1990-94 cams vs 1995-97 cams

[Peewee]

Any one know the exact specs of the cams on the two gens?

Here is what JBrady said a while back

The intake cam ONLY on the 95-97 LS400 and 96-97 SC400 has more lift and duration. Exhaust cam specs remain unchanged.
(still not certain WHY Lexus upgraded the LS400 engine in 1995 but waited until 1996 for the SC400?)

Cam gains an unspecified amount of lift... probably very little, with a best guess being 0.008"/0.10mm. Duration increases by 8 degrees.

1990-1994 1UZFE LS400 engine (1992-1995 SC400)
224 degrees intake duration (3 BTDC, 41 ABDC) apx .301"/7.65mm lift
229 degrees exhaust duration (41 BBDC, 3 ATDC) apx .305"/7.75mm lift

1995-1997 1UZFE LS400 engine (1996-1997 SC400)
232 degrees intake duration (6 BTDC, 46 ABDC)
Intake lift increases over previous design but likely no more than .309"/7.85mm,
I could not find specifics only that it was increased.
Exhaust lift and duration is the same as earlier design.
229 degrees exhaust duration (41 BBDC, 3 ATDC)

Any one have anything definate?

I just have the option of buying a 95-97 motor (ex UFC20 I'd say, *** LS400) and seeing if its really worth it to replace the current 1991 motor in there.

 

[xirforever]

Sorry i dont have an answer to this question, hopefully someone else does. Id just like to add that they also have a higher compression ratio, so that would be another benefit to having the 95-97 motor.

 

[Peewee]

Yeah, I know its 10.5:1 vs 10:1
Its also a lot of effort to swap them over.
If the extra cam lift is only 0.1 or 0.2 mm like JBrady was suggesting, then it makes it less worthwhile.