Better engine as far as reliability? 6.0 or 8.1?

QUIKAG · November 2, 2002

Which motor has better long-term reliability? The 6.0L using the new LS1 derived engine architecture or the 8.1L using the 'old' engine architecture? I obviously know the 8.1L is more powerful, but from an efficiency and reliability standpoint, I wonder if the 6.0L will hold up better over the long-term. Comments?

BDBWTE · November 2, 2002

If I had to take a bet I would go with the 6.0L...its' derived from the 350 and we all know how 350's last plus the 454 BB of the past had oiling and heating problems...CMNT I know they have done a lot to the lay out of the motor which helped...I'm going off of historical data...the 8.1 is a helluva motor no doubt but isn't it a rule of thumb that the bigger a motor is the more wear and tear it puts on its parts??? I thought I learned that in thermo or something oh well just my $0.02..

Tucson_02Silverado · November 3, 2002

This is the info I'm aware of.

The 8.1 is based on the 454/502 MarkV block with project goal of fix the MarkV inherited problems and recast.

The 4.8/5.3/5.7/6.0 is not based on the SBC 283-400. These engines started with a clean sheet of paper. These engines are GM's version of Ford's modular new century engines. This engine project goals was to have modular parts just as SBC 283-400. Without any major upgrades obtain 1HP/1Ftlbs to 1CI at the same time not compromising CAFE ratings. The LS1 was supposedly somewhat an accident, as marketing got in the way and demanded a new engine for the C5 Vette. So the all alloy engine, in which that sheet of paper hit the floor due to manufactuering costs, now got stretched out a bit to a familiar 5.7L to meet market timeframes. The other three siblings now become the iron bastards of the LS1.

That's the outsiders story I've heard.

Doesn't answer your reliability question. Both engines have been out a while now. Both seem to have a majority favorable from their owners. So reliability comes back to what are you going to be doing with that truck. If you are constantly hauling 80% rated load, you should be looking towards the bigger engine for reliability. Although if you do throw the diesel in the reliability question, the diesel should have at least twice the life of a refined dino burner.

2003 2500 2wd RegCab MAX trailer weight

6.0L 4.10 10,600Lbs if constantly at 8500Lbs go to 8.1L

8.1L 4.10 16,100Lbs if constantly at 14,000Lbs go to 6.6L for fuel economy

6.6L 3.73 16,000Lbs (Duramax)

awdvkd · November 4, 2002

Man, talk about a mouth full, I would have to say "In laymans terms". But, is sounds good. He HE!

QUIKAG · November 4, 2002

Wow, thanks for all the good info!! Anybody else want to add anything?

CMNTMXR81 · November 4, 2002

Well you've opened up a can o worms here, BUT BD, the Vortec 6000 IS NOT BASED OFF THE OLD SCHOOL SMALL BLOCK CHEVY V8. It is based off the LS1, which was a complete clean sheet design. The only thing the LS1 shares with it's SBC predecessor is that it is 8 cylinders and bore spacing. Even though it is 5.7L (for marketing) it is technically something like 5.665L, or for you old schoolers, 346 cubic inches, NOT 350.

Anyway, Nothing against the Vortec 6000. I think it is an extremely durable motor in it's own right, BUT it is rather new and only time will tell.

HOWEVER, The Big Block Chevy V8, despite it's oil issues, has been around longer than many of us here have been breathing. It's proven, it's been beat the snot out of, it's been through everything a human can think of. It's the engine of choice for big power applications, big nitrous motors, etc, etc! It's architecture was designed this way, big 4 bolt mains, Big crank, Big IRON block, Big bore, low speed pistons, and BIG heads with splayed valving.

I love small blocks for their high revving, high HP capabilities, especially in 383 format (the best of both worlds), but if sheer bulletproofness, no questions asked, Last through a nuclear blast durability is your goal, a Big Block is unquestionably the way to go.

BDBWTE · November 6, 2002

CMNT the 6.0L has six bolt main caps.. :thumb:

02 2500 Avalanche · November 6, 2002

Im pretty sure the 8.1 has 6 bolt mains aswell.

Alex

CMNTMXR81 · November 11, 2002

Yup.

Tear each motor apart and tell me which one you'd want for durability purposes.

Shotgun · November 11, 2002

I'll take the 6.0 anyday.....Gun

QUIKAG · November 11, 2002

Good discussion guys!! Glad to hear both motors are so durable. My brother mows yards with his 5.3L '99 Z71 extended cab and that poor truck has been to #### and back. Starting and stopping dozens of times a day and it has 87k miles on it and it hasn't missed a lick ONCE.

If my 6.0L daily driver (read: easy life) is more durable, then I have several years of happiness to look forward to.

OCFreedom · December 2, 2002

I'd run my 6.0 against the 8.1 on the street anyday...but it'd pull my bumper off in a hookup. What do you want to do with it is the main question.......and, can you afford the gas? I vote 6.0 as well.