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

The brackets I have are the high mount alternator and P/S pump versions. We were using those to keep the accessories out of the links. Only problem with using those is that the crate motor water pump and harmonic balancer dont work with them. Brackets were designed for truck mount serpentine belt setup.

I'll have to dig in my storage container to find them to get you the part #'s. It may be a few days
 
SLOWPOKE693 said:
The brackets I have are the high mount alternator and P/S pump versions. We were using those to keep the accessories out of the links. Only problem with using those is that the crate motor water pump and harmonic balancer dont work with them. Brackets were designed for truck mount serpentine belt setup.

I'll have to dig in my storage container to find them to get you the part #'s. It may be a few days
Click to expand...

No worries. I'll wait. I'm also interested in the CBR pump pulley. I already have a CBR pump off the Jeep 4.0.
 
The balancer and water pump that come on the crate engines have the corvette spacing. Basically it's the tightest spacing to keep the accessories as close to the engine as possible. Corvette spacing is followed by F-body/GTO and then the truck spacing. I believe the technical term is belt spacing.

Here's how they shake out:

Corvette

F-Body/GTO is + 3/4" over the vette

Truck is + 1.5" over the vette

GM makes one front drive kit that comes with or without ac . It has all the brackets, alt, tensioner, I think the starter and a few other things. It only comes in vette spacing. The ac bracket is a low pass side mount and the alt is a low dvr side mount. They call it the CTS-V drive kit.

Goat built brackets come in F-Body or truck spacing.

I had bought the CTS-V drive kit for my JK, But as soon as I started setting up the double triangulated front links, the ac and alt brackets were in the way (read way too low). I ended up with Goat built high mount alt/ps F-body brackets and ITC high mount ac bracket, also in F-body spacing.
 
gt1guy said:
The balancer and water pump that come on the crate engines have the corvette spacing. Basically it's the tightest spacing to keep the accessories as close to the engine as possible. Corvette spacing is followed by F-body/GTO and then the truck spacing. I believe the technical term is belt spacing.

Here's how they shake out:

Corvette

F-Body/GTO is + 3/4" over the vette

Truck is + 1.5" over the vette

GM makes one front drive kit that comes with or without ac . It has all the brackets, alt, tensioner, I think the starter and a few other things. It only comes in vette spacing. The ac bracket is a low pass side mount and the alt is a low dvr side mount. They call it the CTS-V drive kit.

Goat built brackets come in F-Body or truck spacing.

I had bought the CTS-V drive kit for my JK, But as soon as I started setting up the double triangulated front links, the ac and alt brackets were in the way (read way too low). I ended up with Goat built high mount alt/ps F-body brackets and ITC high mount ac bracket, also in F-body spacing.
Click to expand...

I was starting to look into that... Closer spacing sounds nice but it also sounds like it doesn't allow the accessories to sit as tight in either? Based on my very limited research, it seems like the F-Body spacing is a good compromise.

If I remember correctly, Drew at GoatBuilt said the 2010 Camaro is the one I need (I'll verify that with him before buying parts).

SLOWPOKE693 I was just thinking, that because I'm probably going to be asking a million questions about the different kits GoatBuilt offers (seems that they have 3 or so with very similar spacing to what I'm looking for) I might be best off buying directly from GoatBuilt so I can ask all of my questions about their kits. I wouldn't want to be rude in order to save a little coin. If I knew what I wanted I wouldn't hesitate taking those off your hands. I might buy the alt and PSC pump off you though if they're the ones I need... Doesn't hurt to have a spare.

Once I start looking into pans and such I'll probably be buying some stuff off ya.

I'm running a 3-link+TB front so I can move the engine over to that side more or maybe place an AC pump over there. So far I've looked at the Holley AC low-pro bracket or Dave's Customs high mount (although it's only truck spacing). I'll look at the ITC kit too. Ultimately I'll probably wait to put AC in until I can mock up the engine and have an idea of what space is remaining.

This shows approximately how high the axle travels into the engine bay. Looking at the CTS-V diagram I don't see that working for me either...

Click image for larger version Name: 20190329_UCA.jpg Views: 0 Size: 304.5 KB ID: 32189
 
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gt1guy Which style alternator plug does your GMPP harness have? 2 or 4 pin?
 
My research has come up short... does anyone know of an f-body or corvette (with spacers) depth water pump that fits this radiator with both the inlet and outlet on the passenger side? My research only shows truck spaced pumps that will work.

s-l1600.png
 
Alternator has a two pin plug. My harness isn't from GMPP, it's a stand alone harness from PSI conversions.

