Registry 8x Series V8 Swaps (28 Viewers)

[thatcabledude]

8 years and over 100k miles of Florida heat, towing boat in the summer, lots of time in TX during August AC blasting, summer wheeling in CO, Moab in July etc. Still never had these issues with stock radiator and mech fan. Rarely touches 200. And when it does, it’s brief and never more than like 205.

Just a lowly 5.3 though.

 

[Tinkertoy]

X3 on ron davis radiator last swap I did went to Phoenix AZ I also used gm fan clutch fan and custom fan shroud. I personally prefer mechanical fan with fan shroud. Finishing up a swap now with a ebay or Amazon radiator with two 10 inch fans of I don't know what origin that the customer supplied radiator hoses are two piece witch I hate Ron davis radiator can be made to fit stock 1fz size or ls . Like what @NCFJ mentioned are you sure everything is correct this is also why I asked for pictures of your engine bay but no pictures yet.....

Do you have a couple pictures of the engine bay in a few different angles are you running a aftermarket front bumper what tire size?

Thanks to all who have responded. Below are pics from my rig.

I suspect my problem is airflow so I will change to the Derake fans that I have that are 4000cfm. I will also add back my external oil and trans cooler. The final thing will be to address the IAT to see if I can lower that. Once done then I can reevaluate.

PS ignore the wiring for the fans that is temporary

 

[Tinkertoy]

8 years and over 100k miles of Florida heat, towing boat in the summer, lots of time in TX during August AC blasting, summer wheeling in CO, Moab in July etc. Still never had these issues with stock radiator and mech fan. Rarely touches 200. And when it does, it’s brief and never more than like 205.

Just a lowly 5.3

Thanks. I ran the stock radiator too based on your advice. I also had a 160 thermostat in there with the Derale e fans. I only had issues on long mountain climbs with AC on. I assumed it was the rad so I put in this new one and eliminated the external coolers to help with airflow. Seems like this test went backwards.

Thanks for the input.

 

[wiynwiyn]

Saw that you don't have an air box.
An air intake without a box can contribute to transmission overheating indirectly, especially in hot climates or with poor install. It’s not the intake alone—it’s the combination of airflow, heat, and cooling system efficiency that can lead to problems.
If you're seeing overheating, check cooling system components, and consider reinstalling a heat-shielded intake or factory airbox to isolate the issue.

I'm using this fan (4,000 cfm). I should have used the mechanical fan but too late. Was using a single fan, ford taurus, was a mistake (too loud).

 

[Tinkertoy]

Saw that you don't have an air box.
An air intake without a box can contribute to transmission overheating indirectly, especially in hot climates or with poor install. It’s not the intake alone—it’s the combination of airflow, heat, and cooling system efficiency that can lead to problems.
If you're seeing overheating, check cooling system components, and consider reinstalling a heat-shielded intake or factory airbox to isolate the issue.

I'm using this fan. I should have used the mechanical fan but too late. Was using a single fan, ford taurus, was a mistake (too loud).

View attachment 3940236

Thanks.

I have those fans as well. The mechanical fan moves about 4K CFM as well, so the only issue with these is that they take a lot of AMPS to run. FYI. I am in Seattle too. I am looking for an airbox. I haven't found one that I love yet.

 

[wiynwiyn]

I'm running this transmission cooling fan as well. I like the original air box look. Still putting the rebuilt engine back so it looks messy.

 

[Tinkertoy]

I'm running this transmission cooling fan as well. I like the original air box look. Still putting the rebuilt engine back so it looks messy.
View attachment 3940251

View attachment 3940252

View attachment 3940253

I had the original airbox and my tuner said it was restricting about 20% of airflow. So I pulled it.

I 3D printed a box and ran that for a week or so and while it looked good in there. Still felt like it was restricting air.

 

[tmxmotorsports]

@torfab has a nice air box it's expensive no restrictions only thing I don't like is it doesn't come with anything to fill the gap between the air box and the inner fender where it pulls air from I did message them they recommended something but it doesn't come with anything for the price it should be included cough cough @torfab

 

[tmxmotorsports]

Tire size gearing also is your torque converter locking up?

 

[Tinkertoy]

Tire size gearing also is your torque converter locking up?

35's and no it doesn't lock up until 4th if I remember correctly. I have Matt Sanford tune it. You can find him on YT. Very knowledgeable. I have a few things to do to it...so I will make some changes and report back.

