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

mdmike said:
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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That sucks. Mine just got delivered today. Have they responded to your warranty claim yet?
 
toximus said:
That sucks. Mine just got delivered today. Have they responded to your warranty claim yet?
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To their credit, they responded to my Ebay message the same day I sent it with the response "Send it back to us and we will look at it".

After being told over the phone that, "They know how us Jeep guys are by zip-tying a fan to the radiator and beating it up off road", I had a strong suspicion any warranty claim was a lost cause.

Unfortunately my Jeep was my daily driver at the time, so I couldn't be without it. (Hence me trying to buy another of the same radiator and accepting a refund at a later date.)

I ended up smearing some JB weld on the leak and running it until my new radiator showed up. I had to rework my fan mount and hoses for the new radiator, so a replacement from Superior wouldn't have done me any good after the fact.

I sincerely hope you have better luck with their radiator than I did.
 
mdmike said:
To their credit, they responded to my Ebay message the same day I sent it with the response "Send it back to us and we will look at it".

After being told over the phone that, "They know how us Jeep guys are by zip-tying a fan to the radiator and beating it up off road", I had a strong suspicion any warranty claim was a lost cause.

Unfortunately my Jeep was my daily driver at the time, so I couldn't be without it. (Hence me trying to buy another of the same radiator and accepting a refund at a later date.)

I ended up smearing some JB weld on the leak and running it until my new radiator showed up. I had to rework my fan mount and hoses for the new radiator, so a replacement from Superior wouldn't have done me any good after the fact.

I sincerely hope you have better luck with their radiator than I did.
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That certainly would be frustrating. Coming from the TJ world, it seems that all welded aluminum radiators end up leaking sooner rather than later. Too bad there's no OEM solution...
 
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.
 
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....m=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.
 
If you want a radiator not to spring leaks, you need to allow for movement when you mount it. Core supports twist and flex, radiators don't, so any radiator bolted directly to the core support will spring leaks at some point.
 
gt1guy said:
If you want a radiator not to spring leaks, you need to allow for movement when you mount it. Core supports twist and flex, radiators don't, so any radiator bolted directly to the core support will spring leaks at some point.
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I'll be mounting mine to the TJ grill like OEM which is a firm structure. Fingers crossed!
 
Having never dealt with them before, what is the deal with steam vents on the LS? Do I use stock location vents on the valley cover or tap into the upper radiator hose too? It looks like if I use spacers for the water pump some are already tapped for a vent too.
 
toximus said:
I'll be mounting mine to the TJ grill like OEM which is a firm structure. Fingers crossed!
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I think I got this pic from pirate a while back. It's a great way to mount a radiator and allows flexing in the core support.


radiatorMt.jpg






toximus said:
Having never dealt with them before, what is the deal with steam vents on the LS? Do I use stock location vents on the valley cover or tap into the upper radiator hose too? It looks like if I use spacers for the water pump some are already tapped for a vent too.
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I bought a kit from Summit that ties all 4 steam ports together into one hose to be connected into either the radiator or radiator hose. The LS3 Crate engines come with the rear two steam ports blocked off.

I have a steam port connection on my radiator because everything is hacked up and I had to do a custom radiator.


Quick steam port class:

Basically, on an LS engine, the upper radiator hose is not at the highest point of the engine like the old SBC's. So any bubbles in the system can get stuck and if let to collect, will create hot spots and overheating. The steam ports allow the bubbles a way to escape and end up by the radiator cap
 
gt1guy said:
I think I got this pic from pirate a while back. It's a great way to mount a radiator and allows flexing in the core support.










I bought a kit from Summit that ties all 4 steam ports together into one hose to be connected into either the radiator or radiator hose. The LS3 Crate engines come with the rear two steam ports blocked off.

I have a steam port connection on my radiator because everything is hacked up and I had to do a custom radiator.


