The Monstrous Vortec 8100 496 8.1L Big Block Engine of the 2000's

I bought an 02 Avalanche 2500 4x4. 10 yrs ago never had an issue with it then last year was hauling some water. Got home turned truck off. Started it an hour later and threw check engine power loss code and something to do with my intake. Replaced every sensor on it. It idles high when running no throttle response. Does anyone have any ideas? I miss my truck.

I bought a class B motorhome based on the Express 3500. The 8.1 is very smooth, and it loves running at 75-80.

Dude you need to read more books.

It’s a very popular marine engine too.

Tonawanda 454 EFI nice motor

Putting my 8.1 in my 78 trans am with 6 spd transmission

Trucks with this motor, early on any ways, had a larger tow capacity than the Duramax of the same year for far less money.

all it is is a stroked 454

I really appreciate the review. Thank you

I have a 540 ci industrial version of this motor.plan to stroke and bore it to 621ci with conventional top end had to relocate some head bolts but not too bad

I have this engine with the 5 speed Allison transmission in my 2004 Fleetwood class A motor home. It's a 32 footer and weighs in at around 21000 pounds. Fully loaded with everything including the kitchen sink and pulling a Toyota camery it gets almost 8 MPG and never misses a lick. Strong and dependable, and in my opinion the best non diesel engine ever put in a class A. The Ford Triton V10 is more popular in the older rv's like mine but you have to push them above 4500 rpm to make the power the 8.1 makes at 3200 rpm. I also like the idea of an all cast iron assembly instead of the aluminum heads on a cast iron block like the Ford. If you are thinking of buying an older class A and have a budget of around 25k the Vortec Workhorse chassis is the way to go.

Actually the Buick nail head is the longest production run V8 . When GM stopped using them they sold the design rights to rover and were used into the 2000 teens.

2005 big block with Allison trans has a 6th gear lockout, you can buy a kit to utilize the overdrive gear.
The intake manifold is baffled down to a small opening along with a small MAS change and replace these gain nice power and torque

I have two of these in my 2005 37’ Sea Ray. Great engines !

I'd take any GM big block, especially the 496, over any diesel boat anchor...!!!

A neighbor of mine just put one in an ASTRO van...! It was already LS swapped and not surprisingly because it's a GM product, it sold right in place of the LS with very minimal changes...! It's probably the fastest ASTRO van in Florida... Thanks for sharing... Keep up your awesomeness...!

I have the 2001,
270,000 and it is still as strong as it ever was ,
Love the set up of the Trans and motor ,
Headers and a Big K_N Filter ,

Just power plants when the government wasn't forcing companies to have certain mpg for their entire fleet of vehicles. News flash if someone is buying a dually 5000+ lb truck with a big V8 the gas milage is the last thing we care about. Of course we don't want 7 mpg but if you tell me I'm pushing 400 hp my next question is NOT gas milage haha

I just bought my 1st 8.1 in a 2500 HD GMC Sierra and I fell in love on the test drive. Amazing how quiet it is and how smooth she rides. I’m the 3rd owner. Last guy had it for 3 years and an old man had it from the showroom floor before that and well cared for the whole truck.

what year it comes out of how many km what trans was on it what comes with it

I've got a f350 crew cab and I.also have a 8.1 out of a motorhome with 17300 miles my 7.3 needs lots of tlc you know inj cups clutch fuel sys weak so guess what oddball motor swap I'm planning nothing. gets going more than someone telling me you can't do that wish me luck I'll keep you guys posted ps great video

Fillup is a car payment a month.

My 2004 Suburban tows a 12 ft cargo trailer all over the USA. 15 mpg on a good day. 250,000 miles, zero problems. If it had more gears it would get even better mileage.

I have this motor, my first 8.1 L has 45,000 miles on it, 2000 Chevy 2500hd, great BBC gas motor, though I prefer my 7.5 BBF motor.

Have the marine version in my boat, great motor. Aftermarket isn’t great for this motor though.

with LS's going stupid high prices i think these motors are going to start to shin.

i wanna put one of these in my cadillac brougham

I got one 2003 silverware I’m keeping mine thanks for sharing

Could also get the 8.1 with the 6 speed manual.

Oh, and it gets 15 to 16 MPG ever sense i changed the tires to 275s from the stock 245s.

My 2002 Avalanche 2500 has the 8.1 with 265.000 miles, runs great and will pull any think i hook it to, loves ice and snow also.

Just dropped this beast in my 84 c10!!!

You didn’t have to get this engine with Allison in the truck you could’ve got it with a manuel

I had two of these motors in 37 ft searay for 10 years. Never a problem with heavy use. Compression was the same as when I bought the boat after 10 years.

My 2001 Silverado Crew Cab is my daily driver with the 8.1 and 6 speed manual transmission. We are now shooting for 400,000 miles next year on the original build from GM. When I retire in 3 years, she could have 450,000 all original miles. Yes I have had to change the spark plugs and the oil. I also have gone through two fuel pumps and a clutch. Brakes go without saying. My only issue now is lower body rust. I need to get that fixed! I wonder how much the old girl is worth these days?

Great video, thanks for the info. I am currently rebuilding a Gen VII 8.1 from a 2006 Silverado and cannot find torque specs or head bolt pattern tightening diagrams. Do you have any suggestions for where to find that information? Thanks

I almost killed myself waiting for this guy to stop rambling and get to the point. Jesus Christ

My auto tech class had one of these, It was a seized motor that my class took apart and actually learned on, however the other classes spilled the fluids and put a bunch of components inside of the engine along with food and pencils

Have a 01 2500HD 8.1 love the power, but now I don’t need it. Hopefully I can find a buyer that will know what they are buying

One guy who services irrigation pumps just took an 8.1 out of service with 40000 hrs on it...the equivalent of 2.4 million miles

These engines make more power than they're rated...a 162k mile 8.1 with stock manifolds dynoed at 412hp/545tq...headers raised it to 424/555

Pulls stumps 😂

Anybody found the comparison video he mentioned ford, dodge v10 vs Chevy 8.1? I can’t find it but would love to see it.

I have a 2001 Chevy Silverado 4X4 HD and I love it.. runs great and my fuel mileage is about 15-20 mpg depending on how I drive it.
When I'm on it hotdogging it she burns more fuel, about 8-12 mpg..

i can speak personally for this engine. i had one in a 2009 GMC c7500 and hauled GCWR of over 30k daily. had the 6speed manual trans and was geared very low. this engine spent most of its life at redline. i drove this truck with 75k on the clock for 3 years including a trip from St. Louis mo. to Fresno California. that's 4 days driving almost 12hr days and it topped out at 65 so it was pegged the entire time. the truck/engine never complained. stayed cool and kept running until we retired it at 80k and i was given a 2021 f750 with the 6.7, wish i still had that old gmc lol.

Great video, the 8.1 builds have jumped the last few years. Hope the pushes for a better aftermarket. The Chevy 2500 Avalanche the 8.1 was the only option. My first was a 1500 started towing bigger trailers and purchased the 2500 installed 456 gears. Love 8.1.

I have a 2001 3500 dually with a 8.1 with a Allison trans. and I have 280,000 miles on it and it is a pull monster. I've had a 20' bumper pull trailer with a 580C case backhoe on the back and never felt it back there. I pulled it about 50 miles..