LT1 Vs LS1

[Nima]

Can someone through some light about these engines? what do you prefer if you had options and why?
Thanks

[TravisH]

LS1 > LT1

All I've ever heard about LT1 is the optispark is crap and theres not many complaints on an LS1. Hit up ls1tech.com and you'll find out lots

[68GMCCustom]

The LT1 is a Gen II motor and the LS1 is a Gen III motor. LT1 is an iron block and LS1 is aluminum. Both are 5.7L/350ci. The Gen III's also include the iron 4.8, 5.3, and 6.0 truck motors and a few aluminum 5.3's.

[steelhorse]

The LT1 has just begun to get some aftermarket support.The LS1 is a much better motor with lots of aftermarket support.Just my .02

[TonyJohnson]

The LS1 has better heads, intake, mains, cooling and ignition, IMO. (I was a die-hard LT1 guy since they were introduced...) The LT1 can be built to run just as well as the LS1 with effort and can be had for cheap. The LSx is a really kingpin engineering job and a GREAT bunch of engines. They have issues over 700hp keeping the heads bolted to the block. IMO, LT1s will be orphans in a few years... Go LSx for the future.

[67_C-30]

GM engineers took the best engine platform ever (the SBC) and revised and improved upon it. The LSX engines have crossbolted 6 bolt mains, a front mounted gear driven oil pump, and symmetrical high port 15 degree design is superior to the 23 degree siamesed Gen III and older heads.

With that being said, both the LSX, LT1, and even the old antique TPI's are great engines for our trucks. They're as good as (and usually better) than stock big blocks in terms of performance, and get much better fuel mileage on average. If I were building something to where being fast was most important and economy was not an issue, I'd go Big Block, Gen I, LSX, and LT1 in that order. I put Gen I in front of LSX simply because it costs much less to build max effort HP Gen I than the LSX.

[Billla]

The LT1/4 was a "bridge" engine between the late GEN Is and the LS series. As such, it's basically a GEN I with a few tweaks - the most notable is reverse cooling, which means only heads built specifically for the LT1/4 work. They're solid, workhorse engines with (as noted) improving aftermarket support and pretty much past the some of the early (94) reported problems. The power potential is a bit better than a GEN I, and the FI system is simple, elegant and honestly it's just a good looking engine

The LS is...well, it's magic. The power numbers seen from these engines is incredible, even in very streetable trim. The only downsides are that they require a fair bit of effort to make fit, although the aftermarket is making this easier by the day and that the aluminum ones are still fairly expensive as pull-out engines...but still cheaper (and more driveable with better economy and power) than a GEN I built to the same level.

The bottom line is that if I was starting a new project right now seeking 400+ HP and with $5K or so in the budget, it'd be an LS hands-down. I've got a 6.0L sitting on the floor that I just haven't got to yet

That being said, I'm building an LT1 383 for my Impala SS as the LS swap was just too complex/expensive, and I'm planning on transplanting the existing Impala SS iron LT1/460 trans into my 1972 C10 with a quick refresh. Considering a distributor/carb for that setup...

All IMHO, of course

[piecesparts]

The LT1 is a great motor, but the electronics on it makes it a bit of a pain to deal with. The distributor is finicky if it gets wet and causes one to hate the process of dealing with it. The shaft driven water pump is great UNTIL you have to change out the drive shaft and the bearings (Been there-done that). I have a LT1 in my 95 Impala SS and it runs great, but the LS-1 will walk around it and is also 100 pounds lighter. I have a 2000 LS1 im my garage that I am working to put in my 68 Chevy C-10 and I like the Gen III design. There are so many parts built for them and it does not take much to drive the HP up on one of them.

[ap2002]

do it right the first time, go LS1, there are alot easier to mount and get it up and running, plus are a whole lot more reliable and put down very impressive numbers, thats what im going with on my 68 aswell,

from the info i have gathered, what you need is complete longblock motor with all accesories. painless wiring harness (~$600), motormounts, transmission, and a pcm computer, walbro255 fuel pump, make sure you also get the cable driven throttle body and you are set to go... the painless harness makes it a whole lot easier to install...

[jkade]

LSX all the way, LT1's are to be left where you find them in my book.

[BP68]

LT1 was a cool engine, but LSx is the way to go nowadays. IMO. Start searching and you may find a deal one way or the other. I have a 95 Vette LT1 is need of a cam and basic rebuild (rings/bearings) I am selling it, because I realized if I ever go fuel injected in my 68 it will most likely be a LS series motor.

[68GMCCustom]

some of the various performance mags I read have done tests on LS series motors...the most notable was on an 345hp LQ9 6.0L truck motor. With the stock rotating assembly and upgraded cam and valvetrain, heads, headers, and tuning... they had it over 500hp....before putting a blower on it and taking it up to almost 700hp.

[oscareltemblo]

lsx by far check ot my build ? and you can keep it efi or carbed any way it will be awesome..

[streetstar]

Do an LS unless you can get the LT cheap.

I was (and still am) a die hard big block guy, but the new stuff is pretty cool

[Nima]

I guess the verdict is in, LS series. If you get a donor car, let's say a 2000 and up can you use all the wiring and pcm from it ot it has to be reprogrammed?

[ap2002]

you could use the harnesss but there will be a whole lot of cutting a splicing to use, so alot of people go for a custom harness and saves people alot of headaches and will look alot cleaner, and it is always recommended to reprogram the computer.

[Orange]

LS1 owns the LT1!

DLB

[68GMCCustom]

just set it up with one of these and a good ole carb!



ls1 carb


or....go with the new dual quad seup:


ls1 dual quad