I bought a brand new 1984 GMC High Sierra K2500 J-code 6.2 off the lot. 300,000 miles later, I still use that truck as our livestock water hauler. (Rust-free Wyoming truck). Last year, I did my 2-year maintenance… Changed the AMSOIL synthetic engine oil and dual oil filters… drained, flushed, and refilled coolant… new glow plugs… new air filter… greased hubs… serviced drive train… also removed the stock, troublesome fuel filter and replaced with 90’s GM diesel van filter. I never dicked around with “performance” crap, because the stock engine is RELIABLE.
Yes the 6.2 can be weak, but most of them are worn out. A fresh c-code 6.2 is equivilent to a 305 gasser. J-code is a little better. Definately a noticable increase in power. I installed a 1992 6.5 turbo in my 85 K10. Went from 130 hp to 190hp. The 6.5 is equivilent to a 350 gasser. Made for a nice driver and great on fuel. subbed.
In the 80's, I ran an Army DSU. My F&E (Fuel and Electric) guys were all GM trained on the Stanadyne DB2 fuel systems. They were wizards on injection systems. They tuned over a hundred CUCV and Humvee fuel systems. More power, no smoke and no negative impact on fuel economy. Most of their tuning was done on the vehicle, but they also had an injection test stand in their shop. The military used the "J" 6.2, so there was no EGR, only a CCDR valve. From the factory, all the CUCV engine injection pumps adjusted to the low end, as were the replacement pumps. The M998 pumps had a bit more fuel delivery due to weight of the vehicle.
I knew a guy who advanced the pump timing on his 6.2 and he blew it up!..you can advance the timing but don’t get greedy…1-2 degrees BTDC is fine…maybe even 3 degrees…the guy I knew had his close to 10 degrees and he would shove on it too!..KABOOM!..to put it in perspective, my 2001 Ram Cummins was 17 degrees BTDC…and that’s why those 24 valves rattle so much!…the more you advance them the lousy they get…the more you retard the the quieter they get!
Everyone says the 6.2 is slow and can't keep up. On a hill yes it won't go any faster but it won't slow down either Flat ground my 155hp 6.2 will go 100mph. Just don't get stuck below the torque on the hills and you will be ok
Dont know what you people are talkng about, my dads old non turbo 6.2 diesel g20 van had tons of power. Here was the recipe, not limited to this order... #1. Dual exhaust, his was 2" dual #2. EGR DELETE! Take that thing from the middle of the intake manifold out, plug it up, get rid of it in whatever way you can! #3. Like the video says... turn up the fuel pump. I think my dad turned it up 1/4 of a turn? It could have been 1/8, think it was 1/4. got 22 MPG in the city, then got totalled out, no highway mpg, oh well... anyways. #4. K&N air filter, Just put it on, its not going to destroy your engine, lol. Its does more than you all know. Even in my g20 5.7l v8, seriously! #5. Took out the crappy 3.42 and put in a 4.11 ring and pinion gear. #6. Optional, BUT!!!!!!!!!!! My dad balanced the pistons and rods himself, the heaviest to the lightest in weight was a whole entire handfull of shaved metal. All 6.2 diesels are different, but that made it run better, quieter faster. 7. Raptor transmissions are good also, nice and locking in each gear. It had absolutely TONS of power, TONS, equivalent to my 93' g20 5.7L tbi v8 3.73 rear gear which stock is 200hp with 300Ft pounds of torque, we sort of raced for 1 or 200 feet! My current 6.5 with the db2 setup is slow, which is why Im watching this video, lol to remind myself, its probably a tight transmission, could be out of time, but with the 2nd db2 also... out of time also?
What do you think about plugging the vacuum on the egr in the air cleaner and the manifold? i did in my 6,2 and I get NO black smoke when going up a hill, it used to smoke Black smoke a lot going uphill.
A properly running 6.2l will NOT have any black smoke coming from exhaust. Why would you want unused fuel escaping through the exhaust? That's amateur hour nonsense...
