rich weyand
Full Access Member
- Joined
- May 28, 2014
- Posts
- 967
- Reaction score
- 177
- Location
- Bloomington Indiana
- First Name
- Rich
- Truck Year
- 1978
- Truck Model
- K10
- Engine Size
- 350
One of two things.
1) You didn't mention, but you did disconnect the vacuum advance hose from the carburetor to the distributor, right? If not, it may be in vacuum advance when at idle (depending on which vacuum source is being used), and should be running something like 30 degrees advance.
2) The timing tab on the motor (the metal sawtooth thingie) is in the wrong place. There were three stock locations, basically 12:00, 2:00, and 2:30. The crankshaft keyway at #1TDC is at 45 crankshaft degrees clockwise from straight up on all Chevy small blocks: call it 1:30 o'clock looking at the front of the engine. The three timing tab locations are 40* counterclockwise from the keyway (5* total off vertical, called 12:00), 10* counterclockwise (35* total off vertical, called 2:00, though it's more like 1:00 really), and 2* counterclockwise (about 43* off vertical, called 2:30, though it's more like 1:30 really).
So where is your timing tab? And where is the mark on the flywheel when the engine is at TDC per firebane's instruction?
One permanent solution to this if they are mismatched is to put the correct timing wheel over the flywheel to match the tab location. The other is to mount a new timing tab in the correct location to match the flywheel. Either works. Both are pretty simple to do.
1) You didn't mention, but you did disconnect the vacuum advance hose from the carburetor to the distributor, right? If not, it may be in vacuum advance when at idle (depending on which vacuum source is being used), and should be running something like 30 degrees advance.
2) The timing tab on the motor (the metal sawtooth thingie) is in the wrong place. There were three stock locations, basically 12:00, 2:00, and 2:30. The crankshaft keyway at #1TDC is at 45 crankshaft degrees clockwise from straight up on all Chevy small blocks: call it 1:30 o'clock looking at the front of the engine. The three timing tab locations are 40* counterclockwise from the keyway (5* total off vertical, called 12:00), 10* counterclockwise (35* total off vertical, called 2:00, though it's more like 1:00 really), and 2* counterclockwise (about 43* off vertical, called 2:30, though it's more like 1:30 really).
So where is your timing tab? And where is the mark on the flywheel when the engine is at TDC per firebane's instruction?
One permanent solution to this if they are mismatched is to put the correct timing wheel over the flywheel to match the tab location. The other is to mount a new timing tab in the correct location to match the flywheel. Either works. Both are pretty simple to do.
