The L86 is a Gen. 5, 6.2L, small-block engine powering 2014-present GM trucks and SUVs. They are known as the EcoTec3 6.2L engines.
These engines use a longer intake runner than its cousin, the LT1. This helped the L86 produce peak torque 500 rpm sooner than the car version of the 6.2L engine. However, it falls about 35 horsepower behind the LT1 at maximum output.
The L86 engines are all-aluminum, feature Active Fuel Management (AFM) and Variable Valve Timing (VVT), and are Flex Fuel-capable (E85).
The engines also use direct fuel injection technology, which shoots fuel directly into the combustion chamber instead of the intake runner.
The information listed here is for a stock engine.
(Image/GM – Chevrolet)
L86 Engine Ratings
Compression Ratio
11.5:1
Horsepower Rating
420 hp @ 5,600 rpm
Torque Rating
460 ft.-lbs. @ 4,100 rpm
L86 Application Information
VIN 8th Digit
Year
Make
Model
J
2015-present
Cadillac
Escalade
J
2014-present
Chevrolet
Silverado
J
2014-present
GMC
Sierra
J
2015-present
GMC
Yukon / XL
L86 Engine Block Specs
Part Number
12619171
Material
319-T7 Aluminum
Displacement
6.2L / 376 c.i.d.
Bore Dia.
4.065 in.
Stroke
3.622 in.
Deck Height
9.240 in.
Bore Spacing
4.400 in.
Thrust Bearing Location
#3 Main, 1/2 thrust
Main Cap Style
6-Bolt
Main Housing Bore Dia.
2.751 in.
Cam Housing Bore Dia.
Bore 1/5 = 2.346 in. Bore 2/4 = 2.326 in. Bore 3 = 2.307 in.
Cam-to-Crank Centerline
4.914 in.
Oil Squirters
8
L86 Rotating Assembly Specs
Piston Material
Hypereutectic Cast Aluminum Alloy
Piston Style
Domed (with reliefs for the exhaust valve and direct injector)
Piston Volume
0.6cc (net)
Wrist Pin Dia.
0.9431 in. (full floating)
Connecting Rod Material
Powdered Metal
Connecting Rod Style
I-Beam
Connecting Rod Length
6.098 in.
Connecting Rod Housing Bore
2.225 in.
Connecting Rod Bolts
M9 x 1 x 43
Connecting Rod Part Number
12654242
Crankshaft Material
1538MV Forged Steel
Crankshaft Part Number (Wet Sump)
12623492
Crankshaft Main Journal Dia.
2.559 in.
Crankshaft Rod Journal Dia.
2.100 in.
Reluctor Wheel
58X
Harmonic Balancer
Iron
L86 Cylinder Head Specs
Part Numbers
12678633, 12620544, 12620545
Casting Number
12620549
Material
319-T7 Aluminum
Combustion Chamber Volume
59.02cc
Intake Port Shape
Rectangle
Intake Runner Volume
297cc
Intake Manifold Bolt Pattern
LT1-Specific
Exhaust Port Shape
Flat Oval
Exhaust Runner Volume
107cc
Cylinder Head Bolt Style
Torque to Yield (TTY)
Cylinder Head Bolt Size
(10) M12 x 1.75, M8 corner bolts
L86 Camshaft Specs
Part Number
12629512
Duration @ .050 in. (int./exh.)
200°/207°
Valve Lift (int./exh.)
0.551 in./0.524 in.
Lobe Separation Angle
116.5°
Cam Gear Attachment
1-Bolt
Cam Gear Poles
4X
Active Fuel Management (AFM)
Yes
Variable Valve Timing (VVT)
Yes
L86 Valvetrain Specs
Lifter Style
Hydraulic Roller
Lifter Link Style
Plastic Lifter Tray
Lifter Body Diameter
0.842 in.
Pushrod Dimensions
7.85 in. (long) x 0.342 (dia.)
Rocker Arm Mounting Style
Pedestal
Rocker Arm Style
Die-Cast, Roller Fulcrum
Rocker Ratio
1.8
Rocker Offset
None
Valve Spring Style
Beehive
Valve Spring Color
Natural
Intake Valve Angle
12.5° / Splayed 2.61°
Exhaust Valve Angle
12.0° / Splayed 2.38°
Intake Valve Material
Steel, Hollow Stem
Intake Valve Dia.
2.126 in.
Exhaust Valve Material
Steel, Sodium Filled
Exhaust Valve Dia.
1.590 in.
Timing Chain Guide Style
Spring-Loaded Tensioner
L86 Intake, Throttle Body, Fuel Injector Specs & More
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Thank you for this valuable info! I need to save this to my desktop. I was surprised to find out it has a forged crank. Are all of the other internals cast?
