A Good Oil Pressure Mystery

I'm happy but stumped on what changed my oil pressure for the good. I overhauled this 2N last year with crank ground and new bearings . The oil pump was overhauled and snug. Cold engine and the oil pressure was 80 or more, hot idle it was less than 10. Replaced relief valve and spring and it made no difference. I took the plug out and no oil was getting up there. I Did my best to get mig welding wire down the hole to clear it but assumed it did not help. Eventually the plugged up line must have busted loose because cold it stared reading 30 psi. I took the 80 PSI gauge out and replaced with a 50 PSI gauge but figured I would have to live with the low hot oil pressure because the camshaft bearing must have excess clearance. Now the strange part: the hot oil pressure problem went away! Now I'm seeing 20 PSI hot idle. Any ideas what happened? I'm working on another engine now so hopefully there wont be any more weird questions. Bill
 
" the camshaft bearing must have excess clearance"

The bore might have excess clearance, but the engine did not come w/ camshaft bearings.
75 Tips
 
(quoted from post at 22:42:01 07/12/20) I'm happy but stumped on what changed my oil pressure for the good. I overhauled this 2N last year with crank ground and new bearings . The oil pump was overhauled and snug. Cold engine and the oil pressure was 80 or more, hot idle it was less than 10. Replaced relief valve and spring and it made no difference. I took the plug out and no oil was getting up there. I Did my best to get mig welding wire down the hole to clear it but assumed it did not help. Eventually the plugged up line must have busted loose because cold it stared reading 30 psi. I took the 80 PSI gauge out and replaced with a 50 PSI gauge but figured I would have to live with the low hot oil pressure because the camshaft bearing must have excess clearance. Now the strange part: the hot oil pressure problem went away! [color=red:08ad35310c][b:08ad35310c]Now I'm seeing 20 PSI hot idle. Any ideas what happened?[/b:08ad35310c][/color:08ad35310c] I'm working on another engine now so hopefully there wont be any more weird questions. Bill

Yes - you changed gauges and the new one one reads higher.

TOH
 
The way I read the post, he is saying the cold pressure dropped to 30, then he changed the gauge. No?? I have the same problem with my 2N, but it's never magically fixed itself:( I don't work it hard and it's hanging in there.
 
Nope, was not the gauge, 50 PSI gauge was destroyed from excess pressure and I switched to 80 Psi gauge and it pegged also when engine was cold. I would have to let it warm up a little at idle for pressure to drop. The oil relief valve was unscrewed until very loose and NO OIL WOULD LEAK OUT, so the oil was not getting there. When the weather warmed up I changed to a new 50 PSI gauge and the oil pressure was still excessive when start up but low when hot. I went ahead and plowed a little pasture for sunflowers (Gave it a good workout), and have not had the problem since. Pressure runs a good 30 psi and no more and that could be explained by plugged oil galley to relief valve that open up but I cant understand low pressure being good now. Maybe oil pump broke in for better seal? Is it possible when oil relief opened up, it is applying pressure to camshaft bearing on gear side to help hold pressure?
 
(quoted from post at 23:29:09 07/13/20) Nope, was not the gauge, 50 PSI gauge was destroyed from excess pressure and I switched to 80 Psi gauge and it pegged also when engine was cold. I would have to let it warm up a little at idle for pressure to drop. The oil relief valve was unscrewed until very loose and NO OIL WOULD LEAK OUT, so the oil was not getting there. When the weather warmed up I changed to a new 50 PSI gauge and the oil pressure was still excessive when start up but low when hot. I went ahead and plowed a little pasture for sunflowers (Gave it a good workout), and have not had the problem since. Pressure runs a good 30 psi and no more and that could be explained by plugged oil galley to relief valve that open up but I cant understand low pressure being good now. Maybe oil pump broke in for better seal? Is it possible when oil relief opened up, it is applying pressure to camshaft bearing on gear side to help hold pressure?

Plugged oil pressure relief makes sense for the high pressure. The rest does not. I would suggest you check your engine oil pressure using a more reliable mechanic's oil pressure gauge. Something is highly suspect here.

TOH

PS> I would not be happy at the prospect of junk in the oil gallery of any engine I just rebuilt.
 

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