- Local time
- 9:50 PM
- Joined
- May 14, 2011
- Messages
- 17,433
- Reaction score
- 32,926
- Location
- On the Ridge, TN
Ok, facts first:
Pretty much stock 440 on real low miles since rebuild (less than 1k).
Comp Cams Magnum 270 cam (might as well be stock, just a tad lumpy).
Mopar Performance electronic distributor w/orange box, also purportedly new
(sure looks it, but it came with the car, so...)
Holley 3310 750 vac sec, new and working spiffy.
As you can probably tell from other old threads I started, tuning this thing has proven
to be a bear.
I'm currently running it with vacuum advance disconnected (the thing gets
majorly jumpy if I hook it up). If I try to give it any initial timing advance beyond an
indicated 5TDC, then the engine gets all jumpy and surges over 4k RPMs.
Heck, it even does it AT 5BTDC.
I just held it at an indicated 3500rpms this morning (after a few trial warmup runs) and set the timing by ear while holding the throttle steady there. ANY advancing at all and she got noticeably
rougher; when I scaled timing back, she smoothed right out.
Set it where it felt best at that RPM and then checked the timing with the light - yep, you guessed
it, exactly TDC.
Oy.
Starting to feel like the distributor might have issues beyond my ability.
Since the motor is so close to stock, I'm starting to wonder if I shouldn't just fetch a nice stock
point-type distributor and slap a Pertronix in it or something - maybe then it would tune easier
and I could hook the vacuum advance back up?
Pretty much stock 440 on real low miles since rebuild (less than 1k).
Comp Cams Magnum 270 cam (might as well be stock, just a tad lumpy).
Mopar Performance electronic distributor w/orange box, also purportedly new
(sure looks it, but it came with the car, so...)
Holley 3310 750 vac sec, new and working spiffy.
As you can probably tell from other old threads I started, tuning this thing has proven
to be a bear.
I'm currently running it with vacuum advance disconnected (the thing gets
majorly jumpy if I hook it up). If I try to give it any initial timing advance beyond an
indicated 5TDC, then the engine gets all jumpy and surges over 4k RPMs.
Heck, it even does it AT 5BTDC.
I just held it at an indicated 3500rpms this morning (after a few trial warmup runs) and set the timing by ear while holding the throttle steady there. ANY advancing at all and she got noticeably
rougher; when I scaled timing back, she smoothed right out.
Set it where it felt best at that RPM and then checked the timing with the light - yep, you guessed
it, exactly TDC.
Oy.
Starting to feel like the distributor might have issues beyond my ability.
Since the motor is so close to stock, I'm starting to wonder if I shouldn't just fetch a nice stock
point-type distributor and slap a Pertronix in it or something - maybe then it would tune easier
and I could hook the vacuum advance back up?