Quick steam port class:

Basically, on an LS engine, the upper radiator hose is not at the highest point of the engine like the old SBC's. So any bubbles in the system can get stuck and if let to collect, will create hot spots and overheating. The steam ports allow the bubbles a way to escape and end up by the radiator cap
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So if I understand the steam ports correctly, the steam collects at the block (under the valley plate) and needs to be released into either the upper radiator hose (which the pump spacers allow for) OR the radiator? Since my radiator has a steam port I can route the hoses from the valley plate to the radiator without doing anything with the upper radiator hose?
 
Yes. If you have a steam port in the radiator, you're good to go. The whole goal is to get the bubbles to the radiator.

I would look into the kits that make use of all 4 steam port locations and ties them into one hose. I think the Summit kit I bought was $50. Just seems like good insurance to me.
 
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.
 
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.
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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.
 
I talked to Chris at Circle D this morning and he answered all of my questions about which torque converter to go with for my uses and recommended their 278mm torque converter in 2600-2800 rpm stall: https://www.circledspecialties.com/6...p-series-278mm I'll be able to reuse the stock flex plate.

He mentioned this converter would work well for the stock cam LS3 430 and the hot cam 480 (the one I'm planning on going with) and if I supercharge in the future. It will smooth out the chop from the hot cam so it'll still idle and crawl well at low speeds/rpms. The 278mm converter is 11 inches in diameter making it about an inch smaller in diameter than factory which is where most of the higher stall rpm comes from. The smaller diameter will help to transfer less fluid at idle. This will give less pushing at the brakes, because of the cam. The 2600-2800 stall will allow the pedal to feel connected while not being too tight for the cam. This converter is rated to around 550rwhp or 750rwhp if I upgrade the front cover to billet (which could be good if I boost).

It sounds like Chevy "fixed" the choppy cam by installing their 3000k converter which probably works for 99% of their customers who are installing them into hot rods/drag applications.

Having had no first hand experience, I'm contemplating keeping the 3000k stall in for now and if I don't like it I'll swap it out for the Circle D. That way I'll know why it needs to be changed and gain experience of the difference. It seems like it'd be an easy enough thing to swap on a weekend even after being installed. Unless somebody knows for sure that it's going to be terrible?

What do you guys think?
 
I ended up with a 2800 stall converter from Edge Racing Converters. That was what they recommended after telling them 525hp, 6k weight, 45" tires and 5.13 gears. The guy I know who put the same engine in his 2dr on 40's was recommended a 3200 stall converter from Edge. Same engine, different weight and tire size.

I think it would be cool to try them both out. Give you a chance to actually feel the difference. From my very limited knowledge from talking to the smart people, I'd give the 3k a try first.
 
Welp, I'm learning a lot!

It's sounding like even though the LS3 480 dyno charts all look great and very usable for a Jeep, the quality of the low range RPMs is choppy and will cause the tires to lurch, breaking traction, as the engine chops. This problem can be smoothed out with a different torque converter (as I mentioned in a previous post), but that only trades for another set of problems that I worry I'll still be fighting with a custom torque converter like the Circle D. Additionally, from what I understand the 480 needs a higher idle (not good for a Jeep application). The stock LS3 430 will behave exactly like a production LS3, idle at 550rpm, and I can use a lower stall torque converter.

I asked 2 of the main companies that do LS swaps into JKs their experience with the 430 and 480: They said the 480 can be done and has been done and took a long time to figure out a decent tune. The consensus from both was that they prefer the 430 for crawling, cruising, daily driving, and what they'd choose for their own. The 480, they said, is fun for spirited driving.

It feels wasteful leaving 65hp and 50lbft of torque on the table, but I'm starting to think I'd only be trying to tame how wild the hot cam wants to be. If the stock LS3 at 430hp isn't enough once I get it installed, I suppose I can use that as an excuse for a supercharger which would keep the slow speed/low rpm crawling feeling like stock but still let the Jeep eat with a heavy foot.

I'm still doing research to confirm all of this before ordering but I'll probably error on the safe side of knowing what works instead of trying to be the first...
 
gt1guy said:
I ended up with a 2800 stall converter from Edge Racing Converters. That was what they recommended after telling them 525hp, 6k weight, 45" tires and 5.13 gears. The guy I know who put the same engine in his 2dr on 40's was recommended a 3200 stall converter from Edge. Same engine, different weight and tire size.

