This was the head on my 5.2
Chasing issues can be a PITA and there are times when a complete teardown is your only option. I couldn't ever find this crack by doing leak down tests & compression tests.
LS swap update and questions
- Thread starter Longhorn84
- Start date
This was the head on my 5.2
Chasing issues can be a PITA and there are times when a complete teardown is your only option. I couldn't ever find this crack by doing leak down tests & compression tests.
I'm tempted to build something else outside of the rig and swap it in, could consider a modest crate engine. All the effort, I want this thing to purr!
I had a CRD60 to put in the back of mine when I did the V-8 swap.. I'd bought the axle while I was deployed to Iraq.
I think you're not getting the HP/TQ from your engine since a stock 5.2 was only:
And a 5.9 was only:
It's a place to start before you do other things. Figure out why you're not getting the power you're hoping for first. I chased it...
Added a larger throttle body & larger ratio rocker arms & a canned tune. It already had headers.
Agreed. I didn't even change the spark plugs, injectors, etc. i'm sure there's a bunch of small things that add up to big power loss. I'll probably take it to a shop that's better at dialing it in, I did the heavy lifting with the swap but now I want someone else to fine tune it.
In your video you mentioned the 6l80e. Tox did a comparison on this page
Post in thread 'Higher horses, higher revs & even higher torque, a streetable LJ engine swap'
https://wranglertjforum.com/threads...a-streetable-lj-engine-swap.36240/post-724147
Will it hold 70 MPH on the freeway when climbing a steep hill? That was one of the main things I disliked about my 5.2 but that was due to tuning come to find out.
I understand taking to a shop. But do some of the basic stuff yourself first to save some money. Then take it to a shop for tuning and stuff.
+ 1 on checking the condition of your 5.3 , This combo should run very well , but if you want to run with a 392 , spend 392 money .
You could replace the axles with D-60's and 5.38 gears and a fresh LS-3 with 580 h.p. and 4L80E trans. and an Atlas T-case for 60-75K .
I wonder if your expectations exceed what a TJ can deliver. At some point , a Jeep TJ stops being a Jeep TJ.
I hope you find a solution to your situation .
You could replace the axles with D-60's and 5.38 gears and a fresh LS-3 with 580 h.p. and 4L80E trans. and an Atlas T-case for 60-75K .
I wonder if your expectations exceed what a TJ can deliver. At some point , a Jeep TJ stops being a Jeep TJ.
I hope you find a solution to your situation .
This is the dilemma that keeps bringing me back to the 392. I love the idea of having a unique custom TJ and I've already spent time/effort into suspension and the swap but the outcome is a fairly uncomfortable ride with lacking performance. Don't get me wrong, the kids don't care but I bet a stock JL would beat me off the line and therefore my "swap" was just a fun learning experience with little to show for it. Jeeps make us do silly things!
It sounds to me like you've kinda made up your mind about a 392. For you , this may be a path forward . Since you're comparing the " ride " of a TJ to a 4 dr. JL
I feel you won't be happy with a TJ modded to perform with a 392 in every aspect. I hope you find what will work for you .
I'd figure out if your 5.3 is weak before doing anything else. Once you know that then go from there.
IMO you're going to need a Dana 44 at a minimum once you have a strong engine. If you're set on keeping 35" tires then you for sure need a stronger axle. The Dana 35 even with a Super 35 isn't enough with a V-8 from what I've seen.
I'd agree that it doesn't seem that the engine and transmission are working together right for this application. It seems extremely anemic.
I agree with the compression/leakdown as a good place to start on engine related issues.
If you've never stuck a boroscope down the spark plug holes, I'd check the internals with one. They're not terrible expensive, useful for a surprising number of other jobs, and you'll have an idea what the inside of the cylinders and inside of the heads look like without pulling the heads.
If you don't already have an HP Tuners MPVI2+ or 3 I'd also consider that. You can pull good data off the ODBII as to what's going on with the engine and transmission. The GM community on HP Tuners forum is more helpful than the Chrysler/Dodge/Jeep one I think and they'd likely be able to help sort out some tune issues between the engine and transmission and all of that would be alot cheaper than taking it to a tuner.
I agree with the compression/leakdown as a good place to start on engine related issues.
If you've never stuck a boroscope down the spark plug holes, I'd check the internals with one. They're not terrible expensive, useful for a surprising number of other jobs, and you'll have an idea what the inside of the cylinders and inside of the heads look like without pulling the heads.
If you don't already have an HP Tuners MPVI2+ or 3 I'd also consider that. You can pull good data off the ODBII as to what's going on with the engine and transmission. The GM community on HP Tuners forum is more helpful than the Chrysler/Dodge/Jeep one I think and they'd likely be able to help sort out some tune issues between the engine and transmission and all of that would be alot cheaper than taking it to a tuner.
Just watched your video and I agree, off the line between 1 and 2k seems sluggish, almost like you’re starting out in 2nd. I have a 6.0 in mine so not apples to apples, but mine seems a lot peppier. My advantages are the 6.0 and a low lift cam, but you have better gearing and are at sea level. Im running a 4L80 and 4.10 gears with 35’s, so your first gear has almost a full 1.0 advantage over mine and I’m at 5-6k elevation. Your trans also seems to shift early too, rarely getting to 4k. If I’m aggressively accelerating mine will rev out to 5k plus usually. I agree with a lot of the above. Make sure the engine is in good shape and get a good tune on it.
Interesting observation, thanks, I definitely need to have someone look at the transmission and tune to make sure it's all working properly. I have work to do and will report back!
@Shank just PM'd me and told me that his new LS makes no power, sounds funny, and he wishes that he had done a Hemi...
You've mentioned the 392 a bunch here, and I'm wondering if you've looked closely at that option. The Gen 4 Hemi's - which include the 392 - are a difficult swap into the TJ. The configuration of the accessories requires a decent modification to the frame - on top of everything else required for the swap. The most often performed Hemi swap into the TJ is the Gen 3, for just this reason.
I run a 392 - but it is a stroked and built 5.7. Still a good bit of work - but a good bit easier than the Gen 4.
I would also suggest checking your fuel system. I have a 5.3 LM7 in mine and I was having a similar sluggish experience. Fuel system was the culprit for me. Now it's very responsive and runs a lot stronger.
@Shank just PM'd me and told me that his new LS makes no power, sounds funny, and he wishes that he had done a Hemi...
I didn't want to rain on his parade with the "Dude Ya Could of Had A Hemi"
I wonder how much that Holley front accessory drive kit would help with this? Of course it adds another $4K almost to the cost.
@Shank just PM'd me and told me that his new LS makes no power, sounds funny, and he wishes that he had done a Hemi...
You've mentioned the 392 a bunch here, and I'm wondering if you've looked closely at that option. The Gen 4 Hemi's - which include the 392 - are a difficult swap into the TJ. The configuration of the accessories requires a decent modification to the frame - on top of everything else required for the swap. The most often performed Hemi swap into the TJ is the Gen 3, for just this reason.
I run a 392 - but it is a stroked and built 5.7. Still a good bit of work - but a good bit easier than the Gen 4.
Yes, sorry, I meant buy a JL 392 and sell my TJ, not swap in a 392. I have considered pulling my LS and tearing it down to refresh/upgrade some components but I wouldn't abandon all the GM work I've done to get this TJ operational.
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