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

Having owned a Hellcat Challenger, I can tell you that there is indeed such a thing as too much horsepower 🤣

I mean when just the wrong touch of the throttle can break the tires loose at 70 MPH in 5th gear on the highway, you may have a problem 😉

Seriously though, I’d still take more!
 
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Chris said:
Having owned a Hellcat Challenger, I can tell you that there is indeed such a thing as too much horsepower 🤣

I mean when just the wrong touch of the throttle can break the tires loose at 70 MPH in 5th gear on the highway, you may have a problem 😉

Seriously though, I’d still take more!
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That certainly would be an issue for my Jeep. Especially with ice on the roads around here when a light throttle is everything. But I also have much larger tires than a Hellcat so that probably sides in my favor.

Don't those Hellcats have a "valet key"? I wonder how the engine adjusts for that? If I find that I need a lighter throttle in the winter I wonder if having 2 tunes could be a solution?
 
LQ9 stroker would be my choice for a Jeep. Plenty of HP and TQ for both low and high rpms.

You can add boost but will have to worry about heat since radiator size in a Jeep is not that big.
 
toximus said:
That certainly would be an issue for my Jeep. Especially with ice on the roads around here when a light throttle is everything. But I also have much larger tires than a Hellcat so that probably sides in my favor.

Don't those Hellcats have a "valet key"? I wonder how the engine adjusts for that? If I find that I need a lighter throttle in the winter I wonder if having 2 tunes could be a solution?
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They do indeed have a valet key that restricts them to 300 HP and not being able to rev over a certain RPM. Not sure how it works, but it’s computer controlled for sure.
 
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Im a Mopar guy but I will say, there are not many better-sounding engines then a cammed LS.

An LS swap is not for the faint-hearted which your build isn't anyway. But it adds up quickly.
 
toximus said:
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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Please do not order an ATS transmission. They are not junk, that is not what I am saying. I am just gonna throw out there that your skill set is more than capable of rebuilding your own 42RLE with mods inside similar to what they are doing for probably considerably less money. If, you do the stroker VS V8. Not much is going on inside a 42RLE, they have a solenoid block that runs alot of what is happening and that is it's shortcoming in ways. They also wear valves in the valvebody, you can upgrade the valve body yourself with a shift kit and Sonnax brand valves and be equivalent, possibly better than ATS. I only wonder what Torque converter are they using.

I watched the Video and tried to find what ATS says they are doing. The pump is very small in the 42RLE, so machining it out for larger pump gears would not be some massive gain. I have not called them or anything, but I did not see or hear what parts are billet. The torque converter lid? The price seems high, and you get a neat controller to turn up the line pressure yourself which is neat I will give them that.

I myself can see both ways, of keeping the 4.0 and doing the stroker with supercharger. I would rather see you V8 swap with GM parts.....but I'm a GM guy. I am surprised your 42RLE is hanging in there now with your current setup, which is great honestly. I also understand the whole cost/time thing.

I suppose I can see the desirability of just ordering their purple transmission and it shows up ready, VS the stress of working on the 42RLE yourself. But, you would feel great if you built it yourself succesfully.

So basically just swap in the LS.
 
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toximus said:
Is the LSA compatible with everything the LSx would be? Water pumps, accessory drives, pans, etc? All bolts up the same?
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You’ll have to make sure you have the correct accessory routing ie. water pump, a/c etc. Your best setup would be buying the correct parts from an actual lsa car. The aftermarket brackets often don’t supply enough belt wrap or belt area (6 rib vs 8). This will cause belt slip. Plenty of irritated lsa swap guys fussing about slip with 6 ribs at sub 450hp.

The Lsa swap isn’t as cheap as it use to be. Prior to their popularity you could piece this setup together for roughly $2k. Now days the popularity of this swap has gained so much interest your in the $5k range to do it “correctly”. I’d highly recommend you understanding everything you need prior, build a list and start adding up the costs.

To me the only thing that is appealing is the OEM. The lsa will leave plenty to be desired. It’s really about how far are you going with this swap. A lot of ctsv and zl1 owners swap to aftermarket chargers and turbos. The lsa is limited to upping the power. Most guys cannot get what they want out of them with better cooling pumps, pullies and porting. These guy are also wanting 600-900 rwhp.

I’ve installed a lsa swap in a 65 c10 with an lq9 w/ a 4l80e. Once he had bought all the parts he was easily north of $5k. This swap used the factory lsa engine pullies, hardware, brackets, upgraded pump and cooler. If I recall it put down +500hp. Very safe and reliable. Once we finished the HP bug bit him and he wanted more and realized how small the gains would be retaining the lsa charger. He wished he had gone with a pro charger, at nearly the same cost and more room to build with.

All about your end goal and how cheap you can get parts for.
 
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TDI Sahara said:
Why not a 5.2 or 5.9 magnum dodge engine? GM's have too many stupid variations throughout the years that make engine swaps more frustrating.
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Because to be emissions legal he can not swap a older model year engine into his Jeep. They stopped making the 5.2/5.9 engines in 2002. So he either has to do a Hemi or LS swap.
 
toximus said:
Thankfully that doesn't have to be a concern for me.
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I'm referring to federal emission laws. But yes it's nice not to have to worry about smog checks and such. The other issue with the magnum V-8 engine swap into a new TJ/LJ is that your dash is a PCI Dash and finding a PCM for PCI magnum V-8's is very hard to do. You are going the correct route and I'm sure once you get this figured out you'll be happy.
 
Chris said:
They do indeed have a valet key that restricts them to 300 HP and not being able to rev over a certain RPM. Not sure how it works, but it’s computer controlled for sure.
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Even in my F150 I can program keys to limit top speed and even max radio volume, it’s for the kids.

None of that BS has any place in a TJ, keep it as simple as possible.
 
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BuildBreakRepeat said:
No way he’s getting an 8.3 (not 8.2) in there 🤣 LS like @pagrey said is the best choice for reliable horsepower. Even stock an LS is a monster and power adders can be thrown on later for even more.
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Oh it's 8.3
😂
I don't know much about semi trucks. But those engines are bigger than a lot of small cars.
I've got a small block 350 out of an '87 1ton van if you want it. Had 43k miles on it. Come get it. $100 and you get a RV attached at no extra charge. 😉
 
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Go crate engine. The question is...how fast you wanna go? I think a solid 450-500 horse LS based engine will make you happy. Especially if you liked the 270 horse 4.0.....

and you have room to grow. Build it NA in that range and you can always boost it for loads more smiles. The issue will become...your chassis if your using that 500-800 horses off-road. Look at the KOTH rigs and what they are doing.
 
Rubi04 said:
Go crate engine.
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(y)

Rubi04 said:
The question is...how fast you wanna go? I think a solid 450-500 horse LS based engine will make you happy. Especially if you liked the 270 horse 4.0.....
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If it was even 270hp. Lol. I need to keep in mind that if it wasn't for the issues I did enjoy that little of power (although I had been planning on building a supercharger stroker for another 100hp...). It's easy to say "I want 1000hp" but as Chris alluded to, too much power can become un-fun.

Rubi04 said:
and you have room to grow. Build it NA in that range and you can always boost it for loads more smiles. The issue will become...your chassis if your using that 500-800 horses off-road. Look at the KOTH rigs and what they are doing.
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So far the engines that have caught my eye are the 495hp LS3 and the 627hp LSX 454. The 525hp LS3 I fear could be too lopey to be drivable crawling offroad (although the chop sounds great imo). The LSA seems to be more complex than I'm wanting in my Jeep.
 
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