I think it would be cool to try them both out. Give you a chance to actually feel the difference. From my very limited knowledge from talking to the smart people, I'd give the 3k a try first.
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Has your buddy mentioned if the chop from that ASA cam can be felt while crawling?
 
I hope I'm not exasperating anyone with my research (if so, you might want to check back in 2 months once the major components arrive)! I know this build thread is a much different pace than my main build thread and shares more thoughts, ideas and concerns rather than solutions like my other thread did. The research is so I hopefully can make things work well the first time.

If I had infinite money to try out different engine and transmission combos it'd be fun to try them all and get answers to my concerns and real world data about which combo works best.

Hopefully this thread will still have great solutions to the goals I outlined in my first post!
 
Keep it up. I have no use for any of this tech today, but you never know what tomorrow will bring. I'm here to learn, so keep the tech coming! Thanks!:beer:
 
toximus said:
Has your buddy mentioned if the chop from that ASA cam can be felt while crawling?
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He never mentioned any issues coming off idle (chop) or due to the stall of the converter.

He's since sold the Jeep and got into SxS's.
 
I stumbled across something interesting!!! I'm not going to be the first one to tuck the 6L transmission on an LJ! I sent him a message and the transmission pan doesn't hang below the frame either. It's a bit of a relief to see that it tucks nicely and the amount of cutting required appears to be acceptable.

cutting-for-flat-skid.png


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105926579_10103889528904819_387972966220404085_n.jpg


83870963_10103889528919789_2863954056343654617_n.jpg
 
Yep. If you cut a big enough hole.........anything can fit anywhere.:smokin:

If I'm not mistaken, the G8 pan for the trans is an inch or so shallower too.
 
gt1guy said:
Yep. If you cut a big enough hole.........anything can fit anywhere.:smokin:

If I'm not mistaken, the G8 pan for the trans is an inch or so shallower too.
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That pan is and I plan to use it. 👍
 
I settled on an LS3 430hp (basically the production engine) with a 6L80e in the connect and cruise package. I don't know enough if the hot cam in the 480 will be an issue or not and I'd rather go the easy route for now and stick with what I know will work. If I get bored in the future and want to invite trouble I can always do the cam swap myself. I caught wind that the wiring harnesses for the connect and cruise are drying up since that GM facility is having issue making them due to COVID. On that note I decided to place my order now instead of waiting for the transfer case to be ready.


Here's my updated shopping list:
  1. Radiator fan: Spal 16" brushless 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. Radiator coolant: Decide between G05 (HOAT) or Dexcool (OAT).
  9. Dash gauges: Maybe Autometer for essentials + Torque app for other stuff? I don't love how Autometer gauges look.
  10. Exhaust headers: CTS-V + heat shields (waiting to order until I have a visual on how the engine fits)
  11. Engine oil: 5w30 synthetic Amsoil (leftover from the Jeep 4.0). Driven Racing 5w30 Break in oil first (optional, but not a bad idea).
  12. Air filter: I'm waiting to see what space I have left to fit it in.
  13. Starter + heat shield
  14. 6L80e shallow pan
Ordered:
  1. Radiator: Superior Radiator - I've heard this one lasts longer than others do. (http://rover.ebay.com/rover/1/711-5....m=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
  11. A ton of bolts for attaching enginey parts to the engine.
  12. LS3 430 + 6L80e Connect and Cruise
  13. Transmission fluid: Dexron VI
  14. 4 corner steam vent kit
 
ARP Balancer Bolt 234-2503


This is the balancer bolt to get to replace the TTY factory bolt. It is not a TTY bolt and can be reused. If I remember right it takes 235lt/lbs.
 
gt1guy said:
ARP Balancer Bolt 234-2503


This is the balancer bolt to get to replace the TTY factory bolt. It is not a TTY bolt and can be reused. If I remember right it takes 235lt/lbs.
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Ordered!
 
