XJ LM7 5.3 swap

cleenrob said:

You best off getting the drive train and place, and measuring

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Yes, very true, just trying to get a bit of head start on my expectations.

cleenrob said:

You best off getting the drive train and place, and measuring

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Yup.
Easiest way to do this is with an empty trans and block. Mount them in place, bolt up the transfer case, and start measuring.

It is by no means "light"... but it is "lightER".

Although, in all honesty, I'd probably still put heads/mainfolds.intake loosely in place on the block to make sure that motor is EXACTLY where you want it when you do. It would suck to be off on the driveshaft length by 1" and have to drop another $400 on a custom shaft.

Sucks, but there it is. I think there are plastic "dummy" engines and transmissions you can use as well. They're going to cost a couple hundred bucks a piece, though. That's money that will pay for the driveshaft and beer if you're patient. :rof:

98lsxj said:

Looking good! Do you have your drivelines on yet? I am starting an ls swap next week and am trying to see what areas I haven't figured out yet and the driveline length is one of them.

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like cleenrob wrote, first place the engine with trans and TC and than measure. I had to lengthen the rear driveshaft about 30 mm (1,18") and the front shorten because the 4L60 (21.9" + adapter) is shorter than AW4 (25-3/8"). But it also depends where you place the engine mounts, etc..

wiring clean up almost done


all electrical circuits working: TCC, MIL, VSS from NP231 to GM PCM, and another VSS to jeep gauge, fuel pump relay, starter relay, reverse lamp, P/N start switch, fan control with PWM modulator+GM PCM+manual switch, oil temp sensor from engine and trans to external gauge, oil pressure to jeep gauge, fuel pressure to external gauge, AEM wideband to external gauge + HPtuners, ECT to jeep gauge, 4LOW manual switch to jeep gauge and GM PCM for 4l60 operation.
tach is external gauge now, for jeep gauge I have to buy novak module.

Nice job, it looks like it belongs in there.

Are we certain that tiny little radiator will cool this engine?

burntkat said:

Are we certain that tiny little radiator will cool this engine?

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it´s not so tiny, it´s griffin 22" x 19" x 3" thick, that should work
racer32 uses the same and reports no overheating problems
we will see

Are you going to use an engine-driven fan, or electric?

burntkat said:

Are you going to use an engine-driven fan, or electric?

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Electric fan with PWM modulator so I can ran it with lower RPM all the time like mechanical fan + GM PCM control + manual switch when needed fan always ON

I run the same size rad with no issue

It gets to about 206 sitting in traffic but that's it

Does it extend below the normal radiator's lower edge? got any pics of it installed from the front without the grill, for example?

I am curious if it does extend lower, how is it protected, and why don't more people use this sort of affair to cool a 4.0?

I may have said this before, so if I did, I apologize- and this is surely not to besmirch your work-

I think I'd add a lot more boxing to those motor mounts.

Also, the Jeep CTS adapter is awfully long, with no apparent way to vent.

I say this only because when I did the 350 swap into my S10, I ran a similar adaptation for a BMW dual-range temp sensor (so I could use two-speed fans), only to find out that I developed an air bubble below the sensor and so it didn't work- the air pocket insulated/isolated the CTS from the water, so it never tripped my fans. The solution in that case wound up being removing the adapter, tapping a bushing to fit the stock CTS location for the metric threads needed for the BMW CTS, and moving the stock CTS to the head. This removed all the air pockets in vicinity of the factory and BMW CTS, and it's worked a treat since.

That one took me a little while to suss out. I'm just trying to save you some possible headaches trying to reinvent the wheel.

burntkat said:

Also, the Jeep CTS adapter is awfully long, with no apparent way to vent.

I say this only because when I did the 350 swap into my S10, I ran a similar adaptation for a BMW dual-range temp sensor (so I could use two-speed fans), only to find out that I developed an air bubble below the sensor and so it didn't work- the air pocket insulated/isolated the CTS from the water, so it never tripped my fans. The solution in that case wound up being removing the adapter, tapping a bushing to fit the stock CTS location for the metric threads needed for the BMW CTS, and moving the stock CTS to the head. This removed all the air pockets in vicinity of the factory and BMW CTS, and it's worked a treat since.

