And that compression increase had to come from stroke change. So it'* got a few things going on different. I saw some items somewhere in the past about the valves and/or cams different on the L37 but no source to qualify either.

piston, combustion chamber or even head gasket thickness could have contributed to the compression ratio difference...

i may be able to pull cam specs for different years/motors. what do you want compared?

Just recent LD8/L37. If there was difference then a swap could change things. The LH2 was never made for tranverse mount. Don't see that swap happening.

i'm not very familiar with the N* generation, but IIRC, it'* 93-99, 00-04 and 05-present?

i'm guessing you'll want the 05-up stuff?

04-05 is really all we have to deal with in this Section. I believe the changes were minor for 04 to 05. GM never changed the advertised power between the years and I don't know of any changes.

2004 Cadillac Seville with L37:

exhaust duration at .006: 246*
intake duration at .006: 251*
exhaust lobe lift: .2339"
intake lobe lift: .2421"
overlap at .006: 2.04*

cam event timing:

intake open: .3* ATDC
intake centerline: 122* ATDC
intake close: 246* ATDC
exhaust open: 229.3* BTDC
exhaust centerline: 110* BTDC
exhaust close: 11.2* ATDC

rocker ratio of 1.68:1

want spring rates and valve diameters as well?

2004 Seville with LD8:

exhaust duration at .006: 236*
intake duration at .006: 242*
exhaust lobe lift: .2339"
intake lobe lift: .2421"
overlap at .006: 1.98*

cam event timing:

intake open: 1.3* ATDC
intake centerline: 117* ATDC
intake close: 237.9* ATDC
exhaust open: 226.1* BTDC
exhaust centerline: 111* BTDC
exhaust close: 5.1* ATDC

rocker ratio of 1.68:1

Why Not ROFL! Obviously the cams are altered a bit. Wonder if they played with valve diameters.

04 Seville L37:

exhaust valve head diameter: 1.142"
intake valve head diameter: 1.426"

valve spring free length: 1.663"
valve spring thickness: .1618 X .1291"
valve spring ID: .7087"
valve spring OD: 1.0327"
spring height, valve closed: 1.378"
spring height, valve opened: .9646"
spring load, valve closed: 50lb
spring load, valve opened: 136lb
approx number of coils: 7



04 Seville LD8:

exhaust valve head diameter: 1.142"
intake valve head diameter: 1.426"

valve spring free length: 1.663"
valve spring thickness: .1618 X .1291"
valve spring ID: .7087"
valve spring OD: 1.0327"
spring height, valve closed: 1.378"
spring height, valve opened: .9646"
spring load, valve closed: 50lb
spring load, valve opened: 136lb
approx number of coils: 7

Well now we know.
Same valve setup and different cams.

Sorry about the hijack Matt,
Seems this thread took a hard left turn.