Lots of changes and same problems hahah
Posted: 2026 May 15, 17:13
I have had this SC powered mustang since the late 90s. It was never close to driving a factory car but I enjoyed it for many years. I pulled the driveline to correct everything I knew was wrong and to check on the health of the motor.
The cam is a regrind and I struggled to degree it last time. I have no idea where it was installed but the cam was ground 14' retarded if installed straight up. I had to skip teeth to get it the best I could at 2' retarded. My vacuum went down at idle but power went way up in boost, seat of the pants.
Cam
GROSS VALVE LIFT .548 .548
DURATION @ .006
TAPPET LIFT 263 273
VALVE TIMING OPEN CLOSE
@ .050 INT 5- 39
EXH 48 4-
SPECS FOR CAM INST. @ 112.0 CENTERLINE
INT EXH
DURATION @ .050 214.00 224.00
LOBE LIFT .317 .317
LOBE SEPARATION 114.0
ROCKER ARM RATIO 1.73 1.73 REQ
I found the cam gear worn to knife blades with 60k miles on it. Pulled the original one from the 3.8 NA engine that had maybe 30k miles on it. I did pull the SC oil pump off and used the 3.8 NA pump to reduce the wear on this gear. I only run 5-30 mobil 1, engine RPM is always low and the cam sensor bushing is in great shape with only 60k miles. Still confused why this happened but I did machine some off the back of the hub to get the gear alignment better. Have to wait and see if this is resolved. Oil pressure is still more then enough with the smaller gears. Put new rod and main bearings in it since the metal from that gear did some damage.
Biggest difference was the welding and port work I did to the lower intake manifold. tried to equal out the air flow the best I could using the m90 a high torque drill and a velocity meter. Will have to wait and see if it was worth it.
BHJ dampener I found out the mark needed to sync the cam was not on it. Sat an original balancer on top of the BHJ and used key stock to lock them into place and added the mark. Maybe mine was an early on I have no idea. Not that it changed anything, car still only likes injector timing to be 380.
So tuning is back in effect and man am I rusty. In general I had to pull fuel from the whole MAF and add more air. My main list of issues
Idle - Idle is very delicate and has been for well over a decade. Dashpot has to be painfully slow and fuel must be stupidly lean to try and get this thing to come to a idle without crashing. Turn the light on or cooling fan turns on and it just gets worse.
Start flair - tried removing all rpm adders and it will still start shoot up to 2k then crash into a stall. less dramatic warmer it is but still you have to blip the throttle to save it. Having issues attaching logs, guess I need to change the file.
The cam is a regrind and I struggled to degree it last time. I have no idea where it was installed but the cam was ground 14' retarded if installed straight up. I had to skip teeth to get it the best I could at 2' retarded. My vacuum went down at idle but power went way up in boost, seat of the pants.
Cam
GROSS VALVE LIFT .548 .548
DURATION @ .006
TAPPET LIFT 263 273
VALVE TIMING OPEN CLOSE
@ .050 INT 5- 39
EXH 48 4-
SPECS FOR CAM INST. @ 112.0 CENTERLINE
INT EXH
DURATION @ .050 214.00 224.00
LOBE LIFT .317 .317
LOBE SEPARATION 114.0
ROCKER ARM RATIO 1.73 1.73 REQ
I found the cam gear worn to knife blades with 60k miles on it. Pulled the original one from the 3.8 NA engine that had maybe 30k miles on it. I did pull the SC oil pump off and used the 3.8 NA pump to reduce the wear on this gear. I only run 5-30 mobil 1, engine RPM is always low and the cam sensor bushing is in great shape with only 60k miles. Still confused why this happened but I did machine some off the back of the hub to get the gear alignment better. Have to wait and see if this is resolved. Oil pressure is still more then enough with the smaller gears. Put new rod and main bearings in it since the metal from that gear did some damage.
Biggest difference was the welding and port work I did to the lower intake manifold. tried to equal out the air flow the best I could using the m90 a high torque drill and a velocity meter. Will have to wait and see if it was worth it.
BHJ dampener I found out the mark needed to sync the cam was not on it. Sat an original balancer on top of the BHJ and used key stock to lock them into place and added the mark. Maybe mine was an early on I have no idea. Not that it changed anything, car still only likes injector timing to be 380.
So tuning is back in effect and man am I rusty. In general I had to pull fuel from the whole MAF and add more air. My main list of issues
Idle - Idle is very delicate and has been for well over a decade. Dashpot has to be painfully slow and fuel must be stupidly lean to try and get this thing to come to a idle without crashing. Turn the light on or cooling fan turns on and it just gets worse.
Start flair - tried removing all rpm adders and it will still start shoot up to 2k then crash into a stall. less dramatic warmer it is but still you have to blip the throttle to save it. Having issues attaching logs, guess I need to change the file.