Pirate 4x4 banner

1 - 20 of 40 Posts

·
Registered
Joined
·
484 Posts
Discussion Starter #1
"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.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #2
Here's an overview of the Jeep this engine will be going into. (Full details on my build thread: High travel, high clearance & high octane, a...)


  • 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.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #6
During this dreaming phase I have mulled over many different ideas from the different forums and phone conversations ranging from Hemis which would interface easier with the existing dash electronics, a high horsepower SRT8 Hemi, 1000hp turbo LS, dash ideas, cheap junkyard LS engines, different transmissions, Hellephant engines, exhaust header configurations, various wiring concerns, diesels, turbos, etc etc etc. o_O Somebody even mentioned a '98 Honda Civic 4-banger! 🤷‍♀️:LOL:

To help unmuddle the mixture I got in touch with a guy who does engine swaps for a living and has worked with both the Hemi and LS, he's been kind enough to answer some questions for me and point me in the right direction.

The best advice I received is to do a proven engine swap that's been done before and not be the first to do something. Because reliability and actually getting my Jeep running sounds good to me, this seems to be advice that I'll be following throughout the entire swap even if it means missing out on something new and cool.

From the sounds of it, the LS engine is going to have the best bet of fitting into my build.

All of the Jeep interior stuff will function as long as they're powered up with 12v. The airbags, wipers, lights, turn signal, hvac blower, radio etc do not require the PCM.

If I want the factory gauge cluster to work with an LS then I will need to make a special harness that incorporates the GM side with the Jeep side PCM. However the easiest, most reliable and problem free solution will be aftermarket gauges that will interface directly with the GM ECU.

Even though I will be going with an LS I expect most of what I post about packaging the engine and trans will apply to any high uptravel builds where a high pinion axle housing travels up into the engine bay.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #7
I made my mind up!

I chose to go with a V8 Chevy LS3 6.2L 495hp crate engine. If I ever want more power I can top it off with a Maggie supercharger to make somewhere around 630hp on pump gas or build up the internals to make more power naturally aspirated. If it's too much power I can replace the hot cam with the regular cam to make 430hp.



How I chose this horsepower is the equation that more horsepower = more better. ...at least up to a point... At some point there is a $/HP wall that's expensive and with cheaper power adding mods you run the risk of pushing the engine too far and causing reliability issues. I also have concerns of the throttle being too touchy for slow speed crawling or accidentally spinning the tires on the highway. When you take into account the power to weight ratio of my Jeep and the power required to rotate the 37" tires I think 495hp will start to balance out nicely. My power to weight ratio will be about 1hp:9lbs. In comparison a stock TJ has a ratio of 1hp:18lbs, a 2dr JL is 1:14, a Ford Raptor is 1:12, a Polaris RZR turbo is 1:11, a sports car or top model Jeep STR8 is in the 1:7 range. With my deep 5.38 gears in the axle I probably won't be winning any 1/4 miles but real world driving should be excellent on road and off road.

I did not go with the 530hp crate engine with the ASA cam because the hp/tq chart shows that more power is created at the higher rpms and not as much at the low end like the 430hp and 495hp crate engines do which isn't ideal for me. The lopey cam sounds awesome with good chop but I don't want to have trouble with a low idle either.

The other runner up I considered is the LSX 454. It has 130hp more than the LS3 I chose at the cost of being 150lbs heavier due to having an iron block. In the end I had concerns that it'd have too much power and act more like an on/off switch than incremental throttle, that would only be fun until the first road trip...

I ended up deciding on the crate engine vs junk yard after looking at various used options and finding that the good low mile stuff went before I could nab it. With the crate engine I won't have to worry about preexisting issues, damaged parts, or having to mix and match the best of different stuff together to make the engine the way I want it. From what I've researched mixing and matching different electronic bits from different models and years can also cause electrical connector confusion and ECU reprogramming. Since I'm not familiar with the LS platform that sounded like more than I am willing to take on. What isn't great about the crate engine is that it's not complete and I'm going to have to figure out what's "missing" and finish off the engine.

The LS3 engine is made from aluminum and weighs approximately 100lbs less than the Jeep 4.0L that's coming out. So that's pretty cool!
 

·
Premium Member
Joined
·
1,175 Posts
Definitely looking forward to see how this goes for you! I've been looking at a swap for my TJ. I like your choice of the LS3, that's kind of what I had been leaning towards as well - would love to find a low mileage take out, but the crate engine does have some advantages. What are you going to do about a T-case? I think(?) you still have a 231 or 241, are you planning to swap to an Atlas? I suspect the 231/241 isn't going to live long behind the LS3 - so you better budget another $3K for a transfer case :)
 

·
Registered
Joined
·
484 Posts
Discussion Starter #9
Definitely looking forward to see how this goes for you! I've been looking at a swap for my TJ. I like your choice of the LS3, that's kind of what I had been leaning towards as well - would love to find a low mileage take out, but the crate engine does have some advantages. What are you going to do about a T-case? I think(?) you still have a 231 or 241, are you planning to swap to an Atlas? I suspect the 231/241 isn't going to live long behind the LS3 - so you better budget another $3K for a transfer case :)
If I had time to wait it out and startup the engine outside of the Jeep I think a junkyard engine would be cost effective.

