Engine replacement in Chevy engine

alwechs

Advanced Member
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Jan 3, 2021
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Location
New York
Is it possible to replace an 8.1 liter engine for a Chevy van (early 2000s) with something more fuel efficient? Or are there issues with going smaller? I don't plan to tow anything and I notice most vans from that era seem to be just fine with something around 6.0. Looking to improve mileage. Thanks!
 
Is it possible to replace an 8.1 liter engine for a Chevy van (early 2000s) with something more fuel efficient? Or are there issues with going smaller? I don't plan to tow anything and I notice most vans from that era seem to be just fine with something around 6.0. Looking to improve mileage. Thanks!


The Chevies that had the 8.1 option would have been the previous generation and the smaller engine options would be a 5.7L V8 and maybe a 4.3L V6.



For a swap you would likely need a donor van to get everything, engine, trans, PCM, maybe BCM wiring harnesses, etc.


8.1L are beasts and I think pretty rare.


You probably would be money ahead to sell the 8.1 unit and replace it with a 5.7L or later model by a couple of years which would be a 6.0.
 
I wish mine had the 8.1, it has the 6.0. For most usage the 6.0 is adequate. However, there were many times as I was climbing mountains I would have preferred the 8.1.
I learned long ago that it is not unusual for a larger engine to get close to, or equal a smaller engines gas mileage because it does not have to work as hard. The 6.0 does work hard in these Motor Homes.
 
what mpg do you see?


I have a chev 3500 w the 6.0 and we are at 15/16 at 65ish mph.

a pleasure way at about 9000# wet


the usual fuel economy tips apply, tire inflation, tread type/compound, vehicle weight. soft easy starts vs jackrabbit. steady rolling constant speed.



check you have clean air filter- correct grade oil ( too heavy oil will cause drag- check manual) check sensors and spark advance curves


possible a tuner w/ expert advice could do a little better for you
mike
 
A little data and opinions to put in the decision making hopper.

I have owned a 2001 8.1 4 sp. 4.10 Suburban, and a 2009 6.0 6 sp. 3.73 Suburban. The 2009 gets 1 - 2 more MPG, in the neighborhood of 14 vs 12.

Given the choice I would still own the 2001, with my top criteria being driving pleasure.

Assuming the van’s use is mainly highway and the objective is reducing fuel use, I would change the the differential to a lower numerical value. Much simpler, cheaper, and fewer potential headaches then an engine swap. My guess is the payback for an engine swap would be many years down the road.

I have been told that the market for used 8.1s is poor, but have not verified that. At first this didn’t make sense to me, but the explanation was that most people looking to an engine swap are going the LS route which is where the aftermarket has focused, so the 8.1 doesn’t show up on their radar.
 
You can buy a lot of fuel for the cost of an engine swap. Also putting that much money into something that is not a collectible seems like a weird decision
 
You can buy a lot of fuel for the cost of an engine swap. Also putting that much money into something that is not a collectible seems like a weird decision
But the OPs engine has 300,000 miles on it! I certainly would not be taking any long trips in it!!:flowers:
 
Coss370 couldn’t agree more. This subject makes zero sense, unless maybe the existing engine is shot. 3500 6L at 15mpg. Not bad for an 08 hauling 9300 pounds
 
MPG's

Just to offer an additional data point, MY 2000 RT 190V with the 5.9 seems to have averaged 14.5mpg over the last 5000 miles, no mountains, I am a pretty gentle driver, imagine the mayhem of hard braking!
 
The 8.1L in an Express van is extremely rare and is super reliable. I'd love to get a 8.1 camper because I like towing. If you change to 5.7, you will go back in technology to distributor and all moisture/misfire issues that come with it. Resale will be very hard. And you won't get much better fuel mileage, perhaps 1mpg gain, but you'll suffer climbing hills. The 8.1 is a phenomenal engine, that lasts forever, and the torque it has in unmatched in any other gas engine.
 
Does the OP actually have the van in question, or was it one he was considering? His post of today seems to indicate he is still looking, so all this gets moot.
 
I was not suggesting putting a dodge engine in their Chevy, just offering real world MPG as an FYI
 
You can buy a lot of fuel for the cost of an engine swap. Also putting that much money into something that is not a collectible seems like a weird decision

I can't speak for the OP, but not everything is about money. Some people just want to burn less fuel for the sake of the environment and there's nothing wrong with that!
 
I can't speak for the OP, but not everything is about money. Some people just want to burn less fuel for the sake of the environment and there's nothing wrong with that!

That is faulty thinking and creates a common fallacy. You are looking at only one side of the coin. There was environmental damage caused by the manufacturing of the engine; why create two engines when one will do? Imagine all the toxic waste that is created by manufacturing/disposing of these engines

The swap will cost money. That money was created by doing some sort of production. It can be assumed that that production caused some sort of environmental damage or pollution, and there is a good chance it may be more than the marginal reduction in gas usage will mitigate. (for example, suppose the buyer works for monsanto haha)

Thus it is possible that by installing an engine that gets a couple more gallons/mi will cause more damage to the environment than doing nothing.

"Feeling good" does nothing for the environment
 
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That is faulty thinking and creates a common fallacy. You are looking at only one side of the coin. There was environmental damage caused by the manufacturing of the engine; why create two engines when one will do? Imagine all the toxic waste that is created by manufacturing/disposing of these engines

The swap will cost money. That money was created by doing some sort of production. It can be assumed that that production caused some sort of environmental damage or pollution, and there is a good chance it may be more than the marginal reduction in gas usage will mitigate. (for example, suppose the buyer works for monsanto haha)

Thus it is possible that by installing an engine that gets a couple more gallons/mi will cause more damage to the environment than doing nothing.

"Feeling good" does nothing for the environment

Your thinking is flawed as well, because a second engine does not need to created. In fact a used engine could be used which would save it from the landfill and replace an engine which we are told is well used and potentially no longer efficient and is likely approaching the age where the heads need to be rebuilt or it will suffer blowby.

Of course you are smart enough to know that engines get recycled and the metal reused which reduces the overall enviro impact over throwing it in a dump.

The money was already being eared so your argument there is flawed on it's face and becomes you creating the fallacy.

Before you start with the "save the whales" speech, make sure you get your attempted facts straight and realize that using your computer is likely causing more fossil fuels to be burnt and if you turned it off you would save the environment.
 
you just proved my point. people who think that by purchasing a car or engine that will save them a couple miles a gallon thereby helping save the environment, or a few dollars, are ignorant of the environment and of economics.

One must consider the entire life-cycle of the items involved and the human activity that brings about the change to derive at a NET environmental impact. That NET impact may be a negative
 
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That is faulty thinking and creates a common fallacy. You are looking at only one side of the coin. There was environmental damage caused by the manufacturing of the engine; why create two engines when one will do? Imagine all the toxic waste that is created by manufacturing/disposing of these engines

The swap will cost money. That money was created by doing some sort of production. It can be assumed that that production caused some sort of environmental damage or pollution, and there is a good chance it may be more than the marginal reduction in gas usage will mitigate. (for example, suppose the buyer works for monsanto haha)

Thus it is possible that by installing an engine that gets a couple more gallons/mi will cause more damage to the environment than doing nothing.

"Feeling good" does nothing for the environment

What a load of BS. There is an environmental cost to manufacturing every product people consume. The question is how much you want to add to that environmental cost after the purchase. Burning less carbon based fuel is better for air quality and can also reduce the effects of climate change. This isn't complicated. You're just trying to justify whatever choice YOU want to make when, in fact, you are quite free to drive whatever vehicle you choose without these absurd mental gymnastics.
 
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