Higher horses, higher revs & even higher torque, a streetable LJ engine swap

toximus

I buy Chinese
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"Never let someone tell you that you don’t need more horsepower. Just stop talking to them, who needs that kind of negativity in their life?"

If you missed the main phase of my build, you can find it over here: High travel, high clearance & high octane, a streetable adventure LJ story. I'm still posting non-engine related build updates over there so if you're interested in that type of thing too I suggest you follow both threads!

Ever since I rode along in some Jeeps desert racing and put the supercharger on my Jeep I've turned into a bit of a horsepower junkie. Because ending an addiction is no fun, my methodology here is to throw the biggest, baddest, strongest engine (that doesn't compromise my main build goals) under the hood of my LJ and not be left with wanting anything more.

Unlike the main phase of my build which I received a lot of direction on from MrBlaine and was able to base my build on many many iterations done before mine, this engine phase of my build I'm going to be upfront that I have little to no clue what I'm doing. Don't tell anyone but the most engine speak I do is smiling and nodding when guys talk about their engine's lift, timing, compression, litres, etc — yeah, I have little to no clue what any of that means. HP/TQ charts are about as far as I understand. I'm sure as I do this engine swap that there will be things that work well, things that could be done better but aren't worth redoing, and things that need redoing. This is new territory for me.

My goals are:
  • Reliability is priority.
  • Not compromising phase 1 of my build is non-negotiable.
  • Cramming as many ponies under the hood as I can.
  • Torque and HP curves need to work well for my uses and not focus solely on peak horsepower.
 
easy route stroker or complicated ls swap?

Ultimately it's coming down to what's right for my build long term. Like the rest of my build, time and cost will be considered but what's best will take priority even if it means saving my pennies up or spending a few more months on it (I am accepting donations if somebody wants to start a GoFundMe. 🤣 ).

I did post a cost/time analysis between a inline 6 stroker and a LS over in my main build thread yesterday: https://wranglertjforum.com/threads...e-adventure-lj-story.9956/page-61#post-596977 (Direct link to post.)
 
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LS swap with the LSA supercharger. LS support is pretty good. You wont match the power with any other rational swap. They aren't too expensive and they make real power. You can start with LS with long term plans of the supercharger. If you want to know what it's like go test drive a used CTS-V, they are similar weight. They essentially are stock GM engines so they are reliable. I have no idea how you'll have to build everything else to deal with 700hp.
 
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The mopar guys will say either inline 6 stroker or 5.7 hemi swap.
But in terms of reliability and ease of finding parts I would have to say LS swap, theres really an unlimited amount of support for it. I'd say even a 4.8 LS will put down good numbers with just a cam.
 
LS swap with the LSA supercharger. LS support is pretty good. You wont match the power with any other rational swap. They aren't too expensive and they make real power. You can start with LS with long term plans of the supercharger. If you want to know what it's like go test drive a used CTS-V, they are similar weight. They essentially are stock GM engines so they are reliable. I have no idea how you'll have to build everything else to deal with 700hp.

I was looking at that combo. My understanding is that I'd want to upgrade the internals a little bit and start with an iron block to make 700hp with boost?

My axles are up to the task, and the transfer case needs to be swapped out with an Atlas anyway. So adding horsepower isn't much of a concern.
 
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I was looking at that combo. My understanding is that I'd want to upgrade the internals a little bit and start with an iron block to make 700hp with boost?

My axles are up to the task, and the transfer case needs to be swapped out with an Atlas anyway. So adding horsepower isn't much of a concern.
Bulletproof internals and an iron block make a huge deal for reliability. A cammed turbo LS with a good tune makes solid power plant.
 
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Here's an overview of the Jeep this engine will be going into. (Full details on my build thread: https://wranglertjforum.com/threads...-octane-a-streetable-adventure-lj-story.9956/)


  • 37" MTR tires on 17" TrailReady beadlocks.
  • RockJock 60VXR axles geared to 5.38 front and rear with ARB lockers, RCV front shafts, load bolts, and full floating rear.
  • 14" Fox coilovers front and rear with 7" up and 7" down at an equivalent lift height of 4"
  • 105" wheelbase which is ideal for my tire size
  • Savvy mid-arm 3/4 link.
  • Tucked skids
  • All aluminum armor and synthetic winchline to keep weight to a minimum
  • 4860lbs fully loaded.

