LT1 vs LS1, what are the actual differences?
#1
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I'll list off the differences I know, please add to the list...
LT1
4.000 bore
3.48 stroke
Iron block
Reverse cooled
Traditional SBC firing order?
Cast aluminum intake
LS1
3.900 bore
3.75 stroke
Aluminum block
Different firing order
15 degree heads?
Composite intake
LT1
4.000 bore
3.48 stroke
Iron block
Reverse cooled
Traditional SBC firing order?
Cast aluminum intake
LS1
3.900 bore
3.75 stroke
Aluminum block
Different firing order
15 degree heads?
Composite intake
#2
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LT1=slow
LS1=fast
Sorry, I just had to say it! <img src="gr_grin.gif" border="0">
But seriously, don't forget that the LT1 has the optispark ignition system, while the Ls1 has the much superior single coil per cylinder setup.
LS1=fast
Sorry, I just had to say it! <img src="gr_grin.gif" border="0">
But seriously, don't forget that the LT1 has the optispark ignition system, while the Ls1 has the much superior single coil per cylinder setup.
#3
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Stroke on the LS1 is actually 3.62" (92mm) and not 3.75"
You've listed the major differences between the two, here's what I have to add:
1.7 rocker arm ratio on the LS1 as opposed to 1.5 on the LT1
roller rockers on the LS1 vs stamped rockers on the LT1
hollow camshaft on the LS1
6.098" rods on the LS1 vs. 5.7" rods on the LT1
bigger main journal bearings on the LS1 (2.65"ish vs. 2.45" on the LT1)
and this is pretty significant... 4 head bolts/cyl vs. 5 head bolts/cyl for the LT1 and classic SBC
Also, LS1 has 6 bolt mains vs. 4 or 2 for the LT1
That's all I've got off the top of my head, I'm sure you guys can finish the rest...
[ February 20, 2002: Message edited by: Hydra ]</p>
You've listed the major differences between the two, here's what I have to add:
1.7 rocker arm ratio on the LS1 as opposed to 1.5 on the LT1
roller rockers on the LS1 vs stamped rockers on the LT1
hollow camshaft on the LS1
6.098" rods on the LS1 vs. 5.7" rods on the LT1
bigger main journal bearings on the LS1 (2.65"ish vs. 2.45" on the LT1)
and this is pretty significant... 4 head bolts/cyl vs. 5 head bolts/cyl for the LT1 and classic SBC
Also, LS1 has 6 bolt mains vs. 4 or 2 for the LT1
That's all I've got off the top of my head, I'm sure you guys can finish the rest...
[ February 20, 2002: Message edited by: Hydra ]</p>
#4
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ha! this could go on forever!
LS1:
*6-bolt main bearing caps
*cracked-PM rods
*one coil per cylinder
*factory roller rockers w/ 1.7:1 ratio (vs. stamped steel 1.5's for the LT1)
*larger fuel injectors
*deeper oil pan
*completely different head port design
*deep skirt block
*enclosed lifters
*separate valley cover
*CPS reluctor wheel
*negative deck height
*crankshaft is shorter than the LT1's
*6.1" rods vs. the LT1/4's 5.7" rods
There's a start. <img src="gr_stretch.gif" border="0">
LS1:
*6-bolt main bearing caps
*cracked-PM rods
*one coil per cylinder
*factory roller rockers w/ 1.7:1 ratio (vs. stamped steel 1.5's for the LT1)
*larger fuel injectors
*deeper oil pan
*completely different head port design
*deep skirt block
*enclosed lifters
*separate valley cover
*CPS reluctor wheel
*negative deck height
*crankshaft is shorter than the LT1's
*6.1" rods vs. the LT1/4's 5.7" rods
There's a start. <img src="gr_stretch.gif" border="0">
#5
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[quote]LT1=slow
LS1=fast<hr></blockquote>
I bet Jordon Munsser and a few other 9-10 second LT1 guys would beg to differ with that statement <img src="gr_images/icons/wink.gif" border="0"> .
Everything that's been listed is all I can think of at the moment...
LS1=fast<hr></blockquote>
I bet Jordon Munsser and a few other 9-10 second LT1 guys would beg to differ with that statement <img src="gr_images/icons/wink.gif" border="0"> .
Everything that's been listed is all I can think of at the moment...