I have a 2017 GMC Sierra all terrain with the l86 and my truck is not flex fuel capable. Is specifically states in the owner’s manual not to run e85 in this truck.
I have a 2015 Silverado with the L86 engine. My owner’s manual says I can run E85. Yet my L86 is not a flex fuel engine. No flex fuel stickers, no yellow fuel cap,no e85 fuel sensor.
Thanks for giving me credit on the photo. For those of you who really need to understand what’s involved, please read my Gen V installation guide (updated yesterday). http://automobileman.com/wp/?page_id=993
I agree with Kevin, I have a 2018 Sierra with the 6.2 liter and I have to run 91 octane or higher no flex fuel allowed. I think who ever posted that article might want to recheck their information.
@Jerry, are you saying that your 2018 can’t run flex fuel like E85? Actually it can, you have to add the sensor to the open plug down by the gas tank and turn it on in the ECM. After that you can run up to E85 in the truck. I did some research and also verified the plug was there on my 2018 Sierra 6.2l
All you have to do is cut in the flex fuel sensor in the fuel line under your truck your truck is equipped with the plug that plugs into the sensor. then very little tuning and you can run E85.
Mine is a 6.2 liter in a 2018 Sierra Denali…book says use 0w-20 oil, and 93 octane fuel…have 17 going on 18,000 miles, mostly open road.
Towing a boat, about 800miles round trip, 2-3 times a year…2-fold question: can I or should I use a heavier weight engine oil(seldom driven in mid-west winters) and why would I want to use E85 fuel…
This is a 4-wheel drive truck…
Thanks….
If the 6.2L EcoTec3 engine has an aluminum block, does it run cast iron cylinder liners, or a special aluminum treatment on the liners … Nickel treatment?
Ihave a 2018 Denali 180.000 I have a whining sound comming from the bottom when cold they thought it was a vacuum pump then the oil pump my concern is the main bearing I did change the oil pressure guage switch it made very little difference any thoughts on how to move forward.
Very nice. What’s the recommended oil change and what oil should b used in this engine??
At the factory 0-20 oil is used.
Mine says to use 5w20 synthetic oil.
Where can I find the torque specs for this motor and the sequence for tighten.
Where can I find the torque specs for this motor and the sequence for tighten
Thank you for this valuable info! I need to save this to my desktop. I was surprised to find out it has a forged crank. Are all of the other internals cast?
I have a 2017 GMC Sierra all terrain with the l86 and my truck is not flex fuel capable. Is specifically states in the owner’s manual not to run e85 in this truck.
I have a 2015 Silverado with the L86 engine. My owner’s manual says I can run E85. Yet my L86 is not a flex fuel engine. No flex fuel stickers, no yellow fuel cap,no e85 fuel sensor.
Thanks for giving me credit on the photo. For those of you who really need to understand what’s involved, please read my Gen V installation guide (updated yesterday).
http://automobileman.com/wp/?page_id=993
I agree with Kevin, I have a 2018 Sierra with the 6.2 liter and I have to run 91 octane or higher no flex fuel allowed. I think who ever posted that article might want to recheck their information.
@Jerry, are you saying that your 2018 can’t run flex fuel like E85? Actually it can, you have to add the sensor to the open plug down by the gas tank and turn it on in the ECM. After that you can run up to E85 in the truck. I did some research and also verified the plug was there on my 2018 Sierra 6.2l
All you have to do is cut in the flex fuel sensor in the fuel line under your truck your truck is equipped with the plug that plugs into the sensor. then very little tuning and you can run E85.
Mine is a 6.2 liter in a 2018 Sierra Denali…book says use 0w-20 oil, and 93 octane fuel…have 17 going on 18,000 miles, mostly open road.
Towing a boat, about 800miles round trip, 2-3 times a year…2-fold question: can I or should I use a heavier weight engine oil(seldom driven in mid-west winters) and why would I want to use E85 fuel…
This is a 4-wheel drive truck…
Thanks….
If the 6.2L EcoTec3 engine has an aluminum block, does it run cast iron cylinder liners, or a special aluminum treatment on the liners … Nickel treatment?
Where on here can i find info on 2018 6.2 truck AFM delete?
Hey David, check this out: How to Delete or Disable Active Fuel Management (AFM) on GM Engines
Ihave a 2018 Denali 180.000 I have a whining sound comming from the bottom when cold they thought it was a vacuum pump then the oil pump my concern is the main bearing I did change the oil pressure guage switch it made very little difference any thoughts on how to move forward.
awesome