Breaking in rebuilt 2F

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L

Lmnop Abcde

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Feb 1, 2019
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Hi everyone, quick tech question. Trying to spin the oil pump on a rebuilt 2F to get oil moving through the motor and it feels like there’s a lot of pressure building up in the oil pump to the point that it stops spinning and once stops spinning, pressure seems to be relieved and then it is able to spin again, until it then builds up more pressure and stops spinning. Spinning the pump with a flat head and my drill. Would appreciate any thoughts, troubleshooting, tips, guidance, all of the above before I start tearing the motor apart unnecessarily.
 
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Is it a fresh rebuild with new bearings and all? Full off sticky assembly lube? You could just be hitting the resistance of the assembly lube that the oil can’t displace.
 
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There is a passage in the cam that allows oil to flow to the head/valvetrain. It needs to be lined up in order for the oil to flow so slowly turning the crank while running the oil pump with the drill can help find where it is. If I remember right, it’s when #4 is at TDC (or rockers 10, 11 are both open?) Spin it so number 4 is tdc, run drill and see if you get anything. If not, rotate 1 revolution of crank so 4 is on tdc again and give it another try with the drill. If that doesn’t work, try turning crank 90 degrees at a time and then run drill, 90 degrees and run drill, etc. The cam is moving 1/8 of a turn for every 1/4 turn of crank so you should be able to find the sweet spot this way. I’d be running the drill 20-30 seconds at least each time and looking at all the rockers until you start seeing any dribbles.
Sorry, that got long for something simple.

On a side note, I’ve heard people say oil priming an engine just washes away all that nice, sticky assembly lube and instead, just pour some oil over the valvetrain and send it. I’ve always oil primed every engine I built so who knows. I’m no pro engine builder, but I did do a big smokey burnout today. (Or 6…)
 
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Skreddy said:
There is a passage in the cam that allows oil to flow to the head/valvetrain. It needs to be lined up in order for the oil to flow so slowly turning the crank while running the oil pump with the drill can help find where it is. If I remember right, it’s when #4 is at TDC (or rockers 10, 11 are both open?) Spin it so number 4 is tdc, run drill and see if you get anything. If not, rotate 1 revolution of crank so 4 is on tdc again and give it another try with the drill. If that doesn’t work, try turning crank 90 degrees at a time and then run drill, 90 degrees and run drill, etc. The cam is moving 1/8 of a turn for every 1/4 turn of crank so you should be able to find the sweet spot this way. I’d be running the drill 20-30 seconds at least each time and looking at all the rockers until you start seeing any dribbles.
Sorry, that got long for something simple.

On a side note, I’ve heard people say oil priming an engine just washes away all that nice, sticky assembly lube and instead, just pour some oil over the valvetrain and send it. I’ve always oil primed every engine I built so who knows. I’m no pro engine builder, but I did do a big smokey burnout today. (Or 6…)
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Great information and super helpful, appreciate it
 
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