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TRYING to get a 51 239 to run again. It has run in the past, I checked and have spark going to the plugs. I thought maybe it might be the carb needs a rebuild so I took out all the plugs and turned the motor and blew out the cylinders. I re-gapped every plug and then squirted gas straight into each cylinder. Then I replaced the plugs and re- ran the firing order and connected the plug wires and turned the motor and got nothing. Any suggestions would be greatly helpful.
I ran the firing order twice to verify and I pulled the distributor and lined up the timing mark with the bump pointed them distributor to #1 and inserted it and get nothing. How do I tell if I have it 180 degrees out?
Easiest way to find the compression stroke on #1 cyl is to put a ratchet wrench on the bolt in front of the crankshaft so you can turn the motor by hand. Then, with #1 spark plug removed, put a thumb over the hole while you slowly turn the crankshaft. You should be able to feel a pressure build up in the cyl during the compression stroke and nothing at during the exhaust stroke. I have been able to do this with the other 7 plugs still in place as these old y-blocks are not high compression.
So when I feel the compression, I pull the distributor and check to make sure that it is pointed to #1 and reinsert it?
when you feel compression keep turning until your timing marks show 0 degrees BTDC. Then pull the distributor cap and look to see that the rotor is pointing at the #1 wire
I did this and found the rotor pointed 180 degrees from #1 so I loosened the distributor and rotated it to point the rotor to point to #1. Then I put the cap back on and spun the engine. The rotor was at 180 degrees to #1 again.
I did this and found the rotor pointed 180 degrees from #1 so I loosened the distributor and rotated it to point the rotor to point to #1. Then I put the cap back on and spun the engine. The rotor was at 180 degrees to #1 again.
When you "spun the engine" did you go around once or twice? Every second revolution of the crankshaft should have the rotor pointing in the same direction.
Do it once, and do it right, pull #1 plug, turn the engine with a wrench the right direction, clock wise standing in front looking down at it. With your finger covering the plug hole, turn till you feel compression, keep turning till timing marks are at tdc, install dist with the rotor cap tang pointing at #1 plug with tower. Rewire the other wires, firing order is 1 5 4 8 6 3 7 2 in the direction the dist turns, putting gas in the cyl's means its flooded out of its mind, pull the plugs and put a small amount of engine oil in each cyl. If the battery is good and turns the engine over like it should, it will fire off.
I think this will address your remaining uncertainty:
1) Use the "thumb method" as described above to the motor at #1 top-dead-center on compression.
My Y-block is currently out if the truck so I went and took pictures
Y-block at #1 TDC
2) Pull the distributor cap and set the rotor pointing at your desired #1 plug wire location. On my truck I used a Sharpie Marker to show where the #1 wire on the cap lines up with the lower metal shell.
Rotor at #1 TDC on compression
3) Remove all the plug wires from the distributor cap and install the cap
( I say this to wipe the slate clean and get a fresh start)
4) Put the #1 plug wire in the designated #1 position which is lined up with the copper tip on the rotor
Cap in place, Rotor inside is pointed at the mark
5) attach the remaining plug wires following the firing order.
CAUTION: It looks like flathead distributors rotate CW whereas my Y-block rotates CCW !!
I THINK the picture below is correct but you need to double check.
1949-53 flathead firing order and distributor rotation
In one of your other threads, you tested compression and found -0- psi on all cylinders. Did you confirm that? If it is true, there's no way it's going to fire.
