86 chevy 454. How commen is it to flatten the cam when you are breaking in a new motor. Have new motor that runs ruff and very low power. With a timming light the line on the balencer is 3 '' away from the tdc mark, when try dist to fix it it will die.

You would have other issues if the cam was worn like valve train noises and popping through your intake/exhaust. Make sure your timing chain doesnot have play by trying to move your crank with a breaker bar and seeing how long it takes for the ignition rotor to move when the crank moves.

you might have your timing chain or gears off a tooth or your distributor is bad if it is popping up through the caberator then it is probably a lobe down on your cam you might readjust your valves and make sure they are not to tight when you go back with a new cam if it is a solid lift def adjust your valves the way the specs with the cam says.

The timming mark on the balencer is 3 inches away on the ATDC side from the TDC indicator not 3 deg. When I try to turn the dist closer it will die. I checked the timming chain and it is right. The only thing I can think of is the lobs on the cam got flattened when I was breaking the engine in or I have a really big vacume leak.

The timming mark on the balencer is 3 inches away on the ATDC side from the TDC indicator not 3 deg. When I try to turn the dist closer it will die. I checked the timming chain and it is right. The only thing I can think of is the lobs on the cam got flattened when I was breaking the engine in or I have a really big vacume leak.

the timing is off. The way you describe this it is 3 deg retarded. When you are timing is the 'advance' activaed? Is the advance mechanical or vaccumn? for a 454 you shaould have at least 5 deg advacned timing with no distributer advance
A simple quick fix would be to have someone load the engine in gear while you advance the timing until the engine pings, then back off until the ping is gone. Load the engine to the high end of the torque converter slip.

I have a 86 454 as well. Am presently rebuilding and noticed the timing mark is 180 degrees off, or on the other side of the balancer! Maybe yours is the same. Try timing it to cylinder number 4. That's what I will do. Don't understand this at all though.