I asked Jon at RPM Extreme about their PWM fan controller compatibility with the SPAL brushless fan and he mentioned that he isn't sure if their module would work with the connect and cruise harness/ECU but would work fine with the fan. After discussing his experience integrating with the LS electronics some more, it turns out that the connect and cruise setup may be limited in functionality. Instead, he'll be making me a custom harness with support for the LS3 and 6L80e with all of the features I want and providing a GM E38 ECU for my swap.

For once in my life I was actually thankful to have an order get caught up in the fraud department which allowed me time to cancel my connect and cruise order and order only the LS3 430 engine (19370416).

The transmission is the confusing bit... RPM Extreme has only confirmed their harness to work with the production 2011-2013 Chevy Silverado 6L80e. I talked to several dealers and they are only able to program a new production or performance transmission if it's installed in a Chevy truck with a Chevy VIN. After a few phone calls to aftermarket transmission builders, I talked to Zero Gravity Performance. And that guy really seems to know his stuff! He said he actually worked for Chevy until 2013(iirc) and had worked on the Performance 6L80e design for them. He also can reflash any of the TCMs to be any other TCM and be programmed to work with any of the ECUs (not even limited to GM). And he could help me if I buy the Chevy Performance transmission or one of his. I gave him the specs of my Jeep and what I'm planning to do with it and he'll be getting back to me with a quote for one of his built 6L80e transmissions -- he mentioned it'll probably be somewhere between his stage 1 and stage 2 transmissions.

I'll now need to pick out an accelerator pedal too.

---

The custom harness from RPM Extreme will include:

PWM Fan Controlers

One controller for the main radiator up front and a second controller if I end up running a second transmission cooler with fan. He can add up to 4 fan controllers per harness, after that you have to use multi-speed brushed fans.

This will allow for PWM brushless variable speed fans to work. These fans tend to have longer lasting motors and can slow down or speed up the rotation of the fan based on ECU factors such as radiator temp, if the throttle is above a certain percentage, or if the AC is turned on. It should be less sensitive to stalling so hope it'll fair better if I forget to turn it off during a deep water crossing.

Alternator Voltage Bump

Without, the alternator will fall back to 13.2v. Their module will output the alternator request signal to the GM E38 ECU and command the alternator to 14v which is perfect for the EGM batteries we use.

Reverse Lights

Add an output wire for the reverse lights using the CAN signal from the 6L80e.

Tap Shift

So I can manually select gears. The connect and cruise also has this available.

Tow/Haul Mode

Since my Jeep really isn't set up to do any towing I can use this mode as an alternate shift table. I'm not sure that I'll use it, but it doesn't hurt to have the provision available.

AC Signal

Lets the ECU know when the AC is turned on. This allows for things like RPM bump at idle and turning on the radiator fan when the AC is running.
 
Here's the transmission options I'm considering:

Chevy Performance 6L80e: $3185 shipped ($4145 MSRP).
  • New manufacture
  • 2400-2800k stall
  • Ready to ship
  • 24 months or 50,000 mile warranty.
  • I'm not sure how good Chevy support is.

Zero Gravity 6L80e: $4700 shipped.
  • Added extra clutch plate. Raybestos High energy GPZ Clutches. Tig weld some internal drums.
  • Reman with new pumps and computer ($1000 more for all new)
  • 2800-3000 Stall (can be sold without)
  • 24 months or 24,000 miles warranty.
  • 1.5 to 2 weeks lead time
  • The guy running the company seems like he's more than knowledgeable if there are issues.

Based on my previous research the converter stall speed is on the high end for my application. Another option is buying the Zero Gravity transmission without and going with the Circle-D 278mm 2600-2800 stall converter I mentioned a few weeks ago.

The price difference is nothing to sneeze at. But if the benefits for my uses outweighs the price difference I can make it work.
 
Jon at RPM Extreme really does know his shit doesn't he? I always enjoyed talking with him.

I have read a couple times that there were issues with limits on the tuning ability with the connect and cruise setups. I would guess GM just doesn't want folks digging very deep and screwing things up.

How did Jon say the tow/haul mode would be activated? Is it done by a switch?
 
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