 

[PIP]

My experience with the 80 series cooling package is it will keep anything cool with a mechanical thermostatic fan and shroud.

I drove my 97 120 miles last week when it was 96 degrees. From sitting in traffic with AC on to 80 mph on the freeway it was solid at 180. This is with a 5.9 Cummins though.

I have seen the best electric fans fail to cool swapped 80 series in Arizona and New Mexico heat. Mechanical always works.

Don't believe all the electric hype. You can only pull 40 amps @ 14v through a 10awg wire. That's 560 Watts or .75 HP.

A mechanical fan can easily push 10 times that HP of airflow.

 

[tmxmotorsports]

My experience with the 80 series cooling package is it will keep anything cool with a mechanical thermostatic fan and shroud.

I drove my 97 120 miles last week when it was 96 degrees. From sitting in traffic with AC on to 80 mph on the freeway it was solid at 180. This is with a 5.9 Cummins though.

I have seen the best electric fans fail to cool swapped 80 series in Arizona and New Mexico heat. Mechanical always works.

Don't believe all the electric hype. You can only pull 40 amps @ 14v through a 10awg wire. That's 560 Watts or .75 HP.

A mechanical fan can easily push 10 times that HP of airflow.

This! I love wiring and stuff been into car audio over 30 years was a shop Forman at a car audio shop for years when I started building truck I implemented all my wiring knowledge to that so of course I went with electric everything gauges fuel pump cooing fan whatever cooling fans were the first thing to fail horribly on a vehicle I wanted to be able to drive anytime was also on 44 boggers lol . I've helped build race cars monster trucks pro mega trucks and of course those all had electric fans but they are race vehicles. I've had factory vehicle fans fail also not even from a relay or burnt up wiring but from the temp sensor that controls the factory gauge and the fans. There are situations where electric is the only way to go and that's fine if you can run a mechanical fan with a fan shroud go that route.

 

[cruisermatt]

Let’s see how quick I can get an L96/6l80e combo installed and running in this roller LX I bought last weekend. This one is for me (for now). Interestingly this the truck that had the Duramax/Allison in it.

 

[tmxmotorsports]

A buddy of mine had that same swap in a Tahoe he bought it that way it was a mess but it was different. Are you finished? Lol

 

[NeverFinis]

Just some notes on a recent road trip.

Horsepower​

I happened to look at the Scangauge II as I was accelerating merging into traffic and I saw 387 HP.

I don't think it was floored (probably nearly), or nor did I run it to max rpm.

It is pulling info from the ECM, which needs to know for 6l90e torque management.

Cooling​

I was also stuck in a traffic jam for nearly 2 hours yesterday. It was over 90°F, running A/C full blast the entire time. Ice cold...

During this, engine temp ranged from 193°F to 207°F. Mechanical Fan.

I have read that 210°F is what GM designed to run the motor at for emission reasons and other people have confirmed that is where a LS makes the most power.

Putting in lower temp thermostats in is no bueno.

Electric Fans​

Really hard to find primary information on stock electric fan cooling. Most are parroting what others have written.

Found this electric fan profile graph for a stock 2012 5.3 Silverado. Source

As you can see. Even GM doesn't go 100% fan until 239°F!

These motors can take some heat!

However, I wouldn't be ok with hitting 239°F, with A/C off, like @Tinkertoy did with his electric fan setup.

BTW, I believe the ECM will stop A/C if the engine gets too hot, assuming one did the swap correctly with having the ECM in the A/C control loop. I have to check hp tuners to see what engine temp does the A/C stops running....

 

[girupb]

My97 LX450 LS swap engages the A/C compressor when cranking. I connected it using stock Toyota wiring. Is this normal operation? Of course, this only occurs when the AC switch is left on.

 

[NeverFinis]

My97 LX450 LS swap engages the A/C compressor when cranking. I connected it using stock Toyota wiring. Is this normal operation? Of course, this only occurs when the AC switch is left on.

If wired correctly, your Park/Neutral Switch should disable the A/C compressor via the Starter Cut Relay.

 

[girupb]

If wired correctly, your Park/Neutral Switch should disable the A/C compressor via the Starter Cut Relay.

View attachment 3945471

Thank you! Exactly what I needed.

 

[jdmblingn]

Just some notes on a recent road trip.

Horsepower​

I happened to look at the Scangauge II as I was accelerating merging into traffic and I saw 387 HP.