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#8
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[quote]Originally posted by ChrisB:
<strong>How about you list what is the same
lifters
...
Chris</strong><hr></blockquote>
LMAO! I vote for that, too. The list is much shorter. <img src="gr_stretch.gif" border="0"> They're both OHV pushrod design. And there you have it!
<strong>How about you list what is the same
lifters
...
Chris</strong><hr></blockquote>
LMAO! I vote for that, too. The list is much shorter. <img src="gr_stretch.gif" border="0"> They're both OHV pushrod design. And there you have it!
#10
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What several engineers thought was a real paradigm shift from SBC-2 to SBC-3 was the bore spacing. For the first time ever, it isnt the standard 4.5 (???) inches of the Gen 2 small block. I dont recall what the LS1 bore spacing is. The coil-per-cyl is new for the SBC. Im thinking technology more than parts.
\chris
\chris
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DOH!!
I thought the bore spacing was one of the only things they did carry over from a traditional small block. <img src="images/icons/confused.gif" border="0">
I thought the bore spacing was one of the only things they did carry over from a traditional small block. <img src="images/icons/confused.gif" border="0">
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[quote]Originally posted by ChrisB:
<strong>How about you list what is the same
lifters
...
Chris</strong><hr></blockquote>
Rod bearings are the same as well. <img src="gr_images/icons/wink.gif" border="0">
<strong>How about you list what is the same
lifters
...
Chris</strong><hr></blockquote>
Rod bearings are the same as well. <img src="gr_images/icons/wink.gif" border="0">
#14
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Here's a difference:
LT1 = siamese exhaust ports (o oo o)
LS1 = replicated exhaust ports (o o o o)
Here's a similarity:
LT1 and LS1 have the same bell housing bolt patterns
LT1 = siamese exhaust ports (o oo o)
LS1 = replicated exhaust ports (o o o o)
Here's a similarity:
LT1 and LS1 have the same bell housing bolt patterns
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here's the BIGGEST DIFFERENCE:
LS1= 15* valve angle
LT1= 23* valve angle
^ = makes the LS1 make more power so much easier <img src="gr_stretch.gif" border="0">
LS1= 15* valve angle
LT1= 23* valve angle
^ = makes the LS1 make more power so much easier <img src="gr_stretch.gif" border="0">
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[quote]Originally posted by XLR8NSS:
<strong>DOH!!
I thought the bore spacing was one of the only things they did carry over from a traditional small block. <img src="images/icons/confused.gif" border="0"> </strong><hr></blockquote>
No, you're right. The center to center spacing of the bores was about the only thing carried over from the oldschool block.
Brad
<strong>DOH!!
I thought the bore spacing was one of the only things they did carry over from a traditional small block. <img src="images/icons/confused.gif" border="0"> </strong><hr></blockquote>
No, you're right. The center to center spacing of the bores was about the only thing carried over from the oldschool block.
Brad
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factory intake/exhaust runner volumes are massively different I believe.
Similarity: They both have 8 pistons <img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
[ February 21, 2002: Message edited by: Fireball ]</p>
Similarity: They both have 8 pistons <img src="graemlins/gr_chug.gif" border="0" alt="[chug]" />
[ February 21, 2002: Message edited by: Fireball ]</p>
#19
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[quote]Originally posted by Nightclaw:
<strong>Here's a difference:
LT1 = siamese exhaust ports (o oo o)
LS1 = replicated exhaust ports (o o o o)
Here's a similarity:
LT1 and LS1 have the same bell housing bolt patterns</strong><hr></blockquote>
are you sure about the bellhousing? i had heard they're not the same. If they are cool.
for similarities, i hear that there is one bearing that is interchangable...and thats it.
<strong>Here's a difference:
LT1 = siamese exhaust ports (o oo o)
LS1 = replicated exhaust ports (o o o o)
Here's a similarity:
LT1 and LS1 have the same bell housing bolt patterns</strong><hr></blockquote>
are you sure about the bellhousing? i had heard they're not the same. If they are cool.
for similarities, i hear that there is one bearing that is interchangable...and thats it.
#20
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I know really nothing about LT1's, so this may sound dumb, but it is an honest question. Is the LT1 block the same block as the regular 5.7L that were put in ,say, the trucks of those years and such or is it a completely different casting? One more question is how does the intake on the LT1 compare to the LS1 as far as runner length, etc.?