Jeep 4.0 or more accurately a 4.6 STROKED 4.0 with Jeep injection hardware???

**doc65** · 03-23-2012

I have an early stroker built from an Accurate Power kit that I bought back around 2000 I installed it in a Jeep ZJ. A little too much cam, but runs great and lots of power, too much for the tired old 42RE that it's hooked to, I'm in the final stages of a build on a 96 Block for my DD 98 Ex-USFS Cherokee, same as yours, the engine still runs great, doesn't use oil, very minimal leakage even(it weeps just a tad around the front breather elbow, but those always break when you try to pull them to replace the grommet, and they are a dealer only item which has to be ordered, all of about $4 though, and maybe a little around the main seals, but at 14 years & 200k+ that's nothing) I LOVE that jeep it's got character. The one I'm putting together now for the DD Jeep is a Short Rod(258 rods), with cast pistons for tighter OEM style clearances, and the heavy 12 counterweight crank. I need to mock up the install today or tomorrow to verify how much to deck the block, that's the last bit of machining before final assembly. The OTHER one I'm in acquisition stages for the Red SX/4 is going to get the lighter(46lb vs 66lb) 4 cwt crank, longer 4.0 rods, and Keith Black 944 forged pistons, they make a little more noise when cold, but that can be minimized by careful honing & piston to wall clearance tolerances...

**JeepsAndGuns** · 03-24-2012

Yea I have the lighter crank. Cant remember what year the block is, but I know its the better one and has the main cap brace.
Have you seen those aluminum cyl heads from hesco? Those are truely drool worthy

I have a thread on here somewhere where we have talked some about using the northstar DIS with the 7427. So I know about the coil themselfs and wasted spark. But my AMC 401 has the same firing order as the chebby small blocks, so I didnt think anything of it. I just wasnt sure if the notches on the 3.1 crank had anything to do specificly with the firing order and the timing of the coil firings. Just wasnt sure if dis was compatable with engines that had a diffrent firing order than the engine they came off of. I guess the biggest and hardest issue is gonna be actually machineing the notches in the HB where they need to be. How would one figure out where you need to make the first notch? I suppose you would have to start with the crank sensor, find where your going to put it and get it mounted and finished, then bring engine to TDC of #1 compression, then mark the spot on trigger wheel (or whatever your using, HB, etc) where the center of the sensor is?
If one was to just skip the distributor and go straight to dis, would $A1 be the best mask to run, since it and the bins are 6 cyl and dis stock? What ecm do you plan on running on yours?

I think the northstar DIS is my next step on my 401 once I get the MPFI installed, running, and tuned. So fiddleing with my 4.0 will probably come after that.

**Six_Shooter** · 03-24-2012

The timing notches have nothing to do with firing order, they just provide the (essentially on/off) signal to the ICM as they pass the sensor.

I'm using 60 degree V6 DIS, that has a firing order of 123456, on my Nissan I6, that has a firing order of 153624. ;)
The coils don't care what cylinders they fire, that is where placement of the wires themselves will have it work right, or not. ;)

I don't care who uses the outside of the harmonic balancer for a trigger wheel, it's just overall a bad idea.

As far as setting up the trigger wheel, I used both information I was able to get from the original engine and crank trigger itself, through measurements and observation, and when I adapted it to my I6, information I found in the MegaManual, about the GM DIS set-up, among other sources.

**JeepsAndGuns** · 03-25-2012

I was checking the oil in my YJ this morning and while under the hood, I took a little closer look down there. I dont know about putting the 4.0 in other engines. But on my YJ, there is very little room from the front of the balancer and the fan blades. If you were to put a trigger wheel on the front of it, it looks like it might run dangerously close to the fan. There is also little room for a electric fan. I will need to take my tape measure to it all.

Heres the hesco one:
http://www.hescosc.com/shop.asp?acti...098&catId=7902

That also give you a idea of what the 4.0 balancer looks like. If you were to not use the balancer itself, you would need to make the wheel, and then also some sleeves or spacers to mount the wheel using the 3 bolt holes used for pulling it off. You would probably have to put it in a lathe and true up that surface too. And thats all if you even have the room. My YJ would be uber close, but I cant speak for the OP's eagle.