I don't think it was floored (probably nearly), or nor did I run it to max rpm.

It is pulling info from the ECM, which needs to know for 6l90e torque management.

Cooling​

I was also stuck in a traffic jam for nearly 2 hours yesterday. It was over 90°F, running A/C full blast the entire time. Ice cold...

During this, engine temp ranged from 193°F to 207°F. Mechanical Fan.

I have read that 210°F is what GM designed to run the motor at for emission reasons and other people have confirmed that is where a LS makes the most power.

Putting in lower temp thermostats in is no bueno.

Electric Fans​

Really hard to find primary information on stock electric fan cooling. Most are parroting what others have written.

Found this electric fan profile graph for a stock 2012 5.3 Silverado. Source

View attachment 3944065

As you can see. Even GM doesn't go 100% fan until 239°F!

These motors can take some heat!

However, I wouldn't be ok with hitting 239°F, with A/C off, like @Tinkertoy did with his electric fan setup.

BTW, I believe the ECM will stop A/C if the engine gets too hot, assuming one did the swap correctly with having the ECM in the A/C control loop. I have to check hp tuners to see what engine temp does the A/C stops running....

This is some great info.

I've been chasing temp issues with my swap, but in a different way than most seem to run into here.

I have an iron block LQ9, w/ a stroker kit, cam, and associated bolt on stuff. It's not a racecar, but a bit more than stock. Using an oem LC radiator, a GM mechanical Fan, and a custom fan shroud. Around town, on the highway, even towing a little trailer from Oregon to Colorado, it stays right at about 210. AC, driving it hard, nothing really bothers it. In traffic it will start to creep up a bit, but if you're moving, it comes back down pretty quick.

My issue is when wheeling, in low speed crawling scenarios it creeps up, if you get the engine speed over 2k or so, it'll cool it off pretty quickly. I've seen up to 230 or so in this scenario and as most of you have mentioned, I'm also not happy with it running that hot. It also heat soaks the intake pretty bad (open cone filter, I know...) But I can't imagine that's the only thing contributing to this issue. Especially since my IAT drops significantly again once moving at a reasonable pace.

My thought here was to switch to electric fans to overcome the cooling it needs under 1500 rpm with heavy load in these conditions. Am I way off base here? Is there another issue that I'm missing?

 

[NeverFinis]

This is some great info.

Thanks.

I've been chasing temp issues with my swap, but in a different way than most seem to run into here.

I have an iron block LQ9, w/ a stroker kit, cam, and associated bolt on stuff. It's not a racecar, but a bit more than stock. Using an oem LC radiator, a GM mechanical Fan, and a custom fan shroud. Around town, on the highway, even towing a little trailer from Oregon to Colorado, it stays right at about 210. AC, driving it hard, nothing really bothers it. In traffic it will start to creep up a bit, but if you're moving, it comes back down pretty quick.

My issue is when wheeling, in low speed crawling scenarios it creeps up, if you get the engine speed over 2k or so, it'll cool it off pretty quickly. I've seen up to 230 or so in this scenario and as most of you have mentioned, I'm also not happy with it running that hot. It also heat soaks the intake pretty bad (open cone filter, I know...) But I can't imagine that's the only thing contributing to this issue. Especially since my IAT drops significantly again once moving at a reasonable pace.

My thought here was to switch to electric fans to overcome the cooling it needs under 1500 rpm with heavy load in these conditions. Am I way off base here? Is there another issue that I'm missing?

I have noticed the same, just not to as high. A 20 second blip of the throttle brings it down.

The fact that it comes down fairly quickly with a bit of RPM tells me it might be heat soak of the temp sensor due to its location. I mean, it is right next to the exhaust manifold.

My plan is to wire up Toyota's A/C aux pusher fan into the GM ECM and let the GM ECM handle additional cooling.

This is what HP Tuners is showing me for AC fan control. Note, these are from an ECM (E78) that didn't come with electric fans so the numbers might be bogus.

And Engine Coolant Temperature (ECT).

I have no idea why someone would want a "desired ECT" of 221°F or even 248°F..

As you can see, the above graph is a little different from the 2012 5.3L Silverado that I posted earlier. 100% fan at 213.8°F.

A future project is to wire up that Toyota A/C aux fan, which is still available from Toyota.

My current project is to wire in the fuel tank pressure sensor for the evap system...