@@markelrod814 indeed the best mod you could do is grab a J series manifold ... its more open and doesn't have EGR still only 155HP though. It's enough on my M1009 though. It doesn't have black soot except a bit as RPM catch up to the throttle very slightly.
Hey Ronnie thanks for the video man, I found your videos when I just got my Lincoln 125 welder , learned a lot from you on that to , are you from East Tennessee? That place behind you looks familiar
Rolling coal is wasting good fuel.... and the 6.2 doesn' make any more power if you do so. There are well documented mods to get a little more HP out of them, J code manifolds, turboing with head studs, crank girdle, and fluiddamper... it takes a lot of money to get power out of a 6.2 you are better of letting it run efficiently at near stock settings so it will last a long time rather than trying to make it do something it wasn't designed for.
More likely to blow up past 10psi... you at a minimum need head studs, preferably a crank girdle and a fluidamper installed since the stock damper is shot by now.
@@Wingnut353you don't need head studs or a crank girdle to turbo one of these engines. A buddy of mine runs 25 psi on stock head and main bolts no issues and the engine has 340000 miles on it. I run a maxed out injection pump and 35 to 40 psi on stock main bolt with head studs also no issues.
6.2l J series shouldn't have any black smoke coming from exhaust. Intentionally dumping more fuel through the system than the engine can burn is moronic...
Just bc it's black doesn't mean it's not making more power. Sure black smoke is unburned fuel however it's still burning more, game of diminishing returns.
Best part about a slow truck is you get to see all the cool stuff go by you.
I bought a brand new 1984 GMC High Sierra K2500 J-code 6.2 off the lot. 300,000 miles later, I still use that truck as our livestock water hauler. (Rust-free Wyoming truck). Last year, I did my 2-year maintenance… Changed the AMSOIL synthetic engine oil and dual oil filters… drained, flushed, and refilled coolant… new glow plugs… new air filter… greased hubs… serviced drive train… also removed the stock, troublesome fuel filter and replaced with 90’s GM diesel van filter. I never dicked around with “performance” crap, because the stock engine is RELIABLE.
Yes the 6.2 can be weak, but most of them are worn out. A fresh c-code 6.2 is equivilent to a 305 gasser. J-code is a little better. Definately a noticable increase in power. I installed a 1992 6.5 turbo in my 85 K10. Went from 130 hp to 190hp. The 6.5 is equivilent to a 350 gasser. Made for a nice driver and great on fuel. subbed.
I have a 92 obs with a 6.2, slow as hell but gets great mpg and easy as hell to work on
I love mine wouldn’t trade it for anything
Changing the rag joint and tie rods will help tremendously. With EVERYTHING
In the 80's, I ran an Army DSU. My F&E (Fuel and Electric) guys were all GM trained on the Stanadyne DB2 fuel systems. They were wizards on injection systems. They tuned over a hundred CUCV and Humvee fuel systems. More power, no smoke and no negative impact on fuel economy. Most of their tuning was done on the vehicle, but they also had an injection test stand in their shop. The military used the "J" 6.2, so there was no EGR, only a CCDR valve. From the factory, all the CUCV engine injection pumps adjusted to the low end, as were the replacement pumps. The M998 pumps had a bit more fuel delivery due to weight of the vehicle.
I knew a guy who advanced the pump timing on his 6.2 and he blew it up!..you can advance the timing but don’t get greedy…1-2 degrees BTDC is fine…maybe even 3 degrees…the guy I knew had his close to 10 degrees and he would shove on it too!..KABOOM!..to put it in perspective, my 2001 Ram Cummins was 17 degrees BTDC…and that’s why those 24 valves rattle so much!…the more you advance them the lousy they get…the more you retard the the quieter they get!
Everyone says the 6.2 is slow and can't keep up. On a hill yes it won't go any faster but it won't slow down either Flat ground my 155hp 6.2 will go 100mph. Just don't get stuck below the torque on the hills and you will be ok
I like this build, would love to find one of these trucks!
Spark plugs in a diesel, woah!
Dont know what you people are talkng about, my dads old non turbo 6.2 diesel g20 van had tons of power. Here was the recipe, not limited to this order...
