Posted By: fal3
Carb: rebuild or paperweight - 09/07/17 04:52 PM
I have a 440 w/ a Holley model 4150 0-80770 vacuum secondaries using the heavy spring; jets are 74/78; power valve 6.5 window type; primary metering plate 5271 on left side,right side 5275, underneath 3; secondary plate 11166, underneath 3; 30cc accel pump; primary discharge #25; fuel mixture screws set @ 1 3/4 out. Prior to what happened, carb worked fine. Here's timing if needed for diagnosis, this is with the iron heads: 18 degrees initial; 18 degrees in the distributor. This timing worked for my engine w/ 9.5 CR using premium. Vacuum was 15-16 in neutral; 13-14 in D. Timing is set using vacuum method.
Here's the situation. Installed aluminum heads on engine; had to reset distributor to start engine. I followed the instructions in a BB Mopar manual I used. Had the oil gear slot parallel to cam; engine would not start; the engine was fighting itself. Played around with the oil gear slot, moved the wires around ccw on the distributor. Engine fired but backfired and flamed out through carb. Put wires back to factory setting, engine fired up. At this point idle was 1000rpm, set fuel mixture screws out 1 1/2 turns just to get things going, lowered to 850 with car in D. Was setting the timing, engine stalled. Re-fired engine, idle was high, 1200rpm. Reset idle to 850rpm, went back to timing in D. Engine ran ok meaning it idled smooth, when carb was blipped no hesitations; did not road test. Turned off engine, re-started engine, rpm jumped to 5000rpm, no matter what I did couldn't get idle down. Turned fuel mixture screws all the way in; turned idle screw all the way out. First thought, I blew out the PV. Had a spare one (6.5) and installed. Started engine, again rpm jumped all the way to 5000rpm. I seriously messed up the carb. Does it sound like it can be rebuilt? Or is it a paperweight? I have a rudimentary knowledge of carbs, can rebuild one, but am no expert in the finer details.
Here's the situation. Installed aluminum heads on engine; had to reset distributor to start engine. I followed the instructions in a BB Mopar manual I used. Had the oil gear slot parallel to cam; engine would not start; the engine was fighting itself. Played around with the oil gear slot, moved the wires around ccw on the distributor. Engine fired but backfired and flamed out through carb. Put wires back to factory setting, engine fired up. At this point idle was 1000rpm, set fuel mixture screws out 1 1/2 turns just to get things going, lowered to 850 with car in D. Was setting the timing, engine stalled. Re-fired engine, idle was high, 1200rpm. Reset idle to 850rpm, went back to timing in D. Engine ran ok meaning it idled smooth, when carb was blipped no hesitations; did not road test. Turned off engine, re-started engine, rpm jumped to 5000rpm, no matter what I did couldn't get idle down. Turned fuel mixture screws all the way in; turned idle screw all the way out. First thought, I blew out the PV. Had a spare one (6.5) and installed. Started engine, again rpm jumped all the way to 5000rpm. I seriously messed up the carb. Does it sound like it can be rebuilt? Or is it a paperweight? I have a rudimentary knowledge of carbs, can rebuild one, but am no expert in the finer details.