Swapping L86 6.2 8l90e into 72 k10

[FamilyTruckster65]

Did you do any modifications to the charging system? If the alternator still controlled by the stock ECU?

[barraza]

Originally Posted by FamilyTruckster65

Did you do any modifications to the charging system? If the alternator still controlled by the stock ECU?

Mine, and i think all the conversion harnesses use the stock controls in the ECU to control whatever parts of the engine are usually kept as part of the swap. The alternator is certainly one of these. It also controls the speed of the cooling fans.

[Accelo]

Thanks for the excellent write up.
Some L86 engine background information below;

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

[Hart_Rod]

How's the truck running? We're getting close the L86/8spd swap in the 93 OBS truck. What did you do for transmission dipstick? I'm trying to use a modified one from a 6L90. Hopefully it will work out. We also used the stock 2017 fans and radiator. They fit like a glove. Just need to build a cover for the top. We used a coolant recovery tank from a 2019+ Chevy truck because the mounting points worked out better. Pics included.

[chev-obsession]

This is a cool build and I love that you were able to source OEM parts. I am wanting to do something similar to my K20. Nice work

[NDM]

Originally Posted by barraza

Positioning the engine
It sounded relatively easy to drop the engine in, and the first test fit looked great, but the devil is in the details. I wanted to keep the transfer case in the stock location, so the driveshafts could be reused, and the shifter would be easy to come through the floor in the stock location. Unfortunately, when i put the radiator support back on, the fans were too close to the front of the engine. I didn’t want to cut the firewall for clearance. The drivers side is much tighter than the passenger side. I decided to massage the firewall behind the drivers side head for a little extra room, it cant be seen so i guess i can live with it.
The first photo is oil pan clearance to the crossover steering drag link, the second picture is clearance between the firewall and drivers side cylinder head. Third photo is lifting the passenger side suspension with the hoist to check for oil pan clearance. Everything feeds into the engine placement. Put it to far forward and it would need a shallower oil pan, which is one of the $500 things that sneak up on you. My final position is hard to exactly say, as far rearward as possible. The 3 holes from the original mounts are almost centered in the 4 bolt pattern of the 6.2, but i redrilled the factory engine crossmember holes rearward on the frame 1.25 inches. The transmission crossmember moved rearward 1 7/8” . I made my own mounting plates for the engine out of 1/2” aluminum plate, and used the original engine crossmember with the center cut out and replaced with a 3/8” plate, bent to fit the oil pan as tight as possible.

What headers did you use? I cannot tell from the photo. I was hoping to use factory 21 6.6 liter L8T ones but not sure if they can fit.

[NDM]

Bumpity bump...I am trying to find out if you used factory exhaust manifolds? My L8T is almost ready to install.

[barraza]

Originally Posted by NDM

Bumpity bump...I am trying to find out if you used factory exhaust manifolds? My L8T is almost ready to install.

sorry i didnt see this message, been a while since i logged in. i used late model camaro factory headers. The factory manifolds i had could have worked, but it depends on exactly where the engine ends up being positioned. The only way to know is to just try it.

Been a couple of years now, but if i remember correctly, one side of the iron manifolds points outward slightly and would have been difficult to get the exhaust pipe attached without trimming the frame.

I just re-read this entire posting completely and have to say i probably wouldnt change a single thing. Sometimes when you live with modifications for a while, you realize things you should not have done, but the 6.2Lt/8l90e has been a winner. It completely transformed my old truck. I like it so much i sold my newer Silverado, and i use it for everything. One additional thing i noticed was that i kind of criticized Mitch at SwapTime who did my harness. It was an honest mistake and he ended up being very helpful and getting me running great. I cant figure how to edit the original post so I thought would ad it here that i have used him since, have no problem recommending him.

[NDM]

Originally Posted by barraza

sorry i didnt see this message, been a while since i logged in. i used late model camaro factory headers. The factory manifolds i had could have worked, but it depends on exactly where the engine ends up being positioned. The only way to know is to just try it.

Been a couple of years now, but if i remember correctly, one side of the iron manifolds points outward slightly and would have been difficult to get the exhaust pipe attached without trimming the frame.

I just re-read this entire posting completely and have to say i probably wouldnt change a single thing. Sometimes when you live with modifications for a while, you realize things you should not have done, but the 6.2Lt/8l90e has been a winner. It completely transformed my old truck. I like it so much i sold my newer Silverado, and i use it for everything. One additional thing i noticed was that i kind of criticized Mitch at SwapTime who did my harness. It was an honest mistake and he ended up being very helpful and getting me running great. I cant figure how to edit the original post so I thought would ad it here that i have used him since, have no problem recommending him.

Thanks! I spoke to Mitch one day and he was absolutely great to me. To spend a significant amount of time talking to me with no money exchanged was very awesome of him. His videos have had a huge motivating impact on my courage to take on the gen V swap tgat I am doing.