Are you looking at the "connect and cruise" GMPP setups? I ask because you mentioned the GMPP harness. I wouldn't recommend going that route. The ECU's that come with them, locks you out of a lot of stuff.

I bought a brand new E38 ECU from GM. It was only a couple hundred bucks. I'll be sending that and the trans TCM off to get "loaded, tuned, whatever you call it". That way I'll get all the functionality that the VIV# and OS allow.
 
gt1guy said:
Alternator has a two pin plug. My harness isn't from GMPP, it's a stand alone harness from PSI conversions.

Are you looking at the "connect and cruise" GMPP setups? I ask because you mentioned the GMPP harness. I wouldn't recommend going that route. The ECU's that come with them, locks you out of a lot of stuff.

I bought a brand new E38 ECU from GM. It was only a couple hundred bucks. I'll be sending that and the trans TCM off to get "loaded, tuned, whatever you call it". That way I'll get all the functionality that the VIV# and OS allow.
Click to expand...

That's good to know. Does the E38 swap with the connect and cruise harness? I'm not sure I need a bunch of features right away so it might be easier for me to start with the connect and cruise ECU and swap it out later if I need to.

Edit: It sounds like some of the stuff that used to be inaccessible is now accessible with HPTuners. https://forum.hptuners.com/showthrea...ect-and-cruise
 
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The bracket kit, alternator and PSC pump/pulley came directly from Goat Built along with the water pump and balancer. I ordered it all at once from him to avoid getting the wrong parts. It may be the Camaro stuff and not for truck mount. Like I said.... I'll have to check the invoice and box it's all in.

The pan, mounts and *other shit came from misc vendors
 
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Drew recommended that we used the GMPP harness & computer kit because it was the most reliable setup available. He said other "kits" were hit and miss as far as quality.
 
I don't know those answers. I could come up with some "I think" answers, but that's not what you need.

Call PSI Conversions or anyone who makes conversion harnesses for the LS3's. They'll know all about the connect and cruise stuff and whether it would be a good fit or not for what you want. I mention PSI because they've always answered any questions I had, not just because I bought their harness.

Does GM even make a connect and cruise with the 6l80?
 
gt1guy said:
Does GM even make a connect and cruise with the 6l80?
Click to expand...

Good question.

We were going to use a Jake's Performance built TH400 behind the crate motor so I never even bothered to inquire about that.


I know there are stand alone options for controlling that transmission.
 
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toximus said:
My research has come up short... does anyone know of an f-body or corvette (with spacers) depth water pump that fits this radiator with both the inlet and outlet on the passenger side? My research only shows truck spaced pumps that will work.

Click to expand...

What comes stock on the crate motor as far as water pumps? I don't think the truck, vette or camaro water pumps are any different as far as the inlet goes. All dual pass radiators have the inlet and outlet on the same side. If they are not, it's not a dual pass radiator.

I would use napa flex radiator hoses to make it all work.
 
The LS3 crate engines come with a vette water pump and balancer.

Camaro and Vette water pumps. Top hose placement is slightly different and they take different part # for the thermostat.


DSC06199.JPG



Camaro pump on right, Vette on left. As you can see, the Camaro pump could work with the Vette spacing but, the Vette pump will only work with the Vette spacing.


DSC06202.JPG



Camaro balancer on left, Vette on right.


DSC06213.JPG
 
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:
4l75-gears.jpg


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:
6l80-gears.jpg


Comparing both with a gear chart:
gear-ratio-comparison.png

(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):

    A6 Trial 000ee.jpg


    rsz288 LS1Tech (https://ls1tech.com/forums/conversio...o-does-go.html)

    4L60 vs 6L80:

    4L60 VS 6L80-TOP- VIEW-2.jpg


    4L60 VS 6L80-SIDE VIEW-2.jpg


    Goat1 Pirate4x4 (https://www.pirate4x4.com/threads/wh...#post-26192233)

    6L80e truck pan vs G8 pan:

    6L80 TRUCK VS G8 PAN.jpg


    Goat1 Pirate4x4 (https://www.pirate4x4.com/threads/ke...#post-15045419)

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.
 
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).
  • Radiator: Superior Radiator - I've heard this one lasts longer than others do. (https://www.ebay.com/itm/87-2005-Jee...d/164219718305)
  • 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?
 
Don't know if these pics help any or not. This is a driver drop Hero 3spd and a 6l90.


DSC00768.JPG



Shitty pic but you can see that the driveshaft does clear.


