I have a new rebuilt 357 SBC (350 bore .040 over) I have some issues that I just can't seem to figure out. Here is the run down on the engine
Camshaft- 275/285 .470/470 112 LSA (Flat Tappet Hydraulic lifter)
Heads - Aluminum 64cc Camber 190cc intake runner 2.02/1.60
Intake- Edelbrock Performer RPM
Pistons- Compression Distance 1.560 in Piston Head Volume (cc):+6.00cc
Roller Tip Rocker Arms
GM HEI Distributor, Changed springs, After market coil
Spark Plugs-NGK 7373 gap .038
Timing 34deg at 3000 RPM
Carb- Holley 4150 .028 Primary .031 Secondary 650CFM, float set correctly.
I am having several issues one being it keeps fouling the spark plugs, the plugs are black and fuel fouled with less that 10 min run time. The engine surges at idle (800 RPM) but timing adjustment and idle screw adjustment does not level it out. I started at 1 1/2 turns on the idle screws, opening them up from there, and adjust the timing anywhere from 28deg all the way to 38deg but never could get the surging to level out. If I set the RPM above 1000 the surging is less. With a vacuum gauge connected I get a reading that goes between 16-19 at idle, which the camshaft manufacture said is very good for this camshaft.
I took the carb to have it looked at thinking this had to be my problem, the builder check it out and found everything was fine.
It seems like I would be running lean if anything. I have checked and rechecked for Vacuum leaks, isolating everything I could with no change.
Does anyone have any ideas?
Thanks
Camshaft- 275/285 .470/470 112 LSA (Flat Tappet Hydraulic lifter)
Heads - Aluminum 64cc Camber 190cc intake runner 2.02/1.60
Intake- Edelbrock Performer RPM
Pistons- Compression Distance 1.560 in Piston Head Volume (cc):+6.00cc
Roller Tip Rocker Arms
GM HEI Distributor, Changed springs, After market coil
Spark Plugs-NGK 7373 gap .038
Timing 34deg at 3000 RPM
Carb- Holley 4150 .028 Primary .031 Secondary 650CFM, float set correctly.
I am having several issues one being it keeps fouling the spark plugs, the plugs are black and fuel fouled with less that 10 min run time. The engine surges at idle (800 RPM) but timing adjustment and idle screw adjustment does not level it out. I started at 1 1/2 turns on the idle screws, opening them up from there, and adjust the timing anywhere from 28deg all the way to 38deg but never could get the surging to level out. If I set the RPM above 1000 the surging is less. With a vacuum gauge connected I get a reading that goes between 16-19 at idle, which the camshaft manufacture said is very good for this camshaft.
I took the carb to have it looked at thinking this had to be my problem, the builder check it out and found everything was fine.
It seems like I would be running lean if anything. I have checked and rechecked for Vacuum leaks, isolating everything I could with no change.
Does anyone have any ideas?
Thanks