jenkins71
Well-Known Member
Hi guys. So, I just built a 440 and 4 speed for my 71 Charger. Cam break-in went well, and I am now just seating the rings and trying to get a good tune out of her.
Engine stats are as follows:
2266 TRW Pistons, 9:1 CR
952 heads, port and polish job using the Mopar templates
Holley street dominator intake
Holley 750 carb
Comp Camps XE274 cam
Hooker Super Comp headers
Factory, stock, unmodified Mopar distributor with Accel Wires, Orange Box ECU, MSD Blaster 2 coil.
Centerforce clutch and 4 speed, rebuilt.
So using the vacuum gauge on manifold vacuum, trying to get the highest vacuum reading by advancing the timing, (vacuum advance at dizzy disconnected) it appears that it likes about 25* of initial timing! That to me seems like quite a lot, so I've backed it down to about 15* initial, but it idles worse and RPM drops at that setting.
It's a pig off-idle, and you kind of have to rev it up to keep the clutch from staling it out! Keep in mind, it does at this time have a set of 2.76 gears until I rebuild my 3.55 set up.
Can someone guide me through the process of setting up my ignition timing? This will be the first time I attempt to mess with ignition timing on a true performance motor, and trying to create a good curve other than just setting initial.
I do want to continue using my vacuum advance, to increase MPG hopefully.
Also, my dizzy is the old weld-up-the-slots style.
THANKS!
Engine stats are as follows:
2266 TRW Pistons, 9:1 CR
952 heads, port and polish job using the Mopar templates
Holley street dominator intake
Holley 750 carb
Comp Camps XE274 cam
Hooker Super Comp headers
Factory, stock, unmodified Mopar distributor with Accel Wires, Orange Box ECU, MSD Blaster 2 coil.
Centerforce clutch and 4 speed, rebuilt.
So using the vacuum gauge on manifold vacuum, trying to get the highest vacuum reading by advancing the timing, (vacuum advance at dizzy disconnected) it appears that it likes about 25* of initial timing! That to me seems like quite a lot, so I've backed it down to about 15* initial, but it idles worse and RPM drops at that setting.
It's a pig off-idle, and you kind of have to rev it up to keep the clutch from staling it out! Keep in mind, it does at this time have a set of 2.76 gears until I rebuild my 3.55 set up.
Can someone guide me through the process of setting up my ignition timing? This will be the first time I attempt to mess with ignition timing on a true performance motor, and trying to create a good curve other than just setting initial.
I do want to continue using my vacuum advance, to increase MPG hopefully.
Also, my dizzy is the old weld-up-the-slots style.
THANKS!