I tried finding this gm straight six distributor with google, seems to be as rare as hens teeth. So if DIS is gonna cost too much, then modding a older 258 distributor would probably be the best bet to get a system up and running quickly and on a tight budget.

**Six_Shooter** · 03-25-2012

Another option for the DIS trigger is to weld a wheel to the crank pulley. Some people on TGO have done this. They made a ring that slides over the back of the crank pulley, since in those applications there was space between the pulley grooves and the pulley mounting surface, then welded that ring to the pulley.

The only thing I don't like about that is, if you want to change to a different pulley, it's makes that more difficult, plus you're locked in on actual location of the trigger wheel, so it has to be right before welding.

**doc65** · 03-25-2012

Jeeps. I don't know about a YJ as I don't own one of those, but I just looked down in an XJ and it would be clse, but it would go with like 3/8" clearance, but then the XJ is already injected and runs pretty well with OEM injection, the stroker guys just adjust thier mixture by modifying the voltage applied to the TPS. But on my Eagle project I got LOADS of room, and I intend to loose the engine driven fan in favor of a Taurus fan anyway, that's what I'm running in the ZJ and it's great, and reasonably easy to find for CHEAP.

Side note, I just found out that my late model 258 crank deal fell thru, bummed!!! :(

**JeepsAndGuns** · 03-25-2012

Yea my YJ runs perfectly fine on its stock system too. However I do plan on building a stroker, and I just feel those "tricks" these people do fiddling with the sensors is not the best solutioin. Cheaper yes, but I just think a stroker is just not gonna reach its full potiential like it could with a fully tuneable ecm. Hence my desire to swap in a tuneable ecm. Its not a desicison I took lightly. I really wanted to be able to tune the stock ecm, but there is just so very little support for it, and no one seems to care about hacking it and making tunerpro definations for it.

Anyone know what VSS signal the 7727 needs? I havent found it yet in my shop manual, but I read online the YJ has a 8 pulse vss. I however do not know what type of signal it is (square or sine) But the stock speedo is electronic and needs it to work. Looking at the wiring, the signal wire from it simply comes to a "T" and one goes to the spedo, the other to the pcm.

**doc65** · 03-25-2012

I fully agree that a programable ECU is the ideal, just not quite sure which direction to go with that one yet, ideally a unit that is safe underhood, programmable, supports SPFI & DIS...

**Six_Shooter** · 03-25-2012

The 7730/7727/7749 can use the a 4 PPR signal, this is usually a magnetic trigger, IIRC it's a "hall effect." There's some speculation that the Jeep VSS can be used with the GM ECM, just some adjustment to the VSS dividers would be needed.

doc65: SPFI?

**RobertISaar** · 03-25-2012

sequential port fuel injection....

eh, i've never needed it. maybe if i had to pass emissions testing, but otherwise, it never helped idle quality or fuel economy as some imply. in theory, it could respond to transient fueling better, but that's only if you have it calibrated correctly, otherwise, you'd never know the difference.

**EagleMark** · 03-25-2012

Originally Posted by Six_Shooter

The 7730/7727/7749 can use the a 4 PPR signal, this is usually a magnetic trigger, IIRC it's a "hall effect." There's some speculation that the Jeep VSS can be used with the GM ECM, just some adjustment to the VSS dividers would be needed.

doc65: SPFI?

I think the Jeep VSS is what I have here on the bench. It is 8 PPM and suposedly hall effect so I don't know if it is worth trying?

**RobertISaar** · 03-25-2012

nothing wrong with 8 pulses per rev, better than 4 actually...

in a native application, a 90 grand prix for instance, a 7727 reads somewhere along the lines of 40 pulses per revolution... works fine up to at least 100+ MPH too.

**EagleMark** · 03-25-2012

What about the hall effect VS sine wave or square signal? This was tried by someone knowledgable but ended up have the correct one and gave up...

How would one measue this properly?