wsutard
Well-Known Member
I have been running my newly built 440 for a few weeks now. Now that I have the odds and ends buttoned up I want to address a low power surging that I am experiencing.
At steady throttle, anywhere from 1200-2000ish rpm I feel a “surge”. I can’t tell if it is a power surge (forward) or a loss of power surge (backward). My hunch is it’s loss of power. I can’t feel this at high RPM or high acceleration. It is very evident power coasting downhill in 4th gear around 1300 rpm.
Additionally, when under mid power, heading up hill every once in a while the rpms will quickly dip and then come back up to where they were. However the surge does not happen under this scenario.
I have installed an air fuel gauge and determined that this is not a lean surge situation. At least it’s not showing that on my passenger bank. My air fuel at when this happenes is between 10.3-13. I am also going to be tuning up the carb so I don’t run so rich all the time.
Specs of the engine that I think matter to this:
New Holley 850 DP, has not been messed with other than setting the idle screws.
MSD Digital 6AL, which was successfully igniting my former small block.
MSD Blaster 2 coil, mounted to the intake. Also successful used on my former small block.
MSD Pro-billet distributor, new.
Mechanical fuel pump (pushes anywhere from 7-9 psi. I have a fuel regulator that I will be installing to even out the psi.)
New Accel plug wire set.
Lokar throttle linkage, (new)
Not sure what else I need to list out.
My magnetic pickup wire is shielded and runs from my MSD box mounted under the stock battery spot, straight over to the front driver side of the engine, up and over the water housing and runs along the 4 plug wires till it hits the distributor.
Any questions that might help solve this mystery?
At steady throttle, anywhere from 1200-2000ish rpm I feel a “surge”. I can’t tell if it is a power surge (forward) or a loss of power surge (backward). My hunch is it’s loss of power. I can’t feel this at high RPM or high acceleration. It is very evident power coasting downhill in 4th gear around 1300 rpm.
Additionally, when under mid power, heading up hill every once in a while the rpms will quickly dip and then come back up to where they were. However the surge does not happen under this scenario.
I have installed an air fuel gauge and determined that this is not a lean surge situation. At least it’s not showing that on my passenger bank. My air fuel at when this happenes is between 10.3-13. I am also going to be tuning up the carb so I don’t run so rich all the time.
Specs of the engine that I think matter to this:
New Holley 850 DP, has not been messed with other than setting the idle screws.
MSD Digital 6AL, which was successfully igniting my former small block.
MSD Blaster 2 coil, mounted to the intake. Also successful used on my former small block.
MSD Pro-billet distributor, new.
Mechanical fuel pump (pushes anywhere from 7-9 psi. I have a fuel regulator that I will be installing to even out the psi.)
New Accel plug wire set.
Lokar throttle linkage, (new)
Not sure what else I need to list out.
My magnetic pickup wire is shielded and runs from my MSD box mounted under the stock battery spot, straight over to the front driver side of the engine, up and over the water housing and runs along the 4 plug wires till it hits the distributor.
Any questions that might help solve this mystery?
