LT-1 350 VS Vortec 350

bsdlinux · July 18, 2001

Anybody know the explicit differences in these engines....

76BBSub · July 18, 2001

A big one is that the LT-1 has reverse flow cooling, with the water pump driven by the camshaft. Also the heads are different...Vortec heads are great low-end torque heads, and can make some pretty good HP, but are cast iron. LT-1 heads are aluminum (except on Impala SS engines) and are a higher RPM peak design, and I think the valves are larger as well.

I know the LT-1 is a full roller cammed engine, pretty sure the Vortec 350 is as well but not positive.

96 Vortec · August 13, 2001

Yes, the Vortec 350 is a roller setup as well. What a difference in drivability it made.

quadrunner500 · October 10, 2001

And the LT1 is sequential, multi-port fuel injection. The 350 vortec was throttle body injection.

Redghost · October 18, 2001

The LT1 uses an Opti Spark not a convential distributor.

76BBSub · October 18, 2001

Vortec has coil-on-cylinder distributorless technology.

Also, it's not throttle body injection, it's sequential multi-port FI.

Jeff

Redghost · October 19, 2001

Just like the LS1.

Eric Bryant · January 13, 2002

As previously mentioned, the F- and Y-body LT1s got aluminum heads, but they actually flow worse than the B-body iron LT1 heads and the Vortec heads (which have nearly identical port and chamber designs).

The LT1 also has a tunnel-ram intake, designed specifically to fit under the cowl of the 4th-gen F-body. This is also the main reason for the location of the Opti-spark distributor, which is mounted at the front of engine and driven directly off the end of the camshaft (the waterpump is located slightly above this, and driven from a jackshaft off the cam timing sprocket). The distributor has a pair of optical sensors for high-resolution and low-resolution sensing of cam position.

Due to the reverse-flow cooling, the LT1 runs slightly higher compression (10:1 in the B-body LT1 and 10.5 in the F-/Y-body LT1, compared to 9.4:1 in the Vortec if I'm not mistaken).

Basically, the following components are different:

Block

Heads

Intake

Timing cover

Timing chain/sprockets

Water pump

Distributor

Much of the internals (crank, rods, pistons, oil pump, bearings, cam, valvetrain) are interchangable between the LT1, Vortec 350, and standard late-model SBC 350 with little or no modification.