That one took me a little while to suss out. I'm just trying to save you some possible headaches trying to reinvent the wheel.

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that´s a good point. I also noticed the jeep CTS showed a little bit lower temperature than GM CTS but for me the Jeep CTS is only for gauge information purposes. Yesterday I checked the GM fan control and all ran good.

I adjusted the Fan ON temp to 95° C (203°F) and Fan OFF temp to 90°C (194°F) and the coolant temperature stayed within this range without problems. But this was tested only at idling.

What do you thing guys, what is the best operating temperature for this engine?
I looked at other calibrations like corvette, camaro, etc and every model has another fan control temperatures

burntkat said:

Does it extend below the normal radiator's lower edge? got any pics of it installed from the front without the grill, for example?

I am curious if it does extend lower, how is it protected, and why don't more people use this sort of affair to cool a 4.0?

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it extends not only stock radiator edge, but it extends the lower front crossmember, I will post a pic later

I run my LS swap at ~197 -to- 201. Runs pretty good at that temp. My second fan is programed the same as yours (on at 204 and off at 194). My third fan only comes on with a/c and the first fan comes on at 165...so its always on. I also run a manual switch...just in case. The stock truck runs around 210 I think and the Corvette at 220. Mine only gets up to 210 when pulling a trailer uphill at 70mph.

clydefrog said:

I run my LS swap at ~197 -to- 201. Runs pretty good at that temp. My second fan is programed the same as yours (on at 204 and off at 194). My third fan only comes on with a/c and the first fan comes on at 165...so its always on. I also run a manual switch...just in case. The stock truck runs around 210 I think and the Corvette at 220. Mine only gets up to 210 when pulling a trailer uphill at 70mph.

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thanks clydefrog. I have only one bigger fan, so I will run it always on with the PWM regulator at low rpm and if the temperature rises above 203°F the PCM with turn on to the max rpm

small update:
I have few hudreds of miles on it and have to say this LS swap was the best mod I've ever done to my XJ. The ride is much much better with the V8. It's not about the peak power but the torque delivery in low rpm from this truck engine (LM7) is beautiful.

All gauges except tach are working. I installed small external tach but in the future I would like to have some modul to work with the stock tach. (novak or a home made modul).


I began to mess with HP tuners and the results are noticable:


First I modified the VE table. I went from this:


to this:

and now the fuel trims are about 0 all the time. I also changed the torque management, MAF table, some shift points, etc.. There is a lot to do with this software.

Yesterday I made some underbody protection. I feel the previous color of my rear dif boring so I decided to go the "rat style" way. I grinded the color away and applied few layers of clear paint.


I also sprayed the fender flares with the underbody coating to get similar texture like the raptor bedliner on my body:


Now the XJ looks like this:


Other things:

Transmission - the 4l60e is whining during the ride so I thing the next big repair will be the overhauling of the trans :looney:

Fuel pump - the stock 2001 jeep fuel pump has enough pressure even at WOT (65 psi).

Exhaust - that was a never ending story. First I bought the magnaflow XL chamber muffler, but was too loud for DD, than I bought the Flowmaster 50 delta series - it was a little bit quiter but even thought too loud. The third muffler was the same I used with 4.0 engine but with bigger outlets - dynomax turbomuffler. It was the cheapest but the best sound for me, decent but noticable V8 sound.

If somebody is thinking about LS swap, just do it!

Nice!

Isn't the torque awesome! Looks clean!

Dont know if your intake is still not heat protected (going off the pic above) but on mine I hooked it up to a snorkel for true cold air. If you watch the fuel trims and the intake temp you will start to see it lean out at 150-160 degrees (intake temp F). The biggest power gain I saw on my LM7 was when I made the intake a true cold air intake, HUGE difference in power.

clydefrog said:

Nice!

Isn't the torque awesome! Looks clean!

Dont know if your intake is still not heat protected (going off the pic above) but on mine I hooked it up to a snorkel for true cold air. If you watch the fuel trims and the intake temp you will start to see it lean out at 150-160 degrees (intake temp F). The biggest power gain I saw on my LM7 was when I made the intake a true cold air intake, HUGE difference in power.

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my filter is just behind the grill besides the rad, so my IAT is the same like the temp outside