: cam swap to 4.0l



aurora guy
05-25-11, 11:52 PM
as i may not have a cadillac, but i do have northstar in my aurora. im in the process of rebuilding it along with headstuds. and i want alittle more power, but wanna stay with the 4.0. so i was wondering can i swap cams out of a LD8 to my L47 ? i figured the L37 cams would be to high reving and not enough power for city driving. what do you guys think ? and what would you do ?

thanks

Submariner409
05-26-11, 02:25 PM
Not sure of the mechanical problems, if any - but remember that the L37 cams are ground for a different engine and cylinder displacement - in our case, your engine is about 36 c.i. smaller than the 4.6, so you would have serious airflow imbalance between the cam sets. Also, you need to research valve lift for each cam - I believe your engine has direct-acting hydraulic cam followers, so any valve lift differences might be profound - as in valves hitting piston tops.

LD8 and L37 cam engines have the same 6300 rpm redline. It's the transmission final drive that determines where the power band lies in each gear. Look at an SLS compared to the STS: each has PLENTY of "power" for city driving.

Talk to CHRFAB - they build Northstars for sand rails and kit cars - they might have better info.

BTW......Welcome Aboard !!!....:highfive:

aurora guy
05-26-11, 04:59 PM
thanks,ill look into those specs.
okay a few questions, 1. why a friction drive oil pump ?
and 2. are the main and rods bolts tourqe to yeild ?
im rebuilding mine, ill start a porject thread for it, ill post pics tonight

thanks

Submariner409
05-27-11, 11:46 AM
thanks,ill look into those specs.
okay a few questions, 1. why a friction drive oil pump ?
and 2. are the main and rods bolts tourqe to yeild ?
im rebuilding mine, ill start a porject thread for it, ill post pics tonight

thanks

1. DOHC chain drive makes it impossible to drop an oil pump driveshaft down into the oil pan. Splining or keying the crank snout might have been an option.......

2. You NEED either a GM Service Manual or www.alldatadiy.com for this one. The 4.6 uses an initial torque + so many degrees.

aurora guy
05-27-11, 11:53 AM
yea thats what i ment a slpine on the crank, and it's tty then. so that will make the cost too high for me, ill be buying a LD8 from a junkyard with bad heads. drop a stud kit in and go.
thanks for all the info

89falcon
05-27-11, 01:55 PM
1. DOHC chain drive makes it impossible to drop an oil pump driveshaft down into the oil pan. Splining or keying the crank snout might have been an option.......

2. You NEED either a GM Service Manual or www.alldatadiy.com for this one. The 4.6 uses an initial torque + so many degrees.

WRT the harmonic dampener bolt, is it suggested that it be replaced? I think someone was saying they broke an old one and had to replace it........is it a torque to yield bolt?

89falcon
05-27-11, 02:02 PM
FWIW, looks like the 4.0 cam is the same as the base 4.6 cam.....and the shelby series 1 cam is the same as the vin9 cam.



http://aurorah.proboards.com/index.cgi?board=Zoom&action=display&thread=11302

Cadillac specs


1993 - 1998 Cadillac (LD8 (VIN Y )
• Valve Timing (With Ramp at 0.100 mm Lift)
• Intake Opens 9 degrees BTDC
• Intake Closes 55 degrees ABDC
• Exhaust Opens 51 degrees BBDC
• Exhaust Closes 13 degrees ATDC

• Valve Lift
• Intake 8.6 mm 0.339 in
• Exhaust 8.6 mm 0.339 in

• Duration (@ 0.100 mm Lift)
• Intake 244 degrees
• Exhaust 244 degrees

• Valve Overlap (@ 0.100 mm Lift) 22 degrees

.

1993 - 1999 Cadillac (L37 (VIN 9)
• Valve Timing (With Ramp at 0.100 mm Lift)
• Intake Opens 13 degrees BTDC
• Intake Closes 73 degrees ABDC
• Exhaust Opens 51 degrees BBDC
• Exhaust Closes 13 degrees ATDC

• Valve Lift
• Intake 9.4 mm 0.370 in
• Exhaust 8.6 mm 0.339 in

• Duration (@ 0.100 mm Lift)
• Intake 266 degrees
• Exhaust 244 degrees

• Valve Overlap (@ 0.100 mm Lift) 26 degrees

.

1999 Cadillac (LD8 (VIN Y )
• Valve Timing (With Ramp at 0.100 mm Lift)
• Intake Opens 8 degrees BTDC
• Intake Closes 55 degrees ABDC
• Exhaust Opens 51 degrees BBDC
• Exhaust Closes 13 degrees ATDC

• Valve Lift• Intake 8.6 mm 0.339 in
• Exhaust 8.6 mm 0.339 in

• Duration (@ 0.100 mm Lift)
• Intake 243 degrees
• Exhaust 244 degrees

• Valve Overlap (@ 0.100 mm Lift) 22 degrees

.

2000 - 2003 Cadillac (LD8) 1.68 Rockers
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Exhaust 236 degrees
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Intake 242 degrees
• Camshaft Lobe Lift - Exhaust 5.94 mm 0.2339 in
• Camshaft Lobe Lift - Intake 6.15 mm 0.2421 in

• Camshaft Lobe Overlap @ 0.150 mm (0.006 in) Lift 1.98 degrees

• Camshaft Timing @ 0.150 mm (0.006 in) Lift
• Intake Opens 5.6 degrees BTDC
• Intake Centerline 113.0 degrees ATDC
• Intake Closes 236.8 degrees ATDC
• Exhaust Opens 222.5 degrees BTDC
• Exhaust Centerline 107.0 degrees BTDC
• Exhaust Closes 13.8 degrees ATDC

.

