L83 All motor build

Kuuups · February 27, 2020

Looking for guidance for my 2018 Silverado with the L83 motor. I don’t wanna go forced induction so what can I do besides a cam and ported heads to get the most horsepower out of my engine. And what other supporting mods like intake and fuel injectors if I would need.

SlowGMC · February 27, 2020

Get the l86 intake manifold and l86 TB.

truckguy82 · February 27, 2020

7 hours ago, Kuuups said:

Looking for guidance for my 2018 Silverado with the L83 motor. I don’t wanna go forced induction so what can I do besides a cam and ported heads to get the most horsepower out of my engine. And what other supporting mods like intake and fuel injectors if I would need.

I wouldn’t go cam

Cam is engine out

and if you’re doing cam and forced induction, you’re going to make enough power to need lt4 fueling and a built shortblock

in which case you will have built your entire motor, and you probably would have been better off just buying a 416 long block

edit:oh shoot you said you don’t want to go supercharger!

are you sure? A built NA motor without increasing displacement will shift the power band to the top end. That’s great on a sports car, but less than desirable on a truck.

there’s a reason we all go supercharger

Edited February 27, 2020 by truckguy82

flyingfool · February 27, 2020

search forum for slow1500, he did all the turbo stuff.

best cam is BTR truck torque cam either stage 1 or 2, 6.2 intake manifold, 70 size turbo. you'll have to gap the piston rings if your pushing over 8 psi. the LSA SC seems like a lot of monkey motion for boost, but it has a great torque curve.

Edited February 27, 2020 by flyingfool

SierraHD17 · February 27, 2020

You can for sure. Myself, I grabbed an L86 that tried to eat itself and am stroking it to a 6.6 using the L8T's pistons and crankshaft. The only waiting is for GM to release the crank for sale... and it's cheap too which is nice for a forged piece. Cam, intake, headers, compression increase and 401 cubes should do quite nicely. Staying at 325 cubes you are better off with boost.

Edited February 27, 2020 by SierraHD17

CamGTP · February 27, 2020

Pick a cam, then pick the correct stall converter for that camshaft.

Add a E85 sensor. Do your head work, headers, intake upgrades and see where you stand. It's possible you'll need LT4 injectors for the extra fuel requirements but you'll just have to see. Regular pump gas would let you take the stock injectors farther than E85 would.

Jaychevy81 · February 27, 2020

You sure you don’t wanna go supercharged 480hp in one mod lol.

Sent from my iPhone using Tapatalk

00pooterSS · February 27, 2020

I wouldn't waste my time with a 5.3. I'm in the same boat as you and looking for a L86 now.

Look around you can get an L86 for around 2500 now on offer up and if you look enough in the right places.

Swap in a L86 with cam (you'll then already have the coveted l86 intake) and sell your L83 for 1000-1500

Whole lot of gain going that route for little money.

flyingfool · February 28, 2020

sounds like a 6.2 swap is the smart move or buy a new truck with all the OEM parts installed ready to go.

Kuuups · February 29, 2020

On 2/27/2020 at 1:20 PM, Jaychevy81 said:

You sure you don’t wanna go supercharged 480hp in one mod lol.

Sent from my iPhone using Tapatalk

Honestly I just want to see how much I can make before even thinking of forced induction.

flyingfool · February 29, 2020

wonder if the longer connecting rod from the new 6.6L motor would drop into the 6.2L motor?? I like the increase in crank dwell time.. ???

any chance GM offers the 6.6L in a crate short block?

Edited February 29, 2020 by flyingfool

SierraHD17 · February 29, 2020

Connecting rods are not longer in the 6.6... that's completely backwards. If they went that route the rods would be shorter as the throw of the crank is longer. Connecting rods are identical length to any other LT.

flyingfool · February 29, 2020

the new motor has a 6mm longer powdered forged con rod

you dont understand the idea of increased rod length, wich reduces piston speed and increased crank dwell at tdc and btdc

6.6L is a "detuned" 400hp/400ftlbs

Edited February 29, 2020 by flyingfool

truckguy82 · February 29, 2020

6 minutes ago, flyingfool said:

the new motor has a 6mm longer powdered forged con rod

you dont understand the idea of increased rod length, wich reduces piston speed and increased crank dwell at tdc and btdc

SierraHD17 · February 29, 2020

1 hour ago, flyingfool said:

the new motor has a 6mm longer powdered forged con rod

you dont understand the idea of increased rod length, wich reduces piston speed and increased crank dwell at tdc and btdc

6.6L is a "detuned" 400hp/400ftlbs

Considering I have connecting rod in my possession for a 6.6 that I ordered from the dealer yes I do know what I am talking about thanks. Do you? No.. you don't.

You can manipulate rod length but in this case its piston pin height. Center to center on that rod and an LQ4 rod are identical. Gm is cheap and does things as cost effective as possible... it's a stroked 6.2 and that's all there is too it. 401 hp and 464 lb ft with a timing curve allowing use of 87 fuel means severely detuned...

Edited February 29, 2020 by SierraHD17