and i believe the main bearings are the same between teh 2 motors.

the names have more in common with eachother, than the actual motors do.

Ryan.

 

Firing order is different as well

 

Two different animals....Thank God LOL! the differences are too many to list though <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> .

Joe.

 

i remember reading somewhere that the only interchangeable parts were the connecting rod bearings.

 

Hey Joe watch it <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> How many NA LS1s are faster than Joe Os 9.86 LT1 <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Rod bearings and lifters are stand SBC fair, well the lifters are standard genII roller block stuff same as LT1 and L98

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by GrannySShifting:
<strong> Hey Joe watch it <img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> How many NA LS1s are faster than Joe Os 9.86 LT1 <img border="0" title="" alt="[Wink]" src="gr_images/icons/wink.gif" />

Rod bearings and lifters are stand SBC fair, well the lifters are standard genII roller block stuff same as LT1 and L98 </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Nobody is sayin you cant makem fast

Joe was probably talking about how hard it is to work on an LT-1. I have heard many people complain about how tough they are to work on compared to the LS-1

 

They both have eight cylinders.

 

Why was the LS1 changed to an aluminum block?

 

what is the difference between these two engines?

 

Pretty much everything is different, instead lets ask ourselves what is the same.

Lifters.
Cylinder bore spacing.

I think thats about it. <img border="0" title="" alt="[Razz]" src="gr_images/icons/tongue.gif" />

Eric

 

There are lots of little differences, I am only certain of a few major ones though.

LS1 > aluminum block, LT1 > iron block

LS1 > coil on cylinder ignition, LT1 > opti-spark

LS1 > 6 bolt main, LT1 > 2(F bod) or 4(Y bod) bolt main

These are some of the major ones....I know something about valve sizes being different and cams are IEIEIEIE....for the LS1.
Correct me if I am wrong this is just some of the stuff I know about. I would also like to know some of the the other ways that they are different also.
Joe

 

The differences that I really appritiate in comparison to the LT1 are.
Dollar for dollar, the LS1 produces roughly 100 more flywheel horse over a comparably modded LT1. Lighter motor, Ford styled heads that don't stop producing power when ported correctly, more flexable power band, non siamised exhaust ports, more adaptable PCM program, better ignition system, cam swaps are a breeze, practically limitless power output just keep hitting it with larger cams, 6 bolt mains that are integral to the block, Thrust bearing is FINNALY in the middle of the motor block where it belongs, cam location is higher in the block, Styrean/nylon derivitive intake manifold. and a few other benifits.

What I don't like about the LS1's are.
Only 10 head bolts.
cheap aluminum alloy block material.
valve train related problems.
Hit or miss oil pump related problems.
Cheap swing set type bolts holding the whole motor together, torque to yeild on everything is stupid IMO. All leading edges of the motor are sharp as razor blades! Poor rod bolt design in the early motors. cheap pistons but they do the job. Non adjustable rockers and a couple other peeves but nothing serious. I just prefer the LS1's <img border="0" title="" alt="[Big Grin]" src="gr_grin.gif" />


Joe. <img border="0" alt="[USA]" title="" src="graemlins/patriot.gif" />

 

The 92-97 LT1 is basically the last SBC-based motor other than the L31 Vortec (5.7) in my 99 Tahoe.

LT1 is also:
4.000 bore like SBC
3.480 stroke like SBC

LS1 is:
3.900 bore
3.622 stroke

LS1 heads are much much better than LT1 heads.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JPR:
<strong>
What I don't like about the LS1's are.
Only 10 head bolts.

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Having fewer head bolts is what makes room for better ports that makes the heads flow better than the old designs did with 5 bolts per cylinder.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by chino_man279:
<strong> cams are IEIEIEIE....for the LS1.
Joe </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">This is just another way of saying non siamised exhaust ports." If you look at the old 350 engines there were two adjacent exhaust ports in the middle of the head.

It also should be pointed out that the LS1 is a "clean sheet of paper design" whereas the LT1 evolved from the original SBC design created back in 1955.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Cal:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JPR:
<strong>
What I don't like about the LS1's are.
Only 10 head bolts.

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Having fewer head bolts is what makes room for better ports that makes the heads flow better than the old designs did with 5 bolts per cylinder. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Understood, but it dosen;t provide enough clamping force in FI or high NOS applications as opposed to the LT1 with about 16 head bolts.

<img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Joe.

 

</font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JPR:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by Cal:
<strong> </font><blockquote><font size="1" face="Verdana, Helvetica, sans-serif">quote:</font><hr /><font size="2" face="Verdana, Helvetica, sans-serif">Originally posted by JPR:
<strong>
What I don't like about the LS1's are.
Only 10 head bolts.

</strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Having fewer head bolts is what makes room for better ports that makes the heads flow better than the old designs did with 5 bolts per cylinder. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">Understood, but it dosen;t provide enough clamping force in FI or high NOS applications as opposed to the LT1 with about 16 head bolts.

<img border="0" title="" alt="[Smile]" src="gr_stretch.gif" /> Joe. </strong></font><hr /></blockquote><font size="2" face="Verdana, Helvetica, sans-serif">I assume you are saying this based on seeing a number of blown head-gaskets on customer engines . . . <img border="0" title="" alt="[Frown]" src="gr_sad.gif" /> I wonder if ARP bolts torqued to a higher level would address this?

 

guess thats why you see alot more 700 rwhp lt1's <img border="0" title="" alt="[Frown]" src="gr_sad.gif" />

 

so no one is going to mention one huge difference with the LT1? the LT1 features reverse cooling. instead of cooling the block first then up, it cools heads down. not to mention that peice of **** opti-spark ignition. leaking water pump? bye bye opti-spark! the up side to the LT1 that i owned in a '97 formula. it was hell on the bottom end, torque wise. would ****** your head off. but after second gear, ls1 says bu bye!