Jeep LS swap for the LJ

[zmotorsports]

Subscribed.

You had me at LS.

You'll love the drivability and manners both on and off-road.

I would check with the County because if they follow USEPA rules strictly they won't allow an aftermarket wiring harness as the harness is an integral part of the EPA certified package. Would be worth checking before assuming it will be ok.

You should be fine on the engine because like you stated, it has the be of the same engine family available in the year(s) of your vehicle which the engine is being transplanted into. It's a misconception that the engine itself has to be same or newer, just that engine has to be still available for the year or newer.

I too would keep the OE electric fan and running from the GM ECM preferably as it has all of the safeties and protection features already in place.

Looking forward to seeing this as I love LS's and love LJ's. Great combination.

Mike

 

[Black Label]

That looks great.
Did redline just rework your tach? What made you go that route vs the emulator? I've heard people have success with both.

What radiator/fan are you using?
What shifter are you using?

Thank you. It took me about three months to do.
I went with raceline because I didn't want the headache of that emulator. I've had a lot of previous experience with that thing and it wasn't good. Raceline put all autometer gauges is, OPS, ECT, and tach. I used the Jeep ecm for the speedo. Volts just picked up through the electrical system. It does have the cruise thing that Novak makes and it seems to work well. Jeeps had a little history with Novak. I built my own harness because I hated every stand alone harness, I've looked at and dealt with.

Its Novak's radiator, and a Spal fan I bought off eBay that was cheaper then Novaks price, I hate there radiator shroud and flap Idea so I mounted mine with some custom brackets.

I used the Novak T-case shifter, and a Lokar cable shifter for the 4L60E.

Hope that all helps.
If your worried about emissions, which it sounds like you are, the two biggest rules are, the Engine has to be newer the the vehicle its going in and, you'll need the EVAP sensor, Fuel Tank Pressure sensor also the rear cat 02s. Look for a shop that can do an emission test and know the laws, and maybe have done some conversions before so they know the rules and how to get around some of them.

 

[rholbrook]

Thank you. It took me about three months to do.
I went with raceline because I didn't want the headache of that emulator. I've had a lot of previous experience with that thing and it wasn't good. Raceline put all autometer gauges is, OPS, ECT, and tach. I used the Jeep ecm for the speedo. Volts just picked up through the electrical system. It does have the cruise thing that Novak makes and it seems to work well. Jeeps had a little history with Novak. I built my own harness because I hated every stand alone harness, I've looked at and dealt with.

Its Novak's radiator, and a Spal fan I bought off eBay that was cheaper then Novaks price, I hate there radiator shroud and flap Idea so I mounted mine with some custom brackets.

I used the Novak T-case shifter, and a Lokar cable shifter for the 4L60E.

Hope that all helps.
If your worried about emissions, which it sounds like you are, the two biggest rules are, the Engine has to be newer the the vehicle its going in and, you'll need the EVAP sensor, Fuel Tank Pressure sensor also the rear cat 02s. Look for a shop that can do an emission test and know the laws, and maybe have done some conversions before so they know the rules and how to get around some of them.

@Black Label Why are you going to be swapping to a 6.0?

 

[RockChucker]

@Black Label Why are you going to be swapping to a 6.0?

Probably the same reason I am. Should have done a 6.0 out of the gate. More woopow for basically the same money. I wish I would have done a 6.0 out of the gate.

 

[Greg]

Probably the same reason I am. Should have done a 6.0 out of the gate. More woopow for basically the same money. I wish I would have done a 6.0 out of the gate.

I felt like my 5.3 was lacking bottom end power, but I was also turning 40's. The 6.0 has a much more robust torque curve compared to the 5.3.

 

[Black Label]

@Black Label Why are you going to be swapping to a 6.0?

I have a built 6.0L with a comp cam and 799 heads, and a level 3 4L60E, laying around I was going to use on a J-truck project that fell through.

 

[RockChucker]

I felt like my 5.3 was lacking bottom end power, but I was also turning 40's. The 6.0 has a much more robust torque curve compared to the 5.3.

