Jeep LS swap for the LJ

[LJTim]

I'm happy you're doing this, and will be stalking your progress for the duration. My 4.0 in the LJ has over 230k miles. Runs fine for now, but I am seeing signs of the trans age. I would love to do a swap that took care of both time bombs. I actually prefer mine under powered, so I'm not dying for a V8, but with your hopeful $$ you posted at the start of this, why not? Problem is, I am not an engine guy. You have already done things I am unfamiliar with ["clean the heads up to remove the carbon. I already cleaned the piston tops and checked the cylinder walls for issues" already Spanish to me]. I understand suspension and steering. I'll cut up a body and apparently I chop frames now. But motors and everything connected to them, I just don't get. Especially when it comes to the harness. So I think my cost of labor would drastically change my project over yours. But I'm interested in seeing how it goes. If it goes smoothly for you, maybe I can handle this with a few consulting visits from friends that know more than me.

After reading the posts above, I think mine might benefit from the 6.0 over the 5.3, considering I run 40's. However, I have 5.38's and don't plan on changing that, so I don't know if that's a factor.

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.

Are you saying this is for sale? I'm interested. Not prepared, but I am interested.

 

[Black Label]

No its not for sale. It is going in my LJ as soon as I have time, swapping out the 5.3L

 

[glockman]

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

Please don't. I'm stubborn and need to be beaten over the head with some things

I started this thread to both detail the decisions and process for people like me who can probably do this easily with some small mental blocks clearly explained and to get advice from others with more experience so that I can ignore them to my personal peril.

I'm happy you're doing this, and will be stalking your progress for the duration.

I love your jeep and have oogled it plenty. Glad I can return the favor. Engines really aren't hard. The work you've done shows you are plenty capable. I could have just taken this running engine and dropped it in but engine on stand+spare time+ADD= torn down LS.

 

[glockman]

Like I said, I'm not very knowledgeable on building high output engines. Looking at this dyno sheet which is the TSP stage 2 Greg linked, it looks like torque increases from 330 ft lb at 2700 RPM to 380 right around 3400 RPM. Is that a noticeable amount? I don't really know. My only reference is crap like advertised gains from aftermarket bolt on's which are probably never actually increasing output by the number they claim.

The engine they are running it in also has long tube headers which, as I understand would help increase the gains of the cam right? I am pretty sure long tube headers won't fit in a TJ but I haven't really looked into it much.

 

[DAA]

Under 400 total, 50 ft/lbs will be noticeable for sure. But not happening until 3400 rpm, is not super useful in an LJ. In my opinion. If that was 50 ft/lbs right off idle, it would be a much more noticeable and appreciated gain. Again, IMO. Where it's at 3400, it will be nice for coming up to speed on freeway onramps and such, which is cool and all, but I'd much rather have torque gains lower in the curve, for the application, myself.

- DAA

 

[DAA]

I would add, I guess, that I know nothing of what is actually available in cams for an LS. But I wouldn't be willing to sacrifice much if any smooth idle and off idle torque for higher rpm gains, myself. That's the one thing the 4.0 is good at and it would kind of suck to lose the only redeeming feature it has .

- DAA

 

[Greg]

Like I said, I'm not very knowledgeable on building high output engines. Looking at this dyno sheet which is the TSP stage 2 Greg linked, it looks like torque increases from 330 ft lb at 2700 RPM to 380 right around 3400 RPM. Is that a noticeable amount? I don't really know. My only reference is crap like advertised gains from aftermarket bolt on's which are probably never actually increasing output by the number they claim.

The engine they are running it in also has long tube headers which, as I understand would help increase the gains of the cam right? I am pretty sure long tube headers won't fit in a TJ but I haven't really looked into it much.

Those numbers are pretty significant, I think you'll be seeing plenty of driving at those RPM (2500-4000) and will appreciate the changes compared to a stock 5.3 LM7. Long tube headers do make a difference, but yeah, I don't know of any options that will fit a Jeep. The factory manifolds are actually very well built and free flowing, lots of guys run them and they don't hold back power like manifolds of old. I did run shorty headers on my TJ and they sounded pretty good.

If you want lots of torque under 3000 RPM, better sell the 5.3 and get a 6.0!

 

[frieed]

low end torque is why I'd love to see the 3.5 Ecoboost in a jeep...

 

[rholbrook]

low end torque is why I'd love to see the 3.5 Ecoboost in a jeep...

View attachment 124183

I agree with this but that EB fills out the engine compartment with those turbos. Ford supposedly has come out with a turn key solution but I am really excited to see how Chads LJ runs with the 5.3

 

[rholbrook]

There was a guy that worked for Novak several years ago that put a 5.3 in his LJ and I drove it. The drivers side front wheel got awful light on hard take offs. I think the the 5.3 is going to make this LJ really scoot along just fine. Chad, can you hurry it along please?

 

[RockChucker]

A 6.0 is essentially a bored out 5.3. They share the same 3.622” stroke length. A 6.0 is a 4” bore. Can’t remember what a 5.3 is.

@glockman sounds like you have a solid plan. I said a prayer and threw my 5.3 in. Never looked at anything but the bottom end. And that was because I swapped out the truck oil pan for the f body pan. I would recommend adding in some baffling on the pan to keep oil close to the pickup. Before baffling I would always lose oil pressure while climbing even moderately steep hills. I have a picture somewhere what I did. I’ll try and find it.

@Greg ill let you know how my 6.0 turns out. I got it back from the machine shop earlier this week. Time to start assembling. Had to bore it .030 over. I have a pretty mild cam with .558” lift on the intake, .563” on the exhaust and a wide 115° lobe separation angle. Compression ratio will be 10.4:1 with L92 heads, gen IV truck intake and 90mm throttle body. It will still have way more bottom end than my 5.3, though maybe a little less than a stock 6.0, but should really sing with the high flowing L92 heads.