#1. Dual exhaust, his was 2" dual
#2. EGR DELETE! Take that thing from the middle of the intake manifold out, plug it up, get rid of it in whatever way you can!
#3. Like the video says... turn up the fuel pump. I think my dad turned it up 1/4 of a turn? It could have been 1/8, think it was 1/4. got 22 MPG in the city, then got totalled out, no highway mpg, oh well... anyways.
#4. K&N air filter, Just put it on, its not going to destroy your engine, lol. Its does more than you all know. Even in my g20 5.7l v8, seriously!
#5. Took out the crappy 3.42 and put in a 4.11 ring and pinion gear.
#6. Optional, BUT!!!!!!!!!!! My dad balanced the pistons and rods himself, the heaviest to the lightest in weight was a whole entire handfull of shaved metal. All 6.2 diesels are different, but that made it run better, quieter faster.
7. Raptor transmissions are good also, nice and locking in each gear.
It had absolutely TONS of power, TONS, equivalent to my 93' g20 5.7L tbi v8 3.73 rear gear which stock is 200hp with 300Ft pounds of torque, we sort of raced for 1 or 200 feet! My current 6.5 with the db2 setup is slow, which is why Im watching this video, lol to remind myself, its probably a tight transmission, could be out of time, but with the 2nd db2 also... out of time also?
I’ve got a 83 with a 1993 6.5 injection pump on it.
I’ve got it turned up a 1/4 turn. Rolls hella coal. Egt’s are around 1,000 degrees Fahrenheit
What do you have to monitor it with
@@cherokeeronnie glow shift EGT gauge
Thank you!
What do you think about plugging the vacuum on the egr in the air cleaner and the manifold? i did in my 6,2 and I get NO black smoke when going up a hill, it used to smoke Black smoke a lot going uphill.
A properly running 6.2l will NOT have any black smoke coming from exhaust. Why would you want unused fuel escaping through the exhaust? That's amateur hour nonsense...
@@markelrod814 indeed the best mod you could do is grab a J series manifold ... its more open and doesn't have EGR still only 155HP though. It's enough on my M1009 though. It doesn't have black soot except a bit as RPM catch up to the throttle very slightly.
Hey Ronnie thanks for the video man, I found your videos when I just got my Lincoln 125 welder , learned a lot from you on that to , are you from East Tennessee? That place behind you looks familiar
No from wv
What is your exhaust system in this?
How do you know if this has already been done to a truck i just picked one up with 119000 miles on it
Use your brain
@jacobfleming565 nah I don't think I will
what exhaust system do you have
I'll be damned I got a 00 Cherokee and A 82 K20 6.2l
Rolling coal is wasting good fuel.... and the 6.2 doesn' make any more power if you do so. There are well documented mods to get a little more HP out of them, J code manifolds, turboing with head studs, crank girdle, and fluiddamper... it takes a lot of money to get power out of a 6.2 you are better of letting it run efficiently at near stock settings so it will last a long time rather than trying to make it do something it wasn't designed for.
Well I got tones more power out of mine
Can these motors be turbo'd
Yes use 6.5 intake/exhaust manifolds
More likely to blow up past 10psi... you at a minimum need head studs, preferably a crank girdle and a fluidamper installed since the stock damper is shot by now.
BMI commander 6200 turbo retrofit kit
@@Wingnut353you don't need head studs or a crank girdle to turbo one of these engines. A buddy of mine runs 25 psi on stock head and main bolts no issues and the engine has 340000 miles on it. I run a maxed out injection pump and 35 to 40 psi on stock main bolt with head studs also no issues.
Tell me more about
6.2l J series shouldn't have any black smoke coming from exhaust. Intentionally dumping more fuel through the system than the engine can burn is moronic...
Just bc it's black doesn't mean it's not making more power. Sure black smoke is unburned fuel however it's still burning more, game of diminishing returns.
quit talking stsrt showing
Quit commenting and watch the video
@@cherokeeronnieNGL....funniest shit i read in comments today.😂
I agreee... less talk, more demonstration. Otherwise why make a video