Best performance vs mpg?

[PalumboDesigns]

Hey everyone,

I've been wanting to do an LS swap for quite some time now. I've been looking for a 68 short wheel base and when I get one I'll be wanting to do a swap.

I didn't realize till after some research on wiki that some of the LS engines are 454s which is something I definitely don't want.

Wiki wasn't really that informative on the LS engines so I'm confused what options there are. I'm wanting to make a cruzer that has lots of power if I feel like roasting the tires but still get good mileage when I'm taking a trip. I'm planning on using it to do some traveling around the US so mileage is pretty important.

What type of LS builds have you done and what type of mileage are you getting? What's the best I could expect out of a small block LS?

Thank you guys for your time it's greatly appreciated.

[95 S_Trucker]

There is an Ls out that is a 454, but its not a big block, its based on ls architecture.

thare are all kinds of ls volumes, 4.8, 5.3, 5.7, 6.0, 6.2 and 7.0 came in factory cars and trucks. there are some crate engins that go to 7.4.

An Ls will get better mileage and make more power, but they are more work than a standard big block or small block.

But I really do like my big blocks and would have to think long and hard to do an ls swap

[Keith Seymore]

Originally Posted by PalumboDesigns

I didn't realize till after some research on wiki that some of the LS engines are 454s which is something I definitely don't want.

I think you are confusing some of the old RPO codes with the new "LS" nomenclature.

There were several "MarkIV" based big blocks in the 1970's with LS RPO codes:
LS3 = 215 HP 454
LS4 = 235 HP 454
LS5 = 245 HP 454
LS6 = 450 HP 454
LS7 = 460 HP 454

These are not the same as the new crop of "LS" engines which refer to the next generation small block architecture.

As you can see - RPO codes do get reused and recycled over time.

K

[95 S_Trucker]

And I thought he was confusing it with this:

http://www.summitracing.com/parts/na...4611/overview/

Hopefully we can all be on the same page.

[PalumboDesigns]

I'm confused because there doesn't seem to be enough info about all these engines online I had no idea there are so many I've never owned one in any vehicle I have owned.

what would be the difference between the 4.8, 5.3, and 5.7 on fuel economy and hp/tq and also are there different versions of them? I would think a 5.7 in a Camaro or truck would be different then in a vette. Is there some where online that compare these engines Google and search here isn't helping me at all.

I want something that I was best hp/tq vs fuel economy for a full size pickup.

[csdineley]

Hope this helps. Read Generation III and IV

http://en.wikipedia.org/wiki/General...2.80.932007.29

[PalumboDesigns]

Originally Posted by csdineley

Hope this helps. Read Generation III and IV

http://en.wikipedia.org/wiki/General...2.80.932007.29

Thank you for the link the wiki I ran across mentioned something about a couple ls engines but nothing like this one. This Is exactly what I needed.

Would you guys say that the 5.3L and 5.7L would get around the same mileage? Doesn't seem to be that huge of a difference I like the idea that the 5.7 had aluminum blocks in the cars sounds like they would be pretty easy to get a hold of would help with mileage losing 100 lbs of weight. Probably enough to get the same or better then the 5.3L.

If anyone has any experience with them I'd love your input.

[Orion88]

You'll want an iron block with aluminum heads. They're more durable and can handle higher horsepower than the aluminum blocks Most people go for the 5.3 and 6.0 but you can get plenty of power out of a 4.8 and they're cheaper. Any LT or LS engine if built and geared properly will net you 400+ horsepower and 20+mpg easy, provided you can keep your foot out of it. I'd imagine 30mpg is achievable as well. If you can find an LQ9 block and bolt on some LS3 heads you'll have a great start.

[PalumboDesigns]

Originally Posted by Orion88

You'll want an iron block with aluminum heads. They're more durable and can handle higher horsepower than the aluminum blocks Most people go for the 5.3 and 6.0 but you can get plenty of power out of a 4.8 and they're cheaper. Any LT or LS engine if built and geared properly will net you 400+ horsepower and 20+mpg easy, provided you can keep your foot out of it. I'd imagine 30mpg is achievable as well. If you can find an LQ9 block and bolt on some LS3 heads you'll have a great start.

Yeah both of the LS1 5300 and the LS4 5300 sound really nice. Both around 300 hp though. The 5.7 was around 350+.

[PalumboDesigns]

Originally Posted by Orion88

You'll want an iron block with aluminum heads. They're more durable and can handle higher horsepower than the aluminum blocks Most people go for the 5.3 and 6.0 but you can get plenty of power out of a 4.8 and they're cheaper. Any LT or LS engine if built and geared properly will net you 400+ horsepower and 20+mpg easy, provided you can keep your foot out of it. I'd imagine 30mpg is achievable as well. If you can find an LQ9 block and bolt on some LS3 heads you'll have a great start.

Thank you after looking at the prices on the 5.3L on ebay just to see what they go for they are really cheap compared to the LS1 that's what I will go with for sure. Sounds like a great engine.

