Will Chevrolet Ever Produce The 8.1 Again?

[mark97213]

I special ordered my 2006 2500hd LT, all options, with the 8.1L/6 Spd Allison and love it.

 

But, love the new silverado design and would like to buy a new one. But with my 2006, I finally got the engine I always wanted (8.1L) which is no longer available.

 

So, I'm curious, has the 8.1 gone the way of the Dodo, never to be seen again?

 

I've heard so many conflicting reasons as to why GM decided to omit the 8.1 from it's lineup, I'm curious why exactly they chose against it. Anyone have any info on it's omission and/or if we will ever see such an option on future trucks?

[omegafiler]

Not unless it gest 35mpg.

[ws6_guy]

Its gone for good. Was the worst economical engine they had, & thats that counts anymore, economy. If its bad they wont make it. So either get into Diesels, or enjoy a 6.0L, or even swap in an 8.1 if you desired, but your best off taking care of the 06 for a good long time.

[383]

The 8.1 seems like the perfect engine to drop back to four

cylinders when the power isn't needed, like the new engines do.

[Zembonez]

Unfortunately the design and bore/stroke of the 8.1 are horrible for fuel economy (but great for sheer grunt). Not an equation you will likely see in the future with higher fuel prices. Enjoy what you have... Larger displacement engines are likely gone forever. Future designe will probably be some kind of torgue producing hybrid since electric motors produce 100% of their torque from 0 rpm.

[mark97213]

Ya, that's pretty much what I thought. EPA and the GREEN peoples want to omit any internal combustible engine it seems. But what everyone seems to overlook . . . I didn't buy a full size truck to haul some twigs and get a good MPG, I bought it exactly for what you said... the combination of sheer "grunt" and the smooth silence a diesel motor will never give.

 

But not even diesel can escape the Green world. I wonder what future regulations hold for the what will come by way of the 18 wheelers movin our goods out on the super highways if the EPA and the green fans get to implement their will on more industry.

 

Thank God I got in the last line of the 8.1L

[Riverjet502]

For the sake of conversation..... A big block can still be bought throught the parts dept in a crate. In the non computer days it took minimal effort to yank a small block and replace it with a big block. I never really thought about it till now, but what would it take to yank a 6.0L out and replace it with a 8.1 or 8.2 Gm crate motor. Not including the crate motor price. Guessing the computer & harness, as a big ticket item? Any thoughts on this? I like the thought of a ZZ502/502 sitting between the frame rails.

[Riverjet502]

For the sake of conversation..... A big block can still be bought throught the parts dept in a crate. In the non computer days it took minimal effort to yank a small block and replace it with a big block. I never really thought about it till now, but what would it take to yank a 6.0L out and replace it with a 8.1 or 8.2 Gm crate motor. Not including the crate motor price. Guessing the computer & harness, as a big ticket item? Any thoughts on this? I like the thought of a ZZ502/502 sitting between the frame rails.

[C/K Man]

Some say emissions and fuel economy killed the 8.1L in the pickups, but that's not exactly the case. What happened was that nobody was ordering the 8.1L anymore. In 2006, less than 3% of Silverado/Sierra HD buyers opted for the Big Block, and the 8.1L option was actually cancelled in 2006. No one even noticed! I thought about ordering a 3500HD GMC with the 8.1L in the summer of 2006 because I heard that it was on the way out, but the engine had been already dropped. There could have been a few 2007 Classic Silverado/Sierra HD's built with the Big Block if they had been ordered in May of 2006, but I have not seen an 8.1L 2007. In all fairness, emission regulations probably would have eventually killed the 8.1L due to it's 4.25" bore. The engine is still available in Topkick and Kodiak commercial trucks.

[vranasaurus]

Some say emissions and fuel economy killed the 8.1L in the pickups, but that's not exactly the case. What happened was that nobody was ordering the 8.1L anymore. In 2006, less than 3% of Silverado/Sierra HD buyers opted for the Big Block, and the 8.1L option was actually cancelled in 2006. No one even noticed! I thought about ordering a 3500HD GMC with the 8.1L in the summer of 2006 because I heard that it was on the way out, but the engine had been already dropped. There could have been a few 2007 Classic Silverado/Sierra HD's built with the Big Block if they had been ordered in May of 2006, but I have not seen an 8.1L 2007. In all fairness, emission regulations probably would have eventually killed the 8.1L due to it's 4.25" bore. The engine is still available in Topkick and Kodiak commercial trucks.

