Engine build

[Ironmerganser]

Ok...so just a random thought, but can I use a stock AMC 258 i6 / 4.2l lower (block, crank, pistons, etc) with a new Clearwater 4.0 head and then use a stock 4.0 intake, fuel injection and wire harness from a salvage yard?

I know I will need a few other things (fuel pump, crank sensor, etc, etc) but wondering if that would work? I want to keep the low end torque of the AMC 258 i6 / 4.2l but want to ditch the carb set up for fuel injection. I don't want to spend the $1600 to $2000 though on an MPI or Howell system.....thinking a nice cleaned up intake, wire harness and fuel injection set up off a cherokee or wrangler would be much cheaper from the salvage yard.

Thoughts?

 

[CJim7]

Not a random thought at all...it's been done several times
Your list is pretty complete....remember o2 sensors.

 

[Cheepjeep85]

Yeah its possible, my only thought though is why not just find a complete 4.0 from the vehicles you are talking about instead of trying to adapt the 4.0 stuff onto the AMC 258 i6 / 4.2l , the motors are very similar with about the same power output. Unless you already have a new/rebuilt AMC 258 i6 / 4.2l block, and rotating assembly.

Droooiiddd 2

 

[Ironmerganser]

Yeah its possible, my only thought though is why not just find a complete 4.0 from the vehicles you are talking about instead of trying to adapt the 4.0 stuff onto the AMC 258 i6 / 4.2l , the motors are very similar with about the same power output. Unless you already have a new/rebuilt AMC 258 i6 / 4.2l block, and rotating assembly. Droooiiddd 2

That is what I am going to do. My AMC 258 i6 / 4.2l has who knows how many miles on it. Any 4.0 I find has 100K+ miles on it. I am going to rebuild my block and rotating assembly and add the 4.0 head and fuel injection.

Its a done deal. Going to start yanking it out this weekend and it is off to the machine shop!!!

 

[Cheepjeep85]

Go for it man it'll work, just seems like it would be less trouble to use the 4.0 block.

Droooiiddd 2

 

[cummins2007]

Since you are rebuilding the motor and talking about mixing parts i thought you would if nothing else find this intresting Stroker
Also holley makes a TBI (projection) for just under a grand but i have never used it and know nothing about it but it is considerably cheaper than howell

 

[IOPort51]

I like the stroker idea.

 

[Ironmerganser]

Oh yeah.....a stroker could definitly be in my future. I will be tearing it out and inspecting the motor I have over the next week to see if it is worth using. The block should be good so I am sure I can at least reuse that.

 

[Ironmerganser]

OK...found a 1994 Cherokee with 164K on it. Runns good and only asking $1000. Going to haggle a little, but if I can get it for $1000 or less, I think I am going to jump on it as it would give me everything I need for the fuel injection swap.

Now...i am just trying to decide if I just want to go with my AMC 258 i6 / 4.2l lower and all the 4.0 upper or if I want to build a stroker.........we'll see.

Also......this cherokee has a 5 speed manual. Can I use that mated to my original AMC 258 i6 / 4.2l and get an adapter to mate it to my original xfer case?

 

[Cheepjeep85]

Yes it should be an ax15 and all you should need is a clocking ring to bolt up a Dana 300 , the bellhousing pattern is the same.

Droooiiddd 2

 

[CJim7]

Using the AMC 258 i6 / 4.2l bottom end essentially "gives" you a stroker. The longer stroke of the AMC 258 i6 / 4.2l combined with the better head of the 4.0 is a potent combination.

Guys will take the crank and connecting rods from a AMC 258 i6 / 4.2l and install them in the 4.0 for the stroker effect. Other then the slightly larger bore of the 4.0, keeping the AMC 258 i6 / 4.2l gets you the same results.

I ran a AMC 258 i6 / 4.2l /4.0 hybrid in my CJ and dynoed at just slightly over 300 hp by the time I was done "modifying"

 

[Ironmerganser]

Using the AMC 258 i6 / 4.2l bottom end essentially "gives" you a stroker. The longer stroke of the AMC 258 i6 / 4.2l combined with the better head of the 4.0 is a potent combination.

Guys will take the crank and connecting rods from a AMC 258 i6 / 4.2l and install them in the 4.0 for the stroker effect. Other then the slightly larger bore of the 4.0, keeping the AMC 258 i6 / 4.2l gets you the same results.

I ran a AMC 258 i6 / 4.2l /4.0 hybrid in my CJ and dynoed at just slightly over 300 hp by the time I was done "modifying"

My thoughts exactly. Not searching for 300 ponies but that sounds like a hoot!!!

 

[CJim7]

My thoughts exactly. Not searching for 300 ponies but that sounds like a hoot!!!

I ran a 500cfm Edelbrock 4bbl on this thing, desmogged it, high compression pistons, Comp cam, TFI ignition, and a Clifford intake. It was a screamer....

 

[Ironmerganser]

I ran a 500cfm Edelbrock 4bbl on this thing, desmogged it, high compression pistons, Comp cam, TFI ignition, and a Clifford intake. It was a screamer....

I bet it was!!!!