[ivorton74]

the ls4 is front wheel drive

[Keith Seymore]

Originally Posted by 95 S_Trucker

And I thought he was confusing it with this:

http://www.summitracing.com/parts/na...4611/overview/

Hopefully we can all be on the same page.

Yes - 454 cu in small block certainly doesn't help matters.

It's a crazy mixed up world we live in....

(lol)

Originally Posted by Orion88

You'll want an iron block with aluminum heads. They're more durable and can handle higher horsepower than the aluminum blocks Most people go for the 5.3 and 6.0 but you can get plenty of power out of a 4.8 and they're cheaper. Any LT or LS engine if built and geared properly will net you 400+ horsepower and 20+mpg easy, provided you can keep your foot out of it. I'd imagine 30mpg is achievable as well. If you can find an LQ9 block and bolt on some LS3 heads you'll have a great start.

Agree re: iron block with aluminum heads.

When we came out with these engines in the GMT800 platform we had the 4.8L, the 5.3L and the 6.0L. The strategy (what we hoped would happen) is that the 4.8L would have the best fuel economy and would draw buyers to select that engine for most of the production volume.

It didn't work. There were two factors that messed us up:

a) We really hit a sweet spot with the 5.3L, and it outperformed the 4.8L in every way, including fuel economy.
b) Truck buyers seem to say "...I want the biggest engine I can get" regardless of the offerings.



Bottom line: the 5.3L is an excellent all around performer.

K

[Rich84]

5.3 is a great motor..Makes my 06 Tahoe the best vehicle I ever owned ( beside my '84 Sierra).
I have a GMC van with the 6.0 that just hit 305,000 miles. And it hauls steel and drywall. With longevity like that I don't think I'll ever buy a diesel again.

[PalumboDesigns]

Originally Posted by Rich84

5.3 is a great motor..Makes my 06 Tahoe the best vehicle I ever owned ( beside my '84 Sierra).
I have a GMC van with the 6.0 that just hit 305,000 miles. And it hauls steel and drywall. With longevity like that I don't think I'll ever buy a diesel again.

What type of mileage are you getting in that Tahoe?

[Rich84]

Not great..average is about 15.4 mpg.

It's been extremely dependable..140,000 miles and all I have done is a water pump.

[PalumboDesigns]

Originally Posted by Rich84

Not great..average is about 15.4 mpg.

It's been extremely dependable..140,000 miles and all I have done is a water pump.

That is definitely dependable lol

[aotte1]

Have a 2010, Silverado SB with 5.3 and 6 speed automatic. This is an outstanding combination , great driver, very fast if you WOT it. Easy 22 highway MPG, with some load, and up and down hilly highway. First gear is a real get away from stop light fast option. Agree the 5.3 is a great engine. 2010 has VVT, however, not the cylinder shut down component ( for performance applications it's a few hundred dollars to remove this function, or about $600 on a 6.2)

What I was recommended to do before buying one, was to remove one valve cover to check for sludge build-up, if any pass on that engine. Also stay under 80K miles.


I should not say it but I will anyway, the 5.3 is so good compared to the 2014, V6 3.6 gas hog, I have it in a 2014 Acadia D. What a dog in the Acadia, to Keith's point above, maybe this is why buyers stay away from small engines in heavy vehicles, they are gas hogs. My 1997 Surburban vortec 350 got much better mileage. Enough, I am feeling a little better now

Les

[andrewmp6]

What about a diesel swap?A 4bt cummins is a 4 cylinder but with some upgrades can make enough power and get better mileage then a gas engine.

[Orion88]

A diesel swap can be complicated. A friend of mine did it and said all the changes in the fuel system and electronics was far more trouble than it was worth. Plus diesels are pretty heavy and you'll probably have to put heavier front springs on your truck. An LT or LS swap has some electronic complications as well, but there's a reason you see so many LS swaps today and not so many diesel swaps.

[Edahall]

Plus diesel fuel often costs more money than gasoline at the pump. Where I live, I've seen a 70 cent difference.

The 98 and older Cummins 6BT don't have all the electronics, make more power and get better fuel economy.

[andrewmp6]

Take 12 valve cummins 5.9 and 4bt are mechanical injection.The 12 valve weights a good 1200lbs plus but the 4bt is right around 700lbs about the same as a big block.

[Ziegelsteinfaust]

They made 454 versions of LS motors to win the HP war.

Some of the 400-420 cubic inch LS engines are based off the 6.0, and have a bit of tendency to wear out fast if you drive them a lot. Plus they with just a decent cam max out the blocks design hp limits.

The 454 versions I hear are designed more to be that way, and will last longer.

If your looking for fuel economy, and power I would do up a 4.8 or 5.3. Toss in a tvs supercharger, and watch the competition from the rear view mirror. Both engines especially the 4.8 are rev friendly on mpg. My 07 nnbs rcsb got 22 hwy not matter which normal speed I drove it with 4.56 gears or 3.23 gears.

You can build a 500hp 454 Big Block for 1/5 the price of 454 LS, and have tons of money for the gas necessary to drive it.