LT1 vs. LS1???

[dbiggss]

Can anyone tell me what the major differences are between LT1 and LS1 engines? I know the LS1 is better and is used in the corvette and the newer upper model firebirds but what is it about the engine that makes it so much better? there both 350's right.

[-cy-]

First off, the LT1 was used on vettes and f-bodies, and the LS1 has been used on both as well. The vettes had the LT1 up untill '96, then '97 they got the LS1. F-bodies had the LT1 till '97 and got the LS1 in '98. I don't remember when the vette and f-body first got the LT1 however.

The LS1 is an aluminum block, as compared to the LT1's iron block. There are differences in a number of the parts of the engine, they are just made differently, check into it. Both are 350cu.

[FFCCPresident]

True they are both 350's... the LT1 (I have) came through with 285 bhp and more torque than the LS1, it is a cast iron block. The LS1 has 305 bhp with a little less low end torque, and is an aluminum block. The are both strong and fast engines... and are perfect for the Camaros, Corvettes, and Firebirds that they have been dropped into!

[jonbravo27]

The LT-1 was first used in corvettes in 1992 and F-body in 1993. It shares most of its dimensions with small-blocks from years before. It has a reverse flow coolant system.

The LS-1 came out in the '97 vette. It is a whole new engine from the ground up. It is similar to y-block engines. The main bearings are bolted by four in the bottom and two on the sides. No parts will interchange with the two engines. GM decided to keep a pushrod style engine, but they made a whole new one. Camaros and firebirds have iron block LS-1's vettes have aluminum. The actual displacement of the LS-1 is slightly less than 350. But it is still rounded to 5.7 L. The motor was developed special alongside the new corvette. It had to pump oil in a 1g skid pad test. It holds more oil. The crank is drilled out for weight. It is pretty tricky stuff. The best in pushrod technology.:smoker:

[DVS LT1]

Originally posted by dbiggss
I know the LS1 is better...what is it about the engine that makes it so much better? there both 350's right.

Better depends on how you look at it. In terms of torque, the LT1 was a marvel because it could produce its peak torque at an incredibly low RPM - 325 ft/lbs @ 2400 RPM in the F-Bodies, 330 ft/lbs @ 4000 in the C4's, and was tooled to produce even more low-end TQ for GM's trucks.

Thats the thing about the LT1 - it was designed to be the workhorse for GM. It powered not only the F-Bodies & Vettes, but also the Caprice/Roadmaster/Impalla, and was an option or standard engine on nearly all of GM's mid-full sized trucks & SUV's from '93-'97.

The LS1 in contrast had the benefit of being designed specifically for the new C5 Corvette. Like the LT1 it was slighly downtuned for the F-Bodies, but did not find its way into any GM trucks.

The LT4 engine which was available in 1996 was perhaps the greatest incarnation of the LT1. It was basically a factory hot-roded LT1 which produced the same tire shredding low-end torque but now had the horsepower curve that charged right up to the 6300 RPM redline (whereas the normal LT1's horespower curve tended to back down after about 5000 RPM).

In the long run, the biggest advantage the LT1 has over the LS1 is its cast iron block. GM experimented with aluminum V8's in the '60's only to watch them melt themselves. Even the new aluminum LS1 block has steel sleeves inserted into the piston chambers to prevent the block from warping/cracking. The LT1 block has the advantage when it comes to not only the availability but also the possibility of major modifications because of its durability. True, they are now figuring out ways to really bore and stroke out an LS1 by inserting better/stronger sleeves into the piston chambers, but based on its aluminum block I think it will only be a matter of time before we start seeing a number of these motors coming back with the same kind of serious structural failures that occured to aluminum blocks forty years ago.

[1BAD305]

lt1s are kinda the bitch engine, the reason why is cause small block chevys are popular for interchangability, the fact that the lt1 has reverse cooling and differnt heads and intake bolt pattern makes it harder to fool with. it has the dreadful optispark ignition that most people complain about as well. ls1s and older small block chevys have more advantages

[DeViL]

Camaros and firebirds have iron block LS-1's vettes have aluminum.

Really? I thought the LS1's in the F-bodies were aluminum as well. I don't remember hearing anything about a cast iron ls1.

[-cy-]

Originally posted by DeViL


Really? I thought the LS1's in the F-bodies were aluminum as well. I don't remember hearing anything about a cast iron ls1.

All LS1's and LS6's (in f-bodies and corvettes) are aluminum blocks. There are iron 6.0L blocks, but those are only in trucks stock.

[DVS LT1]

Originally posted by 1BAD305
lt1s are kinda the bitch engine, the reason why is cause small block chevys are popular for interchangability, the fact that the lt1 has reverse cooling and differnt heads and intake bolt pattern makes it harder to fool with. it has the dreadful optispark ignition that most people complain about as well. ls1s and older small block chevys have more advantages

We gonna start comparing the good olde L98 now too?? (lol) I don't know why you're making it sound like such a horror story, cause you can go out and buy just about any set of heads or cam or whatever you'd like for an LT1 - there is absolutely no limit in parts or availability for that motor. In terms of intake, an LT4 can be ported to flow as much air as you could possibly desire - even a stock LT1 intake ported by the right person will make you look again at those flow bench numbers.

And by the way, you ever wonder how after years of milking as much horsepower as possible out of the first generation L98 V8 (5 HP here, another 5 HP the next year), GM managed to seemingly overnight boost the horsepower output of their second generation LT1 V8 by more than twenty percent??

Reverse Cooling :smoker2:

[DVS LT1]

And hey 1BAD305, you and DeViL both have sweet looking F-Body's. Its nice to see those 3rd Gen's in such nice shape (I never see ones in good condition around here anymore). Your rides are the ones that got me interested in F-Body's as a kid.

CHEERS

[1BAD305]

its not a horror story, he asked for a comparison and i gave him the facts. the LT1 is a nice engine but it doesnt share teh interchanability, as other year sbc's. also the optispark is somethin most owners complain about, i didnt say one thing about an L98 in there. thanks for the compliments anyway.

[-cy-]

The optispark really isn't that bad, it is just something you have to watch out for when looking to buy a used LT1 and when you are having problems with your LT1.

I think the 1 downfall of the LT1 is the flow of the heads, and maybe the intake manifold. With heads and a cam, the LT1 is much nicer. LS1's make great power b/c high flowing stock heads, among other things.

[DVS LT1]

Hey 1BAD305, what gears are you running in your IROC?

[1BAD305]

the 13.9 run it had the stock 3.08s

now it has 3.27s and a stock LT1 cam, its pushin 100mph passes, but with out traction i cant beat that 13.9 et, gotta get some stickies, and suspension mods.

[1BAD305]

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