I hear people say that the LT1 is stronger than the LS1 cause of the iron block, but it seems every issue of GMHTP I open has atleast one 400+ cubic inch LS1 in there. Why do I never see or hear of similar LT1s, are they even out there? I even saw a article about a 454 ci LS6 the other day. Why are there no LT1s like this, what gives?

Maybe the LS1 is the god of all engines? Defend yourselves LT1 owners.

 

Build a good 383 with really good heads and put some induction and serious rpm into it and those big inch torque LS1's will be in you rear view mirror. I know it for a fact. The regular SBC and LT1 motor is the best small block. LS1's are very trick but they need really big arms to make serious power. You don't need a big LT1 or big regular SBC to make power.You just really good parts and some decent compression and rpm. It will work.

 

The biggest reason in just as the After market started going good for the LT1 the LS1 was produced knocking the wind out of our sails.

You can not blame them for not producing as much stuff for a motor that only lived six year when the new Platform was here.

The LS1 has 15* heads from the factory and a taller deck with better cam placement.

I Gave and decided to join them in a sense Going to bore and stroke mine then top it off with 18* heads and a Hogin!

 

I Say Lt1's are stronger engines by far, We see alot of problems yes, but how many 120K+ ls1's are there and 120K+ lt1's? my car is sitting at 160k miles and have not had any trouble with it at all other then transmission. And to call the LS1 god of all engines? is ridiculous. Sure good engine but to go that far isnt logical, you look how years by years engine changes they look at the good and bad and make it better, 10 years from now think back about how good you think ls1's are because they will always be making bigger and badder engines.

 

I dunno how much bigger or badder the production engines are gonna get.. I heard emmissions laws are gonna start getting alot tougher because of them damn SUVs doing 7-10 mpg.

 

i dont think u can get a LT1 bigger than 402 or something. i see lots of 396's.

the LS1 guys have the advantage of the 6.0 liter truck block to use which gives them a ton of strength and displacement advantages.

only a few shops in the nation can sleeve an LS1 for big CI applications.

 

Think the biggest LT1's were 407's or something..think the LS1 is a 432...Lt1 block isnt stronger..LS1 block can handle just as much power as the LT1 even being aluminum

 

i know they can definitely go 409 cu in with lt1.

 

I thought LS1 heads were 18*??? Learn somethin' new every day.

I just have a hard time seeing why tons of LS1 owners have the huge engines w/ a weaker block but the guys with stronger blocks seem to be afraid of building such large engines.

Why would the LT1 be limited to 402 ci.? Too much bore?

 

wrong, www.cmotorsports.com offers a 409 LT1 which is pretty common. John Lingenfelter also built his own 427ci LT1.

 

Because there are no aftermarket block vendors for the LT1 and it's reverse flow cooling design we are kind of limited by cubic inch because of the location of the stock cam. Without serious costs and machine work a 3.875 stroke crank and 4.100 bore is about as large as you can economically build an LT1. A 4.00 crank would be nice but the cam gets in the way. Anyway that is probably one of the biggest reasons you don't see larger LT1's. LS1's however have block choices with the larger cube capabilities from GMPP without getting into more exotic machine work and cost.

 

Assuming equal mods, the ls1 will be faster.

Ive seen ported ls1 (not even ls6) heads totally outflow ported AFR LT4 heads. Power is in the heads, simple as that.

I will take a built stroker ls1 over a built stroker lt1 any day of the week without hesitation.

 

atljar I would agree with almost everything you said except that there are a lot of aftermarket heads for Gen 1 small blocks that will outflow LS heads hands down that can be converted to work with an LT1 in the end it just depends on how much money your willing to sink into it for the HP level you want to achieve. I would personally take a 430 cubic in Gen 1 small block over a stroked LS1 anyday.

 

I've personally seen a 406 LT1, and everyone knows about the 427 LS1. Thing is, that the 427 LS1 aparrently has damn near paper thin cylinder walls. The 406 LT1 still has a little overbore room I believe.

About converting a Gen 1 head to the modern LT1, what kind of cost is associated with this? I know you have to get a custom sheet metal manifold which is some serious coin, but converting just the heads themselves????

 

you forgot to add "for very large sums of money"


an ls1 guy can just go port his stock heads and get wicked flow for $1500ish


if you want gen1 heads, ported, and converted to lt1 style.......its gonna cost you atleast $3-4 grand total expenses........thats much more than most people are willing to spend.