2000 - 2003 Cadillac (L37) 1.68 Rockers
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Exhaust 246 degrees
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Intake 251 degrees
• Camshaft Lobe Lift - Exhaust 5.94 mm 0.2339 in
• Camshaft Lobe Lift - Intake 6.15 mm 0.2421 in

• Camshaft Lobe Overlap @ 0.150 mm (0.006 in) Lift 2.04 degrees

• Camshaft Timing @ 0.150 mm (0.006 in) Lift
• Intake Opens 0.0 degrees ATDC
• Intake Centerline 122.0 degrees ATDC
• Intake Closes 251.0 degrees ATDC
• Exhaust Opens 225.5 degrees BTDC
• Exhaust Centerline 106.0 degrees BTDC
• Exhaust Closes 20.5 degrees ATDC
.


2004 - 2008 Cadillac (LD8) 1.68 Rockers
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Exhaust 236 degrees
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Intake 242 degrees
• Camshaft Lobe Lift - Exhaust 5.94 mm 0.2339 in
• Camshaft Lobe Lift - Intake 6.15 mm 0.2421 in

• Camshaft Lobe Overlap @ 0.150 mm (0.006 in) Lift 1.98 degrees

• Camshaft Timing @ 0.150 mm (0.006 in) Lift
• Intake Opens 1.3 degrees BTDC
• Intake Centerline 117.0 degrees ATDC
• Intake Closes 237.9 degrees ATDC
• Exhaust Opens 226.1 degrees BTDC
• Exhaust Centerline 111.0 degrees BTDC
• Exhaust Closes 5.1 degrees ATDC

.

2004 - 2008 Cadillac (L37) 1.68 Rockers
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Exhaust 246 degrees
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Intake 251 degrees
• Camshaft Lobe Lift - Exhaust 5.94 mm 0.2339 in
• Camshaft Lobe Lift - Intake 6.15 mm 0.2421 in

• Camshaft Lobe Overlap @ 0.150 mm (0.006 in) Lift 2.04 degrees

• Camshaft Timing @ 0.150 mm (0.006 in) Lift
• Intake Opens 0.3 degrees ATDC
• Intake Centerline 122.0 degrees ATDC
• Intake Closes 246.0 degrees ATDC
• Exhaust Opens 229.3 degrees BTDC
• Exhaust Centerline 110.0 degrees BTDC
• Exhaust Closes 11.2 degrees ATDC

Olds cam specs
1995 - 1999 Cadillac (L47 (VIN C )
• Valve Timing (With Ramp at 0.100 mm Lift)
• Intake Opens 9 degrees BTDC
• Intake Closes 55 degrees ABDC
• Exhaust Opens 51 degrees BBDC
• Exhaust Closes 13 degrees ATDC

• Valve Lift
• Intake 8.6 mm 0.339 in
• Exhaust 8.6 mm 0.339 in

• Duration (@ 0.100 mm Lift)
• Intake 244 degrees
• Exhaust 244 degrees

• Valve Overlap (@ 0.100 mm Lift) 22 degrees

Shelby Series I

Valve Timing (With Ramp at 0.100 mm Lift)
• Intake Opens 13 degrees BTDC
• Intake Closes 73 degrees ABDC
• Exhaust Opens 51 degrees BBDC
• Exhaust Closes 13 degrees ATDC

• Valve Lift
• Intake 9.4 mm 0.370 in
• Exhaust 8.6 mm 0.339 in

• Duration (@ 0.100 mm Lift)
• Intake 266 degrees
• Exhaust 244 degrees

• Valve Overlap (@ 0.100 mm Lift) 26 degrees



2001 - 2003 (L47) 1.68 Rockers
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Exhaust 236 degrees
• Camshaft Lobe Duration @ 0.150 mm (0.006 in) Lift - Intake 242 degrees
• Camshaft Lobe Lift - Exhaust 5.94 mm 0.2339 in
• Camshaft Lobe Lift - Intake 6.15 mm 0.2421 in

• Camshaft Lobe Overlap @ 0.150 mm (0.006 in) Lift 1.98 degrees

• Camshaft Timing @ 0.150 mm (0.006 in) Lift
• Intake Opens 5.6 degrees BTDC
• Intake Centerline 113.0 degrees ATDC
• Intake Closes 236.8 degrees ATDC
• Exhaust Opens 222.5 degrees BTDC
• Exhaust Centerline 107.0 degrees BTDC
• Exhaust Closes 13.8 degrees ATDC

aurora guy
05-27-11, 02:50 PM
wow very nice find ! so the vin 9 cam is the shelby cam, does anybody know what kind of springs the vin 9 L37's use ? and if there the same as the L47's. hmm very intresting project may not be dead yet

thanks

aurora guy
05-27-11, 03:23 PM
also is there any way to check and see what pistion to valve clearence is with the vin 9 cam ? i think it would work, shelby put the vin 9 cam on a L47 head and it worked.

ponyboyt
05-30-11, 01:30 AM
I have a vin 9 98 engine with a shattered piston and a bent valve stem. I'd like to know this too. This PCM shifts at 7000 rpm (no idea why) and we've talked about doing a set of heads with stronger springs to see how it makes out. (it made power at 7000.....)