December 10, 2019, 06:50:58 PM

Author Topic: Anyone Playing With The New LT Motors Yet  (Read 437 times)

Offline sciff5

Anyone Playing With The New LT Motors Yet
« on: August 08, 2019, 11:58:01 AM »
Sounds like they have all the pros of the LS motor plus some.
Direct injection, variable valve timing (cylinder deactivation depending on how you look at it)

I haven't spent any time looking at them but supposedly the corvette motor is is able to hold a stupid amount of power on the stock bottom end (800-1000) somewhat regularly.
The new 5.3 LT truck motors (L83's) are already getting cheap. Looks like you can pick them up for about $1500 currently, and supposedly can also take 800whp on the stock bottom end, with more power everywhere then the old 5.3s.

I'm starting to feel a bit like an old LT guy. Still living in yester-year LsX heyday.

Offline freeskier7791

Re: Anyone Playing With The New LT Motors Yet
« Reply #1 on: August 08, 2019, 12:21:07 PM »
big question would be tuning, and direct injection motors can have carbon issues. 
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Offline spacevomit

Re: Anyone Playing With The New LT Motors Yet
« Reply #2 on: August 08, 2019, 12:26:05 PM »
Maybe a/w injection would be something to look at for DI motors, just to keep it clean internally.

Offline shainiac

Re: Anyone Playing With The New LT Motors Yet
« Reply #3 on: August 08, 2019, 01:11:33 PM »
The Gen V 5.3L and natrually aspirated 6.2Ls use the same connecting rods as the Gen IV motors (A good friend of mine works in Powertrain at GM and confirmed this to be the case). The pistons are a little different to accommodate the direct injection, but they're not really any stronger than an 05+ engine. They do have better cylinder heads and 12mm head bolts vs 11mm on all the Gen III/IV and older stuff, minus the LS9.

The direct injection is the most challenging stuff part of the swap. I don't know of a conventional (affordable) standalone that can control the GM DI injectors yet. I'm sure it'll come in short time. You can buy a couple different aftermarket intakes (MSD Atomic, Holley Hi Ram) that have port injection bungs and fit the Gen V heads. I think someone makes an adapter plate for Gen V heads and LS7 intake manifold, but couldn't find it when I looked.

For the money, I still think you're better off buying a Gen IV 5.3 if you're planning on boost. A lot of the Gen IV 5.3s came with the 799 heads which are pretty good, too. Gen III/IV have way more options for good cams, and sometimes don't have to delete all of the VVT/DOD stuff. Gen V comes standard with DOD, VVT, and the HPFP stuff that you'd want to delete.
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Offline NOROTOR

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Re: Anyone Playing With The New LT Motors Yet
« Reply #4 on: August 08, 2019, 01:54:29 PM »
I have a L83 and a Magnum waiting to go in my FC. I haven't had much time to play with it.

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Offline Supe

Re: Anyone Playing With The New LT Motors Yet
« Reply #5 on: August 08, 2019, 06:49:32 PM »
The Gen V 5.3L and natrually aspirated 6.2Ls use the same connecting rods as the Gen IV motors (A good friend of mine works in Powertrain at GM and confirmed this to be the case). The pistons are a little different to accommodate the direct injection, but they're not really any stronger than an 05+ engine. They do have better cylinder heads and 12mm head bolts vs 11mm on all the Gen III/IV and older stuff, minus the LS9.

The direct injection is the most challenging stuff part of the swap. I don't know of a conventional (affordable) standalone that can control the GM DI injectors yet. I'm sure it'll come in short time. You can buy a couple different aftermarket intakes (MSD Atomic, Holley Hi Ram) that have port injection bungs and fit the Gen V heads. I think someone makes an adapter plate for Gen V heads and LS7 intake manifold, but couldn't find it when I looked.

For the money, I still think you're better off buying a Gen IV 5.3 if you're planning on boost. A lot of the Gen IV 5.3s came with the 799 heads which are pretty good, too. Gen III/IV have way more options for good cams, and sometimes don't have to delete all of the VVT/DOD stuff. Gen V comes standard with DOD, VVT, and the HPFP stuff that you'd want to delete.

