Building Chevy LT1 engines
m (→General info) |
(Add images) |
||
| Line 5: | Line 5: | ||
[[File:1992 lt1 motor.jpg]] | [[File:1992 lt1 motor.jpg]] | ||
<br style="clear:both"/> | <br style="clear:both"/> | ||
| + | |||
| + | ==Application== | ||
| + | [[File:Lt1 chart1.gif]] | ||
==General info== | ==General info== | ||
| Line 11: | Line 14: | ||
<Blockquote>Compared to the 1991 Chevy 350 L98 with TPI, the LT1 made 20 percent more horsepower, got better fuel mileage, and had a much broader torque band with 90 percent of its peak torque available from just over 1,000 rpm all the way up to nearly 6,000 rpm.<br><br> | <Blockquote>Compared to the 1991 Chevy 350 L98 with TPI, the LT1 made 20 percent more horsepower, got better fuel mileage, and had a much broader torque band with 90 percent of its peak torque available from just over 1,000 rpm all the way up to nearly 6,000 rpm.<br><br> | ||
| + | [[File:Lt1 opti.gif|right]] | ||
GM Powertrain accomplished all of this by reverse cooling the engine so they could bump the compression ratio up to 10.5 to 1, tweaking the airflow in and out of the engine, and using sophisticated electronic controls for both fuel and ignition. This combination gave the LT1 300 hp in 1992 and ultimately led to the 1996 LT4 that used better heads, more cam timing, roller rockers and sequential fuel injection to make 330 hp.<br><br> | GM Powertrain accomplished all of this by reverse cooling the engine so they could bump the compression ratio up to 10.5 to 1, tweaking the airflow in and out of the engine, and using sophisticated electronic controls for both fuel and ignition. This combination gave the LT1 300 hp in 1992 and ultimately led to the 1996 LT4 that used better heads, more cam timing, roller rockers and sequential fuel injection to make 330 hp.<br><br> | ||
Although the LT1 was only around for five years, there were two-bolt and four-bolt blocks, aluminum and cast iron heads, regular and H.O. cams that came with long and short dowels, and three different front covers. There was also the "Baby LT1," the 265 cid version that was the standard engine in the Caprice from 1994-‘96. With all that in mind, let’s take a look at this family of engines and see what goes where.<br><br> | Although the LT1 was only around for five years, there were two-bolt and four-bolt blocks, aluminum and cast iron heads, regular and H.O. cams that came with long and short dowels, and three different front covers. There was also the "Baby LT1," the 265 cid version that was the standard engine in the Caprice from 1994-‘96. With all that in mind, let’s take a look at this family of engines and see what goes where.<br><br> | ||
| Line 20: | Line 24: | ||
'''265''' – The 265 has its own unique crank with a 3.00" stroke. That’s the same stroke the original 265 had back in 1955; it’s funny how things go around and come back full circle. It’s a 10168568 casting.<br><br> | '''265''' – The 265 has its own unique crank with a 3.00" stroke. That’s the same stroke the original 265 had back in 1955; it’s funny how things go around and come back full circle. It’s a 10168568 casting.<br><br> | ||
'''RODS'''<br> | '''RODS'''<br> | ||
| − | [[File:Lt1rods.gif|right]] | + | [[File:Lt1rods.gif|right]][[File:Lt1 pistons.gif|right]] |
'''350''' – The original LT1 came with regular forged 350 rods, that were shot peened for localized hardness under the head of the bolt and nut. Powdered metal rods were phased in for the Corvette around 1994 and used in all of the LT1 engines by 1995. GM made the change because the powdered metal rods were cheaper to make and were much stronger than the GM high performance "pink" rods. In fact, they are supposed to be good for up to 450 hp. They are machined at the parting line so they can be reconditioned.<br><br> | '''350''' – The original LT1 came with regular forged 350 rods, that were shot peened for localized hardness under the head of the bolt and nut. Powdered metal rods were phased in for the Corvette around 1994 and used in all of the LT1 engines by 1995. GM made the change because the powdered metal rods were cheaper to make and were much stronger than the GM high performance "pink" rods. In fact, they are supposed to be good for up to 450 hp. They are machined at the parting line so they can be reconditioned.<br><br> | ||
'''265''' – The 265 rods are 0.240" longer than the ones in the 350. Both blocks are the same height, but the stroke for the 265 is 0.480" shorter, so the rods have to be longer to make up for half the difference. These rods can be identified by the single, raised dot on both sides of the shank. See photo to the right.<br><br> | '''265''' – The 265 rods are 0.240" longer than the ones in the 350. Both blocks are the same height, but the stroke for the 265 is 0.480" shorter, so the rods have to be longer to make up for half the difference. These rods can be identified by the single, raised dot on both sides of the shank. See photo to the right.<br><br> | ||
Your Privacy Choices