 

[glockman]

low end torque is why I'd love to see the 3.5 Ecoboost in a jeep...

View attachment 124183

I'm a Ford guy, I've owned a few GMs but almost every truck I've ever owned has been a Ford. I'd love to put an Ecoboost in a jeep but the mountain of hurdles would be huge.

One thing I'm learning to love about the LS platform is its simplicity. It took 4 sockets to take the motor from this


To this


Motor mounts showed up today and I'm supposed to pick up some corvette ZO6 exhaust manifolds tomorrow.

 

[Greg]

...One thing I'm learning to love about the LS platform is its simplicity. It took 4 sockets to take the motor from this... to this.

...I'm supposed to pick up some corvette ZO6 exhaust manifolds tomorrow.

I think the GM engineers did an amazing job making the LS series very high performance, while maintaining a degree of simplicity. Even working on the LS, you can see how closely related they are to the construction of the old SBC.

Nice find on the Z06 manifolds!

 

[Greg]

A 6.0 is essentially a bored out 5.3. They share the same 3.622” stroke length. A 6.0 is a 4” bore. Can’t remember what a 5.3 is.


@Greg ill let you know how my 6.0 turns out. I got it back from the machine shop earlier this week. Time to start assembling. Had to bore it .030 over. I have a pretty mild cam with .558” lift on the intake, .563” on the exhaust and a wide 115° lobe separation angle. Compression ratio will be 10.4:1 with L92 heads, gen IV truck intake and 90mm throttle body. It will still have way more bottom end than my 5.3, though maybe a little less than a stock 6.0, but should really sing with the high flowing L92 heads.

The 5.3 has a 3.780 bore.... but I've always heard you can't bore a 5.3 to 6.0 size, not enough meat in the block. I did read where people talked about the idea of dropping 4" bore sleeves into a iron block 5.3 but at that point you're so far into the costs of machine work it would be cheaper to start with a 6.0 block.

What's the lift at .050"? Have a part# for the cam? I love reading cam specs! Any thoughts on roller rockers with 1.8 ratio? What are you thinking for HP? Based on what you're saying, I'd think 525-550 HP is within reach.

 

[RockChucker]

The 5.3 has a 3.780 bore.... but I've always heard you can't bore a 5.3 to 6.0 size, not enough meat in the block. I did read where people talked about the idea of dropping 4" bore sleeves into a iron block 5.3 but at that point you're so far into the costs of machine work it would be cheaper to start with a 6.0 block.

What's the lift at .050"? Have a part# for the cam? I love reading cam specs! Any thoughts on roller rockers with 1.8 ratio? What are you thinking for HP? Based on what you're saying, I'd think 525-550 HP is within reach.

Bingo. I wouldn’t waste time turning a 5.3 into a 6.0. The cylinder walls near the water jackets would be way to thin.

Here’s the spec sheet on my cam. I will be using the oem 1.7 rockers. I will be upgrading to a captured trunnion bearing though. I don’t want to have to deal with loosing stock bearings due to the increased spring tension from the upgraded valve springs i installed too.

 

[glockman]

Picked up a superior radiator with trans cooler that I may or may not run and 16" spall fan from a guy with a built LS LJ. It was good to see some different solutions to the swap issues.



He was running camaro cats off od Z06 manifolds with pre and post O2s right there. I will likely go this route. This is his setup.


I picked up the Z06 manifolds Saturday. The corvettea run egr's so I fabled up some block off plates.


Here is the cool thing about the vette manifolds. O2 bungs in the collectors.


Also got the block cleaned up and painted and dropped the heads off at the machine shop.
Next on the list is to figure out the last couple harness issues. I've got most of it sorted but need to figure out the A/C control wiring with two pcms.

 

[glockman]

OK, need some input.
The oil pan needs to go. I had planned on a stock F body but hear lots of complaints about oil starvation at angles. This is easily solved with a trap door oil baffle. Problem is, they are all $200+. Like this one from improved racing.

LS1 Camaro / Firebird (F-Body) Racing Oil Pan Baffle EGM-200

We specialize high-performance oiling system products such as baffled oil pans, thermostats, oil adapters and coolers for GM LS engines and others. We are the oil control experts!

www.improvedracing.com

I can get a used F body pan for $100 and use that baffle or moroso makes a steel pan with baffle for about the same total price.

Moroso 20142 Moroso Drag/Road Race Oil Pans | Summit Racing

Free Shipping - Moroso Drag/Road Race Oil Pans with qualifying orders of $109. Shop Oil Pans at Summit Racing.

www.summitracing.com

Am I overthinking this? Do I Need a baffle to maintain pressure? Seems like a good place to spend money on an offroad rig but I've never lost oil pressure that I was aware of on any extreme angle.
The steel pan would be nice insurance if it contacts a rock too though.

 

[Mouse]

I wouldn't want an engine for an off-road vehicle that loses oil pressure. Any option with trap doors is a good move. If $ isn't an issue an oil accumulator would be a nice addition

 

[Gravy]

The Ultra4 guys I know use accumulators and trap doors.
LS motors don't like to run in their side like a 4.0 or 22re.

 

[RockChucker]

I have a mast pan (almost the same as f body) with some internal baffling. I can park on the helldorado waterfall and maintain 20 psi. When my brother installed his engine, we did a similar baffling setup in the f body pan and he hasn’t had any issues either. I asked him for pics of what we came up with. I’ll post here when he sends it to me.