Yep. This. But even before I was on 40s I felt it wasn't what I wanted. With a 5.3, 4L80, 4.56s and 37s, I barely beat my buddy in a TJ with a 4.0L, AX15, 4.88s and 35s. Granted, there is several hundred pounds in weight difference, but I was surprised at how close the race was (this race was down on the sand highway near Sand Hollow). I had long decided to swap out the 5.3 for a 6.0 before this race due to the weaker bottom end torque of the 5.3. This was magnified further when I moved to 40s. 5.38s made things a little better, but it just doesn't have the bottom end torque to be able to climb some of the bigger dunes down at sand hollow. One of these days I need to get out to little sahara too. After the new motor

@glockman Is the 5.3 sufficient? Absolutely. And a 4L60 is significantly better than the 42rle (?) that comes behind the 4.0 in the LJ. But in my opinion, it is worth getting a 6.0 right out of the gate. The cost of the motor/trans is a relatively small percentage of buying all the other stuff needed to install the motor. IIRC, my 5.3 and 4L80 were less than 1/3 of the cost. Making mine emissions compliant was not a cheap venture. Even better if you get a hold of a Gen IV and a 6L80 behind it. Fuel economy won't be that much different than the 5.3 and the 6.0/6.2 will respond even better to a cam. You can probably find an LY6 (Gen IV iron block 6.0 with "L92/LS3" heads) for a similar price to an LQ4 or maybe even an LM7 (5.3). The 6l80's low first gear couples great with a standard NP241 and the money you can get out of your 241OR will probably about cover the difference of getting a 6L80. I've been through most of what you are wanting to do (with some minor differences) and I'm willing to help answer any questions you have.

One more thing, I know the Lokar shifter is easier to make work with the factory console, but after driving a Jeep with a Lokar shifter, I was soooo glad that I went with a Winters. Much more friendly to find reverse when you get into a sticky situation without the fear of going past and into park.

 

[Greg]

Yep. This. But even before I was on 40s I felt it wasn't what I wanted. With a 5.3, 4L80, 4.56s and 37s, I barely beat my buddy in a TJ with a 4.0L, AX15, 4.88s and 35s. Granted, there is several hundred pounds in weight difference, but I was surprised at how close the race was (this race was down on the sand highway near Sand Hollow). I had long decided to swap out the 5.3 for a 6.0 before this race due to the weaker bottom end torque of the 5.3. This was magnified further when I moved to 40s. 5.38s made things a little better, but it just doesn't have the bottom end torque to be able to climb some of the bigger dunes down at sand hollow. One of these days I need to get out to little sahara too. After the new motor

I wonder how much that had to do with the 5.3/4L80E combo.... I've always heard the TH400/4L80E took an additional 30 HP to spin over the TH350/700R4/4L60E. Crazy that you had a close race against a 4.0! With my TJ and the 5.3, I had a TH350, Atlas 4.3 and 5.38's with heavy 40" Creepy Crawlers. When I needed power to throttle up stuff, it just felt like it didn't do much under 3,000 RPM. The bottom end was just 'soft' and a 6.0 would have added that punch I was missing.

I do think for a street TJ/LJ on 37's the 5.3 & 4L60E will be plenty of power... and a cam upgrade will add that much more.

It would be fun to build up a 6.0 with a healthy cam, 1.7 rockers and a healthy tune, shooting for 500 HP.

 

[glockman]

So....I probably should have started this thread in the planning phase instead of the action phase. I picked up a 5.3 yesterday and started tearing it down for some checks and simple maint today.

I thought about the 6.0, gen 4 and even the 6L80. What it comes down to is simplicity and end use. This rig will never have anything bigger than 37's and may get JK Dana 44's at some point. In my mind, with light axles, a light trans, light 37's (KM3's) and no really heavy wheeling, this combo will work good.
The 6.0 doesn't really add any complexity or cost but I just couldn't find a decent deal on one. I must be looking in the wrong places. My intention going into this was to avoid the "might as well" syndrome. I don't know if that is good or bad. If I move forward with a 5.3, the only thing required to change to a 6.0 down the road is the bock and heads correct? Wiring, trans, exhaust, engine mounts all are interchangeable aren't they? I know do it right the first time, but I really thing the 5.3 with a cam will be enough for my use.


I'm still reading and learning. Any advice on cam's I'm totally clueless on what makes one cam better than another.

I'm also hung up on the VSS location. It makes sense to me that with a GM motor, trans and T-case the PCM should be able to figure it out with the VSS in the T-case tail (factory location) but I get differing info about the PCM not shifting correctly when you are in low. Looks like you need to ground a pin on the PCM to tell it you are in low. I don't quit know how the best do that or if I should buy the AA tone ring kit and put it in the trans tail shaft.

 

[crimsonride]

Great info, thank you. I may try doing my own harness. I'm an electronic tech by trade and lt1swap.com has pretty detailed instructions. If not, it's good to know speartech is the way to go. I kind of thought that, but I think I needed confirmation.
I'll take the Novak parts if you have them and the number for your tuner in Lehi. That would be way better than sending the pcm off.