Even when they come out with standalones that can support it well, the tuning window is really, really small to get it right since you can't pulse any fuel with the valves open. 

If you don't plan on boosting, it'd still be a fun motor to mess with for a swap.  I think some tuners are keeping the VVT but limiting the cam phaser to make crazy flat torque curves.  Could make for some real class killers in dyno-based racing classes like some of the NASA stuff.

Offline Cobranut

Re: Anyone Playing With The New LT Motors Yet
« Reply #6 on: August 08, 2019, 08:42:18 PM »
The Gen V 5.3L and natrually aspirated 6.2Ls use the same connecting rods as the Gen IV motors (A good friend of mine works in Powertrain at GM and confirmed this to be the case). The pistons are a little different to accommodate the direct injection, but they're not really any stronger than an 05+ engine. They do have better cylinder heads and 12mm head bolts vs 11mm on all the Gen III/IV and older stuff, minus the LS9.

The direct injection is the most challenging stuff part of the swap. I don't know of a conventional (affordable) standalone that can control the GM DI injectors yet. I'm sure it'll come in short time. You can buy a couple different aftermarket intakes (MSD Atomic, Holley Hi Ram) that have port injection bungs and fit the Gen V heads. I think someone makes an adapter plate for Gen V heads and LS7 intake manifold, but couldn't find it when I looked.

For the money, I still think you're better off buying a Gen IV 5.3 if you're planning on boost. A lot of the Gen IV 5.3s came with the 799 heads which are pretty good, too. Gen III/IV have way more options for good cams, and sometimes don't have to delete all of the VVT/DOD stuff. Gen V comes standard with DOD, VVT, and the HPFP stuff that you'd want to delete.

NASA already compensates for motors with wide flat torque curves.  They make you test it several thousand rpm below and above peak power, and average those numbers to get an average power rating to base your weight and class off of.

Even when they come out with standalones that can support it well, the tuning window is really, really small to get it right since you can't pulse any fuel with the valves open. 

If you don't plan on boosting, it'd still be a fun motor to mess with for a swap.  I think some tuners are keeping the VVT but limiting the cam phaser to make crazy flat torque curves.  Could make for some real class killers in dyno-based racing classes like some of the NASA stuff.
1995 FD, 7.0 Liter stroked LS3, T56, 8.8, Samberg kit.

Offline carlb

Re: Anyone Playing With The New LT Motors Yet
« Reply #7 on: August 12, 2019, 01:04:07 PM »
The Gen V 5.3L and natrually aspirated 6.2Ls use the same connecting rods as the Gen IV motors (A good friend of mine works in Powertrain at GM and confirmed this to be the case). The pistons are a little different to accommodate the direct injection, but they're not really any stronger than an 05+ engine. They do have better cylinder heads and 12mm head bolts vs 11mm on all the Gen III/IV and older stuff, minus the LS9.

The direct injection is the most challenging stuff part of the swap. I don't know of a conventional (affordable) standalone that can control the GM DI injectors yet. I'm sure it'll come in short time. You can buy a couple different aftermarket intakes (MSD Atomic, Holley Hi Ram) that have port injection bungs and fit the Gen V heads. I think someone makes an adapter plate for Gen V heads and LS7 intake manifold, but couldn't find it when I looked.

For the money, I still think you're better off buying a Gen IV 5.3 if you're planning on boost. A lot of the Gen IV 5.3s came with the 799 heads which are pretty good, too. Gen III/IV have way more options for good cams, and sometimes don't have to delete all of the VVT/DOD stuff. Gen V comes standard with DOD, VVT, and the HPFP stuff that you'd want to delete.

The vast majority of us don't turbo our LS's. Heads, Cam, Headers is what most of us do, if we do anything on our own. I think we'll see the same with the LT motors to kick-off a similar swap boon. I've been noodling a swap for my 84 bmw e24 with an LT1 just because the car is sexy as hell and deserves a kick-ass motor. I'd just use their hot cam 535hp crate package and call it a day. It's just spendy. Very spendy. That's normal this early in a new Gen cycle though. Wanna play with the latest and greatest, gotta pay (in both parts costs and the cost of figuring out how to get around new challenges...).

