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LS swap questions- yes, another one.


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Doing research of engine swaps for if/when my 5psi-oil pressure 4.0 fails.  I know 4.0's swap in (and wouldnt be bad), but I wouldnt mind a 5.3 for power boost.  I've seen how to do the mounts, exhaust, etc, but still have questions.

 

-What do people do for gauges on the early-era?  I assume fuel/volts needs little t no modifivations, and the oil/water can be adapted as well for the stock cluster.  Novak has an adaptor for the 4L60 to run a mechanical speedo- but what about the tach?

 

-Any HVAC things to worry about?  or just change to the Delco compressor, or hook up to the OE condensor and whatnot?

 

-Any issues keeping the column shift?

 

-Does the stock hood work? Many I see run a cowl hood or cut a hole.  Id like to keep it stock appearing (And -gasp- 2wd), but 12/13 second capable.

 

-Electronics.  What stays from the stock Renix wiring, what goes, what stays working or stays but not connected?

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For the gauges I would probably go to an aftermarket speedo and tach, as I think it would wind up costing a lot of money or headache to make the stockers work.  That said, I believe you could probably get the tach working correctly if you spent enough time farting around with it, as the earlier tachs were adjustable between the 4 and 6 cylinder engines, and the LSx type engines put out a standard 8 cylinder tach signal, so there is a chance you could tweak the adjustment to cover that.  Failing that, Dakota Digital or somebody else probably sells a signal converter that would work, but it will be a few bucks and is another module to wind up failing.  For the speedo I don't know what Novak's kit looks like, but I shudder to think that fitting a mechanical speedo is really a good option in this day and age.  The actual speedo output from the ECM might play with the 91/92 HO tach, which will fit in the Renix gauge cluster (or so we proposed in another thread), and I believe the pulse per rev setting can be edited in HPTuners (the VSS setting can for sure).  I also question how Novak's speedo drive kit works, and I hope it does not delete the VSS? 

 

And you're going to use a 4l60E or...?  A 4L65E would be a lot better.  Don't get a 4L60.  Really for simplicity buying the trans with the engine is probably the best bet for the first go at this as then you already know it will play correctly with the engine and ECM.

 

No idea on HVAC, I don't see why it shouldn't work, but I also don't believe in A/C.  You need the heater to be hooked up though, the LS tstat needs a bypass loop.  My main concern with keeping the A/C would be getting it to fit with the motor mounting and exhaust, plus getting a condenser core that will fit with whatever radiator you wind up with.

 

Column shift might be a PITA to hook up correctly, but I'm guessing it will work...  It's a GM column so I'm sure there is a cable that will work if the one you have doesn't.  Or you can have one made.

 

The hood is another matter.  Firstly, what engine are you getting?  In general, car engines with their low intake and accessories will clear the hood assuming the engine is placed correctly.  However, they generally don't clear the steering box.  Truck engines with truck accessories and intake will not clear the stock hood, not even close.  Lots of guys butcher the hood, or just don't run it, as converting to a car intake and then buying an accessory bracket kit that works takes a fair amount of money and some farting around.  I have some accessory drive kits picked out I can share if you want.

 

Electrical is 'easy' with the Renix.  Sorta.  Not.  But basically the Renix already has the ECM and engine harness standalone, so it's fairly easy to pull that part out.  You will want to cut down your new engine harness (fairly easy) and put it on it's own little fuse block.  Then cut all the other uneeded junk out of the Renix harness and integrate the few things that are needed.  Or at least that was how I planned to do it.  I could give you more specifics if you want.

 

I've researched this a bunch but I'm not sure where you're at on picking components.  Getting the motor mounted correctly, the exhaust to fit, and a cooling system that actually works seems to be the biggest hurdles to me for a 2wd swap.

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I was at the PnP yesterday, I casually looked for LS engines, there was one with a head missing. 

LS swaps aren't cheap anymore, you aren't going to pick one up for $150 anymore. On some of the car/racing vids I watch some are complaining that the LSs are getting hard to find. 

I just searched CL locally, $1500 to $3000 now for a complete LS, high to low miles. 

 

I'm going to do a V8 swap in the next year, it's not going to be an LS, I could give reasons but I'm afraid of posting my opinions here anymore for fear of all the ladies getting their panties in a bunch. 

 

There are other options. Better options, IMO. 

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I did a V8 swap with a ‘94 ZJ as a donor. Had plenty of power!... but tons of extra electronic garbage. If I ever do another I’d go with a mildly built old school 360 in front of an AX15 and topped with a Holley Sniper fuel injection. Easy, simple, and they fit under our hoods without the mix and match of different LS donors. 

 

I agree. Lots of other options than the LS. 

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1 hour ago, RustyRodder said:

What else would you guys recommend?  I doubt any OHC engines would fit.  Windsor base? full HO swap and M90? TDI?