You can do the harness on your own easily. I’m a complete idiot most days and I managed to pull it off. There’s a good link on how to do it and the diagrams. I’ll see if I can dig it up for you.

 

[Greg]

So....I probably should have started this thread in the planning phase instead of the action phase. I picked up a 5.3 yesterday and started tearing it down for some checks and simple maint today.

I thought about the 6.0, gen 4 and even the 6L80. What it comes down to is simplicity and end use. This rig will never have anything bigger than 37's and may get JK Dana 44's at some point. In my mind, with light axles, a light trans, light 37's (KM3's) and no really heavy wheeling, this combo will work good.
The 6.0 doesn't really add any complexity or cost but I just couldn't find a decent deal on one. I must be looking in the wrong places. My intention going into this was to avoid the "might as well" syndrome. I don't know if that is good or bad. If I move forward with a 5.3, the only thing required to change to a 6.0 down the road is the bock and heads correct? Wiring, trans, exhaust, engine mounts all are interchangeable aren't they? I know do it right the first time, but I really thing the 5.3 with a cam will be enough for my use.

IMO, I think a 5.3 with a cam and good tune will be enough for your needs. It's be a drastic improvement over the 4.0 and will put a grin on your face when you stand on the throttle and make your wheelin' trips more fun too. If displacement is a hangup, you could probably pick up a cheap LS1 rotating assembly and bore the 5.3 out to a 5.7... but is that worth the additional costs? Probably not.

Far as the 5.3 to 6.0 swap, as long as the engines are from the same Generation, the only change is the bore & stroke, far as I know. So yes, everything else would work.

It's hard (at least for me) not to fall into the 'might as well upgrade' way of thinking when building an engine. I did want my LS build to have new parts and tried to save money, only to end up having to spend more money and buy new... but it was a good thing. My engine is a aluminum block 5.3, I started with a new L33 block (pretty rare aluminum truck block) and added flat top pistons (factory in the L33) rather than dished like a iron block 5.3. I did upgrade the trunions in the rockers and bought a less expensive version that you DIY. I upgraded to a LS6 intake and combined with the flat top pistons and the cam I choose I should be in the 450 HP range, with the engine more focused on making power at higher RPM.

...I'm still reading and learning. Any advice on cam's I'm totally clueless on what makes one cam better than another.

It's pretty easy to go down a deep Rabbit Hole on cams... just keep in mind that a smaller displacement engine (5.3) will make it's power at a higher RPM than a bigger displacement engine (6.0) with the same cam when comparing specs. Look at the RPM operating range and try find something that makes good power down low, like 800 RPM to 5,500 RPM. Searching for 'RV' or 'truck' cam will give you plenty of options, you probably don't really want something with a lumpy idle or something that requires a higher stall convertor. It's quite possible to see gains of 50-60 HP from an aftermarket cam alone without loosing any low RPM torque.

If you're interested in another upgrade to go with the cam, (might as well... ) the TBSS aka Trail Blazer SS intake is a pretty good factory intake that still makes MORE torque than the older truck intakes, yet also flows comparably well to the car (LS1) intakes. They're also pretty affordable, IMO and I think would be worth the effort.

Here's a few cam options I found after a quick search;

Tick Performance towMAX Stage 1 Camshaft for 4.8L, 5.3L, LS2, LQ4 & LQ9 Engines

Late model performance specialists, offering parts at competitive prices, LS1 LS2 LS3 LS6 LS7 LS9 LSX

www.tickperformance.com

TSP Stage 2 Low Lift Truck Camshaft

TSP Stage 2 Low Lift Cathedral Camshaft

www.texas-speed.com

GPI - Low Lift LS Camshaft (4.8L / 5.3L / 6.0L / 6.2L) - Gwatney Performance

Our camshafts are our most popular product, and for good reason - they are pound for pound - the best on the market. These low lift performance truck cams are specifically designed and engineered to take your Silverado, Sierra, Tahoe, Yukon, Avalanche, Suburban, hot rod, or street rod to the...

gwatneyperformance.com

 

[Greg]

Just for comparison, this is the cam I went with for my 5.3 build for the El Camino. - https://www.summitracing.com/parts/cca-54-414-11/

You can see that the RPM range is 1,300-6,300 RPM and the description on the Comp Cams website reads "Great mid-range with superior top end power. Needs computer modifications." IMO this is a great cam for a street car, should make for good driveability with a strong mid-range RPM and pull hard on the top end, when needed. I did upgrade to a higher RPM than stock stall convertor, to help get it into it's power range. And the computer tuning needs adjustments to work with this cam.