Offline jwvand02

Re: Anyone Playing With The New LT Motors Yet
« Reply #8 on: August 13, 2019, 02:41:18 PM »
The Gen V 5.3L and natrually aspirated 6.2Ls use the same connecting rods as the Gen IV motors (A good friend of mine works in Powertrain at GM and confirmed this to be the case). The pistons are a little different to accommodate the direct injection, but they're not really any stronger than an 05+ engine. They do have better cylinder heads and 12mm head bolts vs 11mm on all the Gen III/IV and older stuff, minus the LS9.

The direct injection is the most challenging stuff part of the swap. I don't know of a conventional (affordable) standalone that can control the GM DI injectors yet. I'm sure it'll come in short time. You can buy a couple different aftermarket intakes (MSD Atomic, Holley Hi Ram) that have port injection bungs and fit the Gen V heads. I think someone makes an adapter plate for Gen V heads and LS7 intake manifold, but couldn't find it when I looked.

For the money, I still think you're better off buying a Gen IV 5.3 if you're planning on boost. A lot of the Gen IV 5.3s came with the 799 heads which are pretty good, too. Gen III/IV have way more options for good cams, and sometimes don't have to delete all of the VVT/DOD stuff. Gen V comes standard with DOD, VVT, and the HPFP stuff that you'd want to delete.

The vast majority of us don't turbo our LS's. Heads, Cam, Headers is what most of us do, if we do anything on our own. I think we'll see the same with the LT motors to kick-off a similar swap boon. I've been noodling a swap for my 84 bmw e24 with an LT1 just because the car is sexy as hell and deserves a kick-ass motor. I'd just use their hot cam 535hp crate package and call it a day. It's just spendy. Very spendy. That's normal this early in a new Gen cycle though. Wanna play with the latest and greatest, gotta pay (in both parts costs and the cost of figuring out how to get around new challenges...).
I think the bigger practical limitation is that DI requires a more complicated fuel system, which is a whole lot of work to incorporate into a swap. Just not really worth the trouble when GenIV motors can be cobbled together for next to nothing and make more than enough power.

Offline radiomike

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Re: Anyone Playing With The New LT Motors Yet
« Reply #9 on: August 13, 2019, 04:00:03 PM »

I think the bigger practical limitation is that DI requires a more complicated fuel system, which is a whole lot of work to incorporate into a swap. Just not really worth the trouble when GenIV motors can be cobbled together for next to nothing and make more than enough power.
[/quote]

Why? All the LT1 needs is a 72psi PWM pump in the tank to feed the cam driven HP pump such as #19303293

Offline carlb

Re: Anyone Playing With The New LT Motors Yet
« Reply #10 on: August 13, 2019, 04:59:23 PM »


Why? All the LT1 needs is a 72psi PWM pump in the tank to feed the cam driven HP pump such as #19303293

Exactly, not as challenging as everyone says. It is also possible to run it without a PWM pump, but your pump as I've seen some builds go that way. I'd run the PWM pump as it's just not that difficult to do it right.

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Offline jwvand02

Re: Anyone Playing With The New LT Motors Yet
« Reply #11 on: August 13, 2019, 05:14:21 PM »

I think the bigger practical limitation is that DI requires a more complicated fuel system, which is a whole lot of work to incorporate into a swap. Just not really worth the trouble when GenIV motors can be cobbled together for next to nothing and make more than enough power.

Why? All the LT1 needs is a 72psi PWM pump in the tank to feed the cam driven HP pump such as #19303293
[/quote]
Maybe calling it a whole lot of work was an overstatement, but that's not really what I was trying to get at. It's not to say it's impossible or even that difficult, just that there's (in my opinion) not a really compelling reason to take an LT motor over an LS3 right now. More expensive, more complicated, more points of failure, less flexibility for not a whole lot gained. The main advantages of DI are fuel efficiency and emissions, which are not things at the top of most people's priority list when doing a V8 swap.