20200508_completed-build.jpg
 
Here's an overview of the Jeep this engine will be going into. (Full details on my build thread: https://wranglertjforum.com/threads...-octane-a-streetable-adventure-lj-story.9956/)


  • 37" MTR tires on 17" TrailReady beadlocks.
  • RockJock 60VXR axles geared to 5.38 front and rear with ARB lockers, RCV front shafts, load bolts, and full floating rear.
  • 14" Fox coilovers front and rear with 7" up and 7" down at an equivalent lift height of 4"
  • 105" wheelbase which is ideal for my tire size
  • Savvy mid-arm 3/4 link.
  • Tucked skids
  • All aluminum armor and synthetic winchline to keep weight to a minimum
  • 4860lbs fully loaded.

View attachment 167490
One thing you’ll need to factor in as well is the engine/trans weight. You’ll most likely need to changing your front springs out to keep ride height after it’s said and done.
 
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One thing you’ll need to factor in as well is the engine/trans weight. You’ll most likely need to changing your front springs out to keep ride height after it’s said and done.

For sure.

I also need to factor in gas range. My fuel cell is roughly 21 gallons. I don't have huge MPG concerns but I do want to keep at least 200 miles of range. So no top fuel drag engines for me.
 
For sure.

I also need to factor in gas range. My fuel cell is roughly 21 gallons. I don't have huge MPG concerns but I do want to keep at least 200 miles of range. So no top fuel drag engines for me.
6.2 LSA is looking at 580hp stock, and about 12-14 mpg. Not terrible. But that’s making that kind of power stock without an iron block. Reliability doesn’t always mean heavy and old.
 
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I was looking at that combo. My understanding is that I'd want to upgrade the internals a little bit and start with an iron block to make 700hp with boost?
The modern LSA doen't need the iron block for 700hp and I don't think you'd need to upgrade anything. Yes, the truck engine is iron and people use it but if you aren't going to do 1000hp I don't think it's important. There is a ton of info on building and tuning these things, that is the huge plus, it is what everybody builds. The important part is you probably aren't going to push it at all, that'll keep it reliable and much less expensive. They have superchargers stock.
 
The modern LSA doen't need the iron block for 700hp and I don't think you'd need to upgrade anything. Yes, the truck engine is iron and people use it but if you aren't going to do 1000hp I don't think it's important. There is a ton of info on building and tuning these things, that is the huge plus, it is what everybody builds. The important part is you probably aren't going to push it at all, that'll keep it reliable and much less expensive. They have superchargers stock.
Absolutely agree. Even a stock LSA would make him happy. Not jumping up and down giddy but a good starting place.
 
Here's an overview of the Jeep this engine will be going into. (Full details on my build thread: https://wranglertjforum.com/threads...-octane-a-streetable-adventure-lj-story.9956/)


  • 37" MTR tires on 17" TrailReady beadlocks.
  • RockJock 60VXR axles geared to 5.38 front and rear with ARB lockers, RCV front shafts, load bolts, and full floating rear.
  • 14" Fox coilovers front and rear with 7" up and 7" down at an equivalent lift height of 4"
  • 105" wheelbase which is ideal for my tire size
  • Savvy mid-arm 3/4 link.
  • Tucked skids
  • All aluminum armor and synthetic winchline to keep weight to a minimum
  • 4860lbs fully loaded.

View attachment 167490
The highline is going to be one of the biggest hurdles for engine swapping. Careful placement will be key.
 
Is the LSA compatible with everything the LSx would be? Water pumps, accessory drives, pans, etc? All bolts up the same?
 
You need to talk with Jeff (aka:Nashville Coilover) over on the JeepForum. Yes he has a Hemi swap but I'm just talking about things to look out for and other helpful tips. Also there was someone who just did a LS swap in the build threads.
And if you look there is a huge thread on Pirate about doing LS swaps. I can try to find it for you later. I'm in the garage so can't do it here.
 
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