While this is a decent street car cam, IMO it's not deal for a 5.3 in a Jeep. You want to make good power off idle and lower in the RPM range.

 

[Gravy]

David Frieburger has an interesting conversation about cams in LS motors it's pertainent because he was the chief editor of "4 Wheel and Off-road". Look for the LS episodes on "Engine Masters."

 

[Greg]

David Frieburger has an interesting conversation about cams in LS motors it's pertainent because he was the chief editor of "4 Wheel and Off-road". Look for the LS episodes on "Engine Masters."

Season 2, Episode 19, Camshaft Specs Explained?

It's not a LS specific episode, but I don't recall anything that's only about cams in LS engines.

 

[Gravy]

I'll look up which one I'm thinking of. But it's the one he makes mention of Isky cams and RV cams.

 

[glockman]

IMO, I think a 5.3 with a cam and good tune will be enough for your needs. It's be a drastic improvement over the 4.0 and will put a grin on your face when you stand on the throttle and make your wheelin' trips more fun too. If displacement is a hangup, you could probably pick up a cheap LS1 rotating assembly and bore the 5.3 out to a 5.7... but is that worth the additional costs? Probably not.

Far as the 5.3 to 6.0 swap, as long as the engines are from the same Generation, the only change is the bore & stroke, far as I know. So yes, everything else would work.

It's hard (at least for me) not to fall into the 'might as well upgrade' way of thinking when building an engine. I did want my LS build to have new parts and tried to save money, only to end up having to spend more money and buy new... but it was a good thing. My engine is a aluminum block 5.3, I started with a new L33 block (pretty rare aluminum truck block) and added flat top pistons (factory in the L33) rather than dished like a iron block 5.3. I did upgrade the trunions in the rockers and bought a less expensive version that you DIY. I upgraded to a LS6 intake and combined with the flat top pistons and the cam I choose I should be in the 450 HP range, with the engine more focused on making power at higher RPM.






It's pretty easy to go down a deep Rabbit Hole on cams... just keep in mind that a smaller displacement engine (5.3) will make it's power at a higher RPM than a bigger displacement engine (6.0) with the same cam when comparing specs. Look at the RPM operating range and try find something that makes good power down low, like 800 RPM to 5,500 RPM. Searching for 'RV' or 'truck' cam will give you plenty of options, you probably don't really want something with a lumpy idle or something that requires a higher stall convertor. It's quite possible to see gains of 50-60 HP from an aftermarket cam alone without loosing any low RPM torque.

If you're interested in another upgrade to go with the cam, (might as well... ) the TBSS aka Trail Blazer SS intake is a pretty good factory intake that still makes MORE torque than the older truck intakes, yet also flows comparably well to the car (LS1) intakes. They're also pretty affordable, IMO and I think would be worth the effort.

Here's a few cam options I found after a quick search;

Tick Performance towMAX Stage 1 Camshaft for 4.8L, 5.3L, LS2, LQ4 & LQ9 Engines

Late model performance specialists, offering parts at competitive prices, LS1 LS2 LS3 LS6 LS7 LS9 LSX

www.tickperformance.com

TSP Stage 2 Low Lift Truck Camshaft

TSP Stage 2 Low Lift Cathedral Camshaft

www.texas-speed.com

GPI - Low Lift LS Camshaft (4.8L / 5.3L / 6.0L / 6.2L) - Gwatney Performance

Our camshafts are our most popular product, and for good reason - they are pound for pound - the best on the market. These low lift performance truck cams are specifically designed and engineered to take your Silverado, Sierra, Tahoe, Yukon, Avalanche, Suburban, hot rod, or street rod to the...

gwatneyperformance.com

I feel you on the might as well Greg. You read my 6.0 build. I went all out on every single upgrade part. It cost me a pretty penny.

I've been looking at cam dyno sheets for the past 24 hrs. Most cam's seem to run $300 to $500. I have not seen a single dyno sheet that shows more than a 10HP gain below 3500 RPM's. When I look at how much time I'll spend in the 3500+ RPM range, it's probaly 5% or less. If I replace the cam, I'll most likely have to do valve springs and "might as well" replace the water pump, oil pump, and what do the cam bearings look like? I don't think it's worth the $800+ for this build. So I'm sticking with the stock cam. Maybe Likely I will wish I had upgraded, time will tell.