I do have the stock NP231 2.72:1 with the 42rle transmission it's not deep enough in the woods.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #10
As far as transmissions go, there's 2 main automatic transmission families that mate with the LS. The 4L family is based off of the older 1980s TH400 design: 4L60/4L70/4L75 is the same physical size and the 4L80 is slightly larger. And the 6L family which is a new design since 2006: 6L80 and the slightly larger 6L90. There's more models and history, but that's the important bit.

There's a lot of 4L60/70/80(e) Jeep builds out there and that transmission has been around for a long time now. It's a proven transmission for swaps based on the already proven TH400 that works and doesn't have many complaints (as long as the weaker versions aren't overloaded). Going with a 4L75e would be a huge improvement over my Jeep 4 speed 42RLE.

4l75e gearing:


The 6L80e seems to be better not only because it has 2 more gears, but because it's an entire generation newer than the 4L and everything internal is redesigned and improved. From all of my research and discussions with everyone who's played with both the 4l75e and 6l80e says that the 6L is just better even though they admit the 4L is good too. An interesting tidbit that I came across is that Levi Shirley is using a 6L80e transmission behind his 700hp LSX with a 3:1 transfercase and runs races in low range over 100mph.

6l80e gearing:


Comparing both with a gear chart:

(If this image is too small, click here)

Here's my comparison and thought process deciding between the 6L80e and the 4L75e. Take it all with a grain of sand because this is all just internet research and not my first hand experience.
  1. Both can come configured with the LS3 crate engine and thus will be compatible and easy to tune (...hopefully...).
  2. Both are rated to the same strength of 650lb-ft of torque (this is about 40% more than the production versions).
  3. Both have a similar overdrive top gear for the highway.
  4. Both can be adapted to an Atlas transfercase
  5. The 6L80e has a lower 1st gear and, with my 37" tires and 5.38 gears, Advance Adapters recommends a 3:1 transfer case, for the 4L70 Advance Adapters recommends a 4:1 transfer case. Although it seems that you could upshift early into 2nd with the 6L80e and 4:1 TC?
  6. Both have been fit into long wheelbase Jeeps before.
  7. Both can use tap shift and be forced to stay in a gear.
  8. The 4L can be adapted to use a manual valve body (not beneficial for most of where I'll be going)
  9. Both can be setup with a mode for towing, different shift table for 4low, and the 6L80e also has a "sport mode" (I'm not entirely sure these modes will be beneficial for me).
  10. The 4l70e is proven to work well with a 4low shift table, the people using the 6l80e seem to be using the high range shift table and are reporting good results.
  11. The 6L80e requires only a few wires be connected because the TCM is wired internally. I think this can help with reliability too since there's less exposed wires to get damaged (although a good wire loom could also work fine).
  12. Supposedly the 6L80e can self learn weird shift behavior, and can need to be reset (if for example it's learning period is while bombing sand dunes but then you drive on the road).
  13. The 6l80e will probably get better MPG due to more gears and a modern higher efficiency shift design (not a huge pro for me as long as I can get at least 200 mile range on the highway or spend a day on the trail without running out of gas, but gas savings is a nice bonus).
  14. The 6L80e has better gearing for driving between obstacles while still in low range.
  15. The 4L70e weighs ~50lbs less than the 6L80e (the 42RLE weighs about the same as the 6L80e).
  16. The 6l80e does hang ~1.25" lower than the 4l75e with the truck pan. If it ends up being too deep there are multiple shallower pans from car applications which can save up to 1" at the expense of losing a quart of fluid. Supposedly the Shirley's are running the shallow G8 pan. If they aren't having problems with it, I won't be. (the stock Jeep 42rle transmission from the centerline of the transmission to the bottom of the pan is roughly 8". The 6l80e is ~9.2")
  17. The final concern is that if the 6L80e is too wide, a front driver's side drop driveshaft will have a lot of issues getting around it. This is an issue with high uptravel builds that also have a high pinion axle and something I dealt with my 42RLE. Thankfully I found several comparison pictures:

    4L70 vs 6L90 (the 90 case is slightly different from the 80):



    rsz288 LS1Tech (6L80/6L90 into 68 Camaro does go.... - LS1TECH - Camaro and Firebird Forum Discussion)

    4L60 vs 6L80:





    Goat1 Pirate4x4 (Which 6.0l / Trans combo to go with?)

