to the TCU to shift it. If you want to go V8 I think SBC and a 700 tranny would probably be the easiest. Tranny is self contained as far as control, and you could go carbed 350 or injected.

[DirtyComanche]

You can get/make things to bypass the electronics for the aw4, I believe. However, it would probably be easier to get a donor vehicle (K3000 anyone?) and just steal everything that looks beefy.

 

 

V8s seem to fit better than the I6, nowhere near as long.

 

 

You want this thing to be somewhat streetable? Hmm, I'd just be doing a stroker then.

[Bounty Hunter]

Simply shift the AW4 with a switch like what's sold over on the Naxja forums. You control torque converter lockup manually as well.

[Cooter]

If you're going through the trouble to swap a V8 in, just swap the tranny and t-case as well. The 231 won't live well with V8 power in stock condition.

[Eagle]

The 231 will live fine behind V8 power if you don't get crazy. It's a stronger t-case than the 242, and Jeep offered the 242 behind the 5.2L in the ZJs.

 

An AMC 304, 360 or 401 will bolt right up to an AW4. I am certain because a friend of mine just used an XJ AX-15 and mated it to a 390 for a street rod he's building. Same bellhousing to block pattern, same bellhousing depth. The only thing you'll have to do is adapt a 360 flexplate to accept the AW4 torque converter.

 

It'll be a tight fit, but the AMC engines (all those engines are the same basic block) will fit into the MJ engine room.

[512tr]

I’m new to the MJ and the AW4, and trying to educate myself and do as much research as possible, before I making any decision what to do. :shock: :oops:

 

So fare I have not seen the AW4 electronics as the biggest problem, but finding a V8 bolting up to the AW4. Square mean the AMC V8’s will do, have also read it somewhere, and now eagle confirms it.

 

So an old AMC is an option, but I would prefer an EFI engine before a carb’ed, if possible.

Have heard that the Mustang 5.0 V8 have a ECU that only controls the engine, and not all other functions on the car, so that engine will maybe be a suitable donor, but again I have the ‘bolt up to AW4 problem’ to solve.

 

Please correct me if I'm wrong, but isn’t the AW4 TCU (at least pre 91) a stand alone system, witch only get electrical signal from the ECU (ignition on), to power up the TCU ?

 

The TPS signals have to be dealt with, eider to hack in to the TPS on the new engine (if going EFI), or integrate a TPS on the carb, if going carbed.

The TPS is only a potentiometer with 5V input, and approx. 0.2-4.8V output, depending on the throttle position ?

[87manche]

I don't see why hacking a TPS into another system wouldn't work. It may even be easier to not use the TPS and built a custom pot for the throttle sensor. It might be easier to go with a linear sensor on one of the throttle bellcrank rods. I'm thinking of some stuff I've done for model airplanes here. I don't know what all signals the TCU takes to make it's calculations.

I would imagine that somewhere in there it must measure engine speed, and I imagine it get's that signal from the ECU. You might want to email Brett from AWShifting.

http://awshifting.com/

he may have some insight as to how it works. He's tinkered with it for a while is my understanding.

Edit:

I took my own advice and checked it out.

http://awshifting.com/1-0.htm

he does have a totally self contained shifting system deigned to put an AW4 behinf an older engine or a manual swap. Look like you ony use the shifter to select park forward or reverese, and a switch to control the tranny shifting. I would bet that if you got real creative you could use some relays and a simple binary counter to do an autostick, or even paddle shifters on the steering wheel. I'd love to help engineer that if you're up to it. My brother has an AW4 and was going to get Bretts shifter kit, so ifwe make it work for him I'll give you schematics.

[Cooter]

There's plenty of solutions for running an AW4 stand alone, so that shouldn't hold you up, however, you aren't going to bolt up a Big Three FI engine without major fab work.

 

As for the NP/NV231-

 

I'm eating up t-case chains in my '02 231 right now, and my 4.0 is stone stock.

 

A good HD SYE is $200+, while a D300 tops out at around $150 here.

 

All AMC straight 6s and V8s use a common bellhousing bolt pattern, so swaps are real easy between the two. Howevwer, the AMC V8 is far from a modern engine, and performance parts aren't cheap- FI injection for one is more than double what a good Ford, Chevy or MoPar FI engine complete with harness would cost you. (Don't even get me started on 401 prices)

 

 

Get a modern engine, use the trans that goes with it, and go with a good, gear drive t-case.