 

I would agree that lack of demand probably killed it more than anything. Most people who need the kind of power the 8.1 produces would opt for the Duramax.

 

Since the HD trucks don't have to meet the fuel economy standards that other vehicles do that couldn't have killed it. However emmissions probably would have come into play eventually.

[anteater]

I personally was hoping to see the 6.2L V8 gas as an option for 09 but doesn't look like it will happen!I am still convinced there are more reasons to choose gas over diesel than diesel over gas!

[Riverjet502]

So if the demand goes up maybe GM will start production up again? We need more guys to repower their old rides with Rat motors...That should help huh????

 

 

[k3500CC8.1]

For the sake of conversation..... A big block can still be bought throught the parts dept in a crate. In the non computer days it took minimal effort to yank a small block and replace it with a big block. I never really thought about it till now, but what would it take to yank a 6.0L out and replace it with a 8.1 or 8.2 Gm crate motor. Not including the crate motor price. Guessing the computer & harness, as a big ticket item? Any thoughts on this? I like the thought of a ZZ502/502 sitting between the frame rails.

 

Riverjet502,

 

I'm in the process of doing this very project for an 09 GMC K3500 CC(will be ordered late summer). The 8.1L is still available through your local dealership as a complete fresh(not reman.) crate engine minus the exhaust manifolds. The 09 will be ordred with the base 6.0L. The 6.0L E38 computer will manage the the 8.1L with a software change, so the need to switch back to the P59 engine control module is not needed. I'm currently waiting for confirmation from GM Powertrain that the 6L90 will directly bolt up to the 8.1L, we(team) think it will without a problem. The 6L90 transmission looks to be a good match for the 8.1L, it has maxium hp input of 452 bhp and torque input of 531 lb-ft, and a first gear of 4.03.

 

One of the last issues we're working are to insure that the cam/crank reluctors can be swapped to make the 8.1L compatible with the E38. Without any foreseen hurdles, the truck will come in on the transport, go directly into surgery, and come out with a proper 8.1L... I'm also going to go with a complete new GM 2006 8.1L exhaust set-up from the manifolds back.. The truck should look completely factory built when done...

 

I do have a few questions about some of the minor details about the GMT 900 trucks.. Do the front bumpers between the 6.0L and the Duramax still differ? I know the 8.1L and the Duramax have always had the some front bumper sit-up that includes extra cooling slots.. Also, are the 6.0L running the same full floating rear axle as the Duramax now? In the past the 8.1L and Duramax always ran the same rear axle and I haven't had time to run these issues to ground...

 

I'm really excited about this project, it will be a nice ride to have a new 1 ton SLT GMC with a proper gas engine.. I'm even kicking around the idea of going with 4.56 gears to kick things up a notch.. I'm building this truck because I think the window of opportunity to do something like this is starting to close. No one really knows how much longer factory new 8.1L will be available, most likely only reman. engines will be the only option soon... Also, notice GM Powertrain-Marine is starting to push the supercharged 6.2L in the offshore areana. I'm starting to get the feeling that this engine will be the replacement for the 8.1L on the big water...

[Riverjet502]

That's exactly what I am talking about. A small block should not even be an option in a tonner. It should be a big block or a diesel period. Wake up GM are you listening? There is a reason why people buy this heavy of a truck and the 6.0L small block just doesn't have the torque. You can only mask the lack of torque with lower gears so much. I like your project keep us posted as you go along. I am betting more guys will be following in your foot steps. What about using the front bumper off a "snow plow" prep package this has the slot in it for more cooling?

[C/K Man]

The 6.0L in the HD's was at a disadvantage with the 4L80 transmission. The 4L80 has the old Turbo 400's rather high first gear, and even with a loose convertor and low rear axle the 6.0L had a hard time with very heavy trailers. The current VVT 6.0L coupled with the new 6L90 transmission is a different animal. The gear ratios in the 6L90 are just about perfect, and with the VVT 6.0L actually puts more torque to the wheels than the 8.1L/Allison combination did (though at slightly higher r.p.m.'s). The Allison's gear ratios were more for a diesel engine, and were not the ideal for even the 8.1L. So, I figure the 8.1L with the 6L90 ought to be a great combination.