    6L80e truck pan vs G8 pan:



    Goat1 Pirate4x4 (Kenny Blume's finally going fast..... Ultra 4 build...)
After a lot of deliberation, comparison, and conversations I decided to go with the automatic 6 speed 6L80e transmission paired with the LS3 directly from Chevy as part of their Connect and Cruise combo kits. For my uses it seems to be the better transmission and by buying it married to the engine everything will be compatible. I don't know enough about why but the LS3/480 6L80e kit only comes with the higher 3000-3400k stall speed converter. The LS3 430 comes with the 2400-2800k stall torque converter.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #11
I have started ordering parts!

From the sounds of it, the crate engine and transmission will ship within a couple of days from placing the order and then arrive here within a week or two via Fedex Freight. So to maximize the warranty period I'll be ordering it once I have all of the other major supporting parts on their way.

My initial plan was to figure out what parts I need over the summer and get stuff ordered in time to pull my engine out once the snow starts flying again around November. So this build thread may have a slow start. If parts come in early I'll start right away. In the meantime I've removed the supercharger off my stock 4.0L and I have a few adventures planned! I also have my wife's well built khaki TJR on 35s to play around with once the red LJ is under the knife.

Here's my shopping list and notes so far (this list is subject to change).

  • Water pump + tensioner: I will buy OEM (must fit above radiator and be truck or f-body offset)
  • Harmonic Balancer with correct offset: Does anyone know the difference between OEM and the performance balancers such as ATI?
  • Accessory brackets: I'll be going with GoatBuilt's driver's side brackets for the alternator and PSC CBR pump (truck or f-body offset)
  • Power steering pump: I'll be reusing my CBR pump off the TJ 4.0 but will need a 6" pulley offset for the LS.
  • AC bracket: Holley low-profile or Dave's Customs high mount.
  • Alternator:
  • Transmission shifter: I'm undecided between a Winters + tap or using an OEM tap shifter. It'll probably come down to what fits best.
  • Engine mounts: There's no mounting kits that will work for me so I'll use universal style brackets and make my own.
  • Trans/TC mounts:
  • Engine oil pan:
  • Engine oil: 5w30 synthetic. Break in oil first?
  • Transmission fluid:
  • Radiator coolant:
  • Transfer case: Atlas 2 speed (I still need to configure this)
  • Transfer case fluid:
  • Dash gauges:
  • Ignition switch: Is it possible to retain the stock keyed ignition on the steering column?
 

·
Registered
Joined
·
701 Posts
Your question on the stall speed: Most likely they put the higher stall converter in to match the higher rpm torque peak of the hotter cam. With the lower RPM stall converter combined with the hotter cam, it will feel more sluggish off the line.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #13
Your question on the stall speed: Most likely they put the higher stall converter in to match the higher rpm torque peak of the hotter cam. With the lower RPM stall converter combined with the hotter cam, it will feel more sluggish off the line.
Good to know! Would there be any benefits for Jeeping by replacing it with the lower stall?
 

·
Registered
Joined
·
701 Posts
It will generally run cooler with a lower stall converter and have better economy due to there being less slippage at times that the converter is not locked up in the higher gears.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #16
I ordered an Atlas 2 speed transfer case and the 6L80e adapter (#50-9600) from Advance Adapters.

I decided on a 3:1 ratio to go with the deep gearing of the 6L80e. As seen by the engine this will be roughly similar gearing as a 4:1 transfer case behind the stock TJ or the 4L70 transmission. If I later decide that it's not enough gear the Atlas can be regeared to a different ratio.

For the rear yoke I'm switching to a 1350 joint. This will be stronger than the current 1310 and will better put up with shock loading when getting rowdy with the V8. In the front I'm likely still going to be running a 1.25" driveshaft to clear the transmission and engine and the smallest 1350 driveshaft Tom Woods makes is 2" diameter so I'll be sticking with the 1310 joint up front. Once I get everything in, if I find that I can run a 2" shaft I'll switch the yoke out to 1350.

For the tailhousing there were multiple pros and cons of each choice. Since my engine and transmission computers do not understand what low range is, the computers can not correct the dash speedo when in low range. The GM VSS tailhousing could be used for the dash gauge so it'd always report the correct speed but I can't remember a time that I've looked at what speed I'm going while in low range so I think it'd add unnecessary cost and wiring (although not hard to do if your OCD requires a correct dash speedo). There's also the "standard tailhousing" which allows for the use of a Jeep speedo which could be useful if I were retaining the stock Jeep dash. Since I didn't see a benefit in either of those I decided on the short tailhousing which is cheaper and 2" shorter than the standard tailhousing. With the 4L-series transmissions I'm pretty sure having the GM VSS tailhousing is required.

