I was just wondering what the differences between the two were..... Different heads? they sound different to me.... thanks!

 

This is correct - at least according to the Lextreme website. The question is, what is different between the two heads? I did some research and it appears as though the '98 SC4 and GS4 - both have the same compression ratio, so I'm curious as to what else could be different - valve orientation, exhaust port orientation, accessory bolt locations?

 

Supposedly, the exhaust manifolds are different, accounting for the different sound. The GS is supposed to have more flow hence the slight power advantage over the SC.

Also dont forget that the length of the exhuast and final configuration of the 2 systems are different.

The motor is the same 1UZFE, the exhuast was tailored for each body application.

Bon Appetite.

 

1. Pistons
2. Heads
3. Springs
4. Retainers
5. Cams
6. Gaskets

I have:

One LS400 engine
One SC400 engine
One GS400 engine
One GS430 engine
One Tundra Engine

 

There are 3 basic configurations for the 1UZFE.

1990-1994 LS400 and 1992-1995 SC400, 10.0-1 compression, rated 250hp/260tq (actual more like 230hp/250tq)

1995-1997 LS400 and 1996-1997 SC400, 10.4-1 compression, rated 260hp/270tq

1998-2000 LS400, SC400 and GS400, 10.5-1 compression, rated 300hp/310tq GS400, 290hp/300tq SC400 and LS400.

The first series shares everything except exhaust manifolds, air filter housings and of course exhaust systems.

The second series has same differences as the 1st series.

The 3rd series is nearly identical for each vehicle except for air filter housings and exhaust systems. Exhaust manifolds are effectively identical in the GS and LS and I believe the SC.

Each series shares heads, blocks, pistions, valves, intake manifolds, camshaft profiles and timing. In other words each series engine combination is essentially identical.

 

Don't forget about the Hydraulic Fan and engine mounted pump - SC400 vs. Conventional Mechanical Fan on the LS400/GS400. I like the look on ppl's faces when I tell them I have "fan fluid".

 

haha same here! the first time my brother looked under the hood and saw the fan fluid he was like "what in the hell?! they have fan fluid?! what a cyborg....(inside joke)"

 

I understand there are a few differences between the 4.0L from the SC and the GS. But my question is, can you swap the two motors between 2000 SC and GS if they are the same model??

Thanks

 

Depends on the sensors used, you almost certainly will not be able to use a pre-1996 motor without swapping over the harness and ECU, due to OBD-II implementation. After 1996 I imagine that almost everything is identical except for the ECU programming, which probably isn't any different in the SC/GS, though MAYBE the LS as it's a vastly different target demographic.

The big question is, how is the GS400 so much faster than the SC400 given a 300lbs weight ADVANTAGE for the SC? Sure the GS has another 10hp/10tq but considering the additional 300lbs, the advantage should STILL go to the SC...If I were an SC400 owner, and god willing someday I might be, I would be pissed! Something tells me time disparity is fueled by marketing, has anyone done a side by side with a GS and SC400?