My goal for this project is to keep the cost down while not making big cuts in quality. I'm looking at it as a phase one build.
The engine was running when I got it so I am going to bet on it continuing that trend. Livin on the edge I know but if it blows up, there is a sea of LM7's for under a grand. LS swap isn't meant to be a single iteration is it?

Progress so far.
I stripped it down to a short block this week to check some things.
I have 3 exhaust studs broken off in the heads. I'll get those pulled and clean the heads up to remove the carbon. I already cleaned the piston tops and checked the cylinder walls for issues. They look good and so did the spark plugs.
I'll clean the block up and shoot some paint on it in the next week, then swap the oil pan for an F-body pan and pickup tube.
Next will be new head gaskets, reuse the torque to yield head bolts, this link shows they are fine http://sloppymechanics.com/stud-and-head-bolt-test/ ) and button it back up.
I have a line on a used superior radiator with trans cooler and some LS2 exhaust manifolds that have O2 sensors in the collectors.

I have decided to try and mod my own harness. Whats the worst that can happen, I have to buy a new one

 

[astjp2]

Well I am interested in any takeoff parts from the 4.0, just so I can get my LJ roadworthy without the tire shake and driveshaft vibes. I have a set of stroker rods and a crank in the garage...

 

[glockman]

This is a fantastic series of videos from Brendan at LT1SWAP on how to modify your own harness. This along with the printouts on his site should make it fairly easy.

 

[Hickey]

Forget about the horsepower numbers below 3500. Focus on the torque.

 

[Greg]

I feel you on the might as well Greg. You read my 6.0 build. I went all out on every single upgrade part. It cost me a pretty penny.

I've been looking at cam dyno sheets for the past 24 hrs. Most cam's seem to run $300 to $500. I have not seen a single dyno sheet that shows more than a 10HP gain below 3500 RPM's. When I look at how much time I'll spend in the 3500+ RPM range, it's probaly 5% or less. If I replace the cam, I'll most likely have to do valve springs and "might as well" replace the water pump, oil pump, and what do the cam bearings look like? I don't think it's worth the $800+ for this build. So I'm sticking with the stock cam. Maybe Likely I will wish I had upgraded, time will tell.

My goal for this project is to keep the cost down while not making big cuts in quality. I'm looking at it as a phase one build.
The engine was running when I got it so I am going to bet on it continuing that trend. Livin on the edge I know but if it blows up, there is a sea of LM7's for under a grand. LS swap isn't meant to be a single iteration is it?

What are the torque gains of those cams though? That's where you'll see the value, especially on the street and offroad. HP gains are going to be at higher RPM's, especially with the 5.3 that loves higher RPM's by it's nature.

And yes, a bigger cam requires heavier springs... you'll probably want to run new lifters, too. It's not cheap, but it'll be worth it IMO.

I totally understand the budget, I went thru the same thinking with my LM7 TJ... considered swapping in a cam, but didn't need/want to tear into perfectly fine running engine, so I didn't. I was fairly disappointed in the power delivery after it was all done and really wish I'd have done a cam at the least. If you're tearing it down, it's easy to upgrade while it's apart.

The thing with LS engines is that one upgrade builds upon another... TBSS intake and aftermarket cam together will show very apparent gains, IMO.

Anyway, I'll leave it alone from here... and let you get back to building your LS LJ.

Progress so far.
I stripped it down to a short block this week to check some things.
I have 3 exhaust studs broken off in the heads. I'll get those pulled and clean the heads up to remove the carbon. I already cleaned the piston tops and checked the cylinder walls for issues. They look good and so did the spark plugs.
I'll clean the block up and shoot some paint on it in the next week, then swap the oil pan for an F-body pan and pickup tube.
Next will be new head gaskets, reuse the torque to yield head bolts, this link shows they are fine http://sloppymechanics.com/stud-and-head-bolt-test/ ) and button it back up.
I have a line on a used superior radiator with trans cooler and some LS2 exhaust manifolds that have O2 sensors in the collectors.

I have decided to try and mod my own harness. Whats the worst that can happen, I have to buy a new one

I'm not a fan of TTY head bolts and would be very hesitant to reuse them. New TTY head bolts run around $25 for the set.... personally, I wouldn't risk a blown head gasket at $25. I had a set of new TTY head bolts and decided to ditch them for ARP bolts, just not a fan of the idea of stretching a bolt to get the proper amount of clamping force.