DSC01004.JPG




The drive shaft actually comes closer to the nub things that stick out of the factory cast pan than the trans itself.


DSC00945.JPG



I'd recommend getting a PacificFab steel oil pan and get rid of the factory cast one. Cast aluminum pans don't dent, they shatter.


PacificFab steel pan with the trap doors on the inside and the 1/8" armor on the outside. Comes with a new oil pickup tube.


DSC00981.JPG




Some more data:
The 6l90 is 1.5" longer than the 80. It's due to having more clutch plates inside.
 
Are those pics on your JKU I don't recognize the floor pans? Did you have to remove the sump bulge on the engine pan to clear the front driveshaft?

I think that's the pan SLOWPOKE693 said he had. Once he finds his pile of spare LS parts I'll probably buy it off him.
 
Yes, it's on my JKU. There's not much factory floor pan left to recognize. With having to move the whole drivetrain back 4", the 6l90 being longer and the Hero being a bit larger than the stock 241, all of the factory tunnel was removed and most of the firewall is new. Everything missed the humps and bumps in the factory floor.

I just used the seat mount framework to form the shape of the new tunnel. Lots of room for airflow around the trans and I made a removable access panel right above the back of the trans/TC. She's ugly, but a few coats of LizardSkin might make her doable.

DSC00396.JPG



Didn't have to touch the factory oil pan for the driveshaft to fit. The PacificFab pan isn't any wider than the factory one, so should have no issues.


He's a pic of the two titties sticking off the factory pan. Driveshaft doesn't touch them when the suspension is cycled, they are just the closest things it comes to. You wouldn't need to remove them, but I had planned to just sawzall them off. I honestly have no idea what they are actually for. I would assume some other model vehicle bolts something there. There are a couple other ones up higher too, they might be for the factory trans cooler lines.

You can also see how high the transfer case is clocked so I'd have a flat bottom. So basically I'm just showing you worst case scenario pics.:flipoff2:I'm running the equivalent of 3.25" lift, a flat bottom and 6" of up travel. So the front driveshaft is going way higher than most.


DSC09222.JPG
 
It's been a while since I looked at your build thread (I don't follow many). Oh man, you've done a TON of body work!

Even though yours is a JKU, yours may be the most similar to how mine will fit. I'll hire you to come here and make me a new transmission tunnel! 😁
 
gt1guy What signal do you have set for your dash speedo?

I'd like to display the correct speed on the dash when in low range. My understanding is that there is no good way to use the low range switch to correct the PCM (at least with the connect and cruise kit). I supposedly can use the low range switch to go into tow/haul mode and can change shift points for low range if needed.

I have a few options available...

1) Low range switch.
2) Reluctor ring in adapter
3) VSS in tail housing (makes the tailhousing longer than if I go without)

If I can't correct the PCM speed, ideally I could find a simple A/B program speedohealer that could be toggled by the low range switch (and use the reluctor ring signal if I have to).

Ideas?

Edit: Now that I actually think about it I'm not sure that I've ever looked at my speedo while in low range... I suppose I'll have to make sure any speed limiters are turned off since 45mph * 3 = 135mph. And my dash gauge will probably be past the stop.
 
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I have a VSS in the output of the Hero. If I remember right it's 3 pulses per revolution. That will run through a Dakota Digital signal converter to the ECU (I don't remember off hand what the ECU is looking for) . That should always be the true speed of the vehicle. I have a AEM digital dash display that runs off the OBDII port.

As for low range, I think I'm looking at some kind of toggle to tell the computer it's in low range. My problem, and I need to talk to a tuner about it, is that I have two low ranges, 2.74 and 4.33. I have a hunch it wont matter and all I'll need is the switch to tell it it's in "low range". A toggle just seems like a good quick and dirty solution.....................until you forget to switch it:eek:

As a side note, the factory speedo in my JK did always read the correct speed, even in low.
 
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.
 
toximus said:
Here's my shopping list and notes so far (this list is subject to change).
Click to expand...

Please see post #12 from my Hemi swap thread before you pull the trigger on this radiator.

https://irate4x4.com/jeep/tj/25994-m...emi-powered-lj

Other folks may have had great luck with their Superior radiator, but I did not. A broken/leaking radiator would have been almost acceptable if their customer service wasn't absolute garbage. If you have a problem keep in mind, you will have to remove your radiator, ship it back for "inspection", and only then will they send you a new one if they find themselves at fault. Even offering to buy a new one and accept a refund fell on deaf ears.
 
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