I also specced the case with a sight tube, 4wd switch, and low range switch (although I'm not positive I'll be using these switches yet. As an experienced Jeeper I can't think of a reason to keep the 4wd light on the dash since it'd be pretty obvious if the transfer case didn't go into 4wd or if I forgot to take it out of 4wd on the street?). If I decide that I want a different shift table for low range I can use the low range switch to trigger the 6L80e's tow/haul mode and put my low range table in there.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #17
After being in low range all weekend I can say for certain that I didn't look at the speedo once. As long as I remove any speed governor off the ECU I don't see missing it. I also don't see missing the 4x4 light once the shift levers have positive positions... it's actually more distracting being lit than not.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #18
Just in case you guys are interested in my updated shopping list. I'll probably be doing a huge order on Summit during their next sale.

  1. Radiator fan: Spal 16" (waiting on engine harness to confirm wiring schematic since I'd like to go with PWM)
  2. Water pump + tensioner: I will buy OEM (must fit above radiator and be truck or f-body offset) also need a thermostat?
  3. Harmonic Balancer with correct offset: F-Body offset: ACDelco (OEM) 12553118, Truck offset: ACDelco (OEM) 19300488. Replace TTY bolt.
  4. AC bracket: Holley low-profile or Dave's Customs high mount. I'll get the engine in before deciding which will fit.
  5. Transmission shifter: I'd like a 6 position. I'm undecided between a Winters + tap or using an OEM tap shifter. It'll probably come down to what fits best.
  6. Engine oil pan: Kevko or Tilden/Pacific.
  7. Oil filter relocation kit: Wait on pan.
  8. Transmission fluid: Dexron VI
  9. Radiator coolant: Decide between G05 (HOAT) or Dexcool (OAT).
  10. Dash gauges: Maybe Autometer for essentials + Torque app for other stuff? I don't love how Autometer gauges look.
  11. Exhaust headers: CTS-V + heat shields (waiting to order until I have a visual on how the engine fits)
  12. Engine oil: 5w30 synthetic Amsoil (leftover from the Jeep 4.0). Driven Racing 5w30 Break in oil first (optional, but not a bad idea).
  13. A ton of bolts for attaching enginey parts to the engine.
  14. Air filter: I'm waiting to see what space I have left to fit it in.
Ordered:

  1. Radiator: Superior Radiator - I've heard this one lasts longer than others do. (http://rover.ebay.com/rover/1/711-5...0001&campid=5337789113&icep_item=164219718305)
  2. Accessory brackets: I'll be going with GoatBuilt's driver's side brackets for the alternator and PSC CBR pump (truck or f-body offset)
  3. Power steering pump: I'll be reusing my CBR pump off the TJ 4.0 and bought a 6" pulley offset for the LS.
  4. Alternator: Mechman high output alternator (probably overkill but 180a at idle will be awesome for heavy winching).
  5. Transfer case: Atlas 2 speed 3:1
  6. Transfer case fluid: Comes with Atlas.
  7. Ignition switch: Retain the stock keyed ignition on the steering column.
  8. Spark plug boot pliers
  9. Engine mounts: There's no mounting kits that will work for me so I'll use universal style brackets and make my own.
  10. Trans/TC mounts: AutoFab bushings
I also need an engine hoist and to replace my recalled Harbor Freight jack stands.

I'll probably use pallets and wood for an engine stand since it won't spend much time outside of the Jeep.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #19
A small update:

Advance Adapters recommended the stronger G2 Pro case for me instead of the Trail series (aka. the "normal Atlas" case). They said the Trail series case is typically for stock applications for up to 500hp and the G2 case for over 500hp (although their recommended horsepower does change based on the weight of the vehicle, and my rig is 4800lbs). My engine is a touch under 500hp and if I ever decide to add more power I'd be looking at 630hp so for a few hundred dollars extra I decided the stronger case would be a worthwhile investment to keep the option of more power available. It's also 7-10lbs lighter then the Trail series and exactly the same physical size externally so there's no downside. They also have an even stronger racing case which they did not recommend for me.

They're also having trouble getting small parts due to coronavirus. They project starting work on my case in 6 weeks and shipping it to me in 8 weeks.
 

·
Registered
Joined
·
484 Posts
Discussion Starter #20
toximus said:
I don't know enough about why but the LS3/480 6L80e kit only comes with the higher 3000-3400k stall speed converter. The LS3 430 comes with the 2400-2800k stall torque converter.
I made some calls and found the answer to why the LS3/480 only comes with the 3000 stall. It has to do with the duration of the camshaft. If a lower stall converter is used, the output (ie. the vehicle) would be jumpy/lunges at slow speeds. The downside is that the converter won't lock up until higher rpms and will cause more heat. The transmission will lock up in overdrive so it won't be an issue on the highway.
 
1 - 20 of 40 Posts
Top