This L86 was swapped into a ’56 Bel Air. (Image/Automobileman.com)
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.
| 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 | |
|---|---|
| Intake Manifold | Truck Style |
| Throttle Body | 87mm, 4-Bolt |
| Throttle Control | Electronic (Drive-by-Wire) |
| Fuel Injector P/N | 12656931 |
| Fuel Injector Flow | 123 lbs./hr. (2,205 max psi) |
| Flex Fuel Capable (E-85) | Yes |
| Computer | E92 |
| Crankshaft Reluctor Ring | 58X |
| Camshaft Sensor Location | Timing Cover |
| Oil Pan Capacity | 8 qt. |
| Oil Pump (Wet Sump) | Variable Displacement |
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.