 

 

I debated between the LSx and the TDI.

 

The TDI doesn't seem like a terribly expensive swap and probably would work nicely for a MJ with smaller tires, puttering around town, mild wheeling, etc.  I don't believe they're reliable if you try to get a lot of power out of them, I'm sure people will refute that but I do not believe they are anywhere near as overbuilt as commercial diesel engines are.  There's a lot of different generations with their own unique quirks, so it's a lengthy topic regarding the pros/cons of each and what all is needed to make each swap work.  Adapters are available to go to various transmissions, including the AX-15 and AW4 (you will likely have to manually control the AW4).  Motor mount kits are also out there to go into the XJ/MJ chassis, which may work depending on which engine exactly you get, along with some other needed small parts.  There is tuning software available to make the engine happy after you butcher it out of the car, assuming you go with a newer generation one rather than an older mechanical injected one.  I decided against it because most of the TDI donors I looked at were either of the wrong generation, too much money, or the engine itself was iffy.  I also hate driving diesels in the winter, done way too many years of that, the TDI makes very little waste heat which is a bonus from the aspect of the cooling system, but sucks if you want to be warm when you're driving it.  The lack of power output was another issue, as I wanted to put it in my LWB with some 1-tons and things, so it was going to be heavy.  That said, it's not off the table that I won't do this at some point, but currently I'm swimming in LSx parts for my Gladiator so it makes it easier to go that route.

 

The LSx is not necessarily the easiest engine to swap into things, but the aftermarket does support swapping it into pretty much everything.  I've also had lots of personal experience with the 4.8/5.3 truck engines in their natural habitat, and I think they're hands down better than the comparable Dodge/Ford/Toyota V8s, and that there is almost zero comparison in quality between them and an earlier V8 with the 4.8/5.3 easily being able to last half a million miles with minimal maintenance while getting excellent fuel economy.  The other great thing about GM engines is they're a GM engine, so you can bolt excellent GM patterned transmissions to them, without wasting money on adapters to go to some less than ideal Jeep transmission.  I was going to use a NV4500, which is a truck transmission by nature, but would do exactly what I wanted being that it's brute strength with a bull low and overdrive.  The NV3500 is available as a more compact and slightly nicer shifting option, but it does give up much in regards to brute strength (it's basically the same as the Jeep NV3550).  The 4L60E, 4L65E, 4L80E, 6L90E, etc all also bolt to them and will play with the ECM so they basically just work (there is some odd things that happen when swapping between generations and whatever, but it's all well documented).  The T56 is also natively found behind LSx car engines, and it's a great transmission for the 2wd pavement pounder with double overdrive and very nice shifting.  Tuning software is readily available, along with places that will do a tune for minimal money, and there is access to a ton of parameters doing this; IE you could speed density tune it if you're just looking to make power with minimal sensors, or on the opposite end of the spectrum you can retain the very conservative stock tunes but just delete the VATS and whatever unneeded emissions controls/etc.  The big downside to swapping one in is that it's going to cost a bunch to do it correctly, and it will take a bunch of time.  As I mentioned before, getting the hood to clear, the motor mounts correct, the exhaust to fit, etc, can take some figuring.   Or you could basically just give Novak your credit card, but I really don't recommend that.

 

Any V8 or high HP swap presents issues regarding the cooling system.  Most engines are just not thermally efficient enough to not tax the stock XJ/MJ cooling system when making much more than the original 190~HP.  Engines with aluminum heads and blocks do help shed heat, but you can't expect to throw a 300HP engine in and have the factory radiator keep up.  Adding more cores/thickness to the radiator helps, but ultimately most of the successful higher HP swaps wind up cutting out the core support and going to a totally different radiator.

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38 minutes ago, Jeep Driver said:

My head hurts, watching -------- people -------- things. 

I used to look forward to his vids............

 

 

 

I've always thought he was a colossal idiot but I generally refrain from saying so.

 

Anyways, I think it makes my point that an LS swap is not just that easy. :peep:

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you could do a rebuild the 4.0 as a stroker 4.6  :brows:   but in the end, gearing is the cheapest kick in the pants.  bigger tires make everything feel slower.  aggressive gearing makes even tired engines feel like a rocket :D  

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1 hour ago, RustyRodder said:

After looking at that... I think I may just stay with a 4-liter.  Slow and 'reliable'.

What Matt did was perform an abortion do not use that as an example of an engine swap but  I'll tell you that most people do not know how to plan and do not know how to execute a plan.

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  • 1 month later...

I'll be swapping in a 99 6.0 here soon. Having a wiring harness made, using novak motor mounts and headers I found cheap and they came with full true dual comanche short bed exhaust.

 

I'm not sure why he cut all that frame up...